[gnome-software: 2/18] gs-app: Reduce allocations for storing URLs

[Philip Withnall <pwithnall src gnome org>]

commit 59b1222551eb4e501c94779ff8f64735f1ade96e
Author: Philip Withnall <pwithnall endlessos org>
Date:   Wed Aug 4 12:00:25 2021 +0100

    gs-app: Reduce allocations for storing URLs
    
    Lazily allocate the URLs hash table (which avoids an allocation for a
    `GsApp` if the URLs are never refined), and index the hash table by
    `AsUrlKind` directly rather than a copy of its string form. This should
    save a lot of string duplications.
    
    From a very quick test, this appears to reduce memory usage by 2MB.
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>

 lib/gs-app.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)
---
diff --git a/lib/gs-app.c b/lib/gs-app.c
index 428280a90..2067d2491 100644
--- a/lib/gs-app.c
+++ b/lib/gs-app.c
@@ -79,7 +79,7 @@ typedef struct
        GPtrArray               *screenshots;
        GPtrArray               *categories;
        GArray                  *key_colors;  /* (nullable) (element-type GdkRGBA) */
-       GHashTable              *urls;
+       GHashTable              *urls;  /* (element-type AsUrlKind utf8) (owned) (nullable) */
        GHashTable              *launchables;
        gchar                   *url_missing;
        gchar                   *license;
@@ -616,7 +616,7 @@ gs_app_to_string_append (GsApp *app, GString *str)
                gs_app_kv_lpad (str, "content-rating",
                                as_content_rating_get_kind (priv->content_rating));
        }
-       tmp = g_hash_table_lookup (priv->urls, as_url_kind_to_string (AS_URL_KIND_HOMEPAGE));
+       tmp = gs_app_get_url (app, AS_URL_KIND_HOMEPAGE);
        if (tmp != NULL)
                gs_app_kv_lpad (str, "url{homepage}", tmp);
        keys = g_hash_table_get_keys (priv->launchables);
@@ -2466,7 +2466,7 @@ gs_app_set_description (GsApp *app, GsAppQuality quality, const gchar *descripti
  *
  * Gets a web address of a specific type.
  *
- * Returns: a string, or %NULL for unset
+ * Returns: (nullable): a string, or %NULL for unset
  *
  * Since: 40
  **/
@@ -2477,7 +2477,10 @@ gs_app_get_url (GsApp *app, AsUrlKind kind)
        g_autoptr(GMutexLocker) locker = NULL;
        g_return_val_if_fail (GS_IS_APP (app), NULL);
        locker = g_mutex_locker_new (&priv->mutex);
-       return g_hash_table_lookup (priv->urls, as_url_kind_to_string (kind));
+
+       if (priv->urls == NULL)
+               return NULL;
+       return g_hash_table_lookup (priv->urls, GINT_TO_POINTER (kind));
 }
 
 /**
@@ -2497,8 +2500,13 @@ gs_app_set_url (GsApp *app, AsUrlKind kind, const gchar *url)
        g_autoptr(GMutexLocker) locker = NULL;
        g_return_if_fail (GS_IS_APP (app));
        locker = g_mutex_locker_new (&priv->mutex);
+
+       if (priv->urls == NULL)
+               priv->urls = g_hash_table_new_full (g_direct_hash, g_direct_equal,
+                                                   NULL, g_free);
+
        g_hash_table_insert (priv->urls,
-                            g_strdup (as_url_kind_to_string (kind)),
+                            GINT_TO_POINTER (kind),
                             g_strdup (url));
 }
 
@@ -5004,7 +5012,7 @@ gs_app_finalize (GObject *object)
        g_free (priv->name);
        g_free (priv->renamed_from);
        g_free (priv->url_missing);
-       g_hash_table_unref (priv->urls);
+       g_clear_pointer (&priv->urls, g_hash_table_unref);
        g_hash_table_unref (priv->launchables);
        g_free (priv->license);
        g_strfreev (priv->menu_path);
@@ -5395,10 +5403,6 @@ gs_app_init (GsApp *app)
                                                g_str_equal,
                                                g_free,
                                                (GDestroyNotify) g_variant_unref);
-       priv->urls = g_hash_table_new_full (g_str_hash,
-                                           g_str_equal,
-                                           g_free,
-                                           g_free);
        priv->launchables = g_hash_table_new_full (g_str_hash,
                                                   g_str_equal,
                                                   NULL,