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authordrebs <drebs@leap.se>2012-12-24 10:14:24 -0200
committerdrebs <drebs@leap.se>2012-12-24 10:14:24 -0200
commitca5fb41a55e1292005ed186baf3710831d9ad678 (patch)
treeac7eb9e8f5d993732e769607903ef626518749cd /src/leap/soledad/backends/objectstore.py
parent564b82fa30ebcd8a0abfea54e00506dd77446a54 (diff)
parent277f17aa7b7bbcc48583149a3d72d8621f83c0ff (diff)
Merge branch 'feature/u1db-openstack-backend' into develop
Diffstat (limited to 'src/leap/soledad/backends/objectstore.py')
-rw-r--r--src/leap/soledad/backends/objectstore.py210
1 files changed, 210 insertions, 0 deletions
diff --git a/src/leap/soledad/backends/objectstore.py b/src/leap/soledad/backends/objectstore.py
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+++ b/src/leap/soledad/backends/objectstore.py
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+import uuid
+from u1db.backends import CommonBackend
+from u1db import errors, Document
+from soledad.util import SyncLog, TransactionLog
+
+
+class ObjectStore(CommonBackend):
+ """
+ A backend for storing u1db data in an object store.
+ """
+
+ def __init__(self):
+ # This initialization method should be called after the connection
+ # with the database is established, so it can ensure that u1db data is
+ # configured and up-to-date.
+ self.set_document_factory(Document)
+ self._sync_log = SyncLog()
+ self._transaction_log = TransactionLog()
+ self._ensure_u1db_data()
+
+ #-------------------------------------------------------------------------
+ # implemented methods from Database
+ #-------------------------------------------------------------------------
+
+ def set_document_factory(self, factory):
+ self._factory = factory
+
+ def set_document_size_limit(self, limit):
+ raise NotImplementedError(self.set_document_size_limit)
+
+ def whats_changed(self, old_generation=0):
+ self._get_u1db_data()
+ return self._transaction_log.whats_changed(old_generation)
+
+ def get_doc(self, doc_id, include_deleted=False):
+ doc = self._get_doc(doc_id, check_for_conflicts=True)
+ if doc is None:
+ return None
+ if doc.is_tombstone() and not include_deleted:
+ return None
+ return doc
+
+ def _put_doc(self, doc):
+ raise NotImplementedError(self._put_doc)
+
+ def put_doc(self, doc):
+ # consistency check
+ if doc.doc_id is None:
+ raise errors.InvalidDocId()
+ self._check_doc_id(doc.doc_id)
+ self._check_doc_size(doc)
+ # check if document exists
+ old_doc = self._get_doc(doc.doc_id, check_for_conflicts=True)
+ if old_doc and old_doc.has_conflicts:
+ raise errors.ConflictedDoc()
+ if old_doc and doc.rev is None and old_doc.is_tombstone():
+ new_rev = self._allocate_doc_rev(old_doc.rev)
+ else:
+ if old_doc is not None:
+ if old_doc.rev != doc.rev:
+ raise errors.RevisionConflict()
+ else:
+ if doc.rev is not None:
+ raise errors.RevisionConflict()
+ new_rev = self._allocate_doc_rev(doc.rev)
+ doc.rev = new_rev
+ self._put_doc(doc)
+ # update u1db generation and logs
+ new_gen = self._get_generation() + 1
+ trans_id = self._allocate_transaction_id()
+ self._transaction_log.append((new_gen, doc.doc_id, trans_id))
+ self._set_u1db_data()
+ return doc.rev
+
+ def delete_doc(self, doc):
+ old_doc = self._get_doc(doc.doc_id, check_for_conflicts=True)
+ if old_doc is None:
+ raise errors.DocumentDoesNotExist
+ if old_doc.rev != doc.rev:
+ raise errors.RevisionConflict()
+ if old_doc.is_tombstone():
+ raise errors.DocumentAlreadyDeleted
+ if old_doc.has_conflicts:
+ raise errors.ConflictedDoc()
+ new_rev = self._allocate_doc_rev(doc.rev)
+ doc.rev = new_rev
+ doc.make_tombstone()
+ self._put_doc(doc)
+ return new_rev
+
+ # start of index-related methods: these are not supported by this backend.
