gstreamer/gst/gstregistrybinary.c

/* GStreamer
 * Copyright (C) 2006 Josep Torra <josep@fluendo.com>
 *               2006 Mathieu Garcia <matthieu@fluendo.com>
 *               2006,2007 Stefan Kost <ensonic@users.sf.net>
 *               2008 Sebastian Dröge <slomo@circular-chaos.org>
 *
 * gstregistrybinary.c: GstRegistryBinary object, support routines
 *
 * 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.
 */

/* FIXME:
 * - keep registry binary blob and reference strings
 *   - don't free/unmmap contents when leaving gst_registry_binary_read_cache()
 *     - free at gst_deinit() / _priv_gst_registry_cleanup() ?
 *   - GstPlugin:
 *     - GST_PLUGIN_FLAG_CONST
 *   - GstPluginFeature, GstIndexFactory, GstElementFactory
 *     - needs Flags (GST_PLUGIN_FEATURE_FLAG_CONST)
 *     - can we turn loaded into flag?
 * - why do we collect a list of binary chunks and not write immediately
 *   - because we need to process subchunks, before we can set e.g. nr_of_items
 *     in parent chunk
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <errno.h>
#include <stdio.h>

#if defined (_MSC_VER) && _MSC_VER >= 1400
#include <io.h>
#endif

#include <gst/gst_private.h>
#include <gst/gstconfig.h>
#include <gst/gstelement.h>
#include <gst/gsttypefind.h>
#include <gst/gsttypefindfactory.h>
#include <gst/gsturi.h>
#include <gst/gstinfo.h>
#include <gst/gstenumtypes.h>
#include <gst/gstpadtemplate.h>

#include <gst/gstregistrybinary.h>

#include <glib/gstdio.h>        /* for g_stat(), g_mapped_file(), ... */

#include "glib-compat-private.h"


#define GST_CAT_DEFAULT GST_CAT_REGISTRY

/* count string length, but return -1 if we hit the eof */
static gint
_strnlen (const gchar * str, gint maxlen)
{
  gint len = 0;

  if (len == maxlen)
    return -1;

  while (*str++ != '\0') {
    len++;
    if (len == maxlen)
      return -1;
  }
  return len;
}

/* reading macros */

#define unpack_element(inptr, outptr, element, endptr, error_label) G_STMT_START{ \
  if (inptr + sizeof(element) >= endptr) \
    goto error_label; \
  outptr = (element *) inptr; \
  inptr += sizeof (element); \
}G_STMT_END

#define unpack_const_string(inptr, outptr, endptr, error_label) G_STMT_START{\
  gint _len = _strnlen (inptr, (endptr-inptr)) + 1; \
  if (_len == -1) \
    goto error_label; \
  outptr = g_intern_string ((const gchar *)inptr); \
  inptr += _len; \
}G_STMT_END

#define unpack_string(inptr, outptr, endptr, error_label)  G_STMT_START{\
  gint _len = _strnlen (inptr, (endptr-inptr)) + 1; \
  if (_len == -1) \
    goto error_label; \
  outptr = g_memdup ((gconstpointer)inptr, _len); \
  inptr += _len; \
}G_STMT_END

#define ALIGNMENT            (sizeof (void *))
#define alignment(_address)  (gsize)_address%ALIGNMENT
#define align(_ptr)          _ptr += (( alignment(_ptr) == 0) ? 0 : ALIGNMENT-alignment(_ptr))

/* Registry saving */

#ifdef G_OS_WIN32
/* On win32, we can't use g_mkstmp(), because of cross-DLL file I/O problems.
 * So, we just create the entire binary registry in memory, then write it out
 * with g_file_set_contents(), which creates a temporary file internally
 */

typedef struct BinaryRegistryCache
{
  const char *location;
  guint8 *mem;
  gssize len;
} BinaryRegistryCache;

static BinaryRegistryCache *
gst_registry_binary_cache_init (GstRegistry * registry, const char *location)
{
  BinaryRegistryCache *cache = g_new0 (BinaryRegistryCache, 1);
  cache->location = location;
  return cache;
}

static int
gst_registry_binary_cache_write (GstRegistry * registry,
    BinaryRegistryCache * cache, unsigned long offset,
    const void *data, int length)
{
  cache->len = MAX (offset + length, cache->len);
  cache->mem = g_realloc (cache->mem, cache->len);

  memcpy (cache->mem + offset, data, length);

  return length;
}

static gboolean
gst_registry_binary_cache_finish (GstRegistry * registry,
    BinaryRegistryCache * cache, gboolean success)
{
  gboolean ret = TRUE;
  GError *error = NULL;
  if (!g_file_set_contents (cache->location, (const gchar *) cache->mem,
          cache->len, &error)) {
    /* Probably the directory didn't exist; create it */
    gchar *dir;
    dir = g_path_get_dirname (cache->location);
    g_mkdir_with_parents (dir, 0777);
    g_free (dir);

    g_error_free (error);
    error = NULL;

    if (!g_file_set_contents (cache->location, (const gchar *) cache->mem,
            cache->len, &error)) {
      GST_ERROR ("Failed to write to cache file: %s", error->message);
      g_error_free (error);
      ret = FALSE;
    }
  }

