Merge branch 'master' into 'master'

Update squid charm

See merge request !105

magma/squid_cnf/charms/squid/venv/MarkupSafe-1.1.1.dist-info/RECORD

+MarkupSafe-1.1.1.dist-info/INSTALLER,sha256=zuuue4knoyJ-UwPPXg8fezS7VCrXJQrAP7zeNuwvFQg,4
+MarkupSafe-1.1.1.dist-info/LICENSE.txt,sha256=SJqOEQhQntmKN7uYPhHg9-HTHwvY-Zp5yESOf_N9B-o,1475
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+markupsafe/_speedups.c,sha256=k0fzEIK3CP6MmMqeY0ob43TP90mVN0DTyn7BAl3RqSg,9884
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magma/squid_cnf/charms/squid/venv/MarkupSafe-1.1.1.dist-info/WHEEL

+Wheel-Version: 1.0
+Generator: bdist_wheel (0.31.1)
+Root-Is-Purelib: false
+Tag: cp38-cp38-manylinux1_x86_64
+

magma/squid_cnf/charms/squid/venv/MarkupSafe-1.1.1.dist-info/top_level.txt

+markupsafe

magma/squid_cnf/charms/squid/venv/PyYAML-5.3.1.dist-info/INSTALLER

+pip

magma/squid_cnf/charms/squid/venv/PyYAML-5.3.1.dist-info/LICENSE

+Copyright (c) 2017-2020 Ingy döt Net
+Copyright (c) 2006-2016 Kirill Simonov
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

magma/squid_cnf/charms/squid/venv/PyYAML-5.3.1.dist-info/METADATA

+Metadata-Version: 2.1
+Name: PyYAML
+Version: 5.3.1
+Summary: YAML parser and emitter for Python
+Home-page: https://github.com/yaml/pyyaml
+Author: Kirill Simonov
+Author-email: xi@resolvent.net
+License: MIT
+Download-URL: https://pypi.org/project/PyYAML/
+Platform: Any
+Classifier: Development Status :: 5 - Production/Stable
+Classifier: Intended Audience :: Developers
+Classifier: License :: OSI Approved :: MIT License
+Classifier: Operating System :: OS Independent
+Classifier: Programming Language :: Cython
+Classifier: Programming Language :: Python
+Classifier: Programming Language :: Python :: 2
+Classifier: Programming Language :: Python :: 2.7
+Classifier: Programming Language :: Python :: 3
+Classifier: Programming Language :: Python :: 3.5
+Classifier: Programming Language :: Python :: 3.6
+Classifier: Programming Language :: Python :: 3.7
+Classifier: Programming Language :: Python :: 3.8
+Classifier: Programming Language :: Python :: Implementation :: CPython
+Classifier: Programming Language :: Python :: Implementation :: PyPy
+Classifier: Topic :: Software Development :: Libraries :: Python Modules
+Classifier: Topic :: Text Processing :: Markup
+Requires-Python: >=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*
+
+YAML is a data serialization format designed for human readability
+and interaction with scripting languages.  PyYAML is a YAML parser
+and emitter for Python.
+
+PyYAML features a complete YAML 1.1 parser, Unicode support, pickle
+support, capable extension API, and sensible error messages.  PyYAML
+supports standard YAML tags and provides Python-specific tags that
+allow to represent an arbitrary Python object.
+
+PyYAML is applicable for a broad range of tasks from complex
+configuration files to object serialization and persistence.
+

magma/squid_cnf/charms/squid/venv/PyYAML-5.3.1.dist-info/RECORD

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magma/squid_cnf/charms/squid/venv/PyYAML-5.3.1.dist-info/WHEEL

+Wheel-Version: 1.0
+Generator: bdist_wheel (0.34.2)
+Root-Is-Purelib: false
+Tag: cp38-cp38-linux_x86_64
+

magma/squid_cnf/charms/squid/venv/PyYAML-5.3.1.dist-info/top_level.txt

+_yaml
+yaml

magma/squid_cnf/charms/squid/venv/jinja2/__init__.py

+# -*- coding: utf-8 -*-
+"""Jinja is a template engine written in pure Python. It provides a
+non-XML syntax that supports inline expressions and an optional
+sandboxed environment.
+"""
+from markupsafe import escape
+from markupsafe import Markup
+
+from .bccache import BytecodeCache
+from .bccache import FileSystemBytecodeCache
+from .bccache import MemcachedBytecodeCache
+from .environment import Environment
+from .environment import Template
+from .exceptions import TemplateAssertionError
+from .exceptions import TemplateError
+from .exceptions import TemplateNotFound
+from .exceptions import TemplateRuntimeError
+from .exceptions import TemplatesNotFound
+from .exceptions import TemplateSyntaxError
+from .exceptions import UndefinedError
+from .filters import contextfilter
+from .filters import environmentfilter
+from .filters import evalcontextfilter
+from .loaders import BaseLoader
+from .loaders import ChoiceLoader
+from .loaders import DictLoader
+from .loaders import FileSystemLoader
+from .loaders import FunctionLoader
+from .loaders import ModuleLoader
+from .loaders import PackageLoader
+from .loaders import PrefixLoader
+from .runtime import ChainableUndefined
+from .runtime import DebugUndefined
+from .runtime import make_logging_undefined
+from .runtime import StrictUndefined
+from .runtime import Undefined
+from .utils import clear_caches
+from .utils import contextfunction
+from .utils import environmentfunction
+from .utils import evalcontextfunction
+from .utils import is_undefined
+from .utils import select_autoescape
+
+__version__ = "2.11.2"

magma/squid_cnf/charms/squid/venv/jinja2/_compat.py

+# -*- coding: utf-8 -*-
+# flake8: noqa
+import marshal
+import sys
+
+PY2 = sys.version_info[0] == 2
+PYPY = hasattr(sys, "pypy_translation_info")
+_identity = lambda x: x
+
+if not PY2:
+    unichr = chr
+    range_type = range
+    text_type = str
+    string_types = (str,)
+    integer_types = (int,)
+
+    iterkeys = lambda d: iter(d.keys())
+    itervalues = lambda d: iter(d.values())
+    iteritems = lambda d: iter(d.items())
+
+    import pickle
+    from io import BytesIO, StringIO
+
+    NativeStringIO = StringIO
+
+    def reraise(tp, value, tb=None):
+        if value.__traceback__ is not tb:
+            raise value.with_traceback(tb)
+        raise value
+
+    ifilter = filter
+    imap = map
+    izip = zip
+    intern = sys.intern
+
+    implements_iterator = _identity
+    implements_to_string = _identity
+    encode_filename = _identity
+
+    marshal_dump = marshal.dump
+    marshal_load = marshal.load
+
+else:
+    unichr = unichr
+    text_type = unicode
+    range_type = xrange
+    string_types = (str, unicode)
+    integer_types = (int, long)
+
+    iterkeys = lambda d: d.iterkeys()
+    itervalues = lambda d: d.itervalues()
+    iteritems = lambda d: d.iteritems()
+
+    import cPickle as pickle
+    from cStringIO import StringIO as BytesIO, StringIO
+
+    NativeStringIO = BytesIO
+
+    exec("def reraise(tp, value, tb=None):\n raise tp, value, tb")
+
+    from itertools import imap, izip, ifilter
+
+    intern = intern
+
+    def implements_iterator(cls):
+        cls.next = cls.__next__
+        del cls.__next__
+        return cls
+
+    def implements_to_string(cls):
+        cls.__unicode__ = cls.__str__
+        cls.__str__ = lambda x: x.__unicode__().encode("utf-8")
+        return cls
+
+    def encode_filename(filename):
+        if isinstance(filename, unicode):
+            return filename.encode("utf-8")
+        return filename
+
+    def marshal_dump(code, f):
+        if isinstance(f, file):
+            marshal.dump(code, f)
+        else:
+            f.write(marshal.dumps(code))
+
+    def marshal_load(f):
+        if isinstance(f, file):
+            return marshal.load(f)
+        return marshal.loads(f.read())
+
+
+def with_metaclass(meta, *bases):
+    """Create a base class with a metaclass."""
+    # This requires a bit of explanation: the basic idea is to make a
+    # dummy metaclass for one level of class instantiation that replaces
+    # itself with the actual metaclass.
+    class metaclass(type):
+        def __new__(cls, name, this_bases, d):
+            return meta(name, bases, d)
+
+    return type.__new__(metaclass, "temporary_class", (), {})
+
+
+try:
+    from urllib.parse import quote_from_bytes as url_quote
+except ImportError:
+    from urllib import quote as url_quote
+
+
+try:
+    from collections import abc
+except ImportError:
+    import collections as abc
+
+
+try:
+    from os import fspath
+except ImportError:
+    try:
+        from pathlib import PurePath
+    except ImportError:
+        PurePath = None
+
+    def fspath(path):
+        if hasattr(path, "__fspath__"):
+            return path.__fspath__()
+
+        # Python 3.5 doesn't have __fspath__ yet, use str.
+        if PurePath is not None and isinstance(path, PurePath):
+            return str(path)
+
+        return path

magma/squid_cnf/charms/squid/venv/jinja2/_identifier.py

+import re
+
+# generated by scripts/generate_identifier_pattern.py
+pattern = re.compile(
+    r"[\w·̀-ͯ·҃-֑҇-ׇֽֿׁׂׅׄؐ-ًؚ-ٰٟۖ-ۜ۟-۪ۤۧۨ-ܑۭܰ-݊ަ-ް߫-߳ࠖ-࠙ࠛ-ࠣࠥ-ࠧࠩ-࡙࠭-࡛ࣔ-ࣣ࣡-ःऺ-़ा-ॏ॑-ॗॢॣঁ-ঃ়া-ৄেৈো-্ৗৢৣਁ-ਃ਼ਾ-ੂੇੈੋ-੍ੑੰੱੵઁ-ઃ઼ા-ૅે-ૉો-્ૢૣଁ-ଃ଼ା-ୄେୈୋ-୍ୖୗୢୣஂா-ூெ-ைொ-்ௗఀ-ఃా-ౄె-ైొ-్ౕౖౢౣಁ-ಃ಼ಾ-ೄೆ-ೈೊ-್ೕೖೢೣഁ-ഃാ-ൄെ-ൈൊ-്ൗൢൣංඃ්ා-ුූෘ-ෟෲෳัิ-ฺ็-๎ັິ-ູົຼ່-ໍ༹༘༙༵༷༾༿ཱ-྄྆྇ྍ-ྗྙ-ྼ࿆ါ-ှၖ-ၙၞ-ၠၢ-ၤၧ-ၭၱ-ၴႂ-ႍႏႚ-ႝ፝-፟ᜒ-᜔ᜲ-᜴ᝒᝓᝲᝳ឴-៓៝᠋-᠍ᢅᢆᢩᤠ-ᤫᤰ-᤻ᨗ-ᨛᩕ-ᩞ᩠-᩿᩼᪰-᪽ᬀ-ᬄ᬴-᭄᭫-᭳ᮀ-ᮂᮡ-ᮭ᯦-᯳ᰤ-᰷᳐-᳔᳒-᳨᳭ᳲ-᳴᳸᳹᷀-᷵᷻-᷿‿⁀⁔⃐-⃥⃜⃡-⃰℘℮⳯-⵿⳱ⷠ-〪ⷿ-゙゚〯꙯ꙴ-꙽ꚞꚟ꛰꛱ꠂ꠆ꠋꠣ-ꠧꢀꢁꢴ-ꣅ꣠-꣱ꤦ-꤭ꥇ-꥓ꦀ-ꦃ꦳-꧀ꧥꨩ-ꨶꩃꩌꩍꩻ-ꩽꪰꪲ-ꪴꪷꪸꪾ꪿꫁ꫫ-ꫯꫵ꫶ꯣ-ꯪ꯬꯭ﬞ︀-️︠-︯︳︴﹍-﹏＿𐇽𐋠𐍶-𐍺𐨁-𐨃𐨅𐨆𐨌-𐨏𐨸-𐨿𐨺𐫦𐫥𑀀-𑀂𑀸-𑁆𑁿-𑂂𑂰-𑂺𑄀-𑄂𑄧-𑅳𑄴𑆀-𑆂𑆳-𑇊𑇀-𑇌𑈬-𑈷𑈾𑋟-𑋪𑌀-𑌃𑌼𑌾-𑍄𑍇𑍈𑍋-𑍍𑍗𑍢𑍣𑍦-𑍬𑍰-𑍴𑐵-𑑆𑒰-𑓃𑖯-𑖵𑖸-𑗀𑗜𑗝𑘰-𑙀𑚫-𑚷𑜝-𑜫𑰯-𑰶𑰸-𑰿𑲒-𑲧𑲩-𑲶𖫰-𖫴𖬰-𖬶𖽑-𖽾𖾏-𖾒𛲝𛲞𝅥-𝅩𝅭-𝅲𝅻-𝆂𝆅-𝆋𝆪-𝆭𝉂-𝉄𝨀-𝨶𝨻-𝩬𝩵𝪄𝪛-𝪟𝪡-𝪯𞀀-𞀆𞀈-𞀘𞀛-𞀡𞀣𞀤𞀦-𞣐𞀪-𞣖𞥄-𞥊󠄀-󠇯]+"  # noqa: B950
+)

magma/squid_cnf/charms/squid/venv/jinja2/asyncfilters.py

+from functools import wraps
+
+from . import filters
+from .asyncsupport import auto_aiter
+from .asyncsupport import auto_await
+
+
+async def auto_to_seq(value):
+    seq = []
+    if hasattr(value, "__aiter__"):
+        async for item in value:
+            seq.append(item)
+    else:
+        for item in value:
+            seq.append(item)
+    return seq
+
+
+async def async_select_or_reject(args, kwargs, modfunc, lookup_attr):
+    seq, func = filters.prepare_select_or_reject(args, kwargs, modfunc, lookup_attr)
+    if seq:
+        async for item in auto_aiter(seq):
+            if func(item):
+                yield item
+
+
+def dualfilter(normal_filter, async_filter):
+    wrap_evalctx = False
+    if getattr(normal_filter, "environmentfilter", False) is True:
+
+        def is_async(args):
+            return args[0].is_async
+
+        wrap_evalctx = False
+    else:
+        has_evalctxfilter = getattr(normal_filter, "evalcontextfilter", False) is True
+        has_ctxfilter = getattr(normal_filter, "contextfilter", False) is True
+        wrap_evalctx = not has_evalctxfilter and not has_ctxfilter
+
+        def is_async(args):
+            return args[0].environment.is_async
+
+    @wraps(normal_filter)
+    def wrapper(*args, **kwargs):
+        b = is_async(args)
+        if wrap_evalctx:
+            args = args[1:]
+        if b:
+            return async_filter(*args, **kwargs)
+        return normal_filter(*args, **kwargs)
+
+    if wrap_evalctx:
+        wrapper.evalcontextfilter = True
+
+    wrapper.asyncfiltervariant = True
+
+    return wrapper
+
+
+def asyncfiltervariant(original):
+    def decorator(f):
+        return dualfilter(original, f)
+
+    return decorator
+
+
+@asyncfiltervariant(filters.do_first)
+async def do_first(environment, seq):
+    try:
+        return await auto_aiter(seq).__anext__()
+    except StopAsyncIteration:
+        return environment.undefined("No first item, sequence was empty.")
+
+
+@asyncfiltervariant(filters.do_groupby)
+async def do_groupby(environment, value, attribute):
+    expr = filters.make_attrgetter(environment, attribute)
+    return [
+        filters._GroupTuple(key, await auto_to_seq(values))
+        for key, values in filters.groupby(
+            sorted(await auto_to_seq(value), key=expr), expr
+        )
+    ]
+
+
+@asyncfiltervariant(filters.do_join)
+async def do_join(eval_ctx, value, d=u"", attribute=None):
+    return filters.do_join(eval_ctx, await auto_to_seq(value), d, attribute)
+
+
+@asyncfiltervariant(filters.do_list)
+async def do_list(value):
+    return await auto_to_seq(value)
+
+
+@asyncfiltervariant(filters.do_reject)
+async def do_reject(*args, **kwargs):
+    return async_select_or_reject(args, kwargs, lambda x: not x, False)
+
+
+@asyncfiltervariant(filters.do_rejectattr)
+async def do_rejectattr(*args, **kwargs):
+    return async_select_or_reject(args, kwargs, lambda x: not x, True)
+
+
+@asyncfiltervariant(filters.do_select)
+async def do_select(*args, **kwargs):
+    return async_select_or_reject(args, kwargs, lambda x: x, False)
+
+
+@asyncfiltervariant(filters.do_selectattr)
+async def do_selectattr(*args, **kwargs):
+    return async_select_or_reject(args, kwargs, lambda x: x, True)
+
+
+@asyncfiltervariant(filters.do_map)
+async def do_map(*args, **kwargs):
+    seq, func = filters.prepare_map(args, kwargs)
+    if seq:
+        async for item in auto_aiter(seq):
+            yield await auto_await(func(item))
+
+
+@asyncfiltervariant(filters.do_sum)
+async def do_sum(environment, iterable, attribute=None, start=0):
+    rv = start
+    if attribute is not None:
+        func = filters.make_attrgetter(environment, attribute)
+    else:
+
+        def func(x):
+            return x
+
+    async for item in auto_aiter(iterable):
+        rv += func(item)
+    return rv
+
+
+@asyncfiltervariant(filters.do_slice)
+async def do_slice(value, slices, fill_with=None):
+    return filters.do_slice(await auto_to_seq(value), slices, fill_with)
+
+
+ASYNC_FILTERS = {
+    "first": do_first,
+    "groupby": do_groupby,
+    "join": do_join,
+    "list": do_list,
+    # we intentionally do not support do_last because that would be
+    # ridiculous
+    "reject": do_reject,
+    "rejectattr": do_rejectattr,
+    "map": do_map,
+    "select": do_select,
+    "selectattr": do_selectattr,
+    "sum": do_sum,
+    "slice": do_slice,
+}

