-#
-# Module that parses constraints
-#
-# The current version of juju core expects the client to take
-# constraints given in the form "mem=10G foo=bar" and parse them into
-# json that looks like {"mem": 10240, "foo": "bar"}. This module helps us
-# accomplish that task.
-#
-# We do not attempt to duplicate the checking done in
-# client/_client.py:Value here. That class will verify that the
-# constraints keys are valid, and that we can successfully dump the
-# constraints dict to json.
-#
-# Once https://bugs.launchpad.net/juju/+bug/1645402 is addressed, this
-# module should be deprecated.
-#
-
-import re
-
-# Matches on a string specifying memory size
-MEM = re.compile('^[1-9][0-9]*[MGTP]$')
-
-# Multiplication factors to get Megabytes
-# https://github.com/juju/juju/blob/master/constraints/constraints.go#L666
-FACTORS = {
- "M": 1,
- "G": 1024,
- "T": 1024 * 1024,
- "P": 1024 * 1024 * 1024
-}
-
-LIST_KEYS = {'tags', 'spaces'}
-
-SNAKE1 = re.compile(r'(.)([A-Z][a-z]+)')
-SNAKE2 = re.compile('([a-z0-9])([A-Z])')
-
-
-def parse(constraints):
- """
- Constraints must be expressed as a string containing only spaces
- and key value pairs joined by an '='.
-
- """
- if not constraints:
- return None
-
- if type(constraints) is dict:
- # Fowards compatibilty: already parsed
- return constraints
-
- constraints = {
- normalize_key(k): (
- normalize_list_value(v) if k in LIST_KEYS else
- normalize_value(v)
- ) for k, v in [s.split("=") for s in constraints.split(" ")]}
-
- return constraints
-
-
-def normalize_key(key):
- key = key.strip()
-
- key = key.replace("-", "_") # Our _client lib wants "_" in place of "-"
-
- # Convert camelCase to snake_case
- key = SNAKE1.sub(r'\1_\2', key)
- key = SNAKE2.sub(r'\1_\2', key).lower()
-
- return key
-
-
-def normalize_value(value):
- value = value.strip()
-
- if MEM.match(value):
- # Translate aliases to Megabytes. e.g. 1G = 10240
- return int(value[:-1]) * FACTORS[value[-1:]]
-
- if value.isdigit():
- return int(value)
-
- return value
-
-
-def normalize_list_value(value):
- values = value.strip().split(',')
- return [normalize_value(value) for value in values]