  g_free (cache->mem);
  g_free (cache);
  return ret;
}

#else
typedef struct BinaryRegistryCache
{
  const char *location;
  char *tmp_location;
  unsigned long currentoffset;
} BinaryRegistryCache;

static BinaryRegistryCache *
gst_registry_binary_cache_init (GstRegistry * registry, const char *location)
{
  BinaryRegistryCache *cache = g_new0 (BinaryRegistryCache, 1);

  cache->location = location;
  cache->tmp_location = g_strconcat (location, ".tmpXXXXXX", NULL);
  registry->cache_file = g_mkstemp (cache->tmp_location);
  if (registry->cache_file == -1) {
    gchar *dir;

    /* oops, I bet the directory doesn't exist */
    dir = g_path_get_dirname (location);
    g_mkdir_with_parents (dir, 0777);
    g_free (dir);

    /* the previous g_mkstemp call overwrote the XXXXXX placeholder ... */
    g_free (cache->tmp_location);
    cache->tmp_location = g_strconcat (location, ".tmpXXXXXX", NULL);
    registry->cache_file = g_mkstemp (cache->tmp_location);

    if (registry->cache_file == -1) {
      GST_DEBUG ("g_mkstemp() failed: %s", g_strerror (errno));
      g_free (cache->tmp_location);
      g_free (cache);
      return NULL;
    }
  }

  return cache;
}

static int
gst_registry_binary_cache_write (GstRegistry * registry,
    BinaryRegistryCache * cache, unsigned long offset,
    const void *data, int length)
{
  long written;
  if (offset != cache->currentoffset) {
    if (lseek (registry->cache_file, offset, SEEK_SET) != 0) {
      GST_ERROR ("Seeking to new offset failed");
      return FALSE;
    }
    cache->currentoffset = offset;
  }

  written = write (registry->cache_file, data, length);
  if (written != length) {
    GST_ERROR ("Failed to write to cache file");
  }
  cache->currentoffset += written;

  return written;
}

static gboolean
gst_registry_binary_cache_finish (GstRegistry * registry,
    BinaryRegistryCache * cache, gboolean success)
{
  /* only fsync if we're actually going to use and rename the file below */
  if (success && fsync (registry->cache_file) < 0)
    goto fsync_failed;

  if (close (registry->cache_file) < 0)
    goto close_failed;

  if (success) {
    /* Only do the rename if we wrote the entire file successfully */
    if (g_rename (cache->tmp_location, cache->location) < 0)
      goto rename_failed;
  }

  g_free (cache->tmp_location);
  g_free (cache);
  GST_INFO ("Wrote binary registry cache");
  return TRUE;

/* ERRORS */
fail_after_close:
  {
    g_unlink (cache->tmp_location);
    g_free (cache->tmp_location);
    g_free (cache);
    return FALSE;
  }
fsync_failed:
  {
    GST_ERROR ("fsync() failed: %s", g_strerror (errno));
    goto fail_after_close;
  }
close_failed:
  {
    GST_ERROR ("close() failed: %s", g_strerror (errno));
    goto fail_after_close;
  }
rename_failed:
  {
    GST_ERROR ("g_rename() failed: %s", g_strerror (errno));
    goto fail_after_close;
  }
}
#endif

/*
 * gst_registry_binary_write_chunk:
 *
 * Write from a memory location to the registry cache file
 *
 * Returns: %TRUE for success
 */
inline static gboolean
gst_registry_binary_write_chunk (GstRegistry * registry,
    BinaryRegistryCache * cache, const void *mem,
    const gssize size, unsigned long *file_position, gboolean align)
{
  gchar padder[ALIGNMENT] = { 0, };
  int padsize = 0;

  /* Padding to insert the struct that requiere word alignment */
  if ((align) && (alignment (*file_position) != 0)) {
    padsize = ALIGNMENT - alignment (*file_position);
    if (gst_registry_binary_cache_write (registry, cache, *file_position,
            padder, padsize) != padsize) {
      GST_ERROR ("Failed to write binary registry padder");
      return FALSE;
    }
    *file_position += padsize;
  }

  if (gst_registry_binary_cache_write (registry, cache, *file_position,
          mem, size) != size) {
    GST_ERROR ("Failed to write binary registry element");
    return FALSE;
  }