magma/squid_cnf/charms/squid/venv/jinja2/asyncsupport.py

+# -*- coding: utf-8 -*-
+"""The code for async support. Importing this patches Jinja on supported
+Python versions.
+"""
+import asyncio
+import inspect
+from functools import update_wrapper
+
+from markupsafe import Markup
+
+from .environment import TemplateModule
+from .runtime import LoopContext
+from .utils import concat
+from .utils import internalcode
+from .utils import missing
+
+
+async def concat_async(async_gen):
+    rv = []
+
+    async def collect():
+        async for event in async_gen:
+            rv.append(event)
+
+    await collect()
+    return concat(rv)
+
+
+async def generate_async(self, *args, **kwargs):
+    vars = dict(*args, **kwargs)
+    try:
+        async for event in self.root_render_func(self.new_context(vars)):
+            yield event
+    except Exception:
+        yield self.environment.handle_exception()
+
+
+def wrap_generate_func(original_generate):
+    def _convert_generator(self, loop, args, kwargs):
+        async_gen = self.generate_async(*args, **kwargs)
+        try:
+            while 1:
+                yield loop.run_until_complete(async_gen.__anext__())
+        except StopAsyncIteration:
+            pass
+
+    def generate(self, *args, **kwargs):
+        if not self.environment.is_async:
+            return original_generate(self, *args, **kwargs)
+        return _convert_generator(self, asyncio.get_event_loop(), args, kwargs)
+
+    return update_wrapper(generate, original_generate)
+
+
+async def render_async(self, *args, **kwargs):
+    if not self.environment.is_async:
+        raise RuntimeError("The environment was not created with async mode enabled.")
+
+    vars = dict(*args, **kwargs)
+    ctx = self.new_context(vars)
+
+    try:
+        return await concat_async(self.root_render_func(ctx))
+    except Exception:
+        return self.environment.handle_exception()
+
+
+def wrap_render_func(original_render):
+    def render(self, *args, **kwargs):
+        if not self.environment.is_async:
+            return original_render(self, *args, **kwargs)
+        loop = asyncio.get_event_loop()
+        return loop.run_until_complete(self.render_async(*args, **kwargs))
+
+    return update_wrapper(render, original_render)
+
+
+def wrap_block_reference_call(original_call):
+    @internalcode
+    async def async_call(self):
+        rv = await concat_async(self._stack[self._depth](self._context))
+        if self._context.eval_ctx.autoescape:
+            rv = Markup(rv)
+        return rv
+
+    @internalcode
+    def __call__(self):
+        if not self._context.environment.is_async:
+            return original_call(self)
+        return async_call(self)
+
+    return update_wrapper(__call__, original_call)
+
+
+def wrap_macro_invoke(original_invoke):
+    @internalcode
+    async def async_invoke(self, arguments, autoescape):
+        rv = await self._func(*arguments)
+        if autoescape:
+            rv = Markup(rv)
+        return rv
+
+    @internalcode
+    def _invoke(self, arguments, autoescape):
+        if not self._environment.is_async:
+            return original_invoke(self, arguments, autoescape)
+        return async_invoke(self, arguments, autoescape)
+
+    return update_wrapper(_invoke, original_invoke)
+
+
+@internalcode
+async def get_default_module_async(self):
+    if self._module is not None:
+        return self._module
+    self._module = rv = await self.make_module_async()
+    return rv
+
+
+def wrap_default_module(original_default_module):
+    @internalcode
+    def _get_default_module(self):
+        if self.environment.is_async:
+            raise RuntimeError("Template module attribute is unavailable in async mode")
+        return original_default_module(self)
+
+    return _get_default_module
+
+
+async def make_module_async(self, vars=None, shared=False, locals=None):
+    context = self.new_context(vars, shared, locals)
+    body_stream = []
+    async for item in self.root_render_func(context):
+        body_stream.append(item)
+    return TemplateModule(self, context, body_stream)
+
+
+def patch_template():
+    from . import Template
+
+    Template.generate = wrap_generate_func(Template.generate)
+    Template.generate_async = update_wrapper(generate_async, Template.generate_async)
+    Template.render_async = update_wrapper(render_async, Template.render_async)
+    Template.render = wrap_render_func(Template.render)
+    Template._get_default_module = wrap_default_module(Template._get_default_module)
+    Template._get_default_module_async = get_default_module_async
+    Template.make_module_async = update_wrapper(
+        make_module_async, Template.make_module_async
+    )
+
+
+def patch_runtime():
+    from .runtime import BlockReference, Macro
+
+    BlockReference.__call__ = wrap_block_reference_call(BlockReference.__call__)
+    Macro._invoke = wrap_macro_invoke(Macro._invoke)
+
+
+def patch_filters():
+    from .filters import FILTERS
+    from .asyncfilters import ASYNC_FILTERS
+
+    FILTERS.update(ASYNC_FILTERS)
+
+
+def patch_all():
+    patch_template()
+    patch_runtime()
+    patch_filters()
+
+
+async def auto_await(value):
+    if inspect.isawaitable(value):
+        return await value
+    return value
+
+
+async def auto_aiter(iterable):
+    if hasattr(iterable, "__aiter__"):
+        async for item in iterable:
+            yield item
+        return
+    for item in iterable:
+        yield item
+
+
+class AsyncLoopContext(LoopContext):
+    _to_iterator = staticmethod(auto_aiter)
+
+    @property
+    async def length(self):
+        if self._length is not None:
+            return self._length
+
+        try:
+            self._length = len(self._iterable)
+        except TypeError:
+            iterable = [x async for x in self._iterator]
+            self._iterator = self._to_iterator(iterable)
+            self._length = len(iterable) + self.index + (self._after is not missing)
+
+        return self._length
+
+    @property
+    async def revindex0(self):
+        return await self.length - self.index
+
+    @property
+    async def revindex(self):
+        return await self.length - self.index0
+
+    async def _peek_next(self):
+        if self._after is not missing:
+            return self._after
+
+        try:
+            self._after = await self._iterator.__anext__()
+        except StopAsyncIteration:
+            self._after = missing
+
+        return self._after
+
+    @property
+    async def last(self):
+        return await self._peek_next() is missing
+
+    @property
+    async def nextitem(self):
+        rv = await self._peek_next()
+
+        if rv is missing:
+            return self._undefined("there is no next item")
+
+        return rv
+
+    def __aiter__(self):
+        return self
+
+    async def __anext__(self):
+        if self._after is not missing:
+            rv = self._after
+            self._after = missing
+        else:
+            rv = await self._iterator.__anext__()
+
+        self.index0 += 1
+        self._before = self._current
+        self._current = rv
+        return rv, self
+
+
+async def make_async_loop_context(iterable, undefined, recurse=None, depth0=0):
+    import warnings
+
+    warnings.warn(
+        "This template must be recompiled with at least Jinja 2.11, or"
+        " it will fail in 3.0.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
+    return AsyncLoopContext(iterable, undefined, recurse, depth0)
+
+
+patch_all()

magma/squid_cnf/charms/squid/venv/jinja2/bccache.py

+# -*- coding: utf-8 -*-
+"""The optional bytecode cache system. This is useful if you have very
+complex template situations and the compilation of all those templates
+slows down your application too much.
+
+Situations where this is useful are often forking web applications that
+are initialized on the first request.
+"""
+import errno
+import fnmatch
+import os
+import stat
+import sys
+import tempfile
+from hashlib import sha1
+from os import listdir
+from os import path
+
+from ._compat import BytesIO
+from ._compat import marshal_dump
+from ._compat import marshal_load
+from ._compat import pickle
+from ._compat import text_type
+from .utils import open_if_exists
+
+bc_version = 4
+# Magic bytes to identify Jinja bytecode cache files. Contains the
+# Python major and minor version to avoid loading incompatible bytecode
+# if a project upgrades its Python version.
+bc_magic = (
+    b"j2"
+    + pickle.dumps(bc_version, 2)
+    + pickle.dumps((sys.version_info[0] << 24) | sys.version_info[1], 2)
+)
+
+
+class Bucket(object):
+    """Buckets are used to store the bytecode for one template.  It's created
+    and initialized by the bytecode cache and passed to the loading functions.
+
+    The buckets get an internal checksum from the cache assigned and use this
+    to automatically reject outdated cache material.  Individual bytecode
+    cache subclasses don't have to care about cache invalidation.
+    """
+
+    def __init__(self, environment, key, checksum):
+        self.environment = environment
+        self.key = key
+        self.checksum = checksum
+        self.reset()
+
+    def reset(self):
+        """Resets the bucket (unloads the bytecode)."""
+        self.code = None
+
+    def load_bytecode(self, f):
+        """Loads bytecode from a file or file like object."""
+        # make sure the magic header is correct
+        magic = f.read(len(bc_magic))
+        if magic != bc_magic:
+            self.reset()
+            return
+        # the source code of the file changed, we need to reload
+        checksum = pickle.load(f)
+        if self.checksum != checksum:
+            self.reset()
+            return
+        # if marshal_load fails then we need to reload
+        try:
+            self.code = marshal_load(f)
+        except (EOFError, ValueError, TypeError):
+            self.reset()
+            return
+
+    def write_bytecode(self, f):
+        """Dump the bytecode into the file or file like object passed."""
+        if self.code is None:
+            raise TypeError("can't write empty bucket")
+        f.write(bc_magic)
+        pickle.dump(self.checksum, f, 2)
+        marshal_dump(self.code, f)
+
+    def bytecode_from_string(self, string):
+        """Load bytecode from a string."""
+        self.load_bytecode(BytesIO(string))
+
+    def bytecode_to_string(self):
+        """Return the bytecode as string."""
+        out = BytesIO()
+        self.write_bytecode(out)
+        return out.getvalue()
+
+
+class BytecodeCache(object):
+    """To implement your own bytecode cache you have to subclass this class
+    and override :meth:`load_bytecode` and :meth:`dump_bytecode`.  Both of
+    these methods are passed a :class:`~jinja2.bccache.Bucket`.
+
+    A very basic bytecode cache that saves the bytecode on the file system::
+
+        from os import path
+
+        class MyCache(BytecodeCache):
+
+            def __init__(self, directory):
+                self.directory = directory
+
+            def load_bytecode(self, bucket):
+                filename = path.join(self.directory, bucket.key)
+                if path.exists(filename):
+                    with open(filename, 'rb') as f:
+                        bucket.load_bytecode(f)
+
+            def dump_bytecode(self, bucket):
+                filename = path.join(self.directory, bucket.key)
+                with open(filename, 'wb') as f:
+                    bucket.write_bytecode(f)
+
+    A more advanced version of a filesystem based bytecode cache is part of
+    Jinja.
+    """
+
+    def load_bytecode(self, bucket):
+        """Subclasses have to override this method to load bytecode into a
+        bucket.  If they are not able to find code in the cache for the
+        bucket, it must not do anything.
+        """
+        raise NotImplementedError()
+
+    def dump_bytecode(self, bucket):
+        """Subclasses have to override this method to write the bytecode
+        from a bucket back to the cache.  If it unable to do so it must not
+        fail silently but raise an exception.
+        """
+        raise NotImplementedError()
+
+    def clear(self):
+        """Clears the cache.  This method is not used by Jinja but should be
+        implemented to allow applications to clear the bytecode cache used
+        by a particular environment.
+        """
+
+    def get_cache_key(self, name, filename=None):
+        """Returns the unique hash key for this template name."""
+        hash = sha1(name.encode("utf-8"))
+        if filename is not None:
+            filename = "|" + filename
+            if isinstance(filename, text_type):
+                filename = filename.encode("utf-8")
+            hash.update(filename)
+        return hash.hexdigest()
+
+    def get_source_checksum(self, source):
+        """Returns a checksum for the source."""
+        return sha1(source.encode("utf-8")).hexdigest()
+
+    def get_bucket(self, environment, name, filename, source):
+        """Return a cache bucket for the given template.  All arguments are
+        mandatory but filename may be `None`.
+        """
+        key = self.get_cache_key(name, filename)
+        checksum = self.get_source_checksum(source)
+        bucket = Bucket(environment, key, checksum)
+        self.load_bytecode(bucket)
+        return bucket
+
+    def set_bucket(self, bucket):
+        """Put the bucket into the cache."""
+        self.dump_bytecode(bucket)
+
+
+class FileSystemBytecodeCache(BytecodeCache):
+    """A bytecode cache that stores bytecode on the filesystem.  It accepts
+    two arguments: The directory where the cache items are stored and a
+    pattern string that is used to build the filename.
+
+    If no directory is specified a default cache directory is selected.  On
+    Windows the user's temp directory is used, on UNIX systems a directory
+    is created for the user in the system temp directory.
+
+    The pattern can be used to have multiple separate caches operate on the
+    same directory.  The default pattern is ``'__jinja2_%s.cache'``.  ``%s``
+    is replaced with the cache key.
+
+    >>> bcc = FileSystemBytecodeCache('/tmp/jinja_cache', '%s.cache')
+
+    This bytecode cache supports clearing of the cache using the clear method.
+    """
+
+    def __init__(self, directory=None, pattern="__jinja2_%s.cache"):
+        if directory is None:
+            directory = self._get_default_cache_dir()
+        self.directory = directory
+        self.pattern = pattern
+
+    def _get_default_cache_dir(self):
+        def _unsafe_dir():
+            raise RuntimeError(
+                "Cannot determine safe temp directory.  You "
+                "need to explicitly provide one."
+            )
+
+        tmpdir = tempfile.gettempdir()
+
+        # On windows the temporary directory is used specific unless
+        # explicitly forced otherwise.  We can just use that.
+        if os.name == "nt":
+            return tmpdir
+        if not hasattr(os, "getuid"):
+            _unsafe_dir()
+
+        dirname = "_jinja2-cache-%d" % os.getuid()
+        actual_dir = os.path.join(tmpdir, dirname)
+
+        try:
+            os.mkdir(actual_dir, stat.S_IRWXU)
+        except OSError as e:
+            if e.errno != errno.EEXIST:
+                raise
+        try:
+            os.chmod(actual_dir, stat.S_IRWXU)
+            actual_dir_stat = os.lstat(actual_dir)
+            if (
+                actual_dir_stat.st_uid != os.getuid()
+                or not stat.S_ISDIR(actual_dir_stat.st_mode)
+                or stat.S_IMODE(actual_dir_stat.st_mode) != stat.S_IRWXU
+            ):
+                _unsafe_dir()
+        except OSError as e:
+            if e.errno != errno.EEXIST:
+                raise
+
+        actual_dir_stat = os.lstat(actual_dir)
+        if (
+            actual_dir_stat.st_uid != os.getuid()
+            or not stat.S_ISDIR(actual_dir_stat.st_mode)
+            or stat.S_IMODE(actual_dir_stat.st_mode) != stat.S_IRWXU
+        ):
+            _unsafe_dir()
+
+        return actual_dir
+
+    def _get_cache_filename(self, bucket):
+        return path.join(self.directory, self.pattern % bucket.key)
+
+    def load_bytecode(self, bucket):
+        f = open_if_exists(self._get_cache_filename(bucket), "rb")
+        if f is not None:
+            try:
+                bucket.load_bytecode(f)
+            finally:
+                f.close()
+
+    def dump_bytecode(self, bucket):
+        f = open(self._get_cache_filename(bucket), "wb")
+        try:
+            bucket.write_bytecode(f)
+        finally:
+            f.close()
+
+    def clear(self):
+        # imported lazily here because google app-engine doesn't support
+        # write access on the file system and the function does not exist
+        # normally.
+        from os import remove
+
+        files = fnmatch.filter(listdir(self.directory), self.pattern % "*")
+        for filename in files:
+            try:
+                remove(path.join(self.directory, filename))
+            except OSError:
+                pass
+
+
+class MemcachedBytecodeCache(BytecodeCache):
+    """This class implements a bytecode cache that uses a memcache cache for
+    storing the information.  It does not enforce a specific memcache library
+    (tummy's memcache or cmemcache) but will accept any class that provides
+    the minimal interface required.
+
+    Libraries compatible with this class:
+
+    -   `cachelib <https://github.com/pallets/cachelib>`_
+    -   `python-memcached <https://pypi.org/project/python-memcached/>`_
+
+    (Unfortunately the django cache interface is not compatible because it
+    does not support storing binary data, only unicode.  You can however pass
+    the underlying cache client to the bytecode cache which is available
+    as `django.core.cache.cache._client`.)
+
+    The minimal interface for the client passed to the constructor is this:
+
+    .. class:: MinimalClientInterface
+
+        .. method:: set(key, value[, timeout])
+
+            Stores the bytecode in the cache.  `value` is a string and
+            `timeout` the timeout of the key.  If timeout is not provided
+            a default timeout or no timeout should be assumed, if it's
+            provided it's an integer with the number of seconds the cache
+            item should exist.
+
+        .. method:: get(key)
+
+            Returns the value for the cache key.  If the item does not
+            exist in the cache the return value must be `None`.
+
+    The other arguments to the constructor are the prefix for all keys that
+    is added before the actual cache key and the timeout for the bytecode in
+    the cache system.  We recommend a high (or no) timeout.
+
+    This bytecode cache does not support clearing of used items in the cache.
+    The clear method is a no-operation function.
+
+    .. versionadded:: 2.7
+       Added support for ignoring memcache errors through the
+       `ignore_memcache_errors` parameter.
+    """
+
+    def __init__(
+        self,
+        client,
+        prefix="jinja2/bytecode/",
+        timeout=None,
+        ignore_memcache_errors=True,
+    ):
+        self.client = client
+        self.prefix = prefix
+        self.timeout = timeout
+        self.ignore_memcache_errors = ignore_memcache_errors
+
+    def load_bytecode(self, bucket):
+        try:
+            code = self.client.get(self.prefix + bucket.key)
+        except Exception:
+            if not self.ignore_memcache_errors:
+                raise
+            code = None
+        if code is not None:
+            bucket.bytecode_from_string(code)
+
+    def dump_bytecode(self, bucket):
+        args = (self.prefix + bucket.key, bucket.bytecode_to_string())
+        if self.timeout is not None:
+            args += (self.timeout,)
+        try:
+            self.client.set(*args)
+        except Exception:
+            if not self.ignore_memcache_errors:
+                raise

