[tracker] libtracker-data: Limit update buffer size

[Jürg Billeter <juergbi src gnome org>]

commit 2c8a8ca4843dcea00e37dc8486355af1863ed872
Author: Jürg Billeter <j bitron ch>
Date:   Tue Mar 2 10:51:55 2010 +0100

    libtracker-data: Limit update buffer size
    
    INSERT {...} WHERE {...} updates with many solutions to the WHERE
    clause were causing high memory usage due to the update buffer.

 src/libtracker-data/libtracker-data.vapi      |    1 +
 src/libtracker-data/tracker-data-update.c     |    9 +++++++++
 src/libtracker-data/tracker-data-update.h     |    1 +
 src/libtracker-data/tracker-sparql-query.vala |    2 ++
 4 files changed, 13 insertions(+), 0 deletions(-)
---
diff --git a/src/libtracker-data/libtracker-data.vapi b/src/libtracker-data/libtracker-data.vapi
index 31a04a7..490612c 100644
--- a/src/libtracker-data/libtracker-data.vapi
+++ b/src/libtracker-data/libtracker-data.vapi
@@ -36,6 +36,7 @@ namespace Tracker {
 		public void insert_statement_with_string (string graph, string subject, string predicate, string object) throws DataError;
 		public void delete_resource_description (string graph, string uri) throws DataError;
 		public void update_buffer_flush () throws DBInterfaceError;
+		public void update_buffer_might_flush () throws DBInterfaceError;
 	}
 }
 
diff --git a/src/libtracker-data/tracker-data-update.c b/src/libtracker-data/tracker-data-update.c
index f2713b7..e4ab24d 100644
--- a/src/libtracker-data/tracker-data-update.c
+++ b/src/libtracker-data/tracker-data-update.c
@@ -711,6 +711,15 @@ tracker_data_update_buffer_flush (GError **error)
 	resource_buffer = NULL;
 }
 
+void
+tracker_data_update_buffer_might_flush (GError **error)
+{
+	/* avoid high memory usage by update buffer */
+	if (g_hash_table_size (update_buffer.resources) >= 1000) {
+		tracker_data_update_buffer_flush (error);
+	}
+}
+
 static void
 tracker_data_update_buffer_clear (void)
 {
diff --git a/src/libtracker-data/tracker-data-update.h b/src/libtracker-data/tracker-data-update.h
index da3d429..f239493 100644
--- a/src/libtracker-data/tracker-data-update.h
+++ b/src/libtracker-data/tracker-data-update.h
@@ -85,6 +85,7 @@ GPtrArray *
 tracker_data_update_sparql_blank           (const gchar               *update,
                                             GError                   **error);
 void     tracker_data_update_buffer_flush           (GError                   **error);
+void     tracker_data_update_buffer_might_flush     (GError                   **error);
 
 void     tracker_data_sync                          (void);
 
diff --git a/src/libtracker-data/tracker-sparql-query.vala b/src/libtracker-data/tracker-sparql-query.vala
index ec5599e..88e01ae 100644
--- a/src/libtracker-data/tracker-sparql-query.vala
+++ b/src/libtracker-data/tracker-sparql-query.vala
@@ -1075,6 +1075,8 @@ public class Tracker.SparqlQuery : Object {
 					HashTable<string,string>* ptr = (owned) blank_nodes;
 					update_blank_nodes.add (ptr);
 				}
+
+				Data.update_buffer_might_flush ();
 			} while (result_set.iter_next ());
 		}