Implement icon theme caching. (#154034, Martijn Vernooij, caching schema

2004-10-19  Matthias Clasen  <mclasen@redhat.com>

	Implement icon theme caching.  (#154034, Martijn Vernooij,
	caching schema proposed by Owen Taylor, initial implementation
	by Anders Carlsson)

	* gtk/gtkdebug.h:
	* gtk/gtkmain.c: Add a "icontheme" debug flag.

	* gtk/Makefile.am (gtk_c_sources): Add gtkiconcache.c
	(gtk_private_h_sources): Add gtkiconcache.h
	(bin_PROGRAMS): Add gtk-update-icon-cache

	* gtk/gtkicontheme.c: Use icon caches if they are available.
	Currently, GTK+ uses the cache to get information about the
	available sizes, image file formats and .icon files. The
	actual image data, and the .icon file contents are not
	cached yet.

	* gtk/updateiconcache.c: A cmdline utility for generating
	icon cache files.

	* gtk/gtkiconcache.h:
	* gtk/gtkiconcache.c: The glue code to mmap an icon cache
	file and manage the information it contains.

1 files changed, 280 insertions, 0 deletions

diff --git a/gtk/gtkiconcache.c b/gtk/gtkiconcache.c
new file mode 100644
index 0000000000..766dfa0e23
--- /dev/null
+++ b/gtk/gtkiconcache.c
@@ -0,0 +1,280 @@
+/* gtkiconcache.c
+ * Copyright (C) 2004  Anders Carlsson <andersca@gnome.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <config.h>
+#include "gtkdebug.h"
+#include "gtkiconcache.h"
+
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <fcntl.h>
+#include <string.h>
+
+#define MAJOR_VERSION 1
+#define MINOR_VERSION 0
+
+#define GET_UINT16(cache, offset) (GUINT16_FROM_BE (*(guint16 *)((cache) + (offset))))
+#define GET_UINT32(cache, offset) (GUINT32_FROM_BE (*(guint32 *)((cache) + (offset))))
+
+struct _GtkIconCache {
+  gint ref_count;
+
+  gsize size;
+  gchar *buffer;
+};
+
+GtkIconCache *
+_gtk_icon_cache_ref (GtkIconCache *cache)
+{
+  cache->ref_count ++;
+
+  return cache;
+}
+
+void
+_gtk_icon_cache_unref (GtkIconCache *cache)
+{
+  cache->ref_count --;
+
+  if (cache->ref_count == 0)
+    {
+      GTK_NOTE (ICONTHEME, 
+		g_print ("unmapping icon cache\n"));
+
+      munmap (cache->buffer, cache->size);
+      g_free (cache);
+    }
+}
+
+GtkIconCache *
+_gtk_icon_cache_new_for_path (const gchar *path)
+{
+  gchar *cache_filename;
+  gint fd;
+  struct stat st;
+  struct stat path_st;
+  gchar *buffer;
+  GtkIconCache *cache = NULL;
+
+  if (g_getenv ("GTK_NO_ICON_CACHE"))
+    return NULL;
+
+  /* Check if we have a cache file */
+  cache_filename = g_build_filename (path, "icon-theme.cache", NULL);
+
+  GTK_NOTE (ICONTHEME, 
+	    g_print ("look for cache in %s\n", path));
+
+  if (!g_file_test (cache_filename, G_FILE_TEST_IS_REGULAR))
+    {
+      g_free (cache_filename);
+      return NULL;
+    };
+
+  /* Open the file and mmap it */
+  fd = open (cache_filename, O_RDONLY);
+
+  g_free (cache_filename);
+  
+  if (fd < 0)
+    return NULL;
+  
+  if (fstat (fd, &st) < 0)
+    goto done;
+
+  if (stat (path, &path_st) < 0)
+    goto done;
+
+  /* Verify cache is uptodate */
+  if (st.st_mtime < path_st.st_mtime)
+    {
+      GTK_NOTE (ICONTHEME, 
+		g_print ("cache outdated\n"));
+      goto done; 
+    }
+
+  buffer = mmap (0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
+
+  if (buffer == MAP_FAILED)
+    goto done;
+
+  /* Verify version */
+  if (GET_UINT16 (buffer, 0) != MAJOR_VERSION ||
+      GET_UINT16 (buffer, 2) != MINOR_VERSION)
+    {
+      munmap (buffer, st.st_size);
+      GTK_NOTE (ICONTHEME, 
+		g_print ("wrong cache version\n"));
+      goto done;
+    }
+  
+  GTK_NOTE (ICONTHEME, 
+	    g_print ("found cache for %s\n", path));
+
+  cache = g_new0 (GtkIconCache, 1);