magma/squid_cnf/charms/squid/venv/jinja2/compiler.py

+# -*- coding: utf-8 -*-
+"""Compiles nodes from the parser into Python code."""
+from collections import namedtuple
+from functools import update_wrapper
+from itertools import chain
+from keyword import iskeyword as is_python_keyword
+
+from markupsafe import escape
+from markupsafe import Markup
+
+from . import nodes
+from ._compat import imap
+from ._compat import iteritems
+from ._compat import izip
+from ._compat import NativeStringIO
+from ._compat import range_type
+from ._compat import string_types
+from ._compat import text_type
+from .exceptions import TemplateAssertionError
+from .idtracking import Symbols
+from .idtracking import VAR_LOAD_ALIAS
+from .idtracking import VAR_LOAD_PARAMETER
+from .idtracking import VAR_LOAD_RESOLVE
+from .idtracking import VAR_LOAD_UNDEFINED
+from .nodes import EvalContext
+from .optimizer import Optimizer
+from .utils import concat
+from .visitor import NodeVisitor
+
+operators = {
+    "eq": "==",
+    "ne": "!=",
+    "gt": ">",
+    "gteq": ">=",
+    "lt": "<",
+    "lteq": "<=",
+    "in": "in",
+    "notin": "not in",
+}
+
+# what method to iterate over items do we want to use for dict iteration
+# in generated code?  on 2.x let's go with iteritems, on 3.x with items
+if hasattr(dict, "iteritems"):
+    dict_item_iter = "iteritems"
+else:
+    dict_item_iter = "items"
+
+code_features = ["division"]
+
+# does this python version support generator stops? (PEP 0479)
+try:
+    exec("from __future__ import generator_stop")
+    code_features.append("generator_stop")
+except SyntaxError:
+    pass
+
+# does this python version support yield from?
+try:
+    exec("def f(): yield from x()")
+except SyntaxError:
+    supports_yield_from = False
+else:
+    supports_yield_from = True
+
+
+def optimizeconst(f):
+    def new_func(self, node, frame, **kwargs):
+        # Only optimize if the frame is not volatile
+        if self.optimized and not frame.eval_ctx.volatile:
+            new_node = self.optimizer.visit(node, frame.eval_ctx)
+            if new_node != node:
+                return self.visit(new_node, frame)
+        return f(self, node, frame, **kwargs)
+
+    return update_wrapper(new_func, f)
+
+
+def generate(
+    node, environment, name, filename, stream=None, defer_init=False, optimized=True
+):
+    """Generate the python source for a node tree."""
+    if not isinstance(node, nodes.Template):
+        raise TypeError("Can't compile non template nodes")
+    generator = environment.code_generator_class(
+        environment, name, filename, stream, defer_init, optimized
+    )
+    generator.visit(node)
+    if stream is None:
+        return generator.stream.getvalue()
+
+
+def has_safe_repr(value):
+    """Does the node have a safe representation?"""
+    if value is None or value is NotImplemented or value is Ellipsis:
+        return True
+    if type(value) in (bool, int, float, complex, range_type, Markup) + string_types:
+        return True
+    if type(value) in (tuple, list, set, frozenset):
+        for item in value:
+            if not has_safe_repr(item):
+                return False
+        return True
+    elif type(value) is dict:
+        for key, value in iteritems(value):
+            if not has_safe_repr(key):
+                return False
+            if not has_safe_repr(value):
+                return False
+        return True
+    return False
+
+
+def find_undeclared(nodes, names):
+    """Check if the names passed are accessed undeclared.  The return value
+    is a set of all the undeclared names from the sequence of names found.
+    """
+    visitor = UndeclaredNameVisitor(names)
+    try:
+        for node in nodes:
+            visitor.visit(node)
+    except VisitorExit:
+        pass
+    return visitor.undeclared
+
+
+class MacroRef(object):
+    def __init__(self, node):
+        self.node = node
+        self.accesses_caller = False
+        self.accesses_kwargs = False
+        self.accesses_varargs = False
+
+
+class Frame(object):
+    """Holds compile time information for us."""
+
+    def __init__(self, eval_ctx, parent=None, level=None):
+        self.eval_ctx = eval_ctx
+        self.symbols = Symbols(parent and parent.symbols or None, level=level)
+
+        # a toplevel frame is the root + soft frames such as if conditions.
+        self.toplevel = False
+
+        # the root frame is basically just the outermost frame, so no if
+        # conditions.  This information is used to optimize inheritance
+        # situations.
+        self.rootlevel = False
+
+        # in some dynamic inheritance situations the compiler needs to add
+        # write tests around output statements.
+        self.require_output_check = parent and parent.require_output_check
+
+        # inside some tags we are using a buffer rather than yield statements.
+        # this for example affects {% filter %} or {% macro %}.  If a frame
+        # is buffered this variable points to the name of the list used as
+        # buffer.
+        self.buffer = None
+
+        # the name of the block we're in, otherwise None.
+        self.block = parent and parent.block or None
+
+        # the parent of this frame
+        self.parent = parent
+
+        if parent is not None:
+            self.buffer = parent.buffer
+
+    def copy(self):
+        """Create a copy of the current one."""
+        rv = object.__new__(self.__class__)
+        rv.__dict__.update(self.__dict__)
+        rv.symbols = self.symbols.copy()
+        return rv
+
+    def inner(self, isolated=False):
+        """Return an inner frame."""
+        if isolated:
+            return Frame(self.eval_ctx, level=self.symbols.level + 1)
+        return Frame(self.eval_ctx, self)
+
+    def soft(self):
+        """Return a soft frame.  A soft frame may not be modified as
+        standalone thing as it shares the resources with the frame it
+        was created of, but it's not a rootlevel frame any longer.
+
+        This is only used to implement if-statements.
+        """
+        rv = self.copy()
+        rv.rootlevel = False
+        return rv
+
+    __copy__ = copy
+
+
+class VisitorExit(RuntimeError):
+    """Exception used by the `UndeclaredNameVisitor` to signal a stop."""
+
+
+class DependencyFinderVisitor(NodeVisitor):
+    """A visitor that collects filter and test calls."""
+
+    def __init__(self):
+        self.filters = set()
+        self.tests = set()
+
+    def visit_Filter(self, node):
+        self.generic_visit(node)
+        self.filters.add(node.name)
+
+    def visit_Test(self, node):
+        self.generic_visit(node)
+        self.tests.add(node.name)
+
+    def visit_Block(self, node):
+        """Stop visiting at blocks."""
+
+
+class UndeclaredNameVisitor(NodeVisitor):
+    """A visitor that checks if a name is accessed without being
+    declared.  This is different from the frame visitor as it will
+    not stop at closure frames.
+    """
+
+    def __init__(self, names):
+        self.names = set(names)
+        self.undeclared = set()
+
+    def visit_Name(self, node):
+        if node.ctx == "load" and node.name in self.names:
+            self.undeclared.add(node.name)
+            if self.undeclared == self.names:
+                raise VisitorExit()
+        else:
+            self.names.discard(node.name)
+
+    def visit_Block(self, node):
+        """Stop visiting a blocks."""
+
+
+class CompilerExit(Exception):
+    """Raised if the compiler encountered a situation where it just
+    doesn't make sense to further process the code.  Any block that
+    raises such an exception is not further processed.
+    """
+
+
+class CodeGenerator(NodeVisitor):
+    def __init__(
+        self, environment, name, filename, stream=None, defer_init=False, optimized=True
+    ):
+        if stream is None:
+            stream = NativeStringIO()
+        self.environment = environment
+        self.name = name
+        self.filename = filename
+        self.stream = stream
+        self.created_block_context = False
+        self.defer_init = defer_init
+        self.optimized = optimized
+        if optimized:
+            self.optimizer = Optimizer(environment)
+
+        # aliases for imports
+        self.import_aliases = {}
+
+        # a registry for all blocks.  Because blocks are moved out
+        # into the global python scope they are registered here
+        self.blocks = {}
+
+        # the number of extends statements so far
+        self.extends_so_far = 0
+
+        # some templates have a rootlevel extends.  In this case we
+        # can safely assume that we're a child template and do some
+        # more optimizations.
+        self.has_known_extends = False
+
+        # the current line number
+        self.code_lineno = 1
+
+        # registry of all filters and tests (global, not block local)
+        self.tests = {}
+        self.filters = {}
+
+        # the debug information
+        self.debug_info = []
+        self._write_debug_info = None
+
+        # the number of new lines before the next write()
+        self._new_lines = 0
+
+        # the line number of the last written statement
+        self._last_line = 0
+
+        # true if nothing was written so far.
+        self._first_write = True
+
+        # used by the `temporary_identifier` method to get new
+        # unique, temporary identifier
+        self._last_identifier = 0
+
+        # the current indentation
+        self._indentation = 0
+
+        # Tracks toplevel assignments
+        self._assign_stack = []
+
+        # Tracks parameter definition blocks
+        self._param_def_block = []
+
+        # Tracks the current context.
+        self._context_reference_stack = ["context"]
+
+    # -- Various compilation helpers
+
+    def fail(self, msg, lineno):
+        """Fail with a :exc:`TemplateAssertionError`."""
+        raise TemplateAssertionError(msg, lineno, self.name, self.filename)
+
+    def temporary_identifier(self):
+        """Get a new unique identifier."""
+        self._last_identifier += 1
+        return "t_%d" % self._last_identifier
+
+    def buffer(self, frame):
+        """Enable buffering for the frame from that point onwards."""
+        frame.buffer = self.temporary_identifier()
+        self.writeline("%s = []" % frame.buffer)
+
+    def return_buffer_contents(self, frame, force_unescaped=False):
+        """Return the buffer contents of the frame."""
+        if not force_unescaped:
+            if frame.eval_ctx.volatile:
+                self.writeline("if context.eval_ctx.autoescape:")
+                self.indent()
+                self.writeline("return Markup(concat(%s))" % frame.buffer)
+                self.outdent()
+                self.writeline("else:")
+                self.indent()
+                self.writeline("return concat(%s)" % frame.buffer)
+                self.outdent()
+                return
+            elif frame.eval_ctx.autoescape:
+                self.writeline("return Markup(concat(%s))" % frame.buffer)
+                return
+        self.writeline("return concat(%s)" % frame.buffer)
+
+    def indent(self):
+        """Indent by one."""
+        self._indentation += 1
+
+    def outdent(self, step=1):
+        """Outdent by step."""
+        self._indentation -= step
+
+    def start_write(self, frame, node=None):
+        """Yield or write into the frame buffer."""
+        if frame.buffer is None:
+            self.writeline("yield ", node)
+        else:
+            self.writeline("%s.append(" % frame.buffer, node)
+
+    def end_write(self, frame):
+        """End the writing process started by `start_write`."""
+        if frame.buffer is not None:
+            self.write(")")
+
+    def simple_write(self, s, frame, node=None):
+        """Simple shortcut for start_write + write + end_write."""
+        self.start_write(frame, node)
+        self.write(s)
+        self.end_write(frame)
+
+    def blockvisit(self, nodes, frame):
+        """Visit a list of nodes as block in a frame.  If the current frame
+        is no buffer a dummy ``if 0: yield None`` is written automatically.
+        """
+        try:
+            self.writeline("pass")
+            for node in nodes:
+                self.visit(node, frame)
+        except CompilerExit:
+            pass
+
+    def write(self, x):
+        """Write a string into the output stream."""
+        if self._new_lines:
+            if not self._first_write:
+                self.stream.write("\n" * self._new_lines)
+                self.code_lineno += self._new_lines
+                if self._write_debug_info is not None:
+                    self.debug_info.append((self._write_debug_info, self.code_lineno))
+                    self._write_debug_info = None
+            self._first_write = False
+            self.stream.write("    " * self._indentation)
+            self._new_lines = 0
+        self.stream.write(x)
+
+    def writeline(self, x, node=None, extra=0):
+        """Combination of newline and write."""
+        self.newline(node, extra)
+        self.write(x)
+
+    def newline(self, node=None, extra=0):
+        """Add one or more newlines before the next write."""
+        self._new_lines = max(self._new_lines, 1 + extra)
+        if node is not None and node.lineno != self._last_line:
+            self._write_debug_info = node.lineno
+            self._last_line = node.lineno
+
+    def signature(self, node, frame, extra_kwargs=None):
+        """Writes a function call to the stream for the current node.
+        A leading comma is added automatically.  The extra keyword
+        arguments may not include python keywords otherwise a syntax
+        error could occur.  The extra keyword arguments should be given
+        as python dict.
+        """
+        # if any of the given keyword arguments is a python keyword
+        # we have to make sure that no invalid call is created.
+        kwarg_workaround = False
+        for kwarg in chain((x.key for x in node.kwargs), extra_kwargs or ()):
+            if is_python_keyword(kwarg):
+                kwarg_workaround = True
+                break
+
+        for arg in node.args:
+            self.write(", ")
+            self.visit(arg, frame)
+
+        if not kwarg_workaround:
+            for kwarg in node.kwargs:
+                self.write(", ")
+                self.visit(kwarg, frame)
+            if extra_kwargs is not None:
+                for key, value in iteritems(extra_kwargs):
+                    self.write(", %s=%s" % (key, value))
+        if node.dyn_args:
+            self.write(", *")
+            self.visit(node.dyn_args, frame)
+
+        if kwarg_workaround:
+            if node.dyn_kwargs is not None:
+                self.write(", **dict({")
+            else:
+                self.write(", **{")
+            for kwarg in node.kwargs:
+                self.write("%r: " % kwarg.key)
+                self.visit(kwarg.value, frame)
+                self.write(", ")
+            if extra_kwargs is not None:
+                for key, value in iteritems(extra_kwargs):
+                    self.write("%r: %s, " % (key, value))
+            if node.dyn_kwargs is not None:
+                self.write("}, **")
+                self.visit(node.dyn_kwargs, frame)
+                self.write(")")
+            else:
+                self.write("}")
+
+        elif node.dyn_kwargs is not None:
+            self.write(", **")
+            self.visit(node.dyn_kwargs, frame)
+
+    def pull_dependencies(self, nodes):
+        """Pull all the dependencies."""
+        visitor = DependencyFinderVisitor()
+        for node in nodes:
+            visitor.visit(node)
+        for dependency in "filters", "tests":
+            mapping = getattr(self, dependency)
+            for name in getattr(visitor, dependency):
+                if name not in mapping:
+                    mapping[name] = self.temporary_identifier()
+                self.writeline(
+                    "%s = environment.%s[%r]" % (mapping[name], dependency, name)
+                )
+
+    def enter_frame(self, frame):
+        undefs = []
+        for target, (action, param) in iteritems(frame.symbols.loads):
+            if action == VAR_LOAD_PARAMETER:
+                pass
+            elif action == VAR_LOAD_RESOLVE:
+                self.writeline("%s = %s(%r)" % (target, self.get_resolve_func(), param))
+            elif action == VAR_LOAD_ALIAS:
+                self.writeline("%s = %s" % (target, param))
+            elif action == VAR_LOAD_UNDEFINED:
+                undefs.append(target)
+            else:
+                raise NotImplementedError("unknown load instruction")
+        if undefs:
+            self.writeline("%s = missing" % " = ".join(undefs))
+
+    def leave_frame(self, frame, with_python_scope=False):
+        if not with_python_scope:
+            undefs = []
+            for target, _ in iteritems(frame.symbols.loads):
+                undefs.append(target)
+            if undefs:
+                self.writeline("%s = missing" % " = ".join(undefs))
+
+    def func(self, name):
+        if self.environment.is_async:
+            return "async def %s" % name
+        return "def %s" % name
+
+    def macro_body(self, node, frame):
+        """Dump the function def of a macro or call block."""
+        frame = frame.inner()
+        frame.symbols.analyze_node(node)
+        macro_ref = MacroRef(node)
+
+        explicit_caller = None
+        skip_special_params = set()
+        args = []
+        for idx, arg in enumerate(node.args):
+            if arg.name == "caller":
+                explicit_caller = idx
+            if arg.name in ("kwargs", "varargs"):
+                skip_special_params.add(arg.name)
+            args.append(frame.symbols.ref(arg.name))
+
+        undeclared = find_undeclared(node.body, ("caller", "kwargs", "varargs"))
+
+        if "caller" in undeclared:
+            # In older Jinja versions there was a bug that allowed caller
+            # to retain the special behavior even if it was mentioned in
+            # the argument list.  However thankfully this was only really
+            # working if it was the last argument.  So we are explicitly
+            # checking this now and error out if it is anywhere else in
+            # the argument list.
+            if explicit_caller is not None:
+                try:
+                    node.defaults[explicit_caller - len(node.args)]
+                except IndexError:
+                    self.fail(
+                        "When defining macros or call blocks the "
+                        'special "caller" argument must be omitted '
+                        "or be given a default.",
+                        node.lineno,
+                    )
+            else:
+                args.append(frame.symbols.declare_parameter("caller"))
+            macro_ref.accesses_caller = True
+        if "kwargs" in undeclared and "kwargs" not in skip_special_params:
+            args.append(frame.symbols.declare_parameter("kwargs"))
+            macro_ref.accesses_kwargs = True
+        if "varargs" in undeclared and "varargs" not in skip_special_params:
+            args.append(frame.symbols.declare_parameter("varargs"))
+            macro_ref.accesses_varargs = True
+
+        # macros are delayed, they never require output checks
+        frame.require_output_check = False
+        frame.symbols.analyze_node(node)
+        self.writeline("%s(%s):" % (self.func("macro"), ", ".join(args)), node)
+        self.indent()
+
+        self.buffer(frame)
+        self.enter_frame(frame)
+
+        self.push_parameter_definitions(frame)
+        for idx, arg in enumerate(node.args):
+            ref = frame.symbols.ref(arg.name)
+            self.writeline("if %s is missing:" % ref)
+            self.indent()
+            try:
+                default = node.defaults[idx - len(node.args)]
+            except IndexError:
+                self.writeline(
+                    "%s = undefined(%r, name=%r)"
+                    % (ref, "parameter %r was not provided" % arg.name, arg.name)
+                )
+            else:
+                self.writeline("%s = " % ref)
+                self.visit(default, frame)
+            self.mark_parameter_stored(ref)
+            self.outdent()
+        self.pop_parameter_definitions()
+
+        self.blockvisit(node.body, frame)
+        self.return_buffer_contents(frame, force_unescaped=True)
+        self.leave_frame(frame, with_python_scope=True)
+        self.outdent()
+
+        return frame, macro_ref
+
+    def macro_def(self, macro_ref, frame):
+        """Dump the macro definition for the def created by macro_body."""
+        arg_tuple = ", ".join(repr(x.name) for x in macro_ref.node.args)
+        name = getattr(macro_ref.node, "name", None)
+        if len(macro_ref.node.args) == 1:
+            arg_tuple += ","
+        self.write(
+            "Macro(environment, macro, %r, (%s), %r, %r, %r, "
+            "context.eval_ctx.autoescape)"
+            % (
+                name,
+                arg_tuple,
+                macro_ref.accesses_kwargs,
+                macro_ref.accesses_varargs,
+                macro_ref.accesses_caller,
+            )
+        )
+
+    def position(self, node):
+        """Return a human readable position for the node."""
+        rv = "line %d" % node.lineno
+        if self.name is not None:
+            rv += " in " + repr(self.name)
+        return rv
+
+    def dump_local_context(self, frame):
+        return "{%s}" % ", ".join(
+            "%r: %s" % (name, target)
+            for name, target in iteritems(frame.symbols.dump_stores())
+        )
+
+    def write_commons(self):
+        """Writes a common preamble that is used by root and block functions.
+        Primarily this sets up common local helpers and enforces a generator
+        through a dead branch.
+        """
+        self.writeline("resolve = context.resolve_or_missing")
+        self.writeline("undefined = environment.undefined")
+        # always use the standard Undefined class for the implicit else of
+        # conditional expressions
+        self.writeline("cond_expr_undefined = Undefined")
+        self.writeline("if 0: yield None")
+
+    def push_parameter_definitions(self, frame):
+        """Pushes all parameter targets from the given frame into a local
+        stack that permits tracking of yet to be assigned parameters.  In
+        particular this enables the optimization from `visit_Name` to skip
+        undefined expressions for parameters in macros as macros can reference
