gtk2/gtk/gtkiconcache.c
Alexander Larsson bdbafe63f9 icontheme: Optimize memory use and lookup speed by internalizing icon names
Instead of having the IconTheme have a hashtable that owns
individual strings and then IconThemeDirSize have a similar
hash (but with the strings owned by the other hash), we
have a consecutive memory chunks where we store the icon names
and then the hashtable has pointers into this.

This means we can avoid a bunch of individual strdup()s in a
way that is less fragmented and wastes less space. Additionally,
since we do an initial lookup anyway we have the internalized
icon name during lookup which means we can use g_direct_hash/equal
instead of g_str_hash/equal making the lookup faster too.
2020-02-07 12:00:52 +01:00

273 lines
7.2 KiB
C

/* 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, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "gtkdebug.h"
#include "gtkiconcacheprivate.h"
#include "gtkiconcachevalidatorprivate.h"
#include <glib/gstdio.h>
#include <gdk-pixbuf/gdk-pixdata.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef G_OS_WIN32
#include <io.h>
#endif
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#ifndef _O_BINARY
#define _O_BINARY 0
#endif
#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;
GMappedFile *map;
gchar *buffer;
guint32 last_chain_offset;
};
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_message ("unmapping icon cache"));
if (cache->map)
g_mapped_file_unref (cache->map);
g_free (cache);
}
}
GtkIconCache *
gtk_icon_cache_new_for_path (const gchar *path)
{
GtkIconCache *cache = NULL;
GMappedFile *map;
gchar *cache_filename;
gint fd = -1;
GStatBuf st;
GStatBuf path_st;
/* Check if we have a cache file */
cache_filename = g_build_filename (path, "icon-theme.cache", NULL);
GTK_NOTE (ICONTHEME, g_message ("look for icon cache in %s", path));
if (g_stat (path, &path_st) < 0)
goto done;
/* Open the file and map it into memory */
fd = g_open (cache_filename, O_RDONLY|_O_BINARY, 0);
if (fd < 0)
goto done;
#ifdef G_OS_WIN32
/* Bug 660730: _fstat32 is only defined in msvcrt80.dll+/VS 2005+ */
/* or possibly in the msvcrt.dll linked to by the Windows DDK */
/* (will need to check on the Windows DDK part later) */
#if ((defined (_MSC_VER) && (_MSC_VER >= 1400 || __MSVCRT_VERSION__ >= 0x0800)) || defined (__MINGW64_VERSION_MAJOR)) && !defined(_WIN64)
#undef fstat /* Just in case */
#define fstat _fstat32
#endif
#endif
if (fstat (fd, &st) < 0 || st.st_size < 4)
goto done;
/* Verify cache is uptodate */
if (st.st_mtime < path_st.st_mtime)
{
GTK_NOTE (ICONTHEME, g_message ("icon cache outdated"));
goto done;
}
map = g_mapped_file_new (cache_filename, FALSE, NULL);
if (!map)
goto done;
#ifdef G_ENABLE_DEBUG
if (GTK_DEBUG_CHECK (ICONTHEME))
{
CacheInfo info;
info.cache = g_mapped_file_get_contents (map);
info.cache_size = g_mapped_file_get_length (map);
info.n_directories = 0;
info.flags = CHECK_OFFSETS|CHECK_STRINGS;
if (!gtk_icon_cache_validate (&info))
{
g_mapped_file_unref (map);
g_warning ("Icon cache '%s' is invalid", cache_filename);
goto done;
}
}
#endif
GTK_NOTE (ICONTHEME, g_message ("found icon cache for %s", path));
cache = g_new0 (GtkIconCache, 1);
cache->ref_count = 1;
cache->map = map;
cache->buffer = g_mapped_file_get_contents (map);
done:
g_free (cache_filename);
if (fd >= 0)
close (fd);
return cache;
}
GtkIconCache *
gtk_icon_cache_new (const gchar *data)
{
GtkIconCache *cache;
cache = g_new0 (GtkIconCache, 1);
cache->ref_count = 1;
cache->map = NULL;
cache->buffer = (gchar *)data;
return cache;
}
static gint
get_directory_index (GtkIconCache *cache,
const gchar *directory)
{
guint32 dir_list_offset;
gint n_dirs;
gint 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;
}
GHashTable *
gtk_icon_cache_list_icons_in_directory (GtkIconCache *cache,
const gchar *directory,
GtkStringSet *set)
{
gint directory_index;
guint32 hash_offset, n_buckets;
guint32 chain_offset;
guint32 image_list_offset, n_images;
int i, j;
GHashTable *icons = NULL;
directory_index = get_directory_index (cache, directory);
if (directory_index == -1)
return NULL;
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 flags = 0;
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)
{
flags = GET_UINT16 (cache->buffer, image_list_offset + 4 + 8 * j + 2);
break;
}
}
if (flags != 0)
{
guint32 name_offset = GET_UINT32 (cache->buffer, chain_offset + 4);
const char *name = cache->buffer + name_offset;
const char *interned_name;
guint32 hash_flags = 0;
/* Icons named foo.symbolic.png are stored in the cache as "foo.symbolic" with ICON_CACHE_FLAG_PNG,
* but we convert it internally to ICON_CACHE_FLAG_SYMBOLIC_PNG.
* Otherwise we use the same enum values and names as on disk. */
if (g_str_has_suffix (name, ".symbolic") && (flags & ICON_CACHE_FLAG_PNG_SUFFIX) != 0)
{
char *converted_name = g_strndup (name, strlen (name) - 9);
interned_name = gtk_string_set_add (set, converted_name);
g_free (converted_name);
flags |= ICON_CACHE_FLAG_SYMBOLIC_PNG_SUFFIX;
flags &= ~ICON_CACHE_FLAG_PNG_SUFFIX;
}
else
interned_name = gtk_string_set_add (set, name);
if (!icons)
icons = g_hash_table_new_full (g_direct_hash, g_direct_equal, NULL, NULL);
hash_flags = GPOINTER_TO_INT (g_hash_table_lookup (icons, interned_name));
g_hash_table_replace (icons, (char *)interned_name, GUINT_TO_POINTER (hash_flags|flags));
}
chain_offset = GET_UINT32 (cache->buffer, chain_offset);
}
}
return icons;
}