Rev 112: Use a cursor.lastrowid rather than executemany followed by a SELECT. in http://bazaar.launchpad.net/~bzr/bzr-history-db/trunk

[John Arbash Meinel]

At http://bazaar.launchpad.net/~bzr/bzr-history-db/trunk

------------------------------------------------------------
revno: 112
revision-id: john at arbash-meinel.com-20100427215258-gna8751he7m9vc2h
parent: john at arbash-meinel.com-20100427212204-gzktjcesj9u9eakp
committer: John Arbash Meinel <john at arbash-meinel.com>
branch nick: trunk
timestamp: Tue 2010-04-27 16:52:58 -0500
message:
  Use a cursor.lastrowid rather than executemany followed by a SELECT.
  
  gets us to around 4.6s. Not quite as fast as just doing the INSERT but we had code
  that assumed you didn't need the graph object most of the time.
-------------- next part --------------
=== modified file 'schema.py'
--- a/schema.py	2010-04-27 21:22:04 +0000
+++ b/schema.py	2010-04-27 21:52:58 +0000
@@ -208,20 +208,18 @@
     missing = find_existing()
     if missing:
         ghosts = set()
-        def get_gdfo(rev_id):
-            node = graph._nodes[(rev_id,)]
-            if node.gdfo == 1:
-                # First rev, see if this is actually a ghost
-                if node.parent_keys is None:
+        def insert_new():
+            for rev_id in missing:
+                node = graph._nodes[(rev_id,)]
+                if node.gdfo == 1 and node.parent_keys is None:
+                    # First rev, see if this is actually a ghost
                     ghosts.add(rev_id)
-            return node.gdfo
-        def insert_new():
-            cursor.executemany('INSERT INTO revision (revision_id, gdfo)'
-                               ' VALUES (?, ?)',
-                               [(m, get_gdfo(m)) for m in missing])
+                cursor.execute('INSERT INTO revision (revision_id, gdfo)'
+                               ' VALUES (?, ?)', (rev_id, node.gdfo))
+                db_id = cursor.lastrowid
+                rev_id_to_db_id[rev_id] = db_id
+                db_id_to_rev_id[db_id] = rev_id
         insert_new()
-        ensure_revisions(cursor, missing, rev_id_to_db_id,
-                         db_id_to_rev_id, graph=graph)
         if ghosts:
             # TODO: We could turn this into a "revision_id IN ()", instead...
             cursor.executemany("INSERT INTO ghost (db_id)"