+        otherwise unbound parameters.
+        """
+        self._param_def_block.append(frame.symbols.dump_param_targets())
+
+    def pop_parameter_definitions(self):
+        """Pops the current parameter definitions set."""
+        self._param_def_block.pop()
+
+    def mark_parameter_stored(self, target):
+        """Marks a parameter in the current parameter definitions as stored.
+        This will skip the enforced undefined checks.
+        """
+        if self._param_def_block:
+            self._param_def_block[-1].discard(target)
+
+    def push_context_reference(self, target):
+        self._context_reference_stack.append(target)
+
+    def pop_context_reference(self):
+        self._context_reference_stack.pop()
+
+    def get_context_ref(self):
+        return self._context_reference_stack[-1]
+
+    def get_resolve_func(self):
+        target = self._context_reference_stack[-1]
+        if target == "context":
+            return "resolve"
+        return "%s.resolve" % target
+
+    def derive_context(self, frame):
+        return "%s.derived(%s)" % (
+            self.get_context_ref(),
+            self.dump_local_context(frame),
+        )
+
+    def parameter_is_undeclared(self, target):
+        """Checks if a given target is an undeclared parameter."""
+        if not self._param_def_block:
+            return False
+        return target in self._param_def_block[-1]
+
+    def push_assign_tracking(self):
+        """Pushes a new layer for assignment tracking."""
+        self._assign_stack.append(set())
+
+    def pop_assign_tracking(self, frame):
+        """Pops the topmost level for assignment tracking and updates the
+        context variables if necessary.
+        """
+        vars = self._assign_stack.pop()
+        if not frame.toplevel or not vars:
+            return
+        public_names = [x for x in vars if x[:1] != "_"]
+        if len(vars) == 1:
+            name = next(iter(vars))
+            ref = frame.symbols.ref(name)
+            self.writeline("context.vars[%r] = %s" % (name, ref))
+        else:
+            self.writeline("context.vars.update({")
+            for idx, name in enumerate(vars):
+                if idx:
+                    self.write(", ")
+                ref = frame.symbols.ref(name)
+                self.write("%r: %s" % (name, ref))
+            self.write("})")
+        if public_names:
+            if len(public_names) == 1:
+                self.writeline("context.exported_vars.add(%r)" % public_names[0])
+            else:
+                self.writeline(
+                    "context.exported_vars.update((%s))"
+                    % ", ".join(imap(repr, public_names))
+                )
+
+    # -- Statement Visitors
+
+    def visit_Template(self, node, frame=None):
+        assert frame is None, "no root frame allowed"
+        eval_ctx = EvalContext(self.environment, self.name)
+
+        from .runtime import exported
+
+        self.writeline("from __future__ import %s" % ", ".join(code_features))
+        self.writeline("from jinja2.runtime import " + ", ".join(exported))
+
+        if self.environment.is_async:
+            self.writeline(
+                "from jinja2.asyncsupport import auto_await, "
+                "auto_aiter, AsyncLoopContext"
+            )
+
+        # if we want a deferred initialization we cannot move the
+        # environment into a local name
+        envenv = not self.defer_init and ", environment=environment" or ""
+
+        # do we have an extends tag at all?  If not, we can save some
+        # overhead by just not processing any inheritance code.
+        have_extends = node.find(nodes.Extends) is not None
+
+        # find all blocks
+        for block in node.find_all(nodes.Block):
+            if block.name in self.blocks:
+                self.fail("block %r defined twice" % block.name, block.lineno)
+            self.blocks[block.name] = block
+
+        # find all imports and import them
+        for import_ in node.find_all(nodes.ImportedName):
+            if import_.importname not in self.import_aliases:
+                imp = import_.importname
+                self.import_aliases[imp] = alias = self.temporary_identifier()
+                if "." in imp:
+                    module, obj = imp.rsplit(".", 1)
+                    self.writeline("from %s import %s as %s" % (module, obj, alias))
+                else:
+                    self.writeline("import %s as %s" % (imp, alias))
+
+        # add the load name
+        self.writeline("name = %r" % self.name)
+
+        # generate the root render function.
+        self.writeline(
+            "%s(context, missing=missing%s):" % (self.func("root"), envenv), extra=1
+        )
+        self.indent()
+        self.write_commons()
+
+        # process the root
+        frame = Frame(eval_ctx)
+        if "self" in find_undeclared(node.body, ("self",)):
+            ref = frame.symbols.declare_parameter("self")
+            self.writeline("%s = TemplateReference(context)" % ref)
+        frame.symbols.analyze_node(node)
+        frame.toplevel = frame.rootlevel = True
+        frame.require_output_check = have_extends and not self.has_known_extends
+        if have_extends:
+            self.writeline("parent_template = None")
+        self.enter_frame(frame)
+        self.pull_dependencies(node.body)
+        self.blockvisit(node.body, frame)
+        self.leave_frame(frame, with_python_scope=True)
+        self.outdent()
+
+        # make sure that the parent root is called.
+        if have_extends:
+            if not self.has_known_extends:
+                self.indent()
+                self.writeline("if parent_template is not None:")
+            self.indent()
+            if supports_yield_from and not self.environment.is_async:
+                self.writeline("yield from parent_template.root_render_func(context)")
+            else:
+                self.writeline(
+                    "%sfor event in parent_template."
+                    "root_render_func(context):"
+                    % (self.environment.is_async and "async " or "")
+                )
+                self.indent()
+                self.writeline("yield event")
+                self.outdent()
+            self.outdent(1 + (not self.has_known_extends))
+
+        # at this point we now have the blocks collected and can visit them too.
+        for name, block in iteritems(self.blocks):
+            self.writeline(
+                "%s(context, missing=missing%s):"
+                % (self.func("block_" + name), envenv),
+                block,
+                1,
+            )
+            self.indent()
+            self.write_commons()
+            # It's important that we do not make this frame a child of the
+            # toplevel template.  This would cause a variety of
+            # interesting issues with identifier tracking.
+            block_frame = Frame(eval_ctx)
+            undeclared = find_undeclared(block.body, ("self", "super"))
+            if "self" in undeclared:
+                ref = block_frame.symbols.declare_parameter("self")
+                self.writeline("%s = TemplateReference(context)" % ref)
+            if "super" in undeclared:
+                ref = block_frame.symbols.declare_parameter("super")
+                self.writeline("%s = context.super(%r, block_%s)" % (ref, name, name))
+            block_frame.symbols.analyze_node(block)
+            block_frame.block = name
+            self.enter_frame(block_frame)
+            self.pull_dependencies(block.body)
+            self.blockvisit(block.body, block_frame)
+            self.leave_frame(block_frame, with_python_scope=True)
+            self.outdent()
+
+        self.writeline(
+            "blocks = {%s}" % ", ".join("%r: block_%s" % (x, x) for x in self.blocks),
+            extra=1,
+        )
+
+        # add a function that returns the debug info
+        self.writeline(
+            "debug_info = %r" % "&".join("%s=%s" % x for x in self.debug_info)
+        )
+
+    def visit_Block(self, node, frame):
+        """Call a block and register it for the template."""
+        level = 0
+        if frame.toplevel:
+            # if we know that we are a child template, there is no need to
+            # check if we are one
+            if self.has_known_extends:
+                return
+            if self.extends_so_far > 0:
+                self.writeline("if parent_template is None:")
+                self.indent()
+                level += 1
+
+        if node.scoped:
+            context = self.derive_context(frame)
+        else:
+            context = self.get_context_ref()
+
+        if (
+            supports_yield_from
+            and not self.environment.is_async
+            and frame.buffer is None
+        ):
+            self.writeline(
+                "yield from context.blocks[%r][0](%s)" % (node.name, context), node
+            )
+        else:
+            loop = self.environment.is_async and "async for" or "for"
+            self.writeline(
+                "%s event in context.blocks[%r][0](%s):" % (loop, node.name, context),
+                node,
+            )
+            self.indent()
+            self.simple_write("event", frame)
+            self.outdent()
+
+        self.outdent(level)
+
+    def visit_Extends(self, node, frame):
+        """Calls the extender."""
+        if not frame.toplevel:
+            self.fail("cannot use extend from a non top-level scope", node.lineno)
+
+        # if the number of extends statements in general is zero so
+        # far, we don't have to add a check if something extended
+        # the template before this one.
+        if self.extends_so_far > 0:
+
+            # if we have a known extends we just add a template runtime
+            # error into the generated code.  We could catch that at compile
+            # time too, but i welcome it not to confuse users by throwing the
+            # same error at different times just "because we can".
+            if not self.has_known_extends:
+                self.writeline("if parent_template is not None:")
+                self.indent()
+            self.writeline("raise TemplateRuntimeError(%r)" % "extended multiple times")
+
+            # if we have a known extends already we don't need that code here
+            # as we know that the template execution will end here.
+            if self.has_known_extends:
+                raise CompilerExit()
+            else:
+                self.outdent()
+
+        self.writeline("parent_template = environment.get_template(", node)
+        self.visit(node.template, frame)
+        self.write(", %r)" % self.name)
+        self.writeline(
+            "for name, parent_block in parent_template.blocks.%s():" % dict_item_iter
+        )
+        self.indent()
+        self.writeline("context.blocks.setdefault(name, []).append(parent_block)")
+        self.outdent()
+
+        # if this extends statement was in the root level we can take
+        # advantage of that information and simplify the generated code
+        # in the top level from this point onwards
+        if frame.rootlevel:
+            self.has_known_extends = True
+
+        # and now we have one more
+        self.extends_so_far += 1
+
+    def visit_Include(self, node, frame):
+        """Handles includes."""
+        if node.ignore_missing:
+            self.writeline("try:")
+            self.indent()
+
+        func_name = "get_or_select_template"
+        if isinstance(node.template, nodes.Const):
+            if isinstance(node.template.value, string_types):
+                func_name = "get_template"
+            elif isinstance(node.template.value, (tuple, list)):
+                func_name = "select_template"
+        elif isinstance(node.template, (nodes.Tuple, nodes.List)):
+            func_name = "select_template"
+
+        self.writeline("template = environment.%s(" % func_name, node)
+        self.visit(node.template, frame)
+        self.write(", %r)" % self.name)
+        if node.ignore_missing:
+            self.outdent()
+            self.writeline("except TemplateNotFound:")
+            self.indent()
+            self.writeline("pass")
+            self.outdent()
+            self.writeline("else:")
+            self.indent()
+
+        skip_event_yield = False
+        if node.with_context:
+            loop = self.environment.is_async and "async for" or "for"
+            self.writeline(
+                "%s event in template.root_render_func("
+                "template.new_context(context.get_all(), True, "
+                "%s)):" % (loop, self.dump_local_context(frame))
+            )
+        elif self.environment.is_async:
+            self.writeline(
+                "for event in (await "
+                "template._get_default_module_async())"
+                "._body_stream:"
+            )
+        else:
+            if supports_yield_from:
+                self.writeline("yield from template._get_default_module()._body_stream")
+                skip_event_yield = True
+            else:
+                self.writeline(
+                    "for event in template._get_default_module()._body_stream:"
+                )
+
+        if not skip_event_yield:
+            self.indent()
+            self.simple_write("event", frame)
+            self.outdent()
+
+        if node.ignore_missing:
+            self.outdent()
+
+    def visit_Import(self, node, frame):
+        """Visit regular imports."""
+        self.writeline("%s = " % frame.symbols.ref(node.target), node)
+        if frame.toplevel:
+            self.write("context.vars[%r] = " % node.target)
+        if self.environment.is_async:
+            self.write("await ")
+        self.write("environment.get_template(")
+        self.visit(node.template, frame)
+        self.write(", %r)." % self.name)
+        if node.with_context:
+            self.write(
+                "make_module%s(context.get_all(), True, %s)"
+                % (
+                    self.environment.is_async and "_async" or "",
+                    self.dump_local_context(frame),
+                )
+            )
+        elif self.environment.is_async:
+            self.write("_get_default_module_async()")
+        else:
+            self.write("_get_default_module()")
+        if frame.toplevel and not node.target.startswith("_"):
+            self.writeline("context.exported_vars.discard(%r)" % node.target)
+
+    def visit_FromImport(self, node, frame):
+        """Visit named imports."""
+        self.newline(node)
+        self.write(
+            "included_template = %senvironment.get_template("
+            % (self.environment.is_async and "await " or "")
+        )
+        self.visit(node.template, frame)
+        self.write(", %r)." % self.name)
+        if node.with_context:
+            self.write(
+                "make_module%s(context.get_all(), True, %s)"
+                % (
+                    self.environment.is_async and "_async" or "",
+                    self.dump_local_context(frame),
+                )
+            )
+        elif self.environment.is_async:
+            self.write("_get_default_module_async()")
+        else:
+            self.write("_get_default_module()")
+
+        var_names = []
+        discarded_names = []
+        for name in node.names:
+            if isinstance(name, tuple):
+                name, alias = name
+            else:
+                alias = name
+            self.writeline(
+                "%s = getattr(included_template, "
+                "%r, missing)" % (frame.symbols.ref(alias), name)
+            )
+            self.writeline("if %s is missing:" % frame.symbols.ref(alias))
+            self.indent()
+            self.writeline(
+                "%s = undefined(%r %% "
+                "included_template.__name__, "
+                "name=%r)"
+                % (
+                    frame.symbols.ref(alias),
+                    "the template %%r (imported on %s) does "
+                    "not export the requested name %s"
+                    % (self.position(node), repr(name)),
+                    name,
+                )
+            )
+            self.outdent()
+            if frame.toplevel:
+                var_names.append(alias)
+                if not alias.startswith("_"):
+                    discarded_names.append(alias)
+
+        if var_names:
+            if len(var_names) == 1:
+                name = var_names[0]
+                self.writeline(
+                    "context.vars[%r] = %s" % (name, frame.symbols.ref(name))
+                )
+            else:
+                self.writeline(
+                    "context.vars.update({%s})"
+                    % ", ".join(
+                        "%r: %s" % (name, frame.symbols.ref(name)) for name in var_names
+                    )
+                )
+        if discarded_names:
+            if len(discarded_names) == 1:
+                self.writeline("context.exported_vars.discard(%r)" % discarded_names[0])
+            else:
+                self.writeline(
+                    "context.exported_vars.difference_"
+                    "update((%s))" % ", ".join(imap(repr, discarded_names))
+                )
+
+    def visit_For(self, node, frame):
+        loop_frame = frame.inner()
+        test_frame = frame.inner()
+        else_frame = frame.inner()
+
+        # try to figure out if we have an extended loop.  An extended loop
+        # is necessary if the loop is in recursive mode if the special loop
+        # variable is accessed in the body.
+        extended_loop = node.recursive or "loop" in find_undeclared(
+            node.iter_child_nodes(only=("body",)), ("loop",)
+        )
+
+        loop_ref = None
+        if extended_loop:
+            loop_ref = loop_frame.symbols.declare_parameter("loop")
+
+        loop_frame.symbols.analyze_node(node, for_branch="body")
+        if node.else_:
+            else_frame.symbols.analyze_node(node, for_branch="else")
+
+        if node.test:
+            loop_filter_func = self.temporary_identifier()
+            test_frame.symbols.analyze_node(node, for_branch="test")
+            self.writeline("%s(fiter):" % self.func(loop_filter_func), node.test)
+            self.indent()
+            self.enter_frame(test_frame)
+            self.writeline(self.environment.is_async and "async for " or "for ")
+            self.visit(node.target, loop_frame)
+            self.write(" in ")
+            self.write(self.environment.is_async and "auto_aiter(fiter)" or "fiter")
+            self.write(":")
+            self.indent()
+            self.writeline("if ", node.test)
+            self.visit(node.test, test_frame)
+            self.write(":")
+            self.indent()
+            self.writeline("yield ")
+            self.visit(node.target, loop_frame)
+            self.outdent(3)
+            self.leave_frame(test_frame, with_python_scope=True)
+
+        # if we don't have an recursive loop we have to find the shadowed
+        # variables at that point.  Because loops can be nested but the loop
+        # variable is a special one we have to enforce aliasing for it.
+        if node.recursive:
+            self.writeline(
+                "%s(reciter, loop_render_func, depth=0):" % self.func("loop"), node
+            )
+            self.indent()
+            self.buffer(loop_frame)
+
+            # Use the same buffer for the else frame
+            else_frame.buffer = loop_frame.buffer
+
+        # make sure the loop variable is a special one and raise a template
+        # assertion error if a loop tries to write to loop
+        if extended_loop:
+            self.writeline("%s = missing" % loop_ref)
+
+        for name in node.find_all(nodes.Name):
+            if name.ctx == "store" and name.name == "loop":
+                self.fail(
+                    "Can't assign to special loop variable in for-loop target",
+                    name.lineno,
+                )
+
+        if node.else_:
+            iteration_indicator = self.temporary_identifier()
+            self.writeline("%s = 1" % iteration_indicator)
+
+        self.writeline(self.environment.is_async and "async for " or "for ", node)
+        self.visit(node.target, loop_frame)
+        if extended_loop:
+            if self.environment.is_async:
+                self.write(", %s in AsyncLoopContext(" % loop_ref)
+            else:
+                self.write(", %s in LoopContext(" % loop_ref)
+        else:
+            self.write(" in ")
+
+        if node.test:
+            self.write("%s(" % loop_filter_func)
+        if node.recursive:
+            self.write("reciter")
+        else:
+            if self.environment.is_async and not extended_loop:
+                self.write("auto_aiter(")
+            self.visit(node.iter, frame)
+            if self.environment.is_async and not extended_loop:
+                self.write(")")
+        if node.test:
+            self.write(")")
+
+        if node.recursive:
+            self.write(", undefined, loop_render_func, depth):")
+        else:
+            self.write(extended_loop and ", undefined):" or ":")
+
+        self.indent()
+        self.enter_frame(loop_frame)
+
+        self.blockvisit(node.body, loop_frame)
+        if node.else_:
+            self.writeline("%s = 0" % iteration_indicator)
+        self.outdent()
+        self.leave_frame(
+            loop_frame, with_python_scope=node.recursive and not node.else_
+        )
+
+        if node.else_:
+            self.writeline("if %s:" % iteration_indicator)
+            self.indent()
+            self.enter_frame(else_frame)
+            self.blockvisit(node.else_, else_frame)
+            self.leave_frame(else_frame)
+            self.outdent()
+
+        # if the node was recursive we have to return the buffer contents
+        # and start the iteration code
+        if node.recursive:
+            self.return_buffer_contents(loop_frame)
+            self.outdent()
+            self.start_write(frame, node)
+            if self.environment.is_async:
+                self.write("await ")
+            self.write("loop(")
+            if self.environment.is_async:
+                self.write("auto_aiter(")
+            self.visit(node.iter, frame)
+            if self.environment.is_async:
+                self.write(")")
+            self.write(", loop)")
+            self.end_write(frame)
+
+    def visit_If(self, node, frame):
+        if_frame = frame.soft()
+        self.writeline("if ", node)
+        self.visit(node.test, if_frame)
+        self.write(":")
