from __future__ import unicode_literals import copy import inspect import warnings from django.conf import settings from django.core.exceptions import ImproperlyConfigured from django.utils.datastructures import SortedDict from django.utils import importlib from django.utils.module_loading import module_has_submodule from haystack.constants import Indexable, DEFAULT_ALIAS from haystack.exceptions import NotHandled, SearchFieldError def import_class(path): path_bits = path.split('.') # Cut off the class name at the end. class_name = path_bits.pop() module_path = '.'.join(path_bits) module_itself = importlib.import_module(module_path) if not hasattr(module_itself, class_name): raise ImportError("The Python module '%s' has no '%s' class." % (module_path, class_name)) return getattr(module_itself, class_name) # Load the search backend. def load_backend(full_backend_path): """ Loads a backend for interacting with the search engine. Requires a ``backend_path``. It should be a string resembling a Python import path, pointing to a ``BaseEngine`` subclass. The built-in options available include:: * haystack.backends.solr.SolrEngine * haystack.backends.xapian.XapianEngine (third-party) * haystack.backends.whoosh.WhooshEngine * haystack.backends.simple.SimpleEngine If you've implemented a custom backend, you can provide the path to your backend & matching ``Engine`` class. For example:: ``myapp.search_backends.CustomSolrEngine`` """ path_bits = full_backend_path.split('.') if len(path_bits) < 2: raise ImproperlyConfigured("The provided backend '%s' is not a complete Python path to a BaseEngine subclass." % full_backend_path) return import_class(full_backend_path) def load_router(full_router_path): """ Loads a router for choosing which connection to use. Requires a ``full_router_path``. It should be a string resembling a Python import path, pointing to a ``BaseRouter`` subclass. The built-in options available include:: * haystack.routers.DefaultRouter If you've implemented a custom backend, you can provide the path to your backend & matching ``Engine`` class. For example:: ``myapp.search_routers.MasterSlaveRouter`` """ path_bits = full_router_path.split('.') if len(path_bits) < 2: raise ImproperlyConfigured("The provided router '%s' is not a complete Python path to a BaseRouter subclass." % full_router_path) return import_class(full_router_path) class ConnectionHandler(object): def __init__(self, connections_info): self.connections_info = connections_info self._connections = {} self._index = None def ensure_defaults(self, alias): try: conn = self.connections_info[alias] except KeyError: raise ImproperlyConfigured("The key '%s' isn't an available connection." % alias) if not conn.get('ENGINE'): conn['ENGINE'] = 'haystack.backends.simple_backend.SimpleEngine' def __getitem__(self, key): if key in self._connections: return self._connections[key] self.ensure_defaults(key) self._connections[key] = load_backend(self.connections_info[key]['ENGINE'])(using=key) return self._connections[key] def reload(self, key): try: del self._connections[key] except KeyError: pass return self.__getitem__(key) def all(self): return [self[alias] for alias in self.connections_info] class ConnectionRouter(object): def __init__(self, routers_list=None): self.routers_list = routers_list self.routers = [] if self.routers_list is None: self.routers_list = ['haystack.routers.DefaultRouter'] for router_path in self.routers_list: router_class = load_router(router_path) self.routers.append(router_class()) def for_action(self, action, **hints): conns = [] for router in self.routers: if hasattr(router, action): action_callable = getattr(router, action) connection_to_use = action_callable(**hints) if connection_to_use is not None: conns.append(connection_to_use) return conns def for_write(self, **hints): return self.for_action('for_write', **hints) def for_read(self, **hints): return self.for_action('for_read', **hints) class UnifiedIndex(object): # Used to collect all the indexes into a cohesive whole. def __init__(self, excluded_indexes=None): self.indexes = {} self.fields = SortedDict() self._built = False self.excluded_indexes = excluded_indexes or [] self.excluded_indexes_ids = {} self.document_field = getattr(settings, 'HAYSTACK_DOCUMENT_FIELD', 'text') self._fieldnames = {} self._facet_fieldnames = {} def collect_indexes(self): indexes = [] for app in settings.INSTALLED_APPS: try: mod = importlib.import_module(app) except ImportError: warnings.warn('Installed app %s is not an importable Python module and will be ignored' % app) continue try: search_index_module = importlib.import_module("%s.search_indexes" % app) except ImportError: if module_has_submodule(mod, 'search_indexes'): raise continue for item_name, item in inspect.getmembers(search_index_module, inspect.isclass): if getattr(item, 'haystack_use_for_indexing', False) and getattr(item, 'get_model', None): # We've got an index. Check if we should be ignoring it. class_path = "%s.search_indexes.