[refactor] remove decpool

It's not being used

7 files changed, 20 insertions, 505 deletions

diff --git a/client/src/leap/soledad/client/api.py b/client/src/leap/soledad/client/api.py
index 6870d5ba..cbcae4f7 100644
--- a/client/src/leap/soledad/client/api.py
+++ b/client/src/leap/soledad/client/api.py
@@ -169,7 +169,7 @@ class Soledad(object):
         :type auth_token: str
 
         :param defer_encryption:
-            Whether to defer encryption/decryption of documents, or do it
+            Whether to defer encryption of documents, or do it
             inline while syncing.
         :type defer_encryption: bool
 
@@ -299,9 +299,9 @@ class Soledad(object):
         )
         self._sqlcipher_opts = opts
 
-        # the sync_db is used both for deferred encryption and decryption, so
+        # the sync_db is used both for deferred encryption, so
         # we want to initialize it anyway to allow for all combinations of
-        # deferred encryption and decryption configurations.
+        # deferred encryption configurations.
         self._initialize_sync_db(opts)
         self._dbpool = adbapi.getConnectionPool(
             opts, sync_enc_pool=self._sync_enc_pool)
@@ -700,37 +700,26 @@ class Soledad(object):
         if syncable and not self._dbsyncer:
             self._init_u1db_syncer()
 
-    def sync(self, defer_decryption=True):
+    def sync(self):
         """
         Synchronize documents with the server replica.
 
         This method uses a lock to prevent multiple concurrent sync processes
         over the same local db file.
 
-        :param defer_decryption:
-            Whether to defer decryption of documents, or do it inline while
-            syncing.
-        :type defer_decryption: bool
-
         :return: A deferred lock that will run the actual sync process when
                  the lock is acquired, and which will fire with with the local
                  generation before the synchronization was performed.
         :rtype: twisted.internet.defer.Deferred
         """
         d = self.sync_lock.run(
-            self._sync,
-            defer_decryption)
+            self._sync)
         return d
 
-    def _sync(self, defer_decryption):
+    def _sync(self):
         """
         Synchronize documents with the server replica.
 
-        :param defer_decryption:
-            Whether to defer decryption of documents, or do it inline while
-            syncing.
-        :type defer_decryption: bool
-
         :return: A deferred whose callback will be invoked with the local
             generation before the synchronization was performed.
         :rtype: twisted.internet.defer.Deferred
@@ -740,8 +729,7 @@ class Soledad(object):
             return
         d = self._dbsyncer.sync(
             sync_url,
-            creds=self._creds,
-            defer_decryption=defer_decryption)
+            creds=self._creds)
 
         def _sync_callback(local_gen):
             self._last_received_docs = docs = self._dbsyncer.received_docs
@@ -874,12 +862,9 @@ class Soledad(object):
         """
         maybe_create = "CREATE TABLE IF NOT EXISTS %s (%s)"
         encr = encdecpool.SyncEncrypterPool
-        decr = encdecpool.SyncDecrypterPool
         sql_encr_table_query = (maybe_create % (
             encr.TABLE_NAME, encr.FIELD_NAMES))
-        sql_decr_table_query = (maybe_create % (
-            decr.TABLE_NAME, decr.FIELD_NAMES))
-        return (sql_encr_table_query, sql_decr_table_query)
+        return (sql_encr_table_query,)
 
     #
     # ISecretsStorage
diff --git a/client/src/leap/soledad/client/encdecpool.py b/client/src/leap/soledad/client/encdecpool.py
index 056b012f..8eaefa77 100644
--- a/client/src/leap/soledad/client/encdecpool.py
+++ b/client/src/leap/soledad/client/encdecpool.py
@@ -22,14 +22,9 @@ during synchronization.
 """
 
 
-import json
-from uuid import uuid4
-
-from twisted.internet.task import LoopingCall
 from twisted.internet import threads
 from twisted.internet import defer
 
-from leap.soledad.common.document import SoledadDocument
 from leap.soledad.common import soledad_assert
 from leap.soledad.common.log import getLogger
 
@@ -41,7 +36,7 @@ logger = getLogger(__name__)
 
