Source code for keystone.common.driver_hints

# Copyright 2013 OpenStack Foundation
# Copyright 2013 IBM Corp.
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[docs]class Hints(object): """Encapsulate driver hints for listing entities. Hints are modifiers that affect the return of entities from a list_<entities> operation. They are typically passed to a driver to give direction as to what filtering, pagination or list limiting actions are being requested. It is optional for a driver to action some or all of the list hints, but any filters that it does satisfy must be marked as such by calling removing the filter from the list. A Hint object contains filters, which is a list of dicts that can be accessed publicly. Also it contains a dict called limit, which will indicate the amount of data we want to limit our listing to. If the filter is discovered to never match, then `cannot_match` can be set to indicate that there will not be any matches and the backend work can be short-circuited. Each filter term consists of: * ``name``: the name of the attribute being matched * ``value``: the value against which it is being matched * ``comparator``: the operation, which can be one of ``equals``, ``startswith`` or ``endswith`` * ``case_sensitive``: whether any comparison should take account of case * ``type``: will always be 'filter' """ def __init__(self): self.limit = None self.filters = list() self.cannot_match = False
[docs] def add_filter(self, name, value, comparator='equals', case_sensitive=False): """Adds a filter to the filters list, which is publicly accessible.""" self.filters.append({'name': name, 'value': value, 'comparator': comparator, 'case_sensitive': case_sensitive, 'type': 'filter'})
[docs] def get_exact_filter_by_name(self, name): """Return a filter key and value if exact filter exists for name.""" for entry in self.filters: if (entry['type'] == 'filter' and entry['name'] == name and entry['comparator'] == 'equals'): return entry
[docs] def set_limit(self, limit, truncated=False): """Set a limit to indicate the list should be truncated.""" self.limit = {'limit': limit, 'type': 'limit', 'truncated': truncated}