+        self.indent()
+        self.blockvisit(node.body, if_frame)
+        self.outdent()
+        for elif_ in node.elif_:
+            self.writeline("elif ", elif_)
+            self.visit(elif_.test, if_frame)
+            self.write(":")
+            self.indent()
+            self.blockvisit(elif_.body, if_frame)
+            self.outdent()
+        if node.else_:
+            self.writeline("else:")
+            self.indent()
+            self.blockvisit(node.else_, if_frame)
+            self.outdent()
+
+    def visit_Macro(self, node, frame):
+        macro_frame, macro_ref = self.macro_body(node, frame)
+        self.newline()
+        if frame.toplevel:
+            if not node.name.startswith("_"):
+                self.write("context.exported_vars.add(%r)" % node.name)
+            self.writeline("context.vars[%r] = " % node.name)
+        self.write("%s = " % frame.symbols.ref(node.name))
+        self.macro_def(macro_ref, macro_frame)
+
+    def visit_CallBlock(self, node, frame):
+        call_frame, macro_ref = self.macro_body(node, frame)
+        self.writeline("caller = ")
+        self.macro_def(macro_ref, call_frame)
+        self.start_write(frame, node)
+        self.visit_Call(node.call, frame, forward_caller=True)
+        self.end_write(frame)
+
+    def visit_FilterBlock(self, node, frame):
+        filter_frame = frame.inner()
+        filter_frame.symbols.analyze_node(node)
+        self.enter_frame(filter_frame)
+        self.buffer(filter_frame)
+        self.blockvisit(node.body, filter_frame)
+        self.start_write(frame, node)
+        self.visit_Filter(node.filter, filter_frame)
+        self.end_write(frame)
+        self.leave_frame(filter_frame)
+
+    def visit_With(self, node, frame):
+        with_frame = frame.inner()
+        with_frame.symbols.analyze_node(node)
+        self.enter_frame(with_frame)
+        for target, expr in izip(node.targets, node.values):
+            self.newline()
+            self.visit(target, with_frame)
+            self.write(" = ")
+            self.visit(expr, frame)
+        self.blockvisit(node.body, with_frame)
+        self.leave_frame(with_frame)
+
+    def visit_ExprStmt(self, node, frame):
+        self.newline(node)
+        self.visit(node.node, frame)
+
+    _FinalizeInfo = namedtuple("_FinalizeInfo", ("const", "src"))
+    #: The default finalize function if the environment isn't configured
+    #: with one. Or if the environment has one, this is called on that
+    #: function's output for constants.
+    _default_finalize = text_type
+    _finalize = None
+
+    def _make_finalize(self):
+        """Build the finalize function to be used on constants and at
+        runtime. Cached so it's only created once for all output nodes.
+
+        Returns a ``namedtuple`` with the following attributes:
+
+        ``const``
+            A function to finalize constant data at compile time.
+
+        ``src``
+            Source code to output around nodes to be evaluated at
+            runtime.
+        """
+        if self._finalize is not None:
+            return self._finalize
+
+        finalize = default = self._default_finalize
+        src = None
+
+        if self.environment.finalize:
+            src = "environment.finalize("
+            env_finalize = self.environment.finalize
+
+            def finalize(value):
+                return default(env_finalize(value))
+
+            if getattr(env_finalize, "contextfunction", False) is True:
+                src += "context, "
+                finalize = None  # noqa: F811
+            elif getattr(env_finalize, "evalcontextfunction", False) is True:
+                src += "context.eval_ctx, "
+                finalize = None
+            elif getattr(env_finalize, "environmentfunction", False) is True:
+                src += "environment, "
+
+                def finalize(value):
+                    return default(env_finalize(self.environment, value))
+
+        self._finalize = self._FinalizeInfo(finalize, src)
+        return self._finalize
+
+    def _output_const_repr(self, group):
+        """Given a group of constant values converted from ``Output``
+        child nodes, produce a string to write to the template module
+        source.
+        """
+        return repr(concat(group))
+
+    def _output_child_to_const(self, node, frame, finalize):
+        """Try to optimize a child of an ``Output`` node by trying to
+        convert it to constant, finalized data at compile time.
+
+        If :exc:`Impossible` is raised, the node is not constant and
+        will be evaluated at runtime. Any other exception will also be
+        evaluated at runtime for easier debugging.
+        """
+        const = node.as_const(frame.eval_ctx)
+
+        if frame.eval_ctx.autoescape:
+            const = escape(const)
+
+        # Template data doesn't go through finalize.
+        if isinstance(node, nodes.TemplateData):
+            return text_type(const)
+
+        return finalize.const(const)
+
+    def _output_child_pre(self, node, frame, finalize):
+        """Output extra source code before visiting a child of an
+        ``Output`` node.
+        """
+        if frame.eval_ctx.volatile:
+            self.write("(escape if context.eval_ctx.autoescape else to_string)(")
+        elif frame.eval_ctx.autoescape:
+            self.write("escape(")
+        else:
+            self.write("to_string(")
+
+        if finalize.src is not None:
+            self.write(finalize.src)
+
+    def _output_child_post(self, node, frame, finalize):
+        """Output extra source code after visiting a child of an
+        ``Output`` node.
+        """
+        self.write(")")
+
+        if finalize.src is not None:
+            self.write(")")
+
+    def visit_Output(self, node, frame):
+        # If an extends is active, don't render outside a block.
+        if frame.require_output_check:
+            # A top-level extends is known to exist at compile time.
+            if self.has_known_extends:
+                return
+
+            self.writeline("if parent_template is None:")
+            self.indent()
+
+        finalize = self._make_finalize()
+        body = []
+
+        # Evaluate constants at compile time if possible. Each item in
+        # body will be either a list of static data or a node to be
+        # evaluated at runtime.
+        for child in node.nodes:
+            try:
+                if not (
+                    # If the finalize function requires runtime context,
+                    # constants can't be evaluated at compile time.
+                    finalize.const
+                    # Unless it's basic template data that won't be
+                    # finalized anyway.
+                    or isinstance(child, nodes.TemplateData)
+                ):
+                    raise nodes.Impossible()
+
+                const = self._output_child_to_const(child, frame, finalize)
+            except (nodes.Impossible, Exception):
+                # The node was not constant and needs to be evaluated at
+                # runtime. Or another error was raised, which is easier
+                # to debug at runtime.
+                body.append(child)
+                continue
+
+            if body and isinstance(body[-1], list):
+                body[-1].append(const)
+            else:
+                body.append([const])
+
+        if frame.buffer is not None:
+            if len(body) == 1:
+                self.writeline("%s.append(" % frame.buffer)
+            else:
+                self.writeline("%s.extend((" % frame.buffer)
+
+            self.indent()
+
+        for item in body:
+            if isinstance(item, list):
+                # A group of constant data to join and output.
+                val = self._output_const_repr(item)
+
+                if frame.buffer is None:
+                    self.writeline("yield " + val)
+                else:
+                    self.writeline(val + ",")
+            else:
+                if frame.buffer is None:
+                    self.writeline("yield ", item)
+                else:
+                    self.newline(item)
+
+                # A node to be evaluated at runtime.
+                self._output_child_pre(item, frame, finalize)
+                self.visit(item, frame)
+                self._output_child_post(item, frame, finalize)
+
+                if frame.buffer is not None:
+                    self.write(",")
+
+        if frame.buffer is not None:
+            self.outdent()
+            self.writeline(")" if len(body) == 1 else "))")
+
+        if frame.require_output_check:
+            self.outdent()
+
+    def visit_Assign(self, node, frame):
+        self.push_assign_tracking()
+        self.newline(node)
+        self.visit(node.target, frame)
+        self.write(" = ")
+        self.visit(node.node, frame)
+        self.pop_assign_tracking(frame)
+
+    def visit_AssignBlock(self, node, frame):
+        self.push_assign_tracking()
+        block_frame = frame.inner()
+        # This is a special case.  Since a set block always captures we
+        # will disable output checks.  This way one can use set blocks
+        # toplevel even in extended templates.
+        block_frame.require_output_check = False
+        block_frame.symbols.analyze_node(node)
+        self.enter_frame(block_frame)
+        self.buffer(block_frame)
+        self.blockvisit(node.body, block_frame)
+        self.newline(node)
+        self.visit(node.target, frame)
+        self.write(" = (Markup if context.eval_ctx.autoescape else identity)(")
+        if node.filter is not None:
+            self.visit_Filter(node.filter, block_frame)
+        else:
+            self.write("concat(%s)" % block_frame.buffer)
+        self.write(")")
+        self.pop_assign_tracking(frame)
+        self.leave_frame(block_frame)
+
+    # -- Expression Visitors
+
+    def visit_Name(self, node, frame):
+        if node.ctx == "store" and frame.toplevel:
+            if self._assign_stack:
+                self._assign_stack[-1].add(node.name)
+        ref = frame.symbols.ref(node.name)
+
+        # If we are looking up a variable we might have to deal with the
+        # case where it's undefined.  We can skip that case if the load
+        # instruction indicates a parameter which are always defined.
+        if node.ctx == "load":
+            load = frame.symbols.find_load(ref)
+            if not (
+                load is not None
+                and load[0] == VAR_LOAD_PARAMETER
+                and not self.parameter_is_undeclared(ref)
+            ):
+                self.write(
+                    "(undefined(name=%r) if %s is missing else %s)"
+                    % (node.name, ref, ref)
+                )
+                return
+
+        self.write(ref)
+
+    def visit_NSRef(self, node, frame):
+        # NSRefs can only be used to store values; since they use the normal
+        # `foo.bar` notation they will be parsed as a normal attribute access
+        # when used anywhere but in a `set` context
+        ref = frame.symbols.ref(node.name)
+        self.writeline("if not isinstance(%s, Namespace):" % ref)
+        self.indent()
+        self.writeline(
+            "raise TemplateRuntimeError(%r)"
+            % "cannot assign attribute on non-namespace object"
+        )
+        self.outdent()
+        self.writeline("%s[%r]" % (ref, node.attr))
+
+    def visit_Const(self, node, frame):
+        val = node.as_const(frame.eval_ctx)
+        if isinstance(val, float):
+            self.write(str(val))
+        else:
+            self.write(repr(val))
+
+    def visit_TemplateData(self, node, frame):
+        try:
+            self.write(repr(node.as_const(frame.eval_ctx)))
+        except nodes.Impossible:
+            self.write(
+                "(Markup if context.eval_ctx.autoescape else identity)(%r)" % node.data
+            )
+
+    def visit_Tuple(self, node, frame):
+        self.write("(")
+        idx = -1
+        for idx, item in enumerate(node.items):
+            if idx:
+                self.write(", ")
+            self.visit(item, frame)
+        self.write(idx == 0 and ",)" or ")")
+
+    def visit_List(self, node, frame):
+        self.write("[")
+        for idx, item in enumerate(node.items):
+            if idx:
+                self.write(", ")
+            self.visit(item, frame)
+        self.write("]")
+
+    def visit_Dict(self, node, frame):
+        self.write("{")
+        for idx, item in enumerate(node.items):
+            if idx:
+                self.write(", ")
+            self.visit(item.key, frame)
+            self.write(": ")
+            self.visit(item.value, frame)
+        self.write("}")
+
+    def binop(operator, interceptable=True):  # noqa: B902
+        @optimizeconst
+        def visitor(self, node, frame):
+            if (
+                self.environment.sandboxed
+                and operator in self.environment.intercepted_binops
+            ):
+                self.write("environment.call_binop(context, %r, " % operator)
+                self.visit(node.left, frame)
+                self.write(", ")
+                self.visit(node.right, frame)
+            else:
+                self.write("(")
+                self.visit(node.left, frame)
+                self.write(" %s " % operator)
+                self.visit(node.right, frame)
+            self.write(")")
+
+        return visitor
+
+    def uaop(operator, interceptable=True):  # noqa: B902
+        @optimizeconst
+        def visitor(self, node, frame):
+            if (
+                self.environment.sandboxed
+                and operator in self.environment.intercepted_unops
+            ):
+                self.write("environment.call_unop(context, %r, " % operator)
+                self.visit(node.node, frame)
+            else:
+                self.write("(" + operator)
+                self.visit(node.node, frame)
+            self.write(")")
+
+        return visitor
+
+    visit_Add = binop("+")
+    visit_Sub = binop("-")
+    visit_Mul = binop("*")
+    visit_Div = binop("/")
+    visit_FloorDiv = binop("//")
+    visit_Pow = binop("**")
+    visit_Mod = binop("%")
+    visit_And = binop("and", interceptable=False)
+    visit_Or = binop("or", interceptable=False)
+    visit_Pos = uaop("+")
+    visit_Neg = uaop("-")
+    visit_Not = uaop("not ", interceptable=False)
+    del binop, uaop
+
+    @optimizeconst
+    def visit_Concat(self, node, frame):
+        if frame.eval_ctx.volatile:
+            func_name = "(context.eval_ctx.volatile and markup_join or unicode_join)"
+        elif frame.eval_ctx.autoescape:
+            func_name = "markup_join"
+        else:
+            func_name = "unicode_join"
+        self.write("%s((" % func_name)
+        for arg in node.nodes:
+            self.visit(arg, frame)
+            self.write(", ")
+        self.write("))")
+
+    @optimizeconst
+    def visit_Compare(self, node, frame):
+        self.write("(")
+        self.visit(node.expr, frame)
+        for op in node.ops:
+            self.visit(op, frame)
+        self.write(")")
+
+    def visit_Operand(self, node, frame):
+        self.write(" %s " % operators[node.op])
+        self.visit(node.expr, frame)
+
+    @optimizeconst
+    def visit_Getattr(self, node, frame):
+        if self.environment.is_async:
+            self.write("(await auto_await(")
+
+        self.write("environment.getattr(")
+        self.visit(node.node, frame)
+        self.write(", %r)" % node.attr)
+
+        if self.environment.is_async:
+            self.write("))")
+
+    @optimizeconst
+    def visit_Getitem(self, node, frame):
+        # slices bypass the environment getitem method.
+        if isinstance(node.arg, nodes.Slice):
+            self.visit(node.node, frame)
+            self.write("[")
+            self.visit(node.arg, frame)
+            self.write("]")
+        else:
+            if self.environment.is_async:
+                self.write("(await auto_await(")
+
+            self.write("environment.getitem(")
+            self.visit(node.node, frame)
+            self.write(", ")
+            self.visit(node.arg, frame)
+            self.write(")")
+
+            if self.environment.is_async:
+                self.write("))")
+
+    def visit_Slice(self, node, frame):
+        if node.start is not None:
+            self.visit(node.start, frame)
+        self.write(":")
+        if node.stop is not None:
+            self.visit(node.stop, frame)
+        if node.step is not None:
+            self.write(":")
+            self.visit(node.step, frame)
+
+    @optimizeconst
+    def visit_Filter(self, node, frame):
+        if self.environment.is_async:
+            self.write("await auto_await(")
+        self.write(self.filters[node.name] + "(")
+        func = self.environment.filters.get(node.name)
+        if func is None:
+            self.fail("no filter named %r" % node.name, node.lineno)
+        if getattr(func, "contextfilter", False) is True:
+            self.write("context, ")
+        elif getattr(func, "evalcontextfilter", False) is True:
+            self.write("context.eval_ctx, ")
+        elif getattr(func, "environmentfilter", False) is True:
+            self.write("environment, ")
+
+        # if the filter node is None we are inside a filter block
+        # and want to write to the current buffer
+        if node.node is not None:
+            self.visit(node.node, frame)
+        elif frame.eval_ctx.volatile:
+            self.write(
+                "(context.eval_ctx.autoescape and"
+                " Markup(concat(%s)) or concat(%s))" % (frame.buffer, frame.buffer)
+            )
+        elif frame.eval_ctx.autoescape:
+            self.write("Markup(concat(%s))" % frame.buffer)
+        else:
+            self.write("concat(%s)" % frame.buffer)
+        self.signature(node, frame)
+        self.write(")")
+        if self.environment.is_async:
+            self.write(")")
+
+    @optimizeconst
+    def visit_Test(self, node, frame):
+        self.write(self.tests[node.name] + "(")
+        if node.name not in self.environment.tests:
+            self.fail("no test named %r" % node.name, node.lineno)
+        self.visit(node.node, frame)
+        self.signature(node, frame)
+        self.write(")")
+
+    @optimizeconst
+    def visit_CondExpr(self, node, frame):
+        def write_expr2():
+            if node.expr2 is not None:
+                return self.visit(node.expr2, frame)
+            self.write(
+                "cond_expr_undefined(%r)"
+                % (
+                    "the inline if-"
+                    "expression on %s evaluated to false and "
+                    "no else section was defined." % self.position(node)
+                )
+            )
+
+        self.write("(")
+        self.visit(node.expr1, frame)
+        self.write(" if ")
+        self.visit(node.test, frame)
+        self.write(" else ")
+        write_expr2()
+        self.write(")")
+
+    @optimizeconst
+    def visit_Call(self, node, frame, forward_caller=False):
+        if self.environment.is_async:
+            self.write("await auto_await(")
+        if self.environment.sandboxed:
+            self.write("environment.call(context, ")
+        else:
+            self.write("context.call(")
+        self.visit(node.node, frame)
+        extra_kwargs = forward_caller and {"caller": "caller"} or None
+        self.signature(node, frame, extra_kwargs)
+        self.write(")")
+        if self.environment.is_async:
+            self.write(")")
+
+    def visit_Keyword(self, node, frame):
+        self.write(node.key + "=")
+        self.visit(node.value, frame)
+
+    # -- Unused nodes for extensions
+
+    def visit_MarkSafe(self, node, frame):
+        self.write("Markup(")
+        self.visit(node.expr, frame)
+        self.write(")")
+
+    def visit_MarkSafeIfAutoescape(self, node, frame):
+        self.write("(context.eval_ctx.autoescape and Markup or identity)(")
+        self.visit(node.expr, frame)
+        self.write(")")
+
+    def visit_EnvironmentAttribute(self, node, frame):
+        self.write("environment." + node.name)
+
+    def visit_ExtensionAttribute(self, node, frame):
+        self.write("environment.extensions[%r].%s" % (node.identifier, node.name))
+
+    def visit_ImportedName(self, node, frame):
+        self.write(self.import_aliases[node.importname])
+
+    def visit_InternalName(self, node, frame):
+        self.write(node.name)
+
+    def visit_ContextReference(self, node, frame):
+        self.write("context")
+
+    def visit_DerivedContextReference(self, node, frame):
+        self.write(self.derive_context(frame))
+
+    def visit_Continue(self, node, frame):
+        self.writeline("continue", node)
+
+    def visit_Break(self, node, frame):
+        self.writeline("break", node)
+
+    def visit_Scope(self, node, frame):
+        scope_frame = frame.inner()
+        scope_frame.symbols.analyze_node(node)
+        self.enter_frame(scope_frame)
+        self.blockvisit(node.body, scope_frame)
+        self.leave_frame(scope_frame)
+
+    def visit_OverlayScope(self, node, frame):
+        ctx = self.temporary_identifier()
+        self.writeline("%s = %s" % (ctx, self.derive_context(frame)))
+        self.writeline("%s.vars = " % ctx)
+        self.visit(node.context, frame)
+        self.push_context_reference(ctx)
+
+        scope_frame = frame.inner(isolated=True)
+        scope_frame.symbols.analyze_node(node)
+        self.enter_frame(scope_frame)
+        self.blockvisit(node.body, scope_frame)
+        self.leave_frame(scope_frame)
+        self.pop_context_reference()
+
+    def visit_EvalContextModifier(self, node, frame):
+        for keyword in node.options:
+            self.writeline("context.eval_ctx.%s = " % keyword.key)
+            self.visit(keyword.value, frame)
+            try:
+                val = keyword.value.as_const(frame.eval_ctx)
+            except nodes.Impossible:
+                frame.eval_ctx.volatile = True
+            else:
+                setattr(frame.eval_ctx, keyword.key, val)
+
+    def visit_ScopedEvalContextModifier(self, node, frame):
+        old_ctx_name = self.temporary_identifier()
+        saved_ctx = frame.eval_ctx.save()
+        self.writeline("%s = context.eval_ctx.save()" % old_ctx_name)
+        self.visit_EvalContextModifier(node, frame)
+        for child in node.body:
+            self.visit(child, frame)
+        frame.eval_ctx.revert(saved_ctx)
+        self.writeline("context.eval_ctx.revert(%s)" % old_ctx_name)