 
 #
-# Encrypt/decrypt pools of workers
+# Encrypt pool of workers
 #
 
 class SyncEncryptDecryptPool(object):
@@ -282,376 +277,3 @@ def decrypt_doc_task(doc_id, doc_rev, content, gen, trans_id, key, secret,
     """
     decrypted_content = decrypt_doc_dict(content, doc_id, doc_rev, key, secret)
     return doc_id, doc_rev, decrypted_content, gen, trans_id, idx
-
-
-class SyncDecrypterPool(SyncEncryptDecryptPool):
-    """
-    Pool of workers that spawn subprocesses to execute the symmetric decryption
-    of documents that were received.
-
-    The decryption of the received documents is done in two steps:
-
-        1. Encrypted documents are stored in the sync db by the actual soledad
-           sync loop.
-        2. The soledad sync loop tells us how many documents we should expect
-           to process.
-        3. We start a decrypt-and-process loop:
-
-            a. Encrypted documents are fetched.
-            b. Encrypted documents are decrypted.
-            c. The longest possible list of decrypted documents are inserted
-               in the soledad db (this depends on which documents have already
-               arrived and which documents have already been decrypte, because
-               the order of insertion in the local soledad db matters).
-            d. Processed documents are deleted from the database.
-
-        4. When we have processed as many documents as we should, the loop
-           finishes.
-    """
-    TABLE_NAME = "docs_received"
-    FIELD_NAMES = "doc_id PRIMARY KEY, rev, content, gen, " \
-                  "trans_id, encrypted, idx, sync_id"
-
-    """
-    Period of recurrence of the periodic decrypting task, in seconds.
-    """
-    DECRYPT_LOOP_PERIOD = 0.5
-
-    def __init__(self, *args, **kwargs):
-        """
-        Initialize the decrypter pool, and setup a dict for putting the
-        results of the decrypted docs until they are picked by the insert
-        routine that gets them in order.
-
-        :param insert_doc_cb: A callback for inserting received documents from
-                              target. If not overriden, this will call u1db
-                              insert_doc_from_target in synchronizer, which
-                              implements the TAKE OTHER semantics.
-        :type insert_doc_cb: function
-        :param source_replica_uid: The source replica uid, used to find the
-                                   correct callback for inserting documents.
-        :type source_replica_uid: str
-        """
-        self._insert_doc_cb = kwargs.pop("insert_doc_cb")
-        self.source_replica_uid = kwargs.pop("source_replica_uid")
-
-        SyncEncryptDecryptPool.__init__(self, *args, **kwargs)
-
-        self._docs_to_process = None
-        self._processed_docs = 0
-        self._last_inserted_idx = 0
-
-        self._loop = LoopingCall(self._decrypt_and_recurse)
-
-    def _start_pool(self, period):
-        self._loop.start(period)
-
-    def start(self, docs_to_process):
-        """
-        Set the number of documents we expect to process.
-
-        This should be called by the during the sync exchange process as soon
-        as we know how many documents are arriving from the server.
-
-        :param docs_to_process: The number of documents to process.
-        :type docs_to_process: int
-        """
-        SyncEncryptDecryptPool.start(self)
-        self._decrypted_docs_indexes = set()
-        self._sync_id = uuid4().hex
-        self._docs_to_process = docs_to_process
-        self._deferred = defer.Deferred()
-        d = self._init_db()
-        d.addCallback(lambda _: self._start_pool(self.DECRYPT_LOOP_PERIOD))
-        return d
-
-    def stop(self):
-        if self._loop.running:
-            self._loop.stop()
-        self._finish()
-        SyncEncryptDecryptPool.stop(self)
-
-    def _init_db(self):
-        """
-        Ensure sync_id column is present then
-        Empty the received docs table of the sync database.
-
-        :return: A deferred that will fire when the operation in the database
-                 has finished.
-        :rtype: twisted.internet.defer.Deferred
-        """
-        ensure_sync_id_column = ("ALTER TABLE %s ADD COLUMN sync_id" %
-                                 self.TABLE_NAME)
-        d = self._runQuery(ensure_sync_id_column)
-
-        def empty_received_docs(_):
-            query = "DELETE FROM %s WHERE sync_id <> ?" % (self.TABLE_NAME,)
-            return self._runOperation(query, (self._sync_id,))
-
-        d.addCallbacks(empty_received_docs, empty_received_docs)
-        return d
-
-    def _errback(self, failure):
-        logger.error(failure)
-        self._deferred.errback(failure)
-        self._processed_docs = 0
-        self._last_inserted_idx = 0
-
-    @property
-    def deferred(self):
-        """
-        Deferred that will be fired when the decryption loop has finished
-        processing all the documents.
-        """
-        return self._deferred
-
-    def insert_encrypted_received_doc(
-            self, doc_id, doc_rev, content, gen, trans_id, idx):
-        """
-        Decrypt and insert a received document into local staging area to be
-        processed later on.
-
-        :param doc_id: The document ID.
