[gnome-software] appstream: don't use gzip to decompress the zip file

[Giovanni Campagna <gcampagna src gnome org>]

commit da40e50c8a2dc0776bf9044b1b200625a5ea17f3
Author: Giovanni Campagna <gcampagna src gnome org>
Date:   Sun Sep 1 19:38:08 2013 +0200

    appstream: don't use gzip to decompress the zip file
    
    It's a terrible idea to use predictable names in /tmp, and in
    general we don't need to spawn an external binary, we can use
    GIO for the same.
    Also, improve the thread safety with GOnce instead of GMutex.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=707185

 src/plugins/gs-plugin-appstream.c |  141 ++++++++++++-------------------------
 1 files changed, 45 insertions(+), 96 deletions(-)
---
diff --git a/src/plugins/gs-plugin-appstream.c b/src/plugins/gs-plugin-appstream.c
index 95cf783..a59f643 100644
--- a/src/plugins/gs-plugin-appstream.c
+++ b/src/plugins/gs-plugin-appstream.c
@@ -46,14 +46,13 @@ typedef struct {
 } GsAppstreamItem;
 
 struct GsPluginPrivate {
-       GMutex                   mutex;
        gchar                   *cachedir;
        GsAppstreamXmlSection    section;
        GsAppstreamItem         *item_temp;
        GPtrArray               *array;         /* of GsAppstreamItem */
        GHashTable              *hash_id;       /* of GsAppstreamItem{id} */
        GHashTable              *hash_pkgname;  /* of GsAppstreamItem{pkgname} */
-       gboolean                 done_init;
+       gsize                    done_init;
 };
 
 /**
@@ -139,67 +138,6 @@ out:
 }
 
 /**
- * gs_plugin_decompress_xml:
- */
-static gboolean
-gs_plugin_decompress_xml (GsPlugin *plugin, GError **error)
-{
-       const gchar *argv[6];
-       const gchar *tmpdir = "/tmp";
-       gboolean ret = TRUE;
-       gint exit_status = 0;
-       gchar *data = NULL;
-       gsize len;
-
-       /* already exists */
-       if (g_file_test ("/tmp/appstream.xml.gz", G_FILE_TEST_EXISTS))
-               goto out;
-
-       /* copy to /tmp */
-       ret = g_file_get_contents (DATADIR "/gnome-software/appstream.xml.gz",
-                                  &data,
-                                  &len,
-                                  error);
-       if (!ret)
-               goto out;
-       ret = g_file_set_contents ("/tmp/appstream.xml.gz",
-                                  data,
-                                  len,
-                                  error);
-       if (!ret)
-               goto out;
-
-       /* decompress */
-       argv[0] = "gunzip";
-       argv[1] = "/tmp/appstream.xml.gz";
-       argv[2] = NULL;
-       g_debug ("Decompressing %s to %s", argv[2], tmpdir);
-       ret = g_spawn_sync (tmpdir,
-                           (gchar **) argv,
-                           NULL,
-                           G_SPAWN_SEARCH_PATH,
-                           NULL, NULL,
-                           NULL,
-                           NULL,
-                           &exit_status,
-                           error);
-       if (!ret)
-               goto out;
-       if (exit_status != 0) {
-               ret = FALSE;
-               g_set_error (error,
-                            GS_PLUGIN_ERROR,
-                            GS_PLUGIN_ERROR_FAILED,
-                            "Failed to unzip XML data to %s [%i]",
-                            tmpdir, exit_status);
-               goto out;
-       }
-out:
-       g_free (data);
-       return ret;
-}
-
-/**
  * gs_appstream_selection_from_text:
  */
 static GsAppstreamXmlSection
@@ -454,26 +392,55 @@ gs_plugin_parse_xml (GsPlugin *plugin, GError **error)
        gboolean ret;
        GMarkupParseContext *ctx;
        gchar *data;
-       gsize len;
+       gssize len;
+       GFile *file;
+       GConverter *converter;
+       GInputStream *file_stream;
+       GInputStream *converter_stream;
        const GMarkupParser parser = {
                gs_appstream_start_element_cb,
                gs_appstream_end_element_cb,
                gs_appstream_text_cb,
                NULL /* passthrough */,
                NULL /* error */ };
+
+       file = g_file_new_for_path (DATADIR "/gnome-software/appstream.xml.gz");
+       file_stream = G_INPUT_STREAM (g_file_read (file, NULL, error));
+       g_object_unref (file);
+       if (!file_stream)
+               return FALSE;
+
+       converter = G_CONVERTER (g_zlib_decompressor_new (G_ZLIB_COMPRESSOR_FORMAT_GZIP));
+       converter_stream = g_converter_input_stream_new (file_stream, converter);
+
        ctx = g_markup_parse_context_new (&parser,
                                          G_MARKUP_PREFIX_ERROR_POSITION,
                                          plugin,
                                          NULL);
-       ret = g_file_get_contents ("/tmp/appstream.xml", &data, &len, error);
-       if (!ret)
-               goto out;
-       ret = g_markup_parse_context_parse (ctx, data, len, error);
-       if (!ret)
-               goto out;
-out:
+
+       ret = TRUE;
+       data = g_malloc (32 * 1024);
+       while ((len = g_input_stream_read (converter_stream, data, 32 * 1024, NULL, error)) > 0) {
+               ret = g_markup_parse_context_parse (ctx, data, len, error);
+               if (!ret)
+                       goto out;
+       }
+
+       if (len < 0)
+               ret = FALSE;
+
+ out:
+       /* Reset in case we failed parsing */
+       if (plugin->priv->item_temp) {
+               gs_appstream_item_free (plugin->priv->item_temp);
+               plugin->priv->item_temp = NULL;
+       }
+
        g_markup_parse_context_free (ctx);
        g_free (data);
+       g_object_unref (converter_stream);
+       g_object_unref (file_stream);
+       g_object_unref (converter);
        return ret;
 }
 