magma/squid_cnf/charms/squid/venv/jinja2/constants.py

+# -*- coding: utf-8 -*-
+#: list of lorem ipsum words used by the lipsum() helper function
+LOREM_IPSUM_WORDS = u"""\
+a ac accumsan ad adipiscing aenean aliquam aliquet amet ante aptent arcu at
+auctor augue bibendum blandit class commodo condimentum congue consectetuer
+consequat conubia convallis cras cubilia cum curabitur curae cursus dapibus
+diam dictum dictumst dignissim dis dolor donec dui duis egestas eget eleifend
+elementum elit enim erat eros est et etiam eu euismod facilisi facilisis fames
+faucibus felis fermentum feugiat fringilla fusce gravida habitant habitasse hac
+hendrerit hymenaeos iaculis id imperdiet in inceptos integer interdum ipsum
+justo lacinia lacus laoreet lectus leo libero ligula litora lobortis lorem
+luctus maecenas magna magnis malesuada massa mattis mauris metus mi molestie
+mollis montes morbi mus nam nascetur natoque nec neque netus nibh nisi nisl non
+nonummy nostra nulla nullam nunc odio orci ornare parturient pede pellentesque
+penatibus per pharetra phasellus placerat platea porta porttitor posuere
+potenti praesent pretium primis proin pulvinar purus quam quis quisque rhoncus
+ridiculus risus rutrum sagittis sapien scelerisque sed sem semper senectus sit
+sociis sociosqu sodales sollicitudin suscipit suspendisse taciti tellus tempor
+tempus tincidunt torquent tortor tristique turpis ullamcorper ultrices
+ultricies urna ut varius vehicula vel velit venenatis vestibulum vitae vivamus
+viverra volutpat vulputate"""

magma/squid_cnf/charms/squid/venv/jinja2/debug.py

+import sys
+from types import CodeType
+
+from . import TemplateSyntaxError
+from ._compat import PYPY
+from .utils import internal_code
+from .utils import missing
+
+
+def rewrite_traceback_stack(source=None):
+    """Rewrite the current exception to replace any tracebacks from
+    within compiled template code with tracebacks that look like they
+    came from the template source.
+
+    This must be called within an ``except`` block.
+
+    :param exc_info: A :meth:`sys.exc_info` tuple. If not provided,
+        the current ``exc_info`` is used.
+    :param source: For ``TemplateSyntaxError``, the original source if
+        known.
+    :return: A :meth:`sys.exc_info` tuple that can be re-raised.
+    """
+    exc_type, exc_value, tb = sys.exc_info()
+
+    if isinstance(exc_value, TemplateSyntaxError) and not exc_value.translated:
+        exc_value.translated = True
+        exc_value.source = source
+
+        try:
+            # Remove the old traceback on Python 3, otherwise the frames
+            # from the compiler still show up.
+            exc_value.with_traceback(None)
+        except AttributeError:
+            pass
+
+        # Outside of runtime, so the frame isn't executing template
+        # code, but it still needs to point at the template.
+        tb = fake_traceback(
+            exc_value, None, exc_value.filename or "<unknown>", exc_value.lineno
+        )
+    else:
+        # Skip the frame for the render function.
+        tb = tb.tb_next
+
+    stack = []
+
+    # Build the stack of traceback object, replacing any in template
+    # code with the source file and line information.
+    while tb is not None:
+        # Skip frames decorated with @internalcode. These are internal
+        # calls that aren't useful in template debugging output.
+        if tb.tb_frame.f_code in internal_code:
+            tb = tb.tb_next
+            continue
+
+        template = tb.tb_frame.f_globals.get("__jinja_template__")
+
+        if template is not None:
+            lineno = template.get_corresponding_lineno(tb.tb_lineno)
+            fake_tb = fake_traceback(exc_value, tb, template.filename, lineno)
+            stack.append(fake_tb)
+        else:
+            stack.append(tb)
+
+        tb = tb.tb_next
+
+    tb_next = None
+
+    # Assign tb_next in reverse to avoid circular references.
+    for tb in reversed(stack):
+        tb_next = tb_set_next(tb, tb_next)
+
+    return exc_type, exc_value, tb_next
+
+
+def fake_traceback(exc_value, tb, filename, lineno):
+    """Produce a new traceback object that looks like it came from the
+    template source instead of the compiled code. The filename, line
+    number, and location name will point to the template, and the local
+    variables will be the current template context.
+
+    :param exc_value: The original exception to be re-raised to create
+        the new traceback.
+    :param tb: The original traceback to get the local variables and
+        code info from.
+    :param filename: The template filename.
+    :param lineno: The line number in the template source.
+    """
+    if tb is not None:
+        # Replace the real locals with the context that would be
+        # available at that point in the template.
+        locals = get_template_locals(tb.tb_frame.f_locals)
+        locals.pop("__jinja_exception__", None)
+    else:
+        locals = {}
+
+    globals = {
+        "__name__": filename,
+        "__file__": filename,
+        "__jinja_exception__": exc_value,
+    }
+    # Raise an exception at the correct line number.
+    code = compile("\n" * (lineno - 1) + "raise __jinja_exception__", filename, "exec")
+
+    # Build a new code object that points to the template file and
+    # replaces the location with a block name.
+    try:
+        location = "template"
+
+        if tb is not None:
+            function = tb.tb_frame.f_code.co_name
+
+            if function == "root":
+                location = "top-level template code"
+            elif function.startswith("block_"):
+                location = 'block "%s"' % function[6:]
+
+        # Collect arguments for the new code object. CodeType only
+        # accepts positional arguments, and arguments were inserted in
+        # new Python versions.
+        code_args = []
+
+        for attr in (
+            "argcount",
+            "posonlyargcount",  # Python 3.8
+            "kwonlyargcount",  # Python 3
+            "nlocals",
+            "stacksize",
+            "flags",
+            "code",  # codestring
+            "consts",  # constants
+            "names",
+            "varnames",
+            ("filename", filename),
+            ("name", location),
+            "firstlineno",
+            "lnotab",
+            "freevars",
+            "cellvars",
+        ):
+            if isinstance(attr, tuple):
+                # Replace with given value.
+                code_args.append(attr[1])
+                continue
+
+            try:
+                # Copy original value if it exists.
+                code_args.append(getattr(code, "co_" + attr))
+            except AttributeError:
+                # Some arguments were added later.
+                continue
+
+        code = CodeType(*code_args)
+    except Exception:
+        # Some environments such as Google App Engine don't support
+        # modifying code objects.
+        pass
+
+    # Execute the new code, which is guaranteed to raise, and return
+    # the new traceback without this frame.
+    try:
+        exec(code, globals, locals)
+    except BaseException:
+        return sys.exc_info()[2].tb_next
+
+
+def get_template_locals(real_locals):
+    """Based on the runtime locals, get the context that would be
+    available at that point in the template.
+    """
+    # Start with the current template context.
+    ctx = real_locals.get("context")
+
+    if ctx:
+        data = ctx.get_all().copy()
+    else:
+        data = {}
+
+    # Might be in a derived context that only sets local variables
+    # rather than pushing a context. Local variables follow the scheme
+    # l_depth_name. Find the highest-depth local that has a value for
+    # each name.
+    local_overrides = {}
+
+    for name, value in real_locals.items():
+        if not name.startswith("l_") or value is missing:
+            # Not a template variable, or no longer relevant.
+            continue
+
+        try:
+            _, depth, name = name.split("_", 2)
+            depth = int(depth)
+        except ValueError:
+            continue
+
+        cur_depth = local_overrides.get(name, (-1,))[0]
+
+        if cur_depth < depth:
+            local_overrides[name] = (depth, value)
+
+    # Modify the context with any derived context.
+    for name, (_, value) in local_overrides.items():
+        if value is missing:
+            data.pop(name, None)
+        else:
+            data[name] = value
+
+    return data
+
+
+if sys.version_info >= (3, 7):
+    # tb_next is directly assignable as of Python 3.7
+    def tb_set_next(tb, tb_next):
+        tb.tb_next = tb_next
+        return tb
+
+
+elif PYPY:
+    # PyPy might have special support, and won't work with ctypes.
+    try:
+        import tputil
+    except ImportError:
+        # Without tproxy support, use the original traceback.
+        def tb_set_next(tb, tb_next):
+            return tb
+
+    else:
+        # With tproxy support, create a proxy around the traceback that
+        # returns the new tb_next.
+        def tb_set_next(tb, tb_next):
+            def controller(op):
+                if op.opname == "__getattribute__" and op.args[0] == "tb_next":
+                    return tb_next
+
+                return op.delegate()
+
+            return tputil.make_proxy(controller, obj=tb)
+
+
+else:
+    # Use ctypes to assign tb_next at the C level since it's read-only
+    # from Python.
+    import ctypes
+
+    class _CTraceback(ctypes.Structure):
+        _fields_ = [
+            # Extra PyObject slots when compiled with Py_TRACE_REFS.
+            ("PyObject_HEAD", ctypes.c_byte * object().__sizeof__()),
+            # Only care about tb_next as an object, not a traceback.
+            ("tb_next", ctypes.py_object),
+        ]
+
+    def tb_set_next(tb, tb_next):
+        c_tb = _CTraceback.from_address(id(tb))
+
+        # Clear out the old tb_next.
+        if tb.tb_next is not None:
+            c_tb_next = ctypes.py_object(tb.tb_next)
+            c_tb.tb_next = ctypes.py_object()
+            ctypes.pythonapi.Py_DecRef(c_tb_next)
+
+        # Assign the new tb_next.
+        if tb_next is not None:
+            c_tb_next = ctypes.py_object(tb_next)
+            ctypes.pythonapi.Py_IncRef(c_tb_next)
+            c_tb.tb_next = c_tb_next
+
+        return tb

magma/squid_cnf/charms/squid/venv/jinja2/defaults.py

+# -*- coding: utf-8 -*-
+from ._compat import range_type
+from .filters import FILTERS as DEFAULT_FILTERS  # noqa: F401
+from .tests import TESTS as DEFAULT_TESTS  # noqa: F401
+from .utils import Cycler
+from .utils import generate_lorem_ipsum
+from .utils import Joiner
+from .utils import Namespace
+
+# defaults for the parser / lexer
+BLOCK_START_STRING = "{%"
+BLOCK_END_STRING = "%}"
+VARIABLE_START_STRING = "{{"
+VARIABLE_END_STRING = "}}"
+COMMENT_START_STRING = "{#"
+COMMENT_END_STRING = "#}"
+LINE_STATEMENT_PREFIX = None
+LINE_COMMENT_PREFIX = None
+TRIM_BLOCKS = False
+LSTRIP_BLOCKS = False
+NEWLINE_SEQUENCE = "\n"
+KEEP_TRAILING_NEWLINE = False
+
+# default filters, tests and namespace
+
+DEFAULT_NAMESPACE = {
+    "range": range_type,
+    "dict": dict,
+    "lipsum": generate_lorem_ipsum,
+    "cycler": Cycler,
+    "joiner": Joiner,
+    "namespace": Namespace,
+}
+
+# default policies
+DEFAULT_POLICIES = {
+    "compiler.ascii_str": True,
+    "urlize.rel": "noopener",
+    "urlize.target": None,
+    "truncate.leeway": 5,
+    "json.dumps_function": None,
+    "json.dumps_kwargs": {"sort_keys": True},
+    "ext.i18n.trimmed": False,
+}