-        :type doc_id: str
-        :param doc_rev: The document Revision
-        :param doc_rev: str
-        :param content: The content of the document
-        :type content: dict
-        :param gen: The document Generation
-        :type gen: int
-        :param trans_id: Transaction ID
-        :type trans_id: str
-        :param idx: The index of this document in the current sync process.
-        :type idx: int
-
-        :return: A deferred that will fire after the decrypted document has
-                 been inserted in the sync db.
-        :rtype: twisted.internet.defer.Deferred
-        """
-        soledad_assert(self._crypto is not None, "need a crypto object")
-
-        key = self._crypto.doc_passphrase(doc_id)
-        secret = self._crypto.secret
-        args = doc_id, doc_rev, content, gen, trans_id, key, secret, idx
-        # decrypt asynchronously
-        # TODO use dedicated threadpool / move to ampoule
-        d = threads.deferToThread(
-            decrypt_doc_task, *args)
-        # callback will insert it for later processing
-        d.addCallback(self._decrypt_doc_cb)
-        return d
-
-    def insert_received_doc(
-            self, doc_id, doc_rev, content, gen, trans_id, idx):
-        """
-        Insert a document that is not symmetrically encrypted.
-        We store it in the staging area (the decrypted_docs dictionary) to be
-        picked up in order as the preceding documents are decrypted.
-
-        :param doc_id: The document id
-        :type doc_id: str
-        :param doc_rev: The document revision
-        :param doc_rev: str or dict
-        :param content: The content of the document
-        :type content: dict
-        :param gen: The document generation
-        :type gen: int
-        :param trans_id: The transaction id
-        :type trans_id: str
-        :param idx: The index of this document in the current sync process.
-        :type idx: int
-
-        :return: A deferred that will fire when the operation in the database
-                 has finished.
-        :rtype: twisted.internet.defer.Deferred
-        """
-        if not isinstance(content, str):
-            content = json.dumps(content)
-        query = "INSERT OR REPLACE INTO '%s' VALUES (?, ?, ?, ?, ?, ?, ?, ?)" \
-                % self.TABLE_NAME
-        d = self._runOperation(
-            query, (doc_id, doc_rev, content, gen, trans_id, 0,
-                    idx, self._sync_id))
-        d.addCallback(lambda _: self._decrypted_docs_indexes.add(idx))
-        return d
-
-    def _delete_received_docs(self, doc_ids):
-        """
-        Delete a list of received docs after get them inserted into the db.
-
-        :param doc_id: Document ID list.
-        :type doc_id: list
-
-        :return: A deferred that will fire when the operation in the database
-                 has finished.
-        :rtype: twisted.internet.defer.Deferred
-        """
-        placeholders = ', '.join('?' for _ in doc_ids)
-        query = "DELETE FROM '%s' WHERE doc_id in (%s)" \
-                % (self.TABLE_NAME, placeholders)
-        return self._runOperation(query, (doc_ids))
-
-    def _decrypt_doc_cb(self, result):
-        """
-        Store the decryption result in the sync db from where it will later be
-        picked by _process_decrypted_docs.
-
-        :param result: A tuple containing the document's id, revision,
-                       content, generation, transaction id and sync index.
-        :type result: tuple(str, str, str, int, str, int)
-
-        :return: A deferred that will fire after the document has been
-                 inserted in the sync db.
-        :rtype: twisted.internet.defer.Deferred
-        """
-        doc_id, rev, content, gen, trans_id, idx = result
-        logger.debug("sync decrypter pool: decrypted doc %s: %s %s %s"
-                     % (doc_id, rev, gen, trans_id))
-        return self.insert_received_doc(
-            doc_id, rev, content, gen, trans_id, idx)
-
-    def _get_docs(self, encrypted=None, sequence=None):
-        """
-        Get documents from the received docs table in the sync db.
-
-        :param encrypted: If not None, only return documents with encrypted
-                          field equal to given parameter.
-        :type encrypted: bool or None
-        :param order_by: The name of the field to order results.
-
-        :return: A deferred that will fire with the results of the database
-                 query.
-        :rtype: twisted.internet.defer.Deferred
-        """
-        query = "SELECT doc_id, rev, content, gen, trans_id, encrypted, " \
-                "idx FROM %s" % self.TABLE_NAME
-        parameters = []
-        if encrypted or sequence:
-            query += " WHERE sync_id = ? and"
-            parameters += [self._sync_id]
-        if encrypted:
-            query += " encrypted = ?"
-            parameters += [int(encrypted)]
-        if sequence:
-            query += " idx in (" + ', '.join('?' * len(sequence)) + ")"
-            parameters += [int(i) for i in sequence]
-        query += " ORDER BY idx ASC"
-        return self._runQuery(query, parameters)
-
-    @defer.inlineCallbacks
-    def _get_insertable_docs(self):
-        """