+  cache->ref_count = 1;
+  cache->buffer = buffer;
+  cache->size = st.st_size;
+  
+ done:
+  close (fd);
+
+  return cache;
+}
+
+static int
+get_directory_index (GtkIconCache *cache,
+		     const gchar *directory)
+{
+  guint32 dir_list_offset;
+  int n_dirs;
+  int i;
+  
+  dir_list_offset = GET_UINT32 (cache->buffer, 8);
+
+  n_dirs = GET_UINT32 (cache->buffer, dir_list_offset);
+
+  for (i = 0; i < n_dirs; i++)
+    {
+      guint32 name_offset = GET_UINT32 (cache->buffer, dir_list_offset + 4 + 4 * i);
+      gchar *name = cache->buffer + name_offset;
+      if (strcmp (name, directory) == 0)
+	return i;
+    }
+  
+  return -1;
+}
+
+gboolean
+_gtk_icon_cache_has_directory (GtkIconCache *cache,
+			       const gchar *directory)
+{
+  return get_directory_index (cache, directory) != -1;
+}
+
+static guint
+icon_name_hash (gconstpointer key)
+{
+  const char *p = key;
+  guint h = *p;
+
+  if (h)
+    for (p += 1; *p != '\0'; p++)
+      h = (h << 5) - h + *p;
+
+  return h;
+}
+
+gint
+_gtk_icon_cache_get_icon_flags (GtkIconCache *cache,
+				const gchar  *icon_name,
+				const gchar  *directory)
+{
+  guint32 hash_offset;
+  guint32 n_buckets;
+  guint32 chain_offset;
+  int hash, directory_index;
+  guint32 image_list_offset, n_images;
+  gboolean found = FALSE;
+  int i;
+  
+  hash_offset = GET_UINT32 (cache->buffer, 4);
+  n_buckets = GET_UINT32 (cache->buffer, hash_offset);
+
+  hash = icon_name_hash (icon_name) % n_buckets;
+
+  chain_offset = GET_UINT32 (cache->buffer, hash_offset + 4 + 4 * hash);
+  while (chain_offset != 0xffffffff)
+    {
+      guint32 name_offset = GET_UINT32 (cache->buffer, chain_offset + 4);
+      gchar *name = cache->buffer + name_offset;
+
+      if (strcmp (name, icon_name) == 0)
+	{
+	  found = TRUE;
+	  break;
+	}
+	  
+      chain_offset = GET_UINT32 (cache->buffer, chain_offset);
+    }
+
+  if (!found)
+    return 0;
+
+  /* We've found an icon list, now check if we have the right icon in it */
+  directory_index = get_directory_index (cache, directory);
+  image_list_offset = GET_UINT32 (cache->buffer, chain_offset + 8);
+  n_images = GET_UINT32 (cache->buffer, image_list_offset);
+  
+  for (i = 0; i < n_images; i++)
+    {
+      if (GET_UINT16 (cache->buffer, image_list_offset + 4 + 8 * i) ==
+	  directory_index)
+	return GET_UINT16 (cache->buffer, image_list_offset + 4 + 8 * i + 2);
+    }
+  
+  return 0;
+}
+
+void
+_gtk_icon_cache_add_icons (GtkIconCache *cache,
+			   const gchar  *directory,
+			   GHashTable   *hash_table)
+{
+  int directory_index;
+  guint32 hash_offset, n_buckets;
+  guint32 chain_offset;
+  guint32 image_list_offset, n_images;
+  int i, j;
+  
+  directory_index = get_directory_index (cache, directory);
+
+  if (directory_index == -1)
+    return;
+  
+  hash_offset = GET_UINT32 (cache->buffer, 4);
+  n_buckets = GET_UINT32 (cache->buffer, hash_offset);
+  
+  for (i = 0; i < n_buckets; i++)
+    {
+      chain_offset = GET_UINT32 (cache->buffer, hash_offset + 4 + 4 * i);
+      while (chain_offset != 0xffffffff)
+	{
+	  guint32 name_offset = GET_UINT32 (cache->buffer, chain_offset + 4);
+	  gchar *name = cache->buffer + name_offset;
+	  
+	  image_list_offset = GET_UINT32 (cache->buffer, chain_offset + 8);
+	  n_images = GET_UINT32 (cache->buffer, image_list_offset);
+  
+	  for (j = 0; j < n_images; j++)
+	    {
+	      if (GET_UINT16 (cache->buffer, image_list_offset + 4 + 8 * j) ==
+		  directory_index)
+		g_hash_table_insert (hash_table, name, NULL);
+	    }
+
+	  chain_offset = GET_UINT32 (cache->buffer, chain_offset);
+	}
+    }
+  
+}