magma/squid_cnf/charms/squid/venv/jinja2/environment.py

+# -*- coding: utf-8 -*-
+"""Classes for managing templates and their runtime and compile time
+options.
+"""
+import os
+import sys
+import weakref
+from functools import partial
+from functools import reduce
+
+from markupsafe import Markup
+
+from . import nodes
+from ._compat import encode_filename
+from ._compat import implements_iterator
+from ._compat import implements_to_string
+from ._compat import iteritems
+from ._compat import PY2
+from ._compat import PYPY
+from ._compat import reraise
+from ._compat import string_types
+from ._compat import text_type
+from .compiler import CodeGenerator
+from .compiler import generate
+from .defaults import BLOCK_END_STRING
+from .defaults import BLOCK_START_STRING
+from .defaults import COMMENT_END_STRING
+from .defaults import COMMENT_START_STRING
+from .defaults import DEFAULT_FILTERS
+from .defaults import DEFAULT_NAMESPACE
+from .defaults import DEFAULT_POLICIES
+from .defaults import DEFAULT_TESTS
+from .defaults import KEEP_TRAILING_NEWLINE
+from .defaults import LINE_COMMENT_PREFIX
+from .defaults import LINE_STATEMENT_PREFIX
+from .defaults import LSTRIP_BLOCKS
+from .defaults import NEWLINE_SEQUENCE
+from .defaults import TRIM_BLOCKS
+from .defaults import VARIABLE_END_STRING
+from .defaults import VARIABLE_START_STRING
+from .exceptions import TemplateNotFound
+from .exceptions import TemplateRuntimeError
+from .exceptions import TemplatesNotFound
+from .exceptions import TemplateSyntaxError
+from .exceptions import UndefinedError
+from .lexer import get_lexer
+from .lexer import TokenStream
+from .nodes import EvalContext
+from .parser import Parser
+from .runtime import Context
+from .runtime import new_context
+from .runtime import Undefined
+from .utils import concat
+from .utils import consume
+from .utils import have_async_gen
+from .utils import import_string
+from .utils import internalcode
+from .utils import LRUCache
+from .utils import missing
+
+# for direct template usage we have up to ten living environments
+_spontaneous_environments = LRUCache(10)
+
+
+def get_spontaneous_environment(cls, *args):
+    """Return a new spontaneous environment. A spontaneous environment
+    is used for templates created directly rather than through an
+    existing environment.
+
+    :param cls: Environment class to create.
+    :param args: Positional arguments passed to environment.
+    """
+    key = (cls, args)
+
+    try:
+        return _spontaneous_environments[key]
+    except KeyError:
+        _spontaneous_environments[key] = env = cls(*args)
+        env.shared = True
+        return env
+
+
+def create_cache(size):
+    """Return the cache class for the given size."""
+    if size == 0:
+        return None
+    if size < 0:
+        return {}
+    return LRUCache(size)
+
+
+def copy_cache(cache):
+    """Create an empty copy of the given cache."""
+    if cache is None:
+        return None
+    elif type(cache) is dict:
+        return {}
+    return LRUCache(cache.capacity)
+
+
+def load_extensions(environment, extensions):
+    """Load the extensions from the list and bind it to the environment.
+    Returns a dict of instantiated environments.
+    """
+    result = {}
+    for extension in extensions:
+        if isinstance(extension, string_types):
+            extension = import_string(extension)
+        result[extension.identifier] = extension(environment)
+    return result
+
+
+def fail_for_missing_callable(string, name):
+    msg = string % name
+    if isinstance(name, Undefined):
+        try:
+            name._fail_with_undefined_error()
+        except Exception as e:
+            msg = "%s (%s; did you forget to quote the callable name?)" % (msg, e)
+    raise TemplateRuntimeError(msg)
+
+
+def _environment_sanity_check(environment):
+    """Perform a sanity check on the environment."""
+    assert issubclass(
+        environment.undefined, Undefined
+    ), "undefined must be a subclass of undefined because filters depend on it."
+    assert (
+        environment.block_start_string
+        != environment.variable_start_string
+        != environment.comment_start_string
+    ), "block, variable and comment start strings must be different"
+    assert environment.newline_sequence in (
+        "\r",
+        "\r\n",
+        "\n",
+    ), "newline_sequence set to unknown line ending string."
+    return environment
+
+
+class Environment(object):
+    r"""The core component of Jinja is the `Environment`.  It contains
+    important shared variables like configuration, filters, tests,
+    globals and others.  Instances of this class may be modified if
+    they are not shared and if no template was loaded so far.
+    Modifications on environments after the first template was loaded
+    will lead to surprising effects and undefined behavior.
+
+    Here are the possible initialization parameters:
+
+        `block_start_string`
+            The string marking the beginning of a block.  Defaults to ``'{%'``.
+
+        `block_end_string`
+            The string marking the end of a block.  Defaults to ``'%}'``.
+
+        `variable_start_string`
+            The string marking the beginning of a print statement.
+            Defaults to ``'{{'``.
+
+        `variable_end_string`
+            The string marking the end of a print statement.  Defaults to
+            ``'}}'``.
+
+        `comment_start_string`
+            The string marking the beginning of a comment.  Defaults to ``'{#'``.
+
+        `comment_end_string`
+            The string marking the end of a comment.  Defaults to ``'#}'``.
+
+        `line_statement_prefix`
+            If given and a string, this will be used as prefix for line based
+            statements.  See also :ref:`line-statements`.
+
+        `line_comment_prefix`
+            If given and a string, this will be used as prefix for line based
+            comments.  See also :ref:`line-statements`.
+
+            .. versionadded:: 2.2
+
+        `trim_blocks`
+            If this is set to ``True`` the first newline after a block is
+            removed (block, not variable tag!).  Defaults to `False`.
+
+        `lstrip_blocks`
+            If this is set to ``True`` leading spaces and tabs are stripped
+            from the start of a line to a block.  Defaults to `False`.
+
+        `newline_sequence`
+            The sequence that starts a newline.  Must be one of ``'\r'``,
+            ``'\n'`` or ``'\r\n'``.  The default is ``'\n'`` which is a
+            useful default for Linux and OS X systems as well as web
+            applications.
+
+        `keep_trailing_newline`
+            Preserve the trailing newline when rendering templates.
+            The default is ``False``, which causes a single newline,
+            if present, to be stripped from the end of the template.
+
+            .. versionadded:: 2.7
+
+        `extensions`
+            List of Jinja extensions to use.  This can either be import paths
+            as strings or extension classes.  For more information have a
+            look at :ref:`the extensions documentation <jinja-extensions>`.
+
+        `optimized`
+            should the optimizer be enabled?  Default is ``True``.
+
+        `undefined`
+            :class:`Undefined` or a subclass of it that is used to represent
+            undefined values in the template.
+
+        `finalize`
+            A callable that can be used to process the result of a variable
+            expression before it is output.  For example one can convert
+            ``None`` implicitly into an empty string here.
+
+        `autoescape`
+            If set to ``True`` the XML/HTML autoescaping feature is enabled by
+            default.  For more details about autoescaping see
+            :class:`~markupsafe.Markup`.  As of Jinja 2.4 this can also
+            be a callable that is passed the template name and has to
+            return ``True`` or ``False`` depending on autoescape should be
+            enabled by default.
+
+            .. versionchanged:: 2.4
+               `autoescape` can now be a function
+
+        `loader`
+            The template loader for this environment.
+
+        `cache_size`
+            The size of the cache.  Per default this is ``400`` which means
+            that if more than 400 templates are loaded the loader will clean
+            out the least recently used template.  If the cache size is set to
+            ``0`` templates are recompiled all the time, if the cache size is
+            ``-1`` the cache will not be cleaned.
+
+            .. versionchanged:: 2.8
+               The cache size was increased to 400 from a low 50.
+
+        `auto_reload`
+            Some loaders load templates from locations where the template
+            sources may change (ie: file system or database).  If
+            ``auto_reload`` is set to ``True`` (default) every time a template is
+            requested the loader checks if the source changed and if yes, it
+            will reload the template.  For higher performance it's possible to
+            disable that.
+
+        `bytecode_cache`
+            If set to a bytecode cache object, this object will provide a
+            cache for the internal Jinja bytecode so that templates don't
+            have to be parsed if they were not changed.
+
+            See :ref:`bytecode-cache` for more information.
+
+        `enable_async`
+            If set to true this enables async template execution which allows
+            you to take advantage of newer Python features.  This requires
+            Python 3.6 or later.
+    """
+
+    #: if this environment is sandboxed.  Modifying this variable won't make
+    #: the environment sandboxed though.  For a real sandboxed environment
+    #: have a look at jinja2.sandbox.  This flag alone controls the code
+    #: generation by the compiler.
+    sandboxed = False
+
+    #: True if the environment is just an overlay
+    overlayed = False
+
+    #: the environment this environment is linked to if it is an overlay
+    linked_to = None
+
+    #: shared environments have this set to `True`.  A shared environment
+    #: must not be modified
+    shared = False
+
+    #: the class that is used for code generation.  See
+    #: :class:`~jinja2.compiler.CodeGenerator` for more information.
+    code_generator_class = CodeGenerator
+
+    #: the context class thatis used for templates.  See
+    #: :class:`~jinja2.runtime.Context` for more information.
+    context_class = Context
+
+    def __init__(
+        self,
+        block_start_string=BLOCK_START_STRING,
+        block_end_string=BLOCK_END_STRING,
+        variable_start_string=VARIABLE_START_STRING,
+        variable_end_string=VARIABLE_END_STRING,
+        comment_start_string=COMMENT_START_STRING,
+        comment_end_string=COMMENT_END_STRING,
+        line_statement_prefix=LINE_STATEMENT_PREFIX,
+        line_comment_prefix=LINE_COMMENT_PREFIX,
+        trim_blocks=TRIM_BLOCKS,
+        lstrip_blocks=LSTRIP_BLOCKS,
+        newline_sequence=NEWLINE_SEQUENCE,
+        keep_trailing_newline=KEEP_TRAILING_NEWLINE,
+        extensions=(),
+        optimized=True,
+        undefined=Undefined,
+        finalize=None,
+        autoescape=False,
+        loader=None,
+        cache_size=400,
+        auto_reload=True,
+        bytecode_cache=None,
+        enable_async=False,
+    ):
+        # !!Important notice!!
+        #   The constructor accepts quite a few arguments that should be
+        #   passed by keyword rather than position.  However it's important to
+        #   not change the order of arguments because it's used at least
+        #   internally in those cases:
+        #       -   spontaneous environments (i18n extension and Template)
+        #       -   unittests
+        #   If parameter changes are required only add parameters at the end
+        #   and don't change the arguments (or the defaults!) of the arguments
+        #   existing already.
+
+        # lexer / parser information
+        self.block_start_string = block_start_string
+        self.block_end_string = block_end_string
+        self.variable_start_string = variable_start_string
+        self.variable_end_string = variable_end_string
+        self.comment_start_string = comment_start_string
+        self.comment_end_string = comment_end_string
+        self.line_statement_prefix = line_statement_prefix
+        self.line_comment_prefix = line_comment_prefix
+        self.trim_blocks = trim_blocks
+        self.lstrip_blocks = lstrip_blocks
+        self.newline_sequence = newline_sequence
+        self.keep_trailing_newline = keep_trailing_newline
+
+        # runtime information
+        self.undefined = undefined
+        self.optimized = optimized
+        self.finalize = finalize
+        self.autoescape = autoescape
+
+        # defaults
+        self.filters = DEFAULT_FILTERS.copy()
+        self.tests = DEFAULT_TESTS.copy()
+        self.globals = DEFAULT_NAMESPACE.copy()
+
+        # set the loader provided
+        self.loader = loader
+        self.cache = create_cache(cache_size)
+        self.bytecode_cache = bytecode_cache
+        self.auto_reload = auto_reload
+
+        # configurable policies
+        self.policies = DEFAULT_POLICIES.copy()
+
+        # load extensions
+        self.extensions = load_extensions(self, extensions)
+
+        self.enable_async = enable_async
+        self.is_async = self.enable_async and have_async_gen
+        if self.is_async:
+            # runs patch_all() to enable async support
+            from . import asyncsupport  # noqa: F401
+
+        _environment_sanity_check(self)
+
+    def add_extension(self, extension):
+        """Adds an extension after the environment was created.
+
+        .. versionadded:: 2.5
+        """
+        self.extensions.update(load_extensions(self, [extension]))
+
+    def extend(self, **attributes):
+        """Add the items to the instance of the environment if they do not exist
+        yet.  This is used by :ref:`extensions <writing-extensions>` to register
+        callbacks and configuration values without breaking inheritance.
+        """
+        for key, value in iteritems(attributes):
+            if not hasattr(self, key):
+                setattr(self, key, value)
+
+    def overlay(
+        self,
+        block_start_string=missing,
+        block_end_string=missing,
+        variable_start_string=missing,
+        variable_end_string=missing,
+        comment_start_string=missing,
+        comment_end_string=missing,
+        line_statement_prefix=missing,
+        line_comment_prefix=missing,
+        trim_blocks=missing,
+        lstrip_blocks=missing,
+        extensions=missing,
+        optimized=missing,
+        undefined=missing,
+        finalize=missing,
+        autoescape=missing,
+        loader=missing,
+        cache_size=missing,
+        auto_reload=missing,
+        bytecode_cache=missing,
+    ):
+        """Create a new overlay environment that shares all the data with the
+        current environment except for cache and the overridden attributes.
+        Extensions cannot be removed for an overlayed environment.  An overlayed
+        environment automatically gets all the extensions of the environment it
+        is linked to plus optional extra extensions.
+
+        Creating overlays should happen after the initial environment was set
+        up completely.  Not all attributes are truly linked, some are just
+        copied over so modifications on the original environment may not shine
+        through.
+        """
+        args = dict(locals())
+        del args["self"], args["cache_size"], args["extensions"]
+
+        rv = object.__new__(self.__class__)
+        rv.__dict__.update(self.__dict__)
+        rv.overlayed = True
+        rv.linked_to = self
+
+        for key, value in iteritems(args):
+            if value is not missing:
+                setattr(rv, key, value)
+
+        if cache_size is not missing:
+            rv.cache = create_cache(cache_size)
+        else:
+            rv.cache = copy_cache(self.cache)
+
+        rv.extensions = {}
+        for key, value in iteritems(self.extensions):
+            rv.extensions[key] = value.bind(rv)
+        if extensions is not missing:
+            rv.extensions.update(load_extensions(rv, extensions))
+
+        return _environment_sanity_check(rv)
+
+    lexer = property(get_lexer, doc="The lexer for this environment.")
+
+    def iter_extensions(self):
+        """Iterates over the extensions by priority."""
+        return iter(sorted(self.extensions.values(), key=lambda x: x.priority))
+
+    def getitem(self, obj, argument):
+        """Get an item or attribute of an object but prefer the item."""
+        try:
+            return obj[argument]
+        except (AttributeError, TypeError, LookupError):
+            if isinstance(argument, string_types):
+                try:
+                    attr = str(argument)
+                except Exception:
+                    pass
+                else:
+                    try:
+                        return getattr(obj, attr)
+                    except AttributeError:
+                        pass
+            return self.undefined(obj=obj, name=argument)
+
+    def getattr(self, obj, attribute):
+        """Get an item or attribute of an object but prefer the attribute.
+        Unlike :meth:`getitem` the attribute *must* be a bytestring.
+        """
+        try:
+            return getattr(obj, attribute)
+        except AttributeError:
+            pass
+        try:
+            return obj[attribute]
+        except (TypeError, LookupError, AttributeError):
+            return self.undefined(obj=obj, name=attribute)
+
+    def call_filter(
+        self, name, value, args=None, kwargs=None, context=None, eval_ctx=None
+    ):
+        """Invokes a filter on a value the same way the compiler does it.
+
+        Note that on Python 3 this might return a coroutine in case the
+        filter is running from an environment in async mode and the filter
+        supports async execution.  It's your responsibility to await this
+        if needed.
+
+        .. versionadded:: 2.7
+        """
+        func = self.filters.get(name)
+        if func is None:
+            fail_for_missing_callable("no filter named %r", name)
+        args = [value] + list(args or ())
+        if getattr(func, "contextfilter", False) is True:
+            if context is None:
+                raise TemplateRuntimeError(
+                    "Attempted to invoke context filter without context"
+                )
+            args.insert(0, context)
+        elif getattr(func, "evalcontextfilter", False) is True:
+            if eval_ctx is None:
+                if context is not None:
+                    eval_ctx = context.eval_ctx
+                else:
+                    eval_ctx = EvalContext(self)
+            args.insert(0, eval_ctx)
+        elif getattr(func, "environmentfilter", False) is True:
+            args.insert(0, self)
+        return func(*args, **(kwargs or {}))
+
+    def call_test(self, name, value, args=None, kwargs=None):
+        """Invokes a test on a value the same way the compiler does it.
+
+        .. versionadded:: 2.7
+        """
+        func = self.tests.get(name)
+        if func is None:
+            fail_for_missing_callable("no test named %r", name)
+        return func(value, *(args or ()), **(kwargs or {}))
+
+    @internalcode
+    def parse(self, source, name=None, filename=None):
+        """Parse the sourcecode and return the abstract syntax tree.  This
+        tree of nodes is used by the compiler to convert the template into
+        executable source- or bytecode.  This is useful for debugging or to
+        extract information from templates.
+
+        If you are :ref:`developing Jinja extensions <writing-extensions>`
+        this gives you a good overview of the node tree generated.
+        """
+        try:
+            return self._parse(source, name, filename)
+        except TemplateSyntaxError:
+            self.handle_exception(source=source)
+
+    def _parse(self, source, name, filename):
+        """Internal parsing function used by `parse` and `compile`."""
+        return Parser(self, source, name, encode_filename(filename)).parse()
+
+    def lex(self, source, name=None, filename=None):
+        """Lex the given sourcecode and return a generator that yields
+        tokens as tuples in the form ``(lineno, token_type, value)``.
+        This can be useful for :ref:`extension development <writing-extensions>`
+        and debugging templates.
+
+        This does not perform preprocessing.  If you want the preprocessing
+        of the extensions to be applied you have to filter source through
+        the :meth:`preprocess` method.
+        """
+        source = text_type(source)
+        try:
+            return self.lexer.tokeniter(source, name, filename)
+        except TemplateSyntaxError:
+            self.handle_exception(source=source)
+
+    def preprocess(self, source, name=None, filename=None):
+        """Preprocesses the source with all extensions.  This is automatically
+        called for all parsing and compiling methods but *not* for :meth:`lex`
+        because there you usually only want the actual source tokenized.
+        """
+        return reduce(
+            lambda s, e: e.preprocess(s, name, filename),
+            self.iter_extensions(),
+            text_type(source),
+        )
+
+    def _tokenize(self, source, name, filename=None, state=None):
+        """Called by the parser to do the preprocessing and filtering
+        for all the extensions.  Returns a :class:`~jinja2.lexer.TokenStream`.
+        """
+        source = self.preprocess(source, name, filename)
+        stream = self.lexer.tokenize(source, name, filename, state)
+        for ext in self.iter_extensions():
+            stream = ext.filter_stream(stream)
+            if not isinstance(stream, TokenStream):
+                stream = TokenStream(stream, name, filename)
+        return stream
+
+    def _generate(self, source, name, filename, defer_init=False):
+        """Internal hook that can be overridden to hook a different generate
+        method in.
+
+        .. versionadded:: 2.5
+        """
+        return generate(
+            source,
+            self,
+            name,
+            filename,
+            defer_init=defer_init,
+            optimized=self.optimized,
+        )
+
+    def _compile(self, source, filename):
+        """Internal hook that can be overridden to hook a different compile
+        method in.
+
+        .. versionadded:: 2.5
+        """
+        return compile(source, filename, "exec")
+
+    @internalcode
+    def compile(self, source, name=None, filename=None, raw=False, defer_init=False):
+        """Compile a node or template source code.  The `name` parameter is
+        the load name of the template after it was joined using
+        :meth:`join_path` if necessary, not the filename on the file system.
+        the `filename` parameter is the estimated filename of the template on
+        the file system.  If the template came from a database or memory this
+        can be omitted.
+
+        The return value of this method is a python code object.  If the `raw`
+        parameter is `True` the return value will be a string with python
+        code equivalent to the bytecode returned otherwise.  This method is
+        mainly used internally.
+
+        `defer_init` is use internally to aid the module code generator.  This
+        causes the generated code to be able to import without the global
+        environment variable to be set.
+
+        .. versionadded:: 2.4
+           `defer_init` parameter added.
+        """
+        source_hint = None
+        try:
+            if isinstance(source, string_types):
+                source_hint = source
+                source = self._parse(source, name, filename)
+            source = self._generate(source, name, filename, defer_init=defer_init)
+            if raw:
+                return source
+            if filename is None:
+                filename = "<template>"
+            else:
+                filename = encode_filename(filename)
+            return self._compile(source, filename)
+        except TemplateSyntaxError:
+            self.handle_exception(source=source_hint)
+
+    def compile_expression(self, source, undefined_to_none=True):
+        """A handy helper method that returns a callable that accepts keyword
+        arguments that appear as variables in the expression.  If called it
+        returns the result of the expression.
+
+        This is useful if applications want to use the same rules as Jinja
+        in template "configuration files" or similar situations.
+
+        Example usage:
+
+        >>> env = Environment()
+        >>> expr = env.compile_expression('foo == 42')
+        >>> expr(foo=23)
+        False
+        >>> expr(foo=42)
+        True
+
+        Per default the return value is converted to `None` if the
+        expression returns an undefined value.  This can be changed
+        by setting `undefined_to_none` to `False`.
+
+        >>> env.compile_expression('var')() is None
+        True
+        >>> env.compile_expression('var', undefined_to_none=False)()
+        Undefined
+
+        .. versionadded:: 2.1
+        """
+        parser = Parser(self, source, state="variable")
+        try:
+            expr = parser.parse_expression()
+            if not parser.stream.eos:
+                raise TemplateSyntaxError(
+                    "chunk after expression", parser.stream.current.lineno, None, None
+                )
+            expr.set_environment(self)
+        except TemplateSyntaxError:
