[tracker: 10/21] libtracker-data: Use GLib.Queue instead of native Vala arrays

[Carlos Garnacho <carlosg src gnome org>]

commit f502e6321d62be8be27db8ec7bafa3cd2a223ada
Author: Andrea Azzarone <andrea azzarone canonical com>
Date:   Wed Jan 23 19:25:45 2019 +0000

    libtracker-data: Use GLib.Queue instead of native Vala arrays
    
    Removing elements from a native vala array can cause memory leaks. Let's use
    GLib.Queue both for subject_stack and subject_stack.

 src/libtracker-data/tracker-turtle-reader.vala | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)
---
diff --git a/src/libtracker-data/tracker-turtle-reader.vala b/src/libtracker-data/tracker-turtle-reader.vala
index 5bebdc432..662ce8f43 100644
--- a/src/libtracker-data/tracker-turtle-reader.vala
+++ b/src/libtracker-data/tracker-turtle-reader.vala
@@ -17,6 +17,8 @@
  * Boston, MA  02110-1301, USA.
  */
 
+using GLib;
+
 public class Tracker.TurtleReader : Object {
        SparqlScanner scanner;
 
@@ -56,8 +58,8 @@ public class Tracker.TurtleReader : Object {
 
        HashTable<string,string> prefix_map;
 
-       string[] subject_stack;
-       string[] predicate_stack;
+       GLib.Queue<string> subject_stack;
+       GLib.Queue<string> predicate_stack;
 
        int bnodeid = 0;
        // base UUID used for blank nodes
@@ -88,6 +90,8 @@ public class Tracker.TurtleReader : Object {
 
                tokens = new TokenInfo[BUFFER_SIZE];
                prefix_map = new HashTable<string,string>.full (str_hash, str_equal, g_free, g_free);
+               subject_stack = new GLib.Queue<string> ();
+               predicate_stack = new GLib.Queue<string> ();
        }
 
        private string generate_bnodeid (string? user_bnodeid) {
@@ -266,8 +270,8 @@ public class Tracker.TurtleReader : Object {
                                        return true;
                                } else if (accept (SparqlTokenType.OPEN_BRACKET)) {
                                        // begin of anonymous blank node
-                                       subject_stack += subject;
-                                       predicate_stack += predicate;
+                                       subject_stack.push_tail (subject);
+                                       predicate_stack.push_tail (predicate);
                                        subject = generate_bnodeid (null);
                                        state = State.SUBJECT;
                                        continue;
@@ -355,18 +359,15 @@ public class Tracker.TurtleReader : Object {
                                        }
                                        state = State.SUBJECT;
                                        continue;
-                               } else if (subject_stack.length > 0) {
+                               } else if (!subject_stack.is_empty()) {
                                        // end of anonymous blank node
                                        expect (SparqlTokenType.CLOSE_BRACKET);
 
                                        object = subject;
                                        object_is_uri = true;
 
-                                       subject = subject_stack[subject_stack.length - 1];
-                                       subject_stack.length--;
-
-                                       predicate = predicate_stack[predicate_stack.length - 1];
-                                       predicate_stack.length--;
+                                       subject = subject_stack.pop_tail();
+                                       predicate = predicate_stack.pop_tail();
 
                                        state = State.OBJECT;
                                        return true;