[evolution-data-server/openismus-work] EBookBackendFile: Dont load the revision if the revision is already loaded

[Tristan Van Berkom <tvb src gnome org>]

commit 011911a18717586ee5b98a6ca3dcf52a80bbf08b
Author: Tristan Van Berkom <tristanvb openismus com>
Date:   Tue Feb 26 19:08:59 2013 +0900

    EBookBackendFile: Dont load the revision if the revision is already loaded
    
    This avoids a small memory leak when multiple clients are connected,
    the patch also adds a comment and a little extra locking around access
    to the ->revision variable in the ->open() method.
    
    Fixes bug https://bugzilla.gnome.org/show_bug.cgi?id=694730

 addressbook/backends/file/e-book-backend-file.c |   27 +++++++++++++++-------
 1 files changed, 18 insertions(+), 9 deletions(-)
---
diff --git a/addressbook/backends/file/e-book-backend-file.c b/addressbook/backends/file/e-book-backend-file.c
index 0a51dd6..1f90209 100644
--- a/addressbook/backends/file/e-book-backend-file.c
+++ b/addressbook/backends/file/e-book-backend-file.c
@@ -623,6 +623,8 @@ e_book_backend_file_new_revision (EBookBackendFile *bf)
  * time the revision bumps, this is the safest approach and
  * its unclear so far if bumping the revision string for 
  * every DB modification is going to really be an overhead.
+ *
+ * This is always called with the writer lock held.
  */
 static void
 e_book_backend_file_bump_revision (EBookBackendFile *bf)
@@ -653,15 +655,20 @@ e_book_backend_file_load_revision (EBookBackendFile *bf)
 
        g_rw_lock_writer_lock (&(bf->priv->lock));
 
-       if (!e_book_backend_sqlitedb_get_revision (bf->priv->sqlitedb,
-                                                  SQLITEDB_FOLDER_ID,
-                                                  &bf->priv->revision,
-                                                  &error)) {
-               g_warning (G_STRLOC ": Error loading database revision: %s",
-                          error->message);
-               g_error_free (error);
-       } else if (bf->priv->revision == NULL) {
-               e_book_backend_file_bump_revision (bf);
+       /* Only load the revision if it's not already loaded */
+       if (bf->priv->revision == NULL) {
+
+               if (!e_book_backend_sqlitedb_get_revision (bf->priv->sqlitedb,
+                                                          SQLITEDB_FOLDER_ID,
+                                                          &bf->priv->revision,
+                                                          &error)) {
+                       g_warning (G_STRLOC ": Error loading database revision: %s",
+                                  error->message);
+                       g_error_free (error);
+               } else if (bf->priv->revision == NULL) {
+                       /* If we loaded a NULL revision then we are the first, set the initial revision */
+                       e_book_backend_file_bump_revision (bf);
+               }
        }
 
        g_rw_lock_writer_unlock (&(bf->priv->lock));
@@ -1516,9 +1523,11 @@ e_book_backend_file_open (EBookBackendSync *backend,
        e_book_backend_notify_readonly (E_BOOK_BACKEND (backend), FALSE);
        e_book_backend_notify_opened (E_BOOK_BACKEND (backend), NULL /* Success */);
 
+       g_rw_lock_reader_lock (&(bf->priv->lock));
        e_book_backend_notify_property_changed (E_BOOK_BACKEND (backend),
                                                BOOK_BACKEND_PROPERTY_REVISION,
                                                bf->priv->revision);
+       g_rw_lock_reader_unlock (&(bf->priv->lock));
 }
 
 static gboolean