+            if sys.exc_info() is not None:
+                self.handle_exception(source=source)
+
+        body = [nodes.Assign(nodes.Name("result", "store"), expr, lineno=1)]
+        template = self.from_string(nodes.Template(body, lineno=1))
+        return TemplateExpression(template, undefined_to_none)
+
+    def compile_templates(
+        self,
+        target,
+        extensions=None,
+        filter_func=None,
+        zip="deflated",
+        log_function=None,
+        ignore_errors=True,
+        py_compile=False,
+    ):
+        """Finds all the templates the loader can find, compiles them
+        and stores them in `target`.  If `zip` is `None`, instead of in a
+        zipfile, the templates will be stored in a directory.
+        By default a deflate zip algorithm is used. To switch to
+        the stored algorithm, `zip` can be set to ``'stored'``.
+
+        `extensions` and `filter_func` are passed to :meth:`list_templates`.
+        Each template returned will be compiled to the target folder or
+        zipfile.
+
+        By default template compilation errors are ignored.  In case a
+        log function is provided, errors are logged.  If you want template
+        syntax errors to abort the compilation you can set `ignore_errors`
+        to `False` and you will get an exception on syntax errors.
+
+        If `py_compile` is set to `True` .pyc files will be written to the
+        target instead of standard .py files.  This flag does not do anything
+        on pypy and Python 3 where pyc files are not picked up by itself and
+        don't give much benefit.
+
+        .. versionadded:: 2.4
+        """
+        from .loaders import ModuleLoader
+
+        if log_function is None:
+
+            def log_function(x):
+                pass
+
+        if py_compile:
+            if not PY2 or PYPY:
+                import warnings
+
+                warnings.warn(
+                    "'py_compile=True' has no effect on PyPy or Python"
+                    " 3 and will be removed in version 3.0",
+                    DeprecationWarning,
+                    stacklevel=2,
+                )
+                py_compile = False
+            else:
+                import imp
+                import marshal
+
+                py_header = imp.get_magic() + u"\xff\xff\xff\xff".encode("iso-8859-15")
+
+                # Python 3.3 added a source filesize to the header
+                if sys.version_info >= (3, 3):
+                    py_header += u"\x00\x00\x00\x00".encode("iso-8859-15")
+
+        def write_file(filename, data):
+            if zip:
+                info = ZipInfo(filename)
+                info.external_attr = 0o755 << 16
+                zip_file.writestr(info, data)
+            else:
+                if isinstance(data, text_type):
+                    data = data.encode("utf8")
+
+                with open(os.path.join(target, filename), "wb") as f:
+                    f.write(data)
+
+        if zip is not None:
+            from zipfile import ZipFile, ZipInfo, ZIP_DEFLATED, ZIP_STORED
+
+            zip_file = ZipFile(
+                target, "w", dict(deflated=ZIP_DEFLATED, stored=ZIP_STORED)[zip]
+            )
+            log_function('Compiling into Zip archive "%s"' % target)
+        else:
+            if not os.path.isdir(target):
+                os.makedirs(target)
+            log_function('Compiling into folder "%s"' % target)
+
+        try:
+            for name in self.list_templates(extensions, filter_func):
+                source, filename, _ = self.loader.get_source(self, name)
+                try:
+                    code = self.compile(source, name, filename, True, True)
+                except TemplateSyntaxError as e:
+                    if not ignore_errors:
+                        raise
+                    log_function('Could not compile "%s": %s' % (name, e))
+                    continue
+
+                filename = ModuleLoader.get_module_filename(name)
+
+                if py_compile:
+                    c = self._compile(code, encode_filename(filename))
+                    write_file(filename + "c", py_header + marshal.dumps(c))
+                    log_function('Byte-compiled "%s" as %s' % (name, filename + "c"))
+                else:
+                    write_file(filename, code)
+                    log_function('Compiled "%s" as %s' % (name, filename))
+        finally:
+            if zip:
+                zip_file.close()
+
+        log_function("Finished compiling templates")
+
+    def list_templates(self, extensions=None, filter_func=None):
+        """Returns a list of templates for this environment.  This requires
+        that the loader supports the loader's
+        :meth:`~BaseLoader.list_templates` method.
+
+        If there are other files in the template folder besides the
+        actual templates, the returned list can be filtered.  There are two
+        ways: either `extensions` is set to a list of file extensions for
+        templates, or a `filter_func` can be provided which is a callable that
+        is passed a template name and should return `True` if it should end up
+        in the result list.
+
+        If the loader does not support that, a :exc:`TypeError` is raised.
+
+        .. versionadded:: 2.4
+        """
+        names = self.loader.list_templates()
+
+        if extensions is not None:
+            if filter_func is not None:
+                raise TypeError(
+                    "either extensions or filter_func can be passed, but not both"
+                )
+
+            def filter_func(x):
+                return "." in x and x.rsplit(".", 1)[1] in extensions
+
+        if filter_func is not None:
+            names = [name for name in names if filter_func(name)]
+
+        return names
+
+    def handle_exception(self, source=None):
+        """Exception handling helper.  This is used internally to either raise
+        rewritten exceptions or return a rendered traceback for the template.
+        """
+        from .debug import rewrite_traceback_stack
+
+        reraise(*rewrite_traceback_stack(source=source))
+
+    def join_path(self, template, parent):
+        """Join a template with the parent.  By default all the lookups are
+        relative to the loader root so this method returns the `template`
+        parameter unchanged, but if the paths should be relative to the
+        parent template, this function can be used to calculate the real
+        template name.
+
+        Subclasses may override this method and implement template path
+        joining here.
+        """
+        return template
+
+    @internalcode
+    def _load_template(self, name, globals):
+        if self.loader is None:
+            raise TypeError("no loader for this environment specified")
+        cache_key = (weakref.ref(self.loader), name)
+        if self.cache is not None:
+            template = self.cache.get(cache_key)
+            if template is not None and (
+                not self.auto_reload or template.is_up_to_date
+            ):
+                return template
+        template = self.loader.load(self, name, globals)
+        if self.cache is not None:
+            self.cache[cache_key] = template
+        return template
+
+    @internalcode
+    def get_template(self, name, parent=None, globals=None):
+        """Load a template from the loader.  If a loader is configured this
+        method asks the loader for the template and returns a :class:`Template`.
+        If the `parent` parameter is not `None`, :meth:`join_path` is called
+        to get the real template name before loading.
+
+        The `globals` parameter can be used to provide template wide globals.
+        These variables are available in the context at render time.
+
+        If the template does not exist a :exc:`TemplateNotFound` exception is
+        raised.
+
+        .. versionchanged:: 2.4
+           If `name` is a :class:`Template` object it is returned from the
+           function unchanged.
+        """
+        if isinstance(name, Template):
+            return name
+        if parent is not None:
+            name = self.join_path(name, parent)
+        return self._load_template(name, self.make_globals(globals))
+
+    @internalcode
+    def select_template(self, names, parent=None, globals=None):
+        """Works like :meth:`get_template` but tries a number of templates
+        before it fails.  If it cannot find any of the templates, it will
+        raise a :exc:`TemplatesNotFound` exception.
+
+        .. versionchanged:: 2.11
+            If names is :class:`Undefined`, an :exc:`UndefinedError` is
+            raised instead. If no templates were found and names
+            contains :class:`Undefined`, the message is more helpful.
+
+        .. versionchanged:: 2.4
+           If `names` contains a :class:`Template` object it is returned
+           from the function unchanged.
+
+        .. versionadded:: 2.3
+        """
+        if isinstance(names, Undefined):
+            names._fail_with_undefined_error()
+
+        if not names:
+            raise TemplatesNotFound(
+                message=u"Tried to select from an empty list " u"of templates."
+            )
+        globals = self.make_globals(globals)
+        for name in names:
+            if isinstance(name, Template):
+                return name
+            if parent is not None:
+                name = self.join_path(name, parent)
+            try:
+                return self._load_template(name, globals)
+            except (TemplateNotFound, UndefinedError):
+                pass
+        raise TemplatesNotFound(names)
+
+    @internalcode
+    def get_or_select_template(self, template_name_or_list, parent=None, globals=None):
+        """Does a typecheck and dispatches to :meth:`select_template`
+        if an iterable of template names is given, otherwise to
+        :meth:`get_template`.
+
+        .. versionadded:: 2.3
+        """
+        if isinstance(template_name_or_list, (string_types, Undefined)):
+            return self.get_template(template_name_or_list, parent, globals)
+        elif isinstance(template_name_or_list, Template):
+            return template_name_or_list
+        return self.select_template(template_name_or_list, parent, globals)
+
+    def from_string(self, source, globals=None, template_class=None):
+        """Load a template from a string.  This parses the source given and
+        returns a :class:`Template` object.
+        """
+        globals = self.make_globals(globals)
+        cls = template_class or self.template_class
+        return cls.from_code(self, self.compile(source), globals, None)
+
+    def make_globals(self, d):
+        """Return a dict for the globals."""
+        if not d:
+            return self.globals
+        return dict(self.globals, **d)
+
+
+class Template(object):
+    """The central template object.  This class represents a compiled template
+    and is used to evaluate it.
+
+    Normally the template object is generated from an :class:`Environment` but
+    it also has a constructor that makes it possible to create a template
+    instance directly using the constructor.  It takes the same arguments as
+    the environment constructor but it's not possible to specify a loader.
+
+    Every template object has a few methods and members that are guaranteed
+    to exist.  However it's important that a template object should be
+    considered immutable.  Modifications on the object are not supported.
+
+    Template objects created from the constructor rather than an environment
+    do have an `environment` attribute that points to a temporary environment
+    that is probably shared with other templates created with the constructor
+    and compatible settings.
+
+    >>> template = Template('Hello {{ name }}!')
+    >>> template.render(name='John Doe') == u'Hello John Doe!'
+    True
+    >>> stream = template.stream(name='John Doe')
+    >>> next(stream) == u'Hello John Doe!'
+    True
+    >>> next(stream)
+    Traceback (most recent call last):
+        ...
+    StopIteration
+    """
+
+    #: Type of environment to create when creating a template directly
+    #: rather than through an existing environment.
+    environment_class = Environment
+
+    def __new__(
+        cls,
+        source,
+        block_start_string=BLOCK_START_STRING,
+        block_end_string=BLOCK_END_STRING,
+        variable_start_string=VARIABLE_START_STRING,
+        variable_end_string=VARIABLE_END_STRING,
+        comment_start_string=COMMENT_START_STRING,
+        comment_end_string=COMMENT_END_STRING,
+        line_statement_prefix=LINE_STATEMENT_PREFIX,
+        line_comment_prefix=LINE_COMMENT_PREFIX,
+        trim_blocks=TRIM_BLOCKS,
+        lstrip_blocks=LSTRIP_BLOCKS,
+        newline_sequence=NEWLINE_SEQUENCE,
+        keep_trailing_newline=KEEP_TRAILING_NEWLINE,
+        extensions=(),
+        optimized=True,
+        undefined=Undefined,
+        finalize=None,
+        autoescape=False,
+        enable_async=False,
+    ):
+        env = get_spontaneous_environment(
+            cls.environment_class,
+            block_start_string,
+            block_end_string,
+            variable_start_string,
+            variable_end_string,
+            comment_start_string,
+            comment_end_string,
+            line_statement_prefix,
+            line_comment_prefix,
+            trim_blocks,
+            lstrip_blocks,
+            newline_sequence,
+            keep_trailing_newline,
+            frozenset(extensions),
+            optimized,
+            undefined,
+            finalize,
+            autoescape,
+            None,
+            0,
+            False,
+            None,
+            enable_async,
+        )
+        return env.from_string(source, template_class=cls)
+
+    @classmethod
+    def from_code(cls, environment, code, globals, uptodate=None):
+        """Creates a template object from compiled code and the globals.  This
+        is used by the loaders and environment to create a template object.
+        """
+        namespace = {"environment": environment, "__file__": code.co_filename}
+        exec(code, namespace)
+        rv = cls._from_namespace(environment, namespace, globals)
+        rv._uptodate = uptodate
+        return rv
+
+    @classmethod
+    def from_module_dict(cls, environment, module_dict, globals):
+        """Creates a template object from a module.  This is used by the
+        module loader to create a template object.
+
+        .. versionadded:: 2.4
+        """
+        return cls._from_namespace(environment, module_dict, globals)
+
+    @classmethod
+    def _from_namespace(cls, environment, namespace, globals):
+        t = object.__new__(cls)
+        t.environment = environment
+        t.globals = globals
+        t.name = namespace["name"]
+        t.filename = namespace["__file__"]
+        t.blocks = namespace["blocks"]
+
+        # render function and module
+        t.root_render_func = namespace["root"]
+        t._module = None
+
+        # debug and loader helpers
+        t._debug_info = namespace["debug_info"]
+        t._uptodate = None
+
+        # store the reference
+        namespace["environment"] = environment
+        namespace["__jinja_template__"] = t
+
+        return t
+
+    def render(self, *args, **kwargs):
+        """This method accepts the same arguments as the `dict` constructor:
+        A dict, a dict subclass or some keyword arguments.  If no arguments
+        are given the context will be empty.  These two calls do the same::
+
+            template.render(knights='that say nih')
+            template.render({'knights': 'that say nih'})
+
+        This will return the rendered template as unicode string.
+        """
+        vars = dict(*args, **kwargs)
+        try:
+            return concat(self.root_render_func(self.new_context(vars)))
+        except Exception:
+            self.environment.handle_exception()
+
+    def render_async(self, *args, **kwargs):
+        """This works similar to :meth:`render` but returns a coroutine
+        that when awaited returns the entire rendered template string.  This
+        requires the async feature to be enabled.
+
+        Example usage::
+
+            await template.render_async(knights='that say nih; asynchronously')
+        """
+        # see asyncsupport for the actual implementation
+        raise NotImplementedError(
+            "This feature is not available for this version of Python"
+        )
+
+    def stream(self, *args, **kwargs):
+        """Works exactly like :meth:`generate` but returns a
+        :class:`TemplateStream`.
+        """
+        return TemplateStream(self.generate(*args, **kwargs))
+
+    def generate(self, *args, **kwargs):
+        """For very large templates it can be useful to not render the whole
+        template at once but evaluate each statement after another and yield
+        piece for piece.  This method basically does exactly that and returns
+        a generator that yields one item after another as unicode strings.
+
+        It accepts the same arguments as :meth:`render`.
+        """
+        vars = dict(*args, **kwargs)
+        try:
+            for event in self.root_render_func(self.new_context(vars)):
+                yield event
+        except Exception:
+            yield self.environment.handle_exception()
+
+    def generate_async(self, *args, **kwargs):
+        """An async version of :meth:`generate`.  Works very similarly but
+        returns an async iterator instead.
+        """
+        # see asyncsupport for the actual implementation
+        raise NotImplementedError(
+            "This feature is not available for this version of Python"
+        )
+
+    def new_context(self, vars=None, shared=False, locals=None):
+        """Create a new :class:`Context` for this template.  The vars
+        provided will be passed to the template.  Per default the globals
+        are added to the context.  If shared is set to `True` the data
+        is passed as is to the context without adding the globals.
+
+        `locals` can be a dict of local variables for internal usage.
+        """
+        return new_context(
+            self.environment, self.name, self.blocks, vars, shared, self.globals, locals
+        )
+
+    def make_module(self, vars=None, shared=False, locals=None):
+        """This method works like the :attr:`module` attribute when called
+        without arguments but it will evaluate the template on every call
+        rather than caching it.  It's also possible to provide
+        a dict which is then used as context.  The arguments are the same
+        as for the :meth:`new_context` method.
+        """
+        return TemplateModule(self, self.new_context(vars, shared, locals))
+
+    def make_module_async(self, vars=None, shared=False, locals=None):
+        """As template module creation can invoke template code for
+        asynchronous executions this method must be used instead of the
+        normal :meth:`make_module` one.  Likewise the module attribute
+        becomes unavailable in async mode.
+        """
+        # see asyncsupport for the actual implementation
+        raise NotImplementedError(
+            "This feature is not available for this version of Python"
+        )
+
+    @internalcode
+    def _get_default_module(self):
+        if self._module is not None:
+            return self._module
+        self._module = rv = self.make_module()
+        return rv
+
+    @property
+    def module(self):
+        """The template as module.  This is used for imports in the
+        template runtime but is also useful if one wants to access
+        exported template variables from the Python layer:
+
+        >>> t = Template('{% macro foo() %}42{% endmacro %}23')
+        >>> str(t.module)
+        '23'
+        >>> t.module.foo() == u'42'
+        True
+
+        This attribute is not available if async mode is enabled.
+        """
+        return self._get_default_module()
+
+    def get_corresponding_lineno(self, lineno):
+        """Return the source line number of a line number in the
+        generated bytecode as they are not in sync.
+        """
+        for template_line, code_line in reversed(self.debug_info):
+            if code_line <= lineno:
+                return template_line
+        return 1
+
+    @property
+    def is_up_to_date(self):
+        """If this variable is `False` there is a newer version available."""
+        if self._uptodate is None:
+            return True
+        return self._uptodate()
+
+    @property
+    def debug_info(self):
+        """The debug info mapping."""
+        if self._debug_info:
+            return [tuple(map(int, x.split("="))) for x in self._debug_info.split("&")]
+        return []
+
+    def __repr__(self):
+        if self.name is None:
+            name = "memory:%x" % id(self)
+        else:
+            name = repr(self.name)
+        return "<%s %s>" % (self.__class__.__name__, name)
+
+
+@implements_to_string
+class TemplateModule(object):
+    """Represents an imported template.  All the exported names of the
+    template are available as attributes on this object.  Additionally
+    converting it into an unicode- or bytestrings renders the contents.
+    """
+
+    def __init__(self, template, context, body_stream=None):
+        if body_stream is None:
+            if context.environment.is_async:
+                raise RuntimeError(
+                    "Async mode requires a body stream "
+                    "to be passed to a template module.  Use "
+                    "the async methods of the API you are "
+                    "using."
+                )
+            body_stream = list(template.root_render_func(context))
+        self._body_stream = body_stream
+        self.__dict__.update(context.get_exported())
+        self.__name__ = template.name
+
+    def __html__(self):
+        return Markup(concat(self._body_stream))
+
+    def __str__(self):
+        return concat(self._body_stream)
+
+    def __repr__(self):
+        if self.__name__ is None:
+            name = "memory:%x" % id(self)
+        else:
+            name = repr(self.__name__)
+        return "<%s %s>" % (self.__class__.__name__, name)
+
+
+class TemplateExpression(object):
+    """The :meth:`jinja2.Environment.compile_expression` method returns an
+    instance of this object.  It encapsulates the expression-like access
+    to the template with an expression it wraps.
+    """
+
+    def __init__(self, template, undefined_to_none):
+        self._template = template
+        self._undefined_to_none = undefined_to_none
+
+    def __call__(self, *args, **kwargs):
+        context = self._template.new_context(dict(*args, **kwargs))
+        consume(self._template.root_render_func(context))
+        rv = context.vars["result"]
+        if self._undefined_to_none and isinstance(rv, Undefined):
+            rv = None
+        return rv
+
+
+@implements_iterator
+class TemplateStream(object):
+    """A template stream works pretty much like an ordinary python generator
+    but it can buffer multiple items to reduce the number of total iterations.
+    Per default the output is unbuffered which means that for every unbuffered
+    instruction in the template one unicode string is yielded.
+
+    If buffering is enabled with a buffer size of 5, five items are combined
+    into a new unicode string.  This is mainly useful if you are streaming
+    big templates to a client via WSGI which flushes after each iteration.
+    """
+
+    def __init__(self, gen):
+        self._gen = gen
+        self.disable_buffering()
+
+    def dump(self, fp, encoding=None, errors="strict"):
+        """Dump the complete stream into a file or file-like object.
+        Per default unicode strings are written, if you want to encode
+        before writing specify an `encoding`.
+
+        Example usage::
+
+            Template('Hello {{ name }}!').stream(name='foo').dump('hello.html')
+        """
+        close = False
+        if isinstance(fp, string_types):
+            if encoding is None:
+                encoding = "utf-8"
+            fp = open(fp, "wb")
+            close = True
+        try:
+            if encoding is not None:
+                iterable = (x.encode(encoding, errors) for x in self)
+            else:
+                iterable = self
+            if hasattr(fp, "writelines"):
+                fp.writelines(iterable)
+            else:
+                for item in iterable:
+                    fp.write(item)
+        finally:
+            if close:
+                fp.close()
+
+    def disable_buffering(self):
+        """Disable the output buffering."""
+        self._next = partial(next, self._gen)
+        self.buffered = False
+
+    def _buffered_generator(self, size):
+        buf = []
+        c_size = 0
+        push = buf.append
+
+        while 1:
+            try:
+                while c_size < size:
+                    c = next(self._gen)
+                    push(c)
+                    if c:
+                        c_size += 1
+            except StopIteration:
+                if not c_size:
+                    return
+            yield concat(buf)
+            del buf[:]
+            c_size = 0
+
+    def enable_buffering(self, size=5):
+        """Enable buffering.  Buffer `size` items before yielding them."""
+        if size <= 1:
+            raise ValueError("buffer size too small")
+
+        self.buffered = True
+        self._next = partial(next, self._buffered_generator(size))
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        return self._next()
+
+
+# hook in default template class.  if anyone reads this comment: ignore that
+# it's possible to use custom templates ;-)
+Environment.template_class = Template