%s" % (app, item_name) if class_path in self.excluded_indexes or self.excluded_indexes_ids.get(item_name) == id(item): self.excluded_indexes_ids[str(item_name)] = id(item) continue indexes.append(item()) return indexes def reset(self): self.indexes = {} self.fields = SortedDict() self._built = False self._fieldnames = {} self._facet_fieldnames = {} def build(self, indexes=None): self.reset() if indexes is None: indexes = self.collect_indexes() for index in indexes: model = index.get_model() if model in self.indexes: raise ImproperlyConfigured( "Model '%s' has more than one 'SearchIndex`` handling it. " "Please exclude either '%s' or '%s' using the 'EXCLUDED_INDEXES' " "setting defined in 'settings.HAYSTACK_CONNECTIONS'." % ( model, self.indexes[model], index ) ) self.indexes[model] = index self.collect_fields(index) self._built = True def collect_fields(self, index): for fieldname, field_object in index.fields.items(): if field_object.document is True: if field_object.index_fieldname != self.document_field: raise SearchFieldError("All 'SearchIndex' classes must use the same '%s' fieldname for the 'document=True' field. Offending index is '%s'." % (self.document_field, index)) # Stow the index_fieldname so we don't have to get it the hard way again. if fieldname in self._fieldnames and field_object.index_fieldname != self._fieldnames[fieldname]: # We've already seen this field in the list. Raise an exception if index_fieldname differs. raise SearchFieldError("All uses of the '%s' field need to use the same 'index_fieldname' attribute." % fieldname) self._fieldnames[fieldname] = field_object.index_fieldname # Stow the facet_fieldname so we don't have to look that up either. if hasattr(field_object, 'facet_for'): if field_object.facet_for: self._facet_fieldnames[field_object.facet_for] = fieldname else: self._facet_fieldnames[field_object.instance_name] = fieldname # Copy the field in so we've got a unified schema. if not field_object.index_fieldname in self.fields: self.fields[field_object.index_fieldname] = field_object self.fields[field_object.index_fieldname] = copy.copy(field_object) else: # If the field types are different, we can mostly # safely ignore this. The exception is ``MultiValueField``, # in which case we'll use it instead, copying over the # values. if field_object.is_multivalued == True: old_field = self.fields[field_object.index_fieldname] self.fields[field_object.index_fieldname] = field_object self.fields[field_object.index_fieldname] = copy.copy(field_object) # Switch it so we don't have to dupe the remaining # checks. field_object = old_field # We've already got this field in the list. Ensure that # what we hand back is a superset of all options that # affect the schema. if field_object.indexed is True: self.fields[field_object.index_fieldname].indexed = True if field_object.stored is True: self.fields[field_object.index_fieldname].stored = True if field_object.faceted is True: self.fields[field_object.index_fieldname].faceted = True if field_object.use_template is True: self.fields[field_object.index_fieldname].use_template = True if field_object.null is True: self.fields[field_object.index_fieldname].null = True def get_indexed_models(self): if not self._built: self.build() return list(self.indexes.keys()) def get_index_fieldname(self, field): if not self._built: self.build() return self._fieldnames.get(field) or field def get_index(self, model_klass): if not self._built: self.build() if model_klass not in self.indexes: raise NotHandled('The model %s is not registered' % model_klass.__class__) return self.indexes[model_klass] def get_facet_fieldname(self, field): if not self._built: self.build() for fieldname, field_object in self.fields.items(): if fieldname != field: continue if hasattr(field_object, 'facet_for'): if field_object.facet_for: return field_object.facet_for else: return field_object.instance_name else: return self._facet_fieldnames.get(field) or field return field def all_searchfields(self): if not self._built: self.build() return self.fields