Merge lp:~jameinel/u1db/sync_skip_record_999592 into lp:u1db

[John A Meinel]

This handles the next stage of "don't talk to the server if you don't have to". The three steps today are GET, POST, PUT. Eric's branch handles that if GET says there is nothing to do, we don't POST or PUT. This adds a test that if after POST the remote server knows everything, we don't do a follow up PUT.

Interestingly, the C code already had the check, we just didn't have a test for it.

[Lucio Torre (lucio.torre)]

review: Approve

=== modified file 'src/u1db_sync_target.c'
--- src/u1db_sync_target.c	2012-05-15 09:03:31 +0000
+++ src/u1db_sync_target.c	2012-05-15 12:15:23 +0000
@@ -131,12 +131,19 @@
 st_record_sync_info(u1db_sync_target *st, const char *source_replica_uid,
                     int source_gen)
 {
+    int status;
     u1database *db;
     if (st == NULL || source_replica_uid == NULL) {
         return U1DB_INVALID_PARAMETER;
     }
+    if (st->trace_cb) {
+        status = st->trace_cb(st->trace_context, "record_sync_info");
+        if (status != U1DB_OK) { goto finish; }
+    }
     db = (u1database *)st->implementation;
-    return u1db__set_sync_generation(db, source_replica_uid, source_gen);
+    status = u1db__set_sync_generation(db, source_replica_uid, source_gen);
+finish:
+    return status;
 }
 
 
@@ -593,7 +600,6 @@
             ((*local_gen_before_sync + return_doc_state.num_inserted)
               == local_gen))
     {
-        // fprintf(stderr, "Informing target of local_gen\n", local_gen);
         status = target->record_sync_info(target, local_uid, local_gen);
         if (status != U1DB_OK) { goto finish; }
     }

=== modified file 'u1db/backends/inmemory.py'
--- u1db/backends/inmemory.py	2012-04-27 14:22:47 +0000
+++ u1db/backends/inmemory.py	2012-05-15 12:15:23 +0000
@@ -338,5 +338,7 @@
             self._db._replica_uid, len(self._db._transaction_log), source_gen)
 
     def record_sync_info(self, source_replica_uid, source_replica_generation):
+        if self._trace_hook:
+            self._trace_hook('record_sync_info')
         self._db.set_sync_generation(source_replica_uid,
                                      source_replica_generation)

=== modified file 'u1db/backends/sqlite_backend.py'
--- u1db/backends/sqlite_backend.py	2012-05-10 16:23:47 +0000
+++ u1db/backends/sqlite_backend.py	2012-05-15 12:15:23 +0000
@@ -602,6 +602,8 @@
         return self._db._replica_uid, my_gen, source_gen
 
     def record_sync_info(self, source_replica_uid, source_replica_generation):
+        if self._trace_hook:
+            self._trace_hook('record_sync_info')
         self._db.set_sync_generation(source_replica_uid,
                                      source_replica_generation)
 

=== modified file 'u1db/sync.py'
--- u1db/sync.py	2012-04-30 11:37:13 +0000
+++ u1db/sync.py	2012-05-15 12:15:23 +0000
@@ -82,7 +82,8 @@
         new generation.
         """
         cur_gen = self.source._get_generation()
-        if cur_gen == start_generation + self.num_inserted:
+        if (cur_gen == start_generation + self.num_inserted
+            and self.num_inserted > 0):
             self.sync_target.record_sync_info(self.source._replica_uid,
                                               cur_gen)
 

=== modified file 'u1db/tests/test_sync.py'
--- u1db/tests/test_sync.py	2012-05-09 16:09:04 +0000
+++ u1db/tests/test_sync.py	2012-05-15 12:15:23 +0000
@@ -359,9 +359,12 @@
             called.append(state)
         self.set_trace_hook(cb)
         self.st.sync_exchange([], 'replica', 0, self.receive_doc)
+        self.st.record_sync_info('replica', 0)
         self.assertEqual(['before whats_changed',
                           'after whats_changed',
-                          'before get_docs'],
+                          'before get_docs',
+                          'record_sync_info',
+                          ],
                          called)
 
 
@@ -468,6 +471,17 @@
         # returned from c2.
         self.assertEqual(0, self.db2.get_sync_generation('test1'))
 
+    def test_sync_doesnt_update_other_if_nothing_pulled(self):
+        doc = self.db1.create_doc(simple_doc)
+        def no_record_sync_info(state):
+            if state != 'record_sync_info':
+                return
+            self.fail('SyncTarget.record_sync_info was called')
+        self.assertEqual(1, self.sync(self.db1, self.db2,
+                                      trace_hook=no_record_sync_info))
+        self.assertEqual(1,
+                         self.db2.get_sync_generation(self.db1._replica_uid))
+
     def test_sync_ignores_convergence(self):
         doc = self.db1.create_doc(simple_doc)
         self.db3 = self.create_database('test3')