  *file_position += size;

  return TRUE;
}


/*
 * gst_registry_binary_initialize_magic:
 *
 * Initialize the GstBinaryRegistryMagic, setting both our magic number and
 * gstreamer major/minor version
 */
inline static gboolean
gst_registry_binary_initialize_magic (GstBinaryRegistryMagic * m)
{
  memset (m, 0, sizeof (GstBinaryRegistryMagic));

  if (!strncpy (m->magic, GST_MAGIC_BINARY_REGISTRY_STR,
          GST_MAGIC_BINARY_REGISTRY_LEN)
      || !strncpy (m->version, GST_MAGIC_BINARY_VERSION_STR,
          GST_MAGIC_BINARY_VERSION_LEN)) {
    GST_ERROR ("Failed to write magic to the registry magic structure");
    return FALSE;
  }

  return TRUE;
}


/*
 * gst_registry_binary_save_const_string:
 *
 * Store a const string in a binary chunk.
 *
 * Returns: %TRUE for success
 */
inline static gboolean
gst_registry_binary_save_const_string (GList ** list, const gchar * str)
{
  GstBinaryChunk *chunk;

  if (G_UNLIKELY (str == NULL)) {
    GST_ERROR ("unexpected NULL string in plugin or plugin feature data");
    str = "";
  }

  chunk = g_malloc (sizeof (GstBinaryChunk));
  chunk->data = (gpointer) str;
  chunk->size = strlen ((gchar *) chunk->data) + 1;
  chunk->flags = GST_BINARY_REGISTRY_FLAG_CONST;
  chunk->align = FALSE;
  *list = g_list_prepend (*list, chunk);
  return TRUE;
}

/*
 * gst_registry_binary_save_string:
 *
 * Store a string in a binary chunk.
 *
 * Returns: %TRUE for success
 */
inline static gboolean
gst_registry_binary_save_string (GList ** list, gchar * str)
{
  GstBinaryChunk *chunk;

  chunk = g_malloc (sizeof (GstBinaryChunk));
  chunk->data = str;
  chunk->size = strlen ((gchar *) chunk->data) + 1;
  chunk->flags = GST_BINARY_REGISTRY_FLAG_NONE;
  chunk->align = FALSE;
  *list = g_list_prepend (*list, chunk);
  return TRUE;
}


/*
 * gst_registry_binary_save_data:
 *
 * Store some data in a binary chunk.
 *
 * Returns: the initialized chunk
 */
inline static GstBinaryChunk *
gst_registry_binary_make_data (gpointer data, gulong size)
{
  GstBinaryChunk *chunk;

  chunk = g_malloc (sizeof (GstBinaryChunk));
  chunk->data = data;
  chunk->size = size;
  chunk->flags = GST_BINARY_REGISTRY_FLAG_NONE;
  chunk->align = TRUE;
  return chunk;
}


/*
 * gst_registry_binary_save_pad_template:
 *
 * Store pad_templates in binary chunks.
 *
 * Returns: %TRUE for success
 */
static gboolean
gst_registry_binary_save_pad_template (GList ** list,
    GstStaticPadTemplate * template)
{
  GstBinaryPadTemplate *pt;
  GstBinaryChunk *chk;

  pt = g_malloc0 (sizeof (GstBinaryPadTemplate));
  chk = gst_registry_binary_make_data (pt, sizeof (GstBinaryPadTemplate));

  pt->presence = template->presence;
  pt->direction = template->direction;

  /* pack pad template strings */
  gst_registry_binary_save_const_string (list,
      (gchar *) (template->static_caps.string));
  gst_registry_binary_save_const_string (list, template->name_template);

  *list = g_list_prepend (*list, chk);

  return TRUE;
}


/*
 * gst_registry_binary_save_feature:
 *
 * Store features in binary chunks.
 *
 * Returns: %TRUE for success
 */
static gboolean
gst_registry_binary_save_feature (GList ** list, GstPluginFeature * feature)
{
  const gchar *type_name = g_type_name (G_OBJECT_TYPE (feature));
  GstBinaryPluginFeature *pf = NULL;
  GstBinaryChunk *chk = NULL;
  GList *walk;

  if (!type_name) {
    GST_ERROR ("NULL feature type_name, aborting.");
    return FALSE;
  }

  if (GST_IS_ELEMENT_FACTORY (feature)) {
    GstBinaryElementFactory *ef;
    GstElementFactory *factory = GST_ELEMENT_FACTORY (feature);

    ef = g_malloc0 (sizeof (GstBinaryElementFactory));
    chk = gst_registry_binary_make_data (ef, sizeof (GstBinaryElementFactory));
    ef->npadtemplates = ef->ninterfaces = ef->nuriprotocols = 0;
    pf = (GstBinaryPluginFeature *) ef;

    /* save interfaces */
    for (walk = factory->interfaces; walk;
        walk = g_list_next (walk), ef->ninterfaces++) {
      gst_registry_binary_save_const_string (list, (gchar *) walk->data);
    }
    GST_DEBUG ("Saved %d Interfaces", ef->ninterfaces);
    /* save uritypes */
    if (GST_URI_TYPE_IS_VALID (factory->uri_type)) {
      if (factory->uri_protocols && *factory->uri_protocols) {
        GstBinaryChunk *subchk;
        gchar **protocol;

        subchk =
            gst_registry_binary_make_data (&factory->uri_type,
            sizeof (factory->uri_type));
        subchk->flags = GST_BINARY_REGISTRY_FLAG_CONST;

        protocol = factory->uri_protocols;
        while (*protocol) {
          gst_registry_binary_save_const_string (list, *protocol++);
          ef->nuriprotocols++;
        }
        *list = g_list_prepend (*list, subchk);
        GST_DEBUG ("Saved %d UriTypes", ef->nuriprotocols);
      } else {
        g_warning ("GStreamer feature '%s' is URI handler but does not provide"
            " any protocols it can handle", feature->name);
      }
    }

