[glib] Make g_datalist_get_data not look up the quark

[Matthias Clasen <matthiasc src gnome org>]

commit 1cceda49b60bfd9b326e11996a5c77b10987e57a
Author: Alexander Larsson <alexl redhat com>
Date:   Thu May 19 21:51:49 2011 +0200

    Make g_datalist_get_data not look up the quark
    
    Instead of converting the string to a quark and comparing quarks we
    use the new lockless g_quark_to_string and just compare the quarks
    in the datalist with the given string.
    
    This means we avoid the global lock for string to quark. Additionally
    most of the time the data list will be quite short, so the cost of
    doing the sting comparisons is likely similar to that of the quark
    hashtable lookup (which does at least one string comparison for a
    successfull lookup).
    
    https://bugzilla.gnome.org/show_bug.cgi?id=650458

 glib/gdataset.c   |   52 ++++++++++++++++++++++++++++++++++++++++++----------
 glib/gdataset.h   |    4 ++--
 glib/glib.symbols |    1 +
 3 files changed, 45 insertions(+), 12 deletions(-)
---
diff --git a/glib/gdataset.c b/glib/gdataset.c
index 661c30f..c2582b9 100644
--- a/glib/gdataset.c
+++ b/glib/gdataset.c
@@ -776,16 +776,6 @@ g_dataset_id_get_data (gconstpointer  dataset_location,
  *
  * Retrieves the data element corresponding to @key_id.
  **/
-/**
- * g_datalist_get_data:
- * @dl: a datalist.
- * @k: the string identifying a data element.
- * @Returns: the data element, or %NULL if it is not found.
- *
- * Gets a data element, using its string identifer. This is slower than
- * g_datalist_id_get_data() because the string is first converted to a
- * #GQuark.
- **/
 gpointer
 g_datalist_id_get_data (GData	 **datalist,
 			GQuark     key_id)
@@ -823,6 +813,48 @@ g_datalist_id_get_data (GData	 **datalist,
 }
 
 /**
+ * g_datalist_get_data:
+ * @dl: a datalist.
+ * @k: the string identifying a data element.
+ * @Returns: the data element, or %NULL if it is not found.
+ *
+ * Gets a data element, using its string identifer. This is slower than
+ * g_datalist_id_get_data() because it compares strings.
+ **/
+gpointer
+g_datalist_get_data (GData	 **datalist,
+		     const gchar *key)
+{
+  gpointer res = NULL;
+  GData *d;
+  GDataElt *data, *data_end;
+
+  g_return_val_if_fail (datalist != NULL, NULL);
+
+  g_datalist_lock (datalist);
+
+  d = G_DATALIST_GET_POINTER (datalist);
+  if (d)
+    {
+      data = d->data;
+      data_end = data + d->len;
+      while (data < data_end)
+	{
+	  if (strcmp (g_quark_to_string (data->key), key) == 0)
+	    {
+	      res = data->data;
+	      break;
+	    }
+	  data++;
+	}
+    }
+
+  g_datalist_unlock (datalist);
+
+  return res;
+}
+
+/**
  * GDataForeachFunc:
  * @key_id: the #GQuark id to identifying the data element.
  * @data: the data element.
diff --git a/glib/gdataset.h b/glib/gdataset.h
index 2733ffb..4451c38 100644
--- a/glib/gdataset.h
+++ b/glib/gdataset.h
@@ -76,8 +76,6 @@ guint    g_datalist_get_flags           (GData            **datalist);
      g_datalist_id_set_data_full ((dl), (q), (d), NULL)
 #define   g_datalist_id_remove_data(dl, q)      \
      g_datalist_id_set_data ((dl), (q), NULL)
-#define   g_datalist_get_data(dl, k)            \
-     (g_datalist_id_get_data ((dl), g_quark_try_string (k)))
 #define   g_datalist_set_data_full(dl, k, d, f) \
      g_datalist_id_set_data_full ((dl), g_quark_from_string (k), (d), (f))
 #define   g_datalist_remove_no_notify(dl, k)    \
@@ -93,6 +91,8 @@ guint    g_datalist_get_flags           (GData            **datalist);
 void      g_dataset_destroy             (gconstpointer    dataset_location);
 gpointer  g_dataset_id_get_data         (gconstpointer    dataset_location,
                                          GQuark           key_id);
+gpointer  g_datalist_get_data            (GData	 **datalist,
+					  const gchar *key);
 void      g_dataset_id_set_data_full    (gconstpointer    dataset_location,
                                          GQuark           key_id,
                                          gpointer         data,
diff --git a/glib/glib.symbols b/glib/glib.symbols
index d38450d..d8a18b9 100644
--- a/glib/glib.symbols
+++ b/glib/glib.symbols
@@ -184,6 +184,7 @@ g_filename_to_utf8_utf8
 g_uri_list_extract_uris
 g_datalist_clear
 g_datalist_foreach
+g_datalist_get_data
 g_datalist_get_flags
 g_datalist_id_get_data
 g_datalist_id_remove_no_notify