+
+ def create_index(self, index_name, *index_expressions):
+ return False
+
+ def delete_index(self, index_name):
+ return False
+
+ def list_indexes(self):
+ return []
+
+ def get_from_index(self, index_name, *key_values):
+ return []
+
+ def get_range_from_index(self, index_name, start_value=None,
+ end_value=None):
+ return []
+
+ def get_index_keys(self, index_name):
+ return []
+
+ # end of index-related methods: these are not supported by this backend.
+
+ def get_doc_conflicts(self, doc_id):
+ return []
+
+ def resolve_doc(self, doc, conflicted_doc_revs):
+ raise NotImplementedError(self.resolve_doc)
+
+ def _get_replica_gen_and_trans_id(self, other_replica_uid):
+ self._get_u1db_data()
+ return self._sync_log.get_replica_gen_and_trans_id(other_replica_uid)
+
+ def _set_replica_gen_and_trans_id(self, other_replica_uid,
+ other_generation, other_transaction_id):
+ self._get_u1db_data()
+ self._sync_log.set_replica_gen_and_trans_id(other_replica_uid,
+ other_generation,
+ other_transaction_id)
+ self._set_u1db_data()
+
+ #-------------------------------------------------------------------------
+ # implemented methods from CommonBackend
+ #-------------------------------------------------------------------------
+
+ def _get_generation(self):
+ self._get_u1db_data()
+ return self._transaction_log.get_generation()
+
+ def _get_generation_info(self):
+ self._get_u1db_data()
+ return self._transaction_log.get_generation_info()
+
+ def _has_conflicts(self, doc_id):
+ # Documents never have conflicts on server.
+ return False
+
+ def _put_and_update_indexes(self, doc_id, old_doc, new_rev, content):
+ raise NotImplementedError(self._put_and_update_indexes)
+
+
+ def _get_trans_id_for_gen(self, generation):
+ self._get_u1db_data()
+ trans_id = self._transaction_log.get_trans_id_for_gen(generation)
+ if trans_id is None:
+ raise errors.InvalidGeneration
+ return trans_id
+
+ #-------------------------------------------------------------------------
+ # methods specific for object stores
+ #-------------------------------------------------------------------------
+
+ def _ensure_u1db_data(self):
+ """
+ Guarantee that u1db data (logs and replica info) exists in store.
+ """
+ if not self._is_initialized():
+ self._initialize()
+ self._get_u1db_data()
+
+ U1DB_DATA_DOC_ID = 'u1db_data'
+
+ def _is_initialized(self):
+ """
+ Verify if u1db data exists in store.
+ """
+ doc = self._get_doc(self.U1DB_DATA_DOC_ID)
+ if not self._get_doc(self.U1DB_DATA_DOC_ID):
+ return False
+ return True
+
+ def _initialize(self):
+ """
+ Create u1db data object in store.
+ """
+ self._replica_uid = uuid.uuid4().hex
+ doc = self._factory(doc_id=self.U1DB_DATA_DOC_ID)
+ doc.content = { 'transaction_log' : [],
+ 'sync_log' : [],
+ 'replica_uid' : self._replica_uid }
+ self._put_doc(doc)
+
+ def _get_u1db_data(self, u1db_data_doc_id):
+ """
+ Fetch u1db configuration data from backend storage.
+ """
+ NotImplementedError(self._get_u1db_data)
+
+ def _set_u1db_data(self):
+ """
+ Save u1db configuration data on backend storage.
+ """
+ doc = self._factory(doc_id=self.U1DB_DATA_DOC_ID)
+ doc.content = { 'transaction_log' : self._transaction_log.log,
+ 'sync_log' : self._sync_log.log,
+ 'replica_uid' : self._replica_uid,
+ '_rev' : self._couch_rev}
+ self._put_doc(doc)
+
+