    /* save pad-templates */
    for (walk = factory->staticpadtemplates; walk;
        walk = g_list_next (walk), ef->npadtemplates++) {
      GstStaticPadTemplate *template = walk->data;

      if (!gst_registry_binary_save_pad_template (list, template)) {
        GST_ERROR ("Can't fill pad template, aborting.");
        goto fail;
      }
    }

    /* pack element factory strings */
    gst_registry_binary_save_const_string (list, factory->details.author);
    gst_registry_binary_save_const_string (list, factory->details.description);
    gst_registry_binary_save_const_string (list, factory->details.klass);
    gst_registry_binary_save_const_string (list, factory->details.longname);
  } else if (GST_IS_TYPE_FIND_FACTORY (feature)) {
    GstBinaryTypeFindFactory *tff;
    GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (feature);

    tff = g_malloc0 (sizeof (GstBinaryTypeFindFactory));
    chk =
        gst_registry_binary_make_data (tff, sizeof (GstBinaryTypeFindFactory));
    tff->nextensions = 0;
    pf = (GstBinaryPluginFeature *) tff;

    /* save extensions */
    if (factory->extensions) {
      while (factory->extensions[tff->nextensions]) {
        gst_registry_binary_save_const_string (list,
            factory->extensions[tff->nextensions++]);
      }
    }
    /* save caps */
    if (factory->caps) {
      GstCaps *copy = gst_caps_copy (factory->caps);
      gchar *str;

      /* we copy the caps here so we can simplify them
       * before saving. This is a lot faster when loading
       * them later on */
      gst_caps_do_simplify (copy);
      str = gst_caps_to_string (copy);
      gst_caps_unref (copy);
      gst_registry_binary_save_string (list, str);
    } else {
      gst_registry_binary_save_const_string (list, "");
    }

  } else if (GST_IS_INDEX_FACTORY (feature)) {
    GstIndexFactory *factory = GST_INDEX_FACTORY (feature);

    pf = g_malloc0 (sizeof (GstBinaryPluginFeature));
    chk = gst_registry_binary_make_data (pf, sizeof (GstBinaryPluginFeature));
    pf->rank = feature->rank;

    /* pack element factory strings */
    gst_registry_binary_save_const_string (list, factory->longdesc);
  } else {
    GST_WARNING ("unhandled feature type '%s'", type_name);
  }

  if (pf) {
    pf->rank = feature->rank;
    *list = g_list_prepend (*list, chk);

    /* pack plugin feature strings */
    gst_registry_binary_save_const_string (list, feature->name);
    gst_registry_binary_save_const_string (list, (gchar *) type_name);

    return TRUE;
  }

  /* Errors */
fail:
  g_free (chk);
  g_free (pf);
  return FALSE;
}

static gboolean
gst_registry_binary_save_plugin_dep (GList ** list, GstPluginDep * dep)
{
  GstBinaryDep *ed;
  GstBinaryChunk *chk;
  gchar **s;

  ed = g_new0 (GstBinaryDep, 1);
  chk = gst_registry_binary_make_data (ed, sizeof (GstBinaryDep));

  ed->flags = dep->flags;
  ed->n_env_vars = 0;
  ed->n_paths = 0;
  ed->n_names = 0;

  ed->env_hash = dep->env_hash;
  ed->stat_hash = dep->stat_hash;

  for (s = dep->env_vars; s != NULL && *s != NULL; ++s, ++ed->n_env_vars)
    gst_registry_binary_save_string (list, g_strdup (*s));

  for (s = dep->paths; s != NULL && *s != NULL; ++s, ++ed->n_paths)
    gst_registry_binary_save_string (list, g_strdup (*s));

  for (s = dep->names; s != NULL && *s != NULL; ++s, ++ed->n_names)
    gst_registry_binary_save_string (list, g_strdup (*s));

  *list = g_list_prepend (*list, chk);

  GST_LOG ("Saved external plugin dependency");
  return TRUE;
}

/*
 * gst_registry_binary_save_plugin:
 *
 * Adapt a GstPlugin to our GstBinaryPluginElement structure, and write it to
 * the registry file.
 */
static gboolean
gst_registry_binary_save_plugin (GList ** list, GstRegistry * registry,
    GstPlugin * plugin)
{
  GstBinaryPluginElement *pe;
  GstBinaryChunk *chk;
  GList *plugin_features = NULL;
  GList *walk;

  pe = g_malloc0 (sizeof (GstBinaryPluginElement));
  chk = gst_registry_binary_make_data (pe, sizeof (GstBinaryPluginElement));

  pe->file_size = plugin->file_size;
  pe->file_mtime = plugin->file_mtime;
  pe->n_deps = 0;
  pe->nfeatures = 0;

  /* pack external deps */
  for (walk = plugin->priv->deps; walk != NULL; walk = walk->next) {
    if (!gst_registry_binary_save_plugin_dep (list, walk->data)) {
      GST_ERROR ("Could not save external plugin dependency, aborting.");
      goto fail;
    }
    ++pe->n_deps;
  }

