[gnome-software] Use the SHA1 of the AppStream icons to ensure we re-decompress the icons when required

[Richard Hughes <rhughes src gnome org>]

commit 248776cad111e400aecc326a1811af940ebfc2c9
Author: Richard Hughes <richard hughsie com>
Date:   Mon Sep 2 11:29:23 2013 +0100

    Use the SHA1 of the AppStream icons to ensure we re-decompress the icons when required

 src/plugins/gs-plugin-appstream.c |   40 +++++++++++++++++++++++++-----------
 1 files changed, 28 insertions(+), 12 deletions(-)
---
diff --git a/src/plugins/gs-plugin-appstream.c b/src/plugins/gs-plugin-appstream.c
index a59f643..ac8ed60 100644
--- a/src/plugins/gs-plugin-appstream.c
+++ b/src/plugins/gs-plugin-appstream.c
@@ -23,6 +23,8 @@
 
 #include <gs-plugin.h>
 
+#define GS_PLUGIN_APPSTREAM_ICONS_HASH "e6c366af886562819019fd25b408b7b94a6f9a16"
+
 typedef enum {
        GS_APPSTREAM_XML_SECTION_UNKNOWN,
        GS_APPSTREAM_XML_SECTION_APPLICATIONS,
@@ -87,21 +89,29 @@ gs_plugin_decompress_icons (GsPlugin *plugin, GError **error)
 {
        const gchar *argv[6];
        gboolean ret = TRUE;
+       gchar *hash_check_file = NULL;
        gint exit_status = 0;
 
-       /* cache already exists [FIXME: How to test for new enough...] */
-       if (g_file_test (plugin->priv->cachedir, G_FILE_TEST_EXISTS))
-               goto out;
-
        /* create directory */
-       exit_status = g_mkdir_with_parents (plugin->priv->cachedir, 0700);
-       if (exit_status != 0) {
-               ret = FALSE;
-               g_set_error (error,
-                            GS_PLUGIN_ERROR,
-                            GS_PLUGIN_ERROR_FAILED,
-                            "Failed to create %s",
-                            plugin->priv->cachedir);
+       if (!g_file_test (plugin->priv->cachedir, G_FILE_TEST_EXISTS)) {
+               exit_status = g_mkdir_with_parents (plugin->priv->cachedir, 0700);
+               if (exit_status != 0) {
+                       ret = FALSE;
+                       g_set_error (error,
+                                    GS_PLUGIN_ERROR,
+                                    GS_PLUGIN_ERROR_FAILED,
+                                    "Failed to create %s",
+                                    plugin->priv->cachedir);
+                       goto out;
+               }
+       }
+
+       /* is cache new enough? */
+       hash_check_file = g_build_filename (plugin->priv->cachedir,
+                                           GS_PLUGIN_APPSTREAM_ICONS_HASH,
+                                           NULL);
+       if (g_file_test (hash_check_file, G_FILE_TEST_EXISTS)) {
+               g_debug ("Icon cache new enough, skipping decompression");
                goto out;
        }
 
@@ -133,7 +143,13 @@ gs_plugin_decompress_icons (GsPlugin *plugin, GError **error)
                             plugin->priv->cachedir, exit_status);
                goto out;
        }
+
+       /* mark as done */
+       ret = g_file_set_contents (hash_check_file, "", -1, error);
+       if (!ret)
+               goto out;
 out:
+       g_free (hash_check_file);
        return ret;
 }