[feature] add post-sync hooks using twisted plugins

implementing a generic plugin interface to allow other modules to react
to soledad syncs, receiving a list of document ids that they've
subscribed to.

- Resolves: #6996
- Releases: 0.7.1

6 files changed, 98 insertions, 1 deletions

diff --git a/.gitignore b/.gitignore
index c502541e..6a0003cc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+dropin.cache
 *.log
 *.pyc
 dist/
diff --git a/client/src/leap/soledad/client/adbapi.py b/client/src/leap/soledad/client/adbapi.py
index 5b882bbe..4f75695f 100644
--- a/client/src/leap/soledad/client/adbapi.py
+++ b/client/src/leap/soledad/client/adbapi.py
@@ -217,6 +217,7 @@ class U1DBConnectionPool(adbapi.ConnectionPool):
         """
         meth = getattr(trans, meth)
         return meth(*args, **kw)
+        # XXX should return a fetchall?
 
     def _runInteraction(self, interaction, *args, **kw):
         """
diff --git a/client/src/leap/soledad/client/api.py b/client/src/leap/soledad/client/api.py
index 76d6acc3..63b1dfc0 100644
--- a/client/src/leap/soledad/client/api.py
+++ b/client/src/leap/soledad/client/api.py
@@ -42,6 +42,7 @@ except ImportError:
 from StringIO import StringIO
 from u1db.remote import http_client
 from u1db.remote.ssl_match_hostname import match_hostname
+from twisted.plugin import getPlugins
 from zope.interface import implements
 
 from leap.common.config import get_path_prefix
@@ -70,6 +71,28 @@ Soledad client and server.
 """
 SOLEDAD_CERT = None
 
+# A whitelist of modules from where to collect plugins dynamically.
+# For the moment restricted to leap namespace, but the idea is that we can pass
+# other "trusted" modules as options to the initialization of soledad.
+PLUGGABLE_LEAP_MODULES = ('mail', 'keymanager')
+
+
+# TODO move to leap.common
+
+def collect_plugins(interface):
+    """
+    Traverse a whitelist of modules and collect all the plugins that implement
+    the passed interface.
+    """
+    plugins = []
+    for namespace in PLUGGABLE_LEAP_MODULES:
+        try:
+            module = __import__('leap.%s.plugins' % namespace, fromlist='.')
+            plugins = plugins + list(getPlugins(interface, module))
+        except ImportError:
+            pass
+    return plugins
+
 
 class Soledad(object):
     """
@@ -656,6 +679,20 @@ class Soledad(object):
             defer_decryption=defer_decryption)
 
         def _sync_callback(local_gen):
+            self._last_received_docs = self._dbsyncer.received_docs
+            print "***"
+            print "LAST RECEIVED (API)", self._last_received_docs
+            print "***"
+            received_doc_ids = self._dbsyncer.received_docs
+
+            # Post-Sync Hooks
+            synced_plugin = soledad_interfaces.ISoledadPostSyncPlugin
+            if received_doc_ids:
+                suitable_plugins = collect_plugins(synced_plugin)
+                for plugin in suitable_plugins:
+                    # TODO filter the doc_ids here
+                    plugin.process_received_docs(received_doc_ids)
+
             soledad_events.emit(
                 soledad_events.SOLEDAD_DONE_DATA_SYNC, self.uuid)
             return local_gen
diff --git a/client/src/leap/soledad/client/interfaces.py b/client/src/leap/soledad/client/interfaces.py
index 4f7b0779..14b34d24 100644
--- a/client/src/leap/soledad/client/interfaces.py
+++ b/client/src/leap/soledad/client/interfaces.py
@@ -19,6 +19,37 @@ Interfaces used by the Soledad Client.
 """
 from zope.interface import Interface, Attribute
 