  /* pack plugin features */
  plugin_features =
      gst_registry_get_feature_list_by_plugin (registry, plugin->desc.name);
  for (walk = plugin_features; walk; walk = g_list_next (walk), pe->nfeatures++) {
    GstPluginFeature *feature = GST_PLUGIN_FEATURE (walk->data);

    if (!gst_registry_binary_save_feature (list, feature)) {
      GST_ERROR ("Can't fill plugin feature, aborting.");
      goto fail;
    }
  }
  GST_DEBUG ("Save plugin '%s' with %d feature(s)", plugin->desc.name,
      pe->nfeatures);

  gst_plugin_feature_list_free (plugin_features);

  /* pack plugin element strings */
  gst_registry_binary_save_const_string (list, plugin->desc.origin);
  gst_registry_binary_save_const_string (list, plugin->desc.package);
  gst_registry_binary_save_const_string (list, plugin->desc.source);
  gst_registry_binary_save_const_string (list, plugin->desc.license);
  gst_registry_binary_save_const_string (list, plugin->desc.version);
  gst_registry_binary_save_const_string (list, plugin->filename);
  gst_registry_binary_save_const_string (list, plugin->desc.description);
  gst_registry_binary_save_const_string (list, plugin->desc.name);

  *list = g_list_prepend (*list, chk);

  GST_DEBUG ("Found %d features in plugin \"%s\"", pe->nfeatures,
      plugin->desc.name);
  return TRUE;

  /* Errors */
fail:
  gst_plugin_feature_list_free (plugin_features);
  g_free (chk);
  g_free (pe);
  return FALSE;
}

/**
 * gst_registry_binary_write_cache:
 * @registry: a #GstRegistry
 * @location: a filename
 *
 * Write the @registry to a cache to file at given @location.
 * 
 * Returns: %TRUE on success.
 */
gboolean
gst_registry_binary_write_cache (GstRegistry * registry, const char *location)
{
  GList *walk;
  GstBinaryRegistryMagic magic;
  GList *to_write = NULL;
  unsigned long file_position = 0;
  BinaryRegistryCache *cache;

  GST_INFO ("Building binary registry cache image");

  g_return_val_if_fail (GST_IS_REGISTRY (registry), FALSE);

  if (!gst_registry_binary_initialize_magic (&magic))
    goto fail;

  /* iterate trough the list of plugins and fit them into binary structures */
  for (walk = registry->plugins; walk; walk = g_list_next (walk)) {
    GstPlugin *plugin = GST_PLUGIN (walk->data);

    if (!plugin->filename)
      continue;

    if (plugin->flags & GST_PLUGIN_FLAG_CACHED) {
      struct stat statbuf;

      if (g_stat (plugin->filename, &statbuf) < 0 ||
          plugin->file_mtime != statbuf.st_mtime ||
          plugin->file_size != statbuf.st_size)
        continue;
    }

    if (!gst_registry_binary_save_plugin (&to_write, registry, plugin)) {
      GST_ERROR ("Can't write binary plugin information for \"%s\"",
          plugin->filename);
    }
  }

  GST_INFO ("Writing binary registry cache");

  cache = gst_registry_binary_cache_init (registry, location);
  if (!cache)
    goto fail_free_list;

  /* write magic */
  if (gst_registry_binary_cache_write (registry, cache, file_position,
          &magic, sizeof (GstBinaryRegistryMagic)) !=
      sizeof (GstBinaryRegistryMagic)) {
    GST_ERROR ("Failed to write binary registry magic");
    goto fail_free_list;
  }
  file_position += sizeof (GstBinaryRegistryMagic);

  /* write out data chunks */
  for (walk = to_write; walk; walk = g_list_next (walk)) {
    GstBinaryChunk *cur = walk->data;

    if (!gst_registry_binary_write_chunk (registry, cache, cur->data, cur->size,
            &file_position, cur->align)) {
      goto fail_free_list;
    }
    if (!(cur->flags & GST_BINARY_REGISTRY_FLAG_CONST))
      g_free (cur->data);
    g_free (cur);
    walk->data = NULL;
  }
  g_list_free (to_write);

  if (!gst_registry_binary_cache_finish (registry, cache, TRUE))
    return FALSE;

  return TRUE;

  /* Errors */
fail_free_list:
  {
    for (walk = to_write; walk; walk = g_list_next (walk)) {
      GstBinaryChunk *cur = walk->data;

      if (!(cur->flags & GST_BINARY_REGISTRY_FLAG_CONST))
        g_free (cur->data);
      g_free (cur);
    }
    g_list_free (to_write);

    if (cache)
      (void) gst_registry_binary_cache_finish (registry, cache, FALSE);
    /* fall through */
  }
fail:
  {
    return FALSE;
  }
}


