Adds to Melange a tags framework based on taggable-mixin.
The taggable-mixin allowed only tag per Datastore model. This is extended
framework allows any arbitrary number of tags per Datastore model. Also,
now one can define different models for different Tag types which are all
inherited from the base Tag model provided by taggable-mixin.
The GHOPTask model makes use of 2 tags per model, one for difficulty and the
other for task_type, both using the tags framework.
Reviewed by: Paweł Sołyga
import re
# Valid query types (a dictionary is used for speedy lookups).
QUERY_TERMS = dict([(x, None) for x in (
'exact', 'iexact', 'contains', 'icontains', 'gt', 'gte', 'lt', 'lte', 'in',
'startswith', 'istartswith', 'endswith', 'iendswith', 'range', 'year',
'month', 'day', 'isnull', 'search', 'regex', 'iregex',
)])
# Size of each "chunk" for get_iterator calls.
# Larger values are slightly faster at the expense of more storage space.
GET_ITERATOR_CHUNK_SIZE = 100
# Separator used to split filter strings apart.
LOOKUP_SEP = '__'
# Constants to make looking up tuple values clearer.
# Join lists (indexes into the tuples that are values in the alias_map
# dictionary in the Query class).
TABLE_NAME = 0
RHS_ALIAS = 1
JOIN_TYPE = 2
LHS_ALIAS = 3
LHS_JOIN_COL = 4
RHS_JOIN_COL = 5
NULLABLE = 6
# How many results to expect from a cursor.execute call
MULTI = 'multi'
SINGLE = 'single'
ORDER_PATTERN = re.compile(r'\?|[-+]?[.\w]+$')
ORDER_DIR = {
'ASC': ('ASC', 'DESC'),
'DESC': ('DESC', 'ASC')}