From da071bcb337fe4b1c4d46c02c1a0217c0d32b042 Mon Sep 17 00:00:00 2001
From: Philip Withnall <philip.withnall@collabora.co.uk>
Date: Fri, 15 Aug 2014 15:10:19 -0600
Subject: [PATCH] xdg-cache: Store removable media thumbnails on removable
 media
MIME-Version: 1.0
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This means the files don’t have to be re-thumbnailed for every computer
the drive is mounted on; and conversely, each computer doesn’t have to
worry about the cache lifetime of files on removable disks which it may
never see again.

Based on a patch by Jeremy Whiting <jeremy.whiting@collabora.co.uk>.

https://bugzilla.xfce.org/show_bug.cgi?id=12036
---
 plugins/xdg-cache/xdg-cache-cache.c | 90 +++++++++++++++++++++++++++++++------
 1 file changed, 76 insertions(+), 14 deletions(-)

diff --git a/plugins/xdg-cache/xdg-cache-cache.c b/plugins/xdg-cache/xdg-cache-cache.c
index cd7b19c..8ce3546 100644
--- a/plugins/xdg-cache/xdg-cache-cache.c
+++ b/plugins/xdg-cache/xdg-cache-cache.c
@@ -557,30 +557,97 @@ xdg_cache_cache_get_flavors (TumblerCache *cache)
 
 
 
+static gboolean
+xdg_cache_is_uri_removable (const gchar *uri)
+{
+  GFile *file = NULL;
+  GMount *mount = NULL;
+  gboolean is_removable;
+  GError *error = NULL;
+
+  file = g_file_new_for_uri (uri);
+  mount = g_file_find_enclosing_mount (file, NULL, &error);
+
+  if (mount != NULL) {
+    is_removable = g_mount_can_eject (mount);
+  } else {
+    g_debug ("%s: Error finding enclosing mount for ‘%s’: %s",
+             G_STRFUNC, uri, error->message);
+    g_error_free (error);
+
+    is_removable = FALSE;
+  }
+
+  g_clear_object (&mount);
+  g_clear_object (&file);
+
+  g_debug ("%s: Determined URI ‘%s’ %s removable.",
+           G_STRFUNC, uri, is_removable ? "is" : "is not");
+
+  return is_removable;
+}
+
+/* Build a GFile* pointing to the cache file to use for the given
+ * @uri in @dirname. @cache_filename gives the computed filename to use for
+ * the cache file (for example, a hash). */
+static GFile *
+build_cache_file_path (const gchar *uri,
+                       const gchar *dirname,
+                       const gchar *cache_filename)
+{
+  gchar *path = NULL;
+  GFile *file = NULL;
+
+  if (xdg_cache_is_uri_removable (uri)) {
+    GFile *uri_file = NULL;
+    GFile *uri_parent = NULL;
+    gchar *parent_path = NULL;
+
+    /* For files on a removable device, store the thumbnails on the device too. */
+    uri_file = g_file_new_for_uri (uri);
+    uri_parent = g_file_get_parent (uri_file);
+    parent_path = g_file_get_path (uri_parent);
+
+    path = g_build_filename (parent_path, ".thumbnails", dirname, cache_filename, NULL);
+
+    g_free (parent_path);
+    g_object_unref (uri_parent);
+    g_object_unref (uri_file);
+  } else {
+    const gchar *cachedir;
+
+    /* For files on a non-removable partition, store the thumbnails in the
+     * user’s cache directory. */
+    cachedir = g_get_user_cache_dir ();
+
+    path = g_build_filename (cachedir, "thumbnails", dirname, cache_filename, NULL);
+  }
+
+  g_debug ("%s: Using path ‘%s’.", G_STRFUNC, path);
+  file = g_file_new_for_path (path);
+  g_free (path);
+
+  return file;
+}
+
 GFile *
 xdg_cache_cache_get_file (const gchar            *uri,
                           TumblerThumbnailFlavor *flavor)
 {
-  const gchar *cachedir;
   const gchar *dirname;
   GFile       *file;
   gchar       *filename;
   gchar       *md5_hash;
-  gchar       *path;
 
   g_return_val_if_fail (uri != NULL && *uri != '\0', NULL);
   g_return_val_if_fail (TUMBLER_IS_THUMBNAIL_FLAVOR (flavor), NULL);
 
-  cachedir = g_get_user_cache_dir ();
-  dirname = tumbler_thumbnail_flavor_get_name (flavor);
-
   md5_hash = g_compute_checksum_for_string (G_CHECKSUM_MD5, uri, -1);
+  dirname = tumbler_thumbnail_flavor_get_name (flavor);
   filename = g_strdup_printf ("%s.png", md5_hash);
-  path = g_build_filename (cachedir, "thumbnails", dirname, filename, NULL);
 
-  file = g_file_new_for_path (path);
+  file = build_cache_file_path (uri, dirname, filename);
 
-  g_free (path);
   g_free (filename);
   g_free (md5_hash);
 
@@ -593,18 +660,15 @@ GFile *
 xdg_cache_cache_get_temp_file (const gchar            *uri,
                                TumblerThumbnailFlavor *flavor)
 {
-  const gchar *cachedir;
   const gchar *dirname;
   GTimeVal     current_time = { 0, 0 };
   GFile       *file;
   gchar       *filename;
   gchar       *md5_hash;
-  gchar       *path;
 
   g_return_val_if_fail (uri != NULL && *uri != '\0', NULL);
   g_return_val_if_fail (TUMBLER_IS_THUMBNAIL_FLAVOR (flavor), NULL);
 
-  cachedir = g_get_user_cache_dir ();
   dirname = tumbler_thumbnail_flavor_get_name (flavor);
 
   g_get_current_time (&current_time);
@@ -612,11 +676,9 @@ xdg_cache_cache_get_temp_file (const gchar            *uri,
   md5_hash = g_compute_checksum_for_string (G_CHECKSUM_MD5, uri, -1);
   filename = g_strdup_printf ("%s-%ld-%ld.png", md5_hash,
                               current_time.tv_sec, current_time.tv_usec);
-  path = g_build_filename (cachedir, "thumbnails", dirname, filename, NULL);
 
-  file = g_file_new_for_path (path);
+  file = build_cache_file_path (uri, dirname, filename);
 
-  g_free (path);
   g_free (filename);
   g_free (md5_hash);
 
-- 
2.4.3