/* Registry loading */

/*
 * gst_registry_binary_check_magic:
 *
 * Check GstBinaryRegistryMagic validity.
 * Return < 0 if something is wrong, -2 means
 * that just the version of the registry is out of
 * date, -1 is a general failure.
 */
static gint
gst_registry_binary_check_magic (gchar ** in, gsize size)
{
  GstBinaryRegistryMagic *m;

  align (*in);
  GST_DEBUG ("Reading/casting for GstBinaryRegistryMagic at address %p", *in);
  unpack_element (*in, m, GstBinaryRegistryMagic, (*in + size), fail);

  if (strncmp (m->magic, GST_MAGIC_BINARY_REGISTRY_STR,
          GST_MAGIC_BINARY_REGISTRY_LEN) != 0) {
    GST_WARNING
        ("Binary registry magic is different : %02x%02x%02x%02x != %02x%02x%02x%02x",
        GST_MAGIC_BINARY_REGISTRY_STR[0] & 0xff,
        GST_MAGIC_BINARY_REGISTRY_STR[1] & 0xff,
        GST_MAGIC_BINARY_REGISTRY_STR[2] & 0xff,
        GST_MAGIC_BINARY_REGISTRY_STR[3] & 0xff, m->magic[0] & 0xff,
        m->magic[1] & 0xff, m->magic[2] & 0xff, m->magic[3] & 0xff);
    return -1;
  }
  if (strncmp (m->version, GST_MAGIC_BINARY_VERSION_STR,
          GST_MAGIC_BINARY_VERSION_LEN)) {
    GST_WARNING ("Binary registry magic version is different : %s != %s",
        GST_MAGIC_BINARY_VERSION_STR, m->version);
    return -2;
  }

  return 0;

fail:
  GST_WARNING ("Not enough data for binary registry magic structure");
  return -1;
}


/*
 * gst_registry_binary_load_pad_template:
 *
 * Make a new GstStaticPadTemplate from current GstBinaryPadTemplate structure
 *
 * Returns: new GstStaticPadTemplate
 */
static gboolean
gst_registry_binary_load_pad_template (GstElementFactory * factory, gchar ** in,
    gchar * end)
{
  GstBinaryPadTemplate *pt;
  GstStaticPadTemplate *template;

  align (*in);
  GST_DEBUG ("Reading/casting for GstBinaryPadTemplate at address %p", *in);
  unpack_element (*in, pt, GstBinaryPadTemplate, end, fail);

  template = g_new0 (GstStaticPadTemplate, 1);
  template->presence = pt->presence;
  template->direction = pt->direction;

  /* unpack pad template strings */
  unpack_const_string (*in, template->name_template, end, fail);
  unpack_string (*in, template->static_caps.string, end, fail);

  __gst_element_factory_add_static_pad_template (factory, template);
  GST_DEBUG ("Added pad_template %s", template->name_template);

  return TRUE;

fail:
  GST_INFO ("Reading pad template failed");
  return FALSE;
}


/*
 * gst_registry_binary_load_feature:
 *
 * Make a new GstPluginFeature from current binary plugin feature structure
 *
 * Returns: new GstPluginFeature
 */
static gboolean
gst_registry_binary_load_feature (GstRegistry * registry, gchar ** in,
    gchar * end, const gchar * plugin_name)
{
  GstBinaryPluginFeature *pf = NULL;
  GstPluginFeature *feature = NULL;
  gchar *type_name = NULL, *str;
  GType type;
  guint i;

  /* unpack plugin feature strings */
  unpack_string (*in, type_name, end, fail);

  if (!type_name) {
    GST_ERROR ("No feature type name");
    return FALSE;
  }

  GST_DEBUG ("Plugin '%s' feature typename : '%s'", plugin_name, type_name);

  if (!(type = g_type_from_name (type_name))) {
    GST_ERROR ("Unknown type from typename '%s' for plugin '%s'", type_name,
        plugin_name);
    g_free (type_name);
    return FALSE;
  }
  if ((feature = g_object_new (type, NULL)) == NULL) {
    GST_ERROR ("Can't create feature from type");
    g_free (type_name);
    return FALSE;
  }

  if (!GST_IS_PLUGIN_FEATURE (feature)) {
    GST_ERROR ("typename : '%s' is not a plugin feature", type_name);
    goto fail;
  }

  /* unpack more plugin feature strings */
  unpack_string (*in, feature->name, end, fail);

  if (GST_IS_ELEMENT_FACTORY (feature)) {
    GstBinaryElementFactory *ef;
    GstElementFactory *factory = GST_ELEMENT_FACTORY_CAST (feature);

    align (*in);
    GST_LOG ("Reading/casting for GstBinaryElementFactory at address %p", *in);
    unpack_element (*in, ef, GstBinaryElementFactory, end, fail);
    pf = (GstBinaryPluginFeature *) ef;

    /* unpack element factory strings */
    unpack_string (*in, factory->details.longname, end, fail);
    unpack_string (*in, factory->details.klass, end, fail);
    unpack_string (*in, factory->details.description, end, fail);
    unpack_string (*in, factory->details.author, end, fail);
    GST_DEBUG ("Element factory : '%s' with npadtemplates=%d",
        factory->details.longname, ef->npadtemplates);

    /* load pad templates */
    for (i = 0; i < ef->npadtemplates; i++) {
      if (!gst_registry_binary_load_pad_template (factory, in, end)) {
        GST_ERROR ("Error while loading binary pad template");
        goto fail;
      }
    }