-        Return a list of non-encrypted documents ready to be inserted.
-
-        :return: A deferred that will fire with the list of insertable
-                 documents.
-        :rtype: twisted.internet.defer.Deferred
-        """
-        # Here, check in memory what are the insertable indexes that can
-        # form a sequence starting from the last inserted index
-        sequence = []
-        insertable_docs = []
-        next_index = self._last_inserted_idx + 1
-        while next_index in self._decrypted_docs_indexes:
-            sequence.append(str(next_index))
-            next_index += 1
-            if len(sequence) > 900:
-                # 999 is the default value of SQLITE_MAX_VARIABLE_NUMBER
-                # if we try to query more, SQLite will refuse
-                # we need to find a way to improve this
-                # being researched in #7669
-                break
-        # Then fetch all the ones ready for insertion.
-        if sequence:
-            insertable_docs = yield self._get_docs(encrypted=False,
-                                                   sequence=sequence)
-        defer.returnValue(insertable_docs)
-
-    @defer.inlineCallbacks
-    def _process_decrypted_docs(self):
-        """
-        Fetch as many decrypted documents as can be taken from the expected
-        order and insert them in the local replica.
-
-        :return: A deferred that will fire with the list of inserted
-                 documents.
-        :rtype: twisted.internet.defer.Deferred
-        """
-        insertable = yield self._get_insertable_docs()
-        processed_docs_ids = []
-        for doc_fields in insertable:
-            method = self._insert_decrypted_local_doc
-            # FIXME: This is used only because SQLCipherU1DBSync is synchronous
-            # When adbapi is used there is no need for an external thread
-            # Without this the reactor can freeze and fail docs download
-            yield threads.deferToThread(method, *doc_fields)
-            processed_docs_ids.append(doc_fields[0])
-        yield self._delete_received_docs(processed_docs_ids)
-
-    def _insert_decrypted_local_doc(self, doc_id, doc_rev, content,
-                                    gen, trans_id, encrypted, idx):
-        """
-        Insert the decrypted document into the local replica.
-
-        Make use of the passed callback `insert_doc_cb` passed to the caller
-        by u1db sync.
-
-        :param doc_id: The document id.
-        :type doc_id: str
-        :param doc_rev: The document revision.
-        :type doc_rev: str
-        :param content: The serialized content of the document.
-        :type content: str
-        :param gen: The generation corresponding to the modification of that
-                    document.
-        :type gen: int
-        :param trans_id: The transaction id corresponding to the modification
-                         of that document.
-        :type trans_id: str
-        """
-        # could pass source_replica in params for callback chain
-        logger.debug("sync decrypter pool: inserting doc in local db: "
-                     "%s:%s %s" % (doc_id, doc_rev, gen))
-
-        # convert deleted documents to avoid error on document creation
-        if content == 'null':
-            content = None
-        doc = SoledadDocument(doc_id, doc_rev, content)
-        gen = int(gen)
-        self._insert_doc_cb(doc, gen, trans_id)
-
-        # store info about processed docs
-        self._last_inserted_idx = idx
-        self._processed_docs += 1
-
-    @defer.inlineCallbacks
-    def _decrypt_and_recurse(self):
-        """
-        Decrypt the documents received from remote replica and insert them
-        into the local one.
-
-        This method implicitelly returns a defferred (see the decorator
-        above). It should only be called by _launch_decrypt_and_process().
-        because this way any exceptions raised here will be stored by the
-        errback attached to the deferred returned.
-
-        :return: A deferred which will fire after all decrypt, process and
-                 delete operations have been executed.
-        :rtype: twisted.internet.defer.Deferred
-        """
-        if not self.running:
-            defer.returnValue(None)
-        processed = self._processed_docs
-        pending = self._docs_to_process
-
-        if processed < pending:
-            yield self._process_decrypted_docs()
-        else:
-            self._finish()
-
-    def _finish(self):
-        self._processed_docs = 0
-        self._last_inserted_idx = 0
-        self._decrypted_docs_indexes = set()
-        if not self._deferred.called:
-            self._deferred.callback(None)
diff --git a/client/src/leap/soledad/client/http_target/api.py b/client/src/leap/soledad/client/http_target/api.py
index 3c8e3764..c9da939c 100644
--- a/client/src/leap/soledad/client/http_target/api.py
+++ b/client/src/leap/soledad/client/http_target/api.py
@@ -43,8 +43,6 @@ class SyncTargetAPI(SyncTarget):
     def close(self):
         if self._sync_enc_pool:
             self._sync_enc_pool.stop()
-        if self._sync_decr_pool:
-            self._sync_decr_pool.stop()
         yield self._http.close()
 
