[tracker/fts4: 5/17] libtracker-fts: Add the tracker_rank() sqlite function
- From: Carlos Garnacho <carlosg src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [tracker/fts4: 5/17] libtracker-fts: Add the tracker_rank() sqlite function
- Date: Mon, 28 Jan 2013 17:27:08 +0000 (UTC)
commit 4a3d238811dd46f1eac60640160e005f113289f3
Author: Carlos Garnacho <carlos lanedo com>
Date: Fri Nov 4 12:49:34 2011 +0100
libtracker-fts: Add the tracker_rank() sqlite function
This is now used in FTS searches to provide the rank based on
the matched columns and their respective property weight.
src/libtracker-data/tracker-sparql-pattern.vala | 3 +-
src/libtracker-fts/tracker-fts.c | 84 +++++++++++++++++++++++
2 files changed, 86 insertions(+), 1 deletions(-)
---
diff --git a/src/libtracker-data/tracker-sparql-pattern.vala b/src/libtracker-data/tracker-sparql-pattern.vala
index 8e5bba3..a12dc3e 100644
--- a/src/libtracker-data/tracker-sparql-pattern.vala
+++ b/src/libtracker-data/tracker-sparql-pattern.vala
@@ -1470,7 +1470,8 @@ class Tracker.Sparql.Pattern : Object {
binding.sql_db_column_name = "fts";
triple_context.bindings.append (binding);
- sql.append_printf ("rank(\"%s\".\"fts\") AS \"%s_u_rank\", ",
+ sql.append_printf ("tracker_rank(matchinfo(\"%s\".\"fts\", 'cl'),fts_column_weights()) " +
+ "AS \"%s_u_rank\", ",
binding.table.sql_query_tablename,
context.get_variable (current_subject).name);
sql.append_printf ("offsets(\"%s\".\"fts\") AS \"%s_u_offsets\", ",
diff --git a/src/libtracker-fts/tracker-fts.c b/src/libtracker-fts/tracker-fts.c
index 23c6f46..8909687 100644
--- a/src/libtracker-fts/tracker-fts.c
+++ b/src/libtracker-fts/tracker-fts.c
@@ -37,12 +37,96 @@ tracker_fts_init (void) {
return (module_initialized != 0);
}
+static void
+function_rank (sqlite3_context *context,
+ int argc,
+ sqlite3_value *argv[])
+{
+ guint *matchinfo, *weights;
+ gdouble rank = 0;
+ gint i, n_columns;
+
+ if (argc != 2) {
+ sqlite3_result_error(context,
+ "wrong number of arguments to function rank()",
+ -1);
+ return;
+ }
+
+ matchinfo = (unsigned int *) sqlite3_value_blob (argv[0]);
+ weights = (unsigned int *) sqlite3_value_blob (argv[1]);
+ n_columns = matchinfo[0];
+
+ for (i = 0; i < n_columns; i++) {
+ if (matchinfo[i + 1] != 0) {
+ rank += (gdouble) weights[i];
+ }
+ }
+
+ sqlite3_result_double(context, rank);
+}
+
+static void
+function_weights (sqlite3_context *context,
+ int argc,
+ sqlite3_value *argv[])
+{
+ static guint *weights = NULL;
+ static gsize weights_initialized = 0;
+
+ if (g_once_init_enter (&weights_initialized)) {
+ GArray *weight_array;
+ sqlite3_stmt *stmt;
+ sqlite3 *db;
+ int rc;
+
+ weight_array = g_array_new (FALSE, FALSE, sizeof (guint));
+ db = sqlite3_context_db_handle (context);
+ rc = sqlite3_prepare_v2 (db,
+ "SELECT \"rdf:Property\".\"tracker:weight\" "
+ "FROM \"rdf:Property\" "
+ "WHERE \"rdf:Property\".\"tracker:fulltextIndexed\" = 1 "
+ "ORDER BY \"rdf:Property\".ID ",
+ -1, &stmt, NULL);
+
+ while ((rc = sqlite3_step (stmt)) != SQLITE_DONE) {
+ if (rc == SQLITE_ROW) {
+ guint weight;
+ weight = sqlite3_column_int (stmt, 0);
+ g_array_append_val (weight_array, weight);
+ }
+ }
+
+ if (rc == SQLITE_DONE) {
+ rc = sqlite3_finalize (stmt);
+ }
+
+ weights = g_array_free (weight_array, FALSE);
+ g_once_init_leave (&weights_initialized, (rc == SQLITE_OK));
+ }
+
+ sqlite3_result_blob (context, weights, sizeof (weights), NULL);
+}
+
+
+static void
+tracker_fts_register_functions (sqlite3 *db)
+{
+ sqlite3_create_function (db, "tracker_rank", 2, SQLITE_ANY,
+ NULL, &function_rank,
+ NULL, NULL);
+ sqlite3_create_function (db, "fts_column_weights", 0, SQLITE_ANY,
+ NULL, &function_weights,
+ NULL, NULL);
+}
+
gboolean
tracker_fts_init_db (sqlite3 *db) {
if (!tracker_tokenizer_initialize (db)) {
return FALSE;
}
+ tracker_fts_register_functions (db);
return TRUE;
}
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