    /* load uritypes */
    if (ef->nuriprotocols) {
      GST_DEBUG ("Reading %d UriTypes at address %p", ef->nuriprotocols, *in);

      align (*in);
      factory->uri_type = *((guint *) * in);
      *in += sizeof (factory->uri_type);
      /*unpack_element(*in, &factory->uri_type, factory->uri_type, end, fail); */

      factory->uri_protocols = g_new0 (gchar *, ef->nuriprotocols + 1);
      for (i = 0; i < ef->nuriprotocols; i++) {
        unpack_string (*in, str, end, fail);
        factory->uri_protocols[i] = str;
      }
    }
    /* load interfaces */
    GST_DEBUG ("Reading %d Interfaces at address %p", ef->ninterfaces, *in);
    for (i = 0; i < ef->ninterfaces; i++) {
      unpack_string (*in, str, end, fail);
      __gst_element_factory_add_interface (factory, str);
      g_free (str);
    }
  } else if (GST_IS_TYPE_FIND_FACTORY (feature)) {
    GstBinaryTypeFindFactory *tff;
    GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (feature);

    align (*in);
    GST_DEBUG ("Reading/casting for GstBinaryPluginFeature at address %p", *in);
    unpack_element (*in, tff, GstBinaryTypeFindFactory, end, fail);
    pf = (GstBinaryPluginFeature *) tff;

    /* load caps */
    unpack_string (*in, str, end, fail);
    factory->caps = (str && *str) ? gst_caps_from_string (str) : NULL;
    g_free (str);
    /* load extensions */
    if (tff->nextensions) {
      GST_DEBUG ("Reading %d Typefind extensions at address %p",
          tff->nextensions, *in);
      factory->extensions = g_new0 (gchar *, tff->nextensions + 1);
      for (i = 0; i < tff->nextensions; i++) {
        unpack_string (*in, str, end, fail);
        factory->extensions[i] = str;
      }
    }
  } else if (GST_IS_INDEX_FACTORY (feature)) {
    GstIndexFactory *factory = GST_INDEX_FACTORY (feature);

    align (*in);
    GST_DEBUG ("Reading/casting for GstBinaryPluginFeature at address %p", *in);
    unpack_element (*in, pf, GstBinaryPluginFeature, end, fail);

    /* unpack index factory strings */
    unpack_string (*in, factory->longdesc, end, fail);
  } else {
    GST_WARNING ("unhandled factory type : %s", G_OBJECT_TYPE_NAME (feature));
    goto fail;
  }

  feature->rank = pf->rank;

  /* should already be the interned string, but better make sure */
  feature->plugin_name = g_intern_string (plugin_name);

  gst_registry_add_feature (registry, feature);
  GST_DEBUG ("Added feature %s", feature->name);

  g_free (type_name);
  return TRUE;

  /* Errors */
fail:
  GST_INFO ("Reading plugin feature failed");
  g_free (type_name);
  if (GST_IS_OBJECT (feature))
    gst_object_unref (feature);
  else
    g_object_unref (feature);
  return FALSE;
}

static gchar **
gst_registry_binary_load_plugin_dep_strv (gchar ** in, gchar * end, guint n)
{
  gchar **arr;

  if (n == 0)
    return NULL;

  arr = g_new0 (gchar *, n + 1);
  while (n > 0) {
    unpack_string (*in, arr[n - 1], end, fail);
    --n;
  }
  return arr;
fail:
  GST_INFO ("Reading plugin dependency strings failed");
  return NULL;
}

static gboolean
gst_registry_binary_load_plugin_dep (GstPlugin * plugin, gchar ** in,
    gchar * end)
{
  GstPluginDep *dep;
  GstBinaryDep *d;
  gchar **s;

  align (*in);
  GST_LOG_OBJECT (plugin, "Unpacking GstBinaryDep from %p", *in);
  unpack_element (*in, d, GstBinaryDep, end, fail);

  dep = g_new0 (GstPluginDep, 1);

  dep->env_hash = d->env_hash;
  dep->stat_hash = d->stat_hash;

  dep->flags = d->flags;

  dep->names = gst_registry_binary_load_plugin_dep_strv (in, end, d->n_names);
  dep->paths = gst_registry_binary_load_plugin_dep_strv (in, end, d->n_paths);
  dep->env_vars =
      gst_registry_binary_load_plugin_dep_strv (in, end, d->n_env_vars);

  plugin->priv->deps = g_list_append (plugin->priv->deps, dep);

  GST_DEBUG_OBJECT (plugin, "Loaded external plugin dependency from registry: "
      "env_hash: %08x, stat_hash: %08x", dep->env_hash, dep->stat_hash);
  for (s = dep->env_vars; s != NULL && *s != NULL; ++s)
    GST_LOG_OBJECT (plugin, " evar: %s", *s);
  for (s = dep->paths; s != NULL && *s != NULL; ++s)
    GST_LOG_OBJECT (plugin, " path: %s", *s);
  for (s = dep->names; s != NULL && *s != NULL; ++s)
    GST_LOG_OBJECT (plugin, " name: %s", *s);

  return TRUE;
fail:
  GST_INFO ("Reading plugin dependency failed");
  return FALSE;
}