     @property
@@ -153,7 +151,7 @@ class SyncTargetAPI(SyncTarget):
     def sync_exchange(self, docs_by_generation, source_replica_uid,
                       last_known_generation, last_known_trans_id,
                       insert_doc_cb, ensure_callback=None,
-                      defer_decryption=True, sync_id=None):
+                      sync_id=None):
         """
         Find out which documents the remote database does not know about,
         encrypt and send them. After that, receive documents from the remote
@@ -185,11 +183,6 @@ class SyncTargetAPI(SyncTarget):
                                 created.
         :type ensure_callback: function
 
-        :param defer_decryption: Whether to defer the decryption process using
-                                 the intermediate database. If False,
-                                 decryption will be done inline.
-        :type defer_decryption: bool
-
         :return: A deferred which fires with the new generation and
                  transaction id of the target replica.
         :rtype: twisted.internet.defer.Deferred
@@ -221,8 +214,7 @@ class SyncTargetAPI(SyncTarget):
 
         cur_target_gen, cur_target_trans_id = yield self._receive_docs(
             last_known_generation, last_known_trans_id,
-            ensure_callback, sync_id,
-            defer_decryption=defer_decryption)
+            ensure_callback, sync_id)
 
         # update gen and trans id info in case we just sent and did not
         # receive docs.
diff --git a/client/src/leap/soledad/client/http_target/fetch.py b/client/src/leap/soledad/client/http_target/fetch.py
index 26606e9b..1f1bc480 100644
--- a/client/src/leap/soledad/client/http_target/fetch.py
+++ b/client/src/leap/soledad/client/http_target/fetch.py
@@ -21,7 +21,6 @@ from twisted.internet import defer
 from leap.soledad.client.events import SOLEDAD_SYNC_RECEIVE_STATUS
 from leap.soledad.client.events import emit_async
 from leap.soledad.client.crypto import is_symmetrically_encrypted
-from leap.soledad.client.encdecpool import SyncDecrypterPool
 from leap.soledad.client.http_target.support import RequestBody
 from leap.soledad.common.log import getLogger
 from leap.soledad.common.document import SoledadDocument
@@ -50,26 +49,11 @@ class HTTPDocFetcher(object):
 
     @defer.inlineCallbacks
     def _receive_docs(self, last_known_generation, last_known_trans_id,
-                      ensure_callback, sync_id, defer_decryption):
-        defer_decryption = False
-
-        self._queue_for_decrypt = defer_decryption \
-            and self._sync_db is not None
+                      ensure_callback, sync_id):
 
         new_generation = last_known_generation
         new_transaction_id = last_known_trans_id
 