+#
+# Plugins
+#
+
+
+class ISoledadPostSyncPlugin(Interface):
+    """
+    I implement the minimal methods and attributes for a plugin that can be
+    called after a soledad synchronization has ended.
+    """
+
+    def process_received_docs(self, doc_id_list):
+        """
+        Do something with the passed list of doc_ids received after the last
+        sync.
+
+        :param doc_id_list: a list of strings for the received doc_ids
+        """
+
+    watched_doc_types = Attribute("""
+        a tuple of the watched doc types for this plugin. So far, the
+        `doc-types` convention is just the preffix of the doc_id, which is
+        basically its first character, followed by a dash. So, for instance,
+        `M-` is used for meta-docs in mail, and `F-` is used for flag-docs in
+        mail. For now there's no central register of all the doc-types
+        used.""")
+
+
+#
+# Soledad storage
+#
 
 class ILocalStorage(Interface):
     """
diff --git a/client/src/leap/soledad/client/sqlcipher.py b/client/src/leap/soledad/client/sqlcipher.py
index b2025130..75d786a6 100644
--- a/client/src/leap/soledad/client/sqlcipher.py
+++ b/client/src/leap/soledad/client/sqlcipher.py
@@ -456,6 +456,9 @@ class SQLCipherU1DBSync(SQLCipherDatabase):
 
         self._syncers = {}
 
+        # Storage for the documents received during a sync
+        self.received_docs = []
+
         self.running = False
         self._sync_threadpool = None
         self._initialize_sync_threadpool()
@@ -587,8 +590,16 @@ class SQLCipherU1DBSync(SQLCipherDatabase):
         # the following context manager blocks until the syncing lock can be
         # acquired.
         with self._syncer(url, creds=creds) as syncer:
+
+            def _record_received_docs(result):
+                # beware, closure. syncer is in scope.
+                self.received_docs = syncer.received_docs
+                return result
+
             # XXX could mark the critical section here...
-            return syncer.sync(defer_decryption=defer_decryption)
+            d = syncer.sync(defer_decryption=defer_decryption)
+            d.addCallback(_record_received_docs)
+            return d
 
     @contextmanager
     def _syncer(self, url, creds=None):
diff --git a/client/src/leap/soledad/client/sync.py b/client/src/leap/soledad/client/sync.py
index 53172f31..917c21ea 100644
--- a/client/src/leap/soledad/client/sync.py
+++ b/client/src/leap/soledad/client/sync.py
@@ -39,6 +39,7 @@ class SoledadSynchronizer(Synchronizer):
 
     Also modified to allow for interrupting the synchronization process.
     """
+    received_docs = []
 
     @defer.inlineCallbacks
     def sync(self, defer_decryption=True):
@@ -62,6 +63,7 @@ class SoledadSynchronizer(Synchronizer):
         :rtype: twisted.internet.defer.Deferred
         """
         sync_target = self.sync_target
+        self.received_docs = []
 
         # get target identifier, its current generation,
         # and its last-seen database generation for this source
@@ -123,12 +125,14 @@ class SoledadSynchronizer(Synchronizer):
         changed_doc_ids = [doc_id for doc_id, _, _ in changes]
         docs_to_send = self.source.get_docs(
             changed_doc_ids, check_for_conflicts=False, include_deleted=True)
+        ids_sent = []
         docs_by_generation = []
         idx = 0
         for doc in docs_to_send:
             _, gen, trans = changes[idx]
             docs_by_generation.append((doc, gen, trans))
             idx += 1
+            ids_sent.append(doc.doc_id)
 
         # exchange documents and try to insert the returned ones with
         # the target, return target synced-up-to gen.
@@ -151,6 +155,18 @@ class SoledadSynchronizer(Synchronizer):
         self._syncing_info = info
         yield self.complete_sync()
 
+        _, _, changes = self.source.whats_changed(target_my_gen)
+        changed_doc_ids = [doc_id for doc_id, _, _ in changes]
+
+        print "--------------------------"
+        print "SENT", ids_sent
+        print "CHANGED_DOC_IDS", changed_doc_ids
+
+        just_received = list(set(changed_doc_ids) - set(ids_sent))
+        print "RECEIVED:", just_received
+        print "--------------------------"
+
+        self.received_docs = just_received
         defer.returnValue(my_gen)
 
     def complete_sync(self):