@@ -499,9 +466,6 @@ gs_plugin_initialize (GsPlugin *plugin)
        plugin->priv->cachedir = g_build_filename (g_get_user_cache_dir(),
                                                   "gnome-software",
                                                   NULL);
-
-       /* can only load from one thread */
-       g_mutex_init (&plugin->priv->mutex);
 }
 
 /**
@@ -523,7 +487,6 @@ gs_plugin_destroy (GsPlugin *plugin)
        g_ptr_array_unref (plugin->priv->array);
        g_hash_table_unref (plugin->priv->hash_id);
        g_hash_table_unref (plugin->priv->hash_pkgname);
-       g_mutex_clear (&plugin->priv->mutex);
 }
 
 
@@ -536,13 +499,6 @@ gs_plugin_startup (GsPlugin *plugin, GError **error)
        gboolean ret = TRUE;
        GTimer *timer = NULL;
 
-       /* protect */
-       g_mutex_lock (&plugin->priv->mutex);
-
-       /* already done */
-       if (plugin->priv->done_init)
-               goto out;
-
        /* get the icons ready for use */
        timer = g_timer_new ();
        ret = gs_plugin_decompress_icons (plugin, error);
@@ -550,14 +506,6 @@ gs_plugin_startup (GsPlugin *plugin, GError **error)
                goto out;
        g_debug ("Decompressing icons\t:%.1fms", g_timer_elapsed (timer, NULL) * 1000);
 
-       /* Decompress the XML ready for use */
-       g_timer_reset (timer);
-       ret = gs_plugin_decompress_xml (plugin, error);
-       if (!ret)
-               goto out;
-       g_debug ("Decompressing XML\t:%.1fms",
-                g_timer_elapsed (timer, NULL) * 1000);
-
        /* Parse the XML */
        g_timer_reset (timer);
        ret = gs_plugin_parse_xml (plugin, error);
@@ -567,12 +515,9 @@ gs_plugin_startup (GsPlugin *plugin, GError **error)
                 plugin->priv->array->len,
                 g_timer_elapsed (timer, NULL) * 1000);
 
-       /* done */
-       plugin->priv->done_init = TRUE;
 out:
        if (timer != NULL)
                g_timer_destroy (timer);
-       g_mutex_unlock (&plugin->priv->mutex);
        return ret;
 }
 
@@ -708,9 +653,13 @@ gs_plugin_refine (GsPlugin *plugin,
        GsApp *app;
 
        /* load XML files */
-       ret = gs_plugin_startup (plugin, error);
-       if (!ret)
-               goto out;
+       if (g_once_init_enter (&plugin->priv->done_init)) {
+               ret = gs_plugin_startup (plugin, error);
+               g_once_init_leave (&plugin->priv->done_init, TRUE);
+
+               if (!ret)
+                       goto out;
+       }
 
        for (l = list; l != NULL; l = l->next) {
                app = GS_APP (l->data);