-        if self._queue_for_decrypt:
-            logger.debug(
-                "Soledad sync: will queue received docs for decrypting.")
-
-        if defer_decryption:
-            self._setup_sync_decr_pool()
-
-        # ---------------------------------------------------------------------
-        # maybe receive the first document
-        # ---------------------------------------------------------------------
-
         # we fetch the first document before fetching the rest because we need
         # to know the total number of documents to be received, and this
         # information comes as metadata to each request.
@@ -85,14 +69,6 @@ class HTTPDocFetcher(object):
             new_generation = ngen
             new_transaction_id = ntrans
 
-        # ---------------------------------------------------------------------
-        # wait for async decryption to finish
-        # ---------------------------------------------------------------------
-
-        if defer_decryption:
-            yield self._sync_decr_pool.deferred
-            self._sync_decr_pool.stop()
-
         defer.returnValue([new_generation, new_transaction_id])
 
     def _fetch_all(self, last_known_generation,
@@ -126,9 +102,6 @@ class HTTPDocFetcher(object):
         new_generation, new_transaction_id, number_of_changes, entries =\
             self._parse_received_doc_response(response)
 
-        if self._sync_decr_pool and not self._sync_decr_pool.running:
-            self._sync_decr_pool.start(number_of_changes)
-
         for doc_id, rev, content, gen, trans_id in entries:
             if doc_id is not None:
                 # decrypt incoming document and insert into local database
@@ -136,31 +109,10 @@ class HTTPDocFetcher(object):
                 # symmetric decryption of document's contents
                 # ---------------------------------------------------------
                 # If arriving content was symmetrically encrypted, we decrypt
-                # it.  We do it inline if defer_decryption flag is False or no
-                # sync_db was defined, otherwise we defer it writing it to the
-                # received docs table.
                 doc = SoledadDocument(doc_id, rev, content)
                 if is_symmetrically_encrypted(doc):
-                    if self._queue_for_decrypt:
-                        self._sync_decr_pool.insert_encrypted_received_doc(
-                            doc.doc_id, doc.rev, doc.content, gen, trans_id,
-                            idx)
-                    else:
-                        # defer_decryption is False or no-sync-db fallback
-                        doc.set_json(self._crypto.decrypt_doc(doc))
-                        self._insert_doc_cb(doc, gen, trans_id)
-                else:
-                    # not symmetrically encrypted doc, insert it directly
-                    # or save it in the decrypted stage.
-                    if self._queue_for_decrypt:
-                        self._sync_decr_pool.insert_received_doc(
-                            doc.doc_id, doc.rev, doc.content, gen, trans_id,
-                            idx)
-                    else:
-                        self._insert_doc_cb(doc, gen, trans_id)
-                # -------------------------------------------------------------
-                # end of symmetric decryption
-                # -------------------------------------------------------------
+                    doc.set_json(self._crypto.decrypt_doc(doc))
+                self._insert_doc_cb(doc, gen, trans_id)
             self._received_docs += 1
             user_data = {'uuid': self.uuid, 'userid': self.userid}
             _emit_receive_status(user_data, self._received_docs, total)
@@ -212,18 +164,6 @@ class HTTPDocFetcher(object):
         return new_generation, new_transaction_id, number_of_changes, \
             entries
 
-    def _setup_sync_decr_pool(self):
-        """
-        Set up the SyncDecrypterPool for deferred decryption.
-        """
-        if self._sync_decr_pool is None and self._sync_db is not None:
-            # initialize syncing queue decryption pool
-            self._sync_decr_pool = SyncDecrypterPool(
-                self._crypto,
-                self._sync_db,
-                insert_doc_cb=self._insert_doc_cb,
-                source_replica_uid=self.source_replica_uid)
-
 
 def _emit_receive_status(user_data, received_docs, total):
     content = {'received': received_docs, 'total': total}
diff --git a/client/src/leap/soledad/client/interfaces.py b/client/src/leap/soledad/client/interfaces.py
index 14b34d24..82927ff4 100644
--- a/client/src/leap/soledad/client/interfaces.py
+++ b/client/src/leap/soledad/client/interfaces.py
@@ -321,7 +321,7 @@ class ISyncableStorage(Interface):
         "Property, True if the syncer is syncing.")
     token = Attribute("The authentication Token.")
 
-    def sync(self, defer_decryption=True):
+    def sync(self):
         """
         Synchronize the local encrypted replica with a remote replica.
 
