[tracker/wip/carlosg/bindings-in-service: 1/6] libtracker-data: Reorder columns in "services" virtual table

[Carlos Garnacho <carlosg src gnome org>]

commit 4a3f808c32b5a23112c6e26e30906a61a875512e
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon May 4 01:25:34 2020 +0200

    libtracker-data: Reorder columns in "services" virtual table
    
    So it's easier to extend with extra columns

 src/libtracker-data/tracker-vtab-service.c | 51 +++++++++++++++++++++---------
 1 file changed, 36 insertions(+), 15 deletions(-)
---
diff --git a/src/libtracker-data/tracker-vtab-service.c b/src/libtracker-data/tracker-vtab-service.c
index c0e4e894a..0311b67f3 100644
--- a/src/libtracker-data/tracker-vtab-service.c
+++ b/src/libtracker-data/tracker-vtab-service.c
@@ -24,10 +24,12 @@
 #include "tracker-vtab-service.h"
 #include <libtracker-sparql/tracker-sparql.h>
 
-#define N_VIRTUAL_COLUMNS 100
-#define COL_SERVICE 101
-#define COL_QUERY 102
-#define COL_SILENT 103
+#define N_VARIABLES 100
+#define COL_SERVICE 0
+#define COL_QUERY 1
+#define COL_SILENT 2
+#define COL_LAST 3
+#define COL_FIRST_VARIABLE COL_LAST
 
 typedef struct {
        sqlite3 *db;
@@ -104,13 +106,16 @@ service_create (sqlite3            *db,
 
        str = g_string_new ("CREATE TABLE x(\n");
 
-       for (i = 0; i <= N_VIRTUAL_COLUMNS; i++)
-               g_string_append_printf (str, "col%d TEXT, ", i);
-
        g_string_append (str,
                         "service TEXT HIDDEN, "
                         "query TEXT HIDDEN, "
-                        "silent INTEGER HIDDEN)");
+                        "silent INTEGER HIDDEN");
+
+       for (i = 0; i < N_VARIABLES; i++)
+               g_string_append_printf (str, ", col%d TEXT", i);
+
+       g_string_append (str, ")");
+
        rc = sqlite3_declare_vtab (module->db, str->str);
        g_string_free (str, TRUE);
 
@@ -208,6 +213,7 @@ service_filter (sqlite3_vtab_cursor  *vtab_cursor,
 {
        TrackerServiceCursor *cursor = (TrackerServiceCursor *) vtab_cursor;
        const ConstraintData *constraints = (const ConstraintData *) idx_str;
+       TrackerSparqlStatement *statement;
        gchar *uri_scheme = NULL;
        GError *error = NULL;
        gint i;
@@ -268,9 +274,17 @@ service_filter (sqlite3_vtab_cursor  *vtab_cursor,
                goto fail;
        }
 
-       cursor->sparql_cursor = tracker_sparql_connection_query (cursor->conn,
-                                                                cursor->query,
-                                                                NULL, &error);
+       statement = tracker_sparql_connection_query_statement (cursor->conn,
+                                                              cursor->query,
+                                                              NULL, &error);
+       if (error)
+               goto fail;
+
+       cursor->sparql_cursor = tracker_sparql_statement_execute (statement,
+                                                                 NULL,
+                                                                 &error);
+       g_object_unref (statement);
+
        if (error)
                goto fail;
 
@@ -335,10 +349,17 @@ service_column (sqlite3_vtab_cursor *vtab_cursor,
                sqlite3_result_text (context, cursor->query, -1, NULL);
        } else if (n_col == COL_SILENT) {
                sqlite3_result_int (context, cursor->silent);
-       } else if (n_col < tracker_sparql_cursor_get_n_columns (cursor->sparql_cursor)) {
-               /* FIXME: Handle other types better */
-               str = tracker_sparql_cursor_get_string (cursor->sparql_cursor, n_col, NULL);
-               sqlite3_result_text (context, g_strdup (str), -1, g_free);
+       } else if (n_col >= COL_FIRST_VARIABLE &&
+                  n_col < COL_FIRST_VARIABLE + N_VARIABLES) {
+               gint query_col = n_col - COL_FIRST_VARIABLE;
+
+               if (query_col < tracker_sparql_cursor_get_n_columns (cursor->sparql_cursor)) {
+                       /* FIXME: Handle other types better */
+                       str = tracker_sparql_cursor_get_string (cursor->sparql_cursor, query_col, NULL);
+                       sqlite3_result_text (context, g_strdup (str), -1, g_free);
+               } else {
+                       sqlite3_result_null (context);
+               }
        } else {
                sqlite3_result_null (context);
        }