diff options
Diffstat (limited to 'client/src/leap/soledad/client/sqlcipher.py')
| -rw-r--r-- | client/src/leap/soledad/client/sqlcipher.py | 44 |
1 files changed, 38 insertions, 6 deletions
diff --git a/client/src/leap/soledad/client/sqlcipher.py b/client/src/leap/soledad/client/sqlcipher.py index 04f8ebf9..5ffa9c7e 100644 --- a/client/src/leap/soledad/client/sqlcipher.py +++ b/client/src/leap/soledad/client/sqlcipher.py @@ -52,17 +52,18 @@ import json from hashlib import sha256 from contextlib import contextmanager +from collections import defaultdict from pysqlcipher import dbapi2 from u1db.backends import sqlite_backend -from u1db.sync import Synchronizer from u1db import errors as u1db_errors +from leap.soledad.client.sync import Synchronizer from leap.soledad.client.target import SoledadSyncTarget from leap.soledad.common.document import SoledadDocument -logger = logging.getLogger(__name__) +logger = logging.getLogger(__name__) # Monkey-patch u1db.backends.sqlite_backend with pysqlcipher.dbapi2 sqlite_backend.dbapi2 = dbapi2 @@ -153,6 +154,13 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): create_doc_lock = threading.Lock() update_indexes_lock = threading.Lock() + syncing_lock = defaultdict(threading.Lock) + """ + A dictionary that hold locks which avoid multiple sync attempts from the + same database replica. + """ + + def __init__(self, sqlcipher_file, password, document_factory=None, crypto=None, raw_key=False, cipher='aes-256-cbc', kdf_iter=4000, cipher_page_size=1024): @@ -343,6 +351,10 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): """ Synchronize documents with remote replica exposed at url. + There can be at most one instance syncing the same database replica at + the same time, so this method will block until the syncing lock can be + acquired. + :param url: The url of the target replica to sync with. :type url: str :param creds: optional dictionary giving credentials. @@ -355,18 +367,34 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): :rtype: int """ res = None + # the following context manager blocks until the syncing lock can be + # acquired. with self.syncer(url, creds=creds) as syncer: res = syncer.sync(autocreate=autocreate) return res + def stop_sync(self): + """ + Interrupt all ongoing syncs. + """ + for url in self._syncers: + _, syncer = self._syncers[url] + syncer.stop() + @contextmanager def syncer(self, url, creds=None): """ Accesor for synchronizer. + + As we reuse the same synchronizer for every sync, there can be only + one instance synchronizing the same database replica at the same time. + Because of that, this method blocks until the syncing lock can be + acquired. """ - syncer = self._get_syncer(url, creds=creds) - yield syncer - syncer.sync_target.close() + with SQLCipherDatabase.syncing_lock[self._get_replica_uid()]: + syncer = self._get_syncer(url, creds=creds) + yield syncer + syncer.sync_target.close() def _get_syncer(self, url, creds=None): """ @@ -379,7 +407,7 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): :type creds: dict :return: A synchronizer. - :rtype: u1db.sync.Synchronizer + :rtype: Synchronizer """ # we want to store at most one syncer for each url, so we also store a # hash of the connection credentials and replace the stored syncer for @@ -393,6 +421,10 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase): creds=creds, crypto=self._crypto)) self._syncers[url] = (h, syncer) + # in order to reuse the same synchronizer multiple times we have to + # reset its state (i.e. the number of documents received from target + # and inserted in the local replica). + syncer.num_inserted = 0 return syncer def _extra_schema_init(self, c): |