@@ -331,11 +331,6 @@ class ISyncableStorage(Interface):
         :param url: the url of the target replica to sync with
         :type url: str
 
-        :param defer_decryption:
-            Whether to defer the decryption process using the intermediate
-            database. If False, decryption will be done inline.
-        :type defer_decryption: bool
-
         :return:
             A deferred that will fire with the local generation before the
             synchronisation was performed.
diff --git a/client/src/leap/soledad/client/sqlcipher.py b/client/src/leap/soledad/client/sqlcipher.py
index b198607d..ba341bbf 100644
--- a/client/src/leap/soledad/client/sqlcipher.py
+++ b/client/src/leap/soledad/client/sqlcipher.py
@@ -164,7 +164,7 @@ class SQLCipherOptions(object):
         :param cipher_page_size: The page size.
         :type cipher_page_size: int
         :param defer_encryption:
-            Whether to defer encryption/decryption of documents, or do it
+            Whether to defer encryption of documents, or do it
             inline while syncing.
         :type defer_encryption: bool
         """
@@ -480,7 +480,7 @@ class SQLCipherU1DBSync(SQLCipherDatabase):
             raise DatabaseAccessError(str(e))
 
     @defer.inlineCallbacks
-    def sync(self, url, creds=None, defer_decryption=True):
+    def sync(self, url, creds=None):
         """
         Synchronize documents with remote replica exposed at url.
 
@@ -495,10 +495,6 @@ class SQLCipherU1DBSync(SQLCipherDatabase):
         :param creds: optional dictionary giving credentials to authorize the
                       operation with the server.
         :type creds: dict
-        :param defer_decryption:
-            Whether to defer the decryption process using the intermediate
-            database. If False, decryption will be done inline.
-        :type defer_decryption: bool
 
         :return:
             A Deferred, that will fire with the local generation (type `int`)
@@ -510,8 +506,7 @@ class SQLCipherU1DBSync(SQLCipherDatabase):
             self.sync_phase = syncer.sync_phase
             self.syncer = syncer
             self.sync_exchange_phase = syncer.sync_exchange_phase
-        local_gen_before_sync = yield syncer.sync(
-            defer_decryption=defer_decryption)
+        local_gen_before_sync = yield syncer.sync()
         self.received_docs = syncer.received_docs
         defer.returnValue(local_gen_before_sync)
 
diff --git a/client/src/leap/soledad/client/sync.py b/client/src/leap/soledad/client/sync.py
index 4cbd9f2a..d3cfe029 100644
--- a/client/src/leap/soledad/client/sync.py
+++ b/client/src/leap/soledad/client/sync.py
@@ -56,23 +56,10 @@ class SoledadSynchronizer(Synchronizer):
             self.sync_exchange_phase = None
 
     @defer.inlineCallbacks
-    def sync(self, defer_decryption=True):
+    def sync(self):
         """
         Synchronize documents between source and target.
 
-        Differently from u1db `Synchronizer.sync` method, this one allows to
-        pass a `defer_decryption` flag that will postpone the last
-        step in the synchronization dance, namely, the setting of the last
-        known generation and transaction id for a given remote replica.
-
-        This is done to allow the ongoing parallel decryption of the incoming
-        docs to proceed without `InvalidGeneration` conflicts.
-
-        :param defer_decryption: Whether to defer the decryption process using
-                                 the intermediate database. If False,
-                                 decryption will be done inline.
-        :type defer_decryption: bool
-
         :return: A deferred which will fire after the sync has finished with
                  the local generation before the synchronization was performed.
         :rtype: twisted.internet.defer.Deferred
@@ -172,8 +159,7 @@ class SoledadSynchronizer(Synchronizer):
         new_gen, new_trans_id = yield sync_target.sync_exchange(
             docs_by_generation, self.source._replica_uid,
             target_last_known_gen, target_last_known_trans_id,
-            self._insert_doc_from_target, ensure_callback=ensure_callback,
-            defer_decryption=defer_decryption)
+            self._insert_doc_from_target, ensure_callback=ensure_callback)
         logger.debug("target gen after sync: %d" % new_gen)
         logger.debug("target trans_id after sync: %s" % new_trans_id)
         if hasattr(self.source, 'commit'):