/*
 * gst_registry_binary_load_plugin:
 *
 * Make a new GstPlugin from current GstBinaryPluginElement structure
 * and save it to the GstRegistry. Return an offset to the next
 * GstBinaryPluginElement structure.
 */
static gboolean
gst_registry_binary_load_plugin (GstRegistry * registry, gchar ** in,
    gchar * end)
{
  GstBinaryPluginElement *pe;
  GstPlugin *plugin = NULL;
  guint i;

  align (*in);
  GST_LOG ("Reading/casting for GstBinaryPluginElement at address %p", *in);
  unpack_element (*in, pe, GstBinaryPluginElement, end, fail);

  plugin = g_object_new (GST_TYPE_PLUGIN, NULL);

  /* TODO: also set GST_PLUGIN_FLAG_CONST */
  plugin->flags |= GST_PLUGIN_FLAG_CACHED;
  plugin->file_mtime = pe->file_mtime;
  plugin->file_size = pe->file_size;

  /* unpack plugin element strings */
  unpack_const_string (*in, plugin->desc.name, end, fail);
  unpack_string (*in, plugin->desc.description, end, fail);
  unpack_string (*in, plugin->filename, end, fail);
  unpack_const_string (*in, plugin->desc.version, end, fail);
  unpack_const_string (*in, plugin->desc.license, end, fail);
  unpack_const_string (*in, plugin->desc.source, end, fail);
  unpack_const_string (*in, plugin->desc.package, end, fail);
  unpack_const_string (*in, plugin->desc.origin, end, fail);
  GST_LOG ("read strings for name='%s'", plugin->desc.name);
  GST_LOG ("  desc.description='%s'", plugin->desc.description);
  GST_LOG ("  filename='%s'", plugin->filename);
  GST_LOG ("  desc.version='%s'", plugin->desc.version);
  GST_LOG ("  desc.license='%s'", plugin->desc.license);
  GST_LOG ("  desc.source='%s'", plugin->desc.source);
  GST_LOG ("  desc.package='%s'", plugin->desc.package);
  GST_LOG ("  desc.origin='%s'", plugin->desc.origin);

  plugin->basename = g_path_get_basename (plugin->filename);

  /* Takes ownership of plugin */
  gst_registry_add_plugin (registry, plugin);
  GST_DEBUG ("Added plugin '%s' plugin with %d features from binary registry",
      plugin->desc.name, pe->nfeatures);

  /* Load plugin features */
  for (i = 0; i < pe->nfeatures; i++) {
    if (!gst_registry_binary_load_feature (registry, in, end,
            plugin->desc.name)) {
      GST_ERROR ("Error while loading binary feature");
      gst_registry_remove_plugin (registry, plugin);
      goto fail;
    }
  }

  /* Load external plugin dependencies */
  for (i = 0; i < pe->n_deps; ++i) {
    if (!gst_registry_binary_load_plugin_dep (plugin, in, end)) {
      GST_ERROR_OBJECT (plugin, "Could not read external plugin dependency");
      gst_registry_remove_plugin (registry, plugin);
      goto fail;
    }
  }

  return TRUE;

  /* Errors */
fail:
  GST_INFO ("Reading plugin failed");
  return FALSE;
}


/**
 * gst_registry_binary_read_cache:
 * @registry: a #GstRegistry
 * @location: a filename
 *
 * Read the contents of the binary cache file at @location into @registry.
 *
 * Returns: %TRUE on success.
 */
gboolean
gst_registry_binary_read_cache (GstRegistry * registry, const char *location)
{
  GMappedFile *mapped = NULL;
  gchar *contents = NULL;
  gchar *in = NULL;
  gsize size;
  GError *err = NULL;
  gboolean res = FALSE;
  gint check_magic_result;
#ifndef GST_DISABLE_GST_DEBUG
  GTimer *timer = NULL;
  gdouble seconds;
#endif

  /* make sure these types exist */
  GST_TYPE_ELEMENT_FACTORY;
  GST_TYPE_TYPE_FIND_FACTORY;
  GST_TYPE_INDEX_FACTORY;

#ifndef GST_DISABLE_GST_DEBUG
  timer = g_timer_new ();
#endif

  mapped = g_mapped_file_new (location, FALSE, &err);
  if (err != NULL) {
    GST_INFO ("Unable to mmap file %s : %s", location, err->message);
    g_error_free (err);
    err = NULL;

    g_file_get_contents (location, &contents, &size, &err);
    if (err != NULL) {
      GST_INFO ("Unable to read file %s : %s", location, err->message);
#ifndef GST_DISABLE_GST_DEBUG
      g_timer_destroy (timer);
#endif
      g_error_free (err);
      return FALSE;
    }
  } else {
    if ((contents = g_mapped_file_get_contents (mapped)) == NULL) {
      GST_ERROR ("Can't load file %s : %s", location, g_strerror (errno));
      goto Error;
    }
    /* check length for header */
    size = g_mapped_file_get_length (mapped);
  }

  /* in is a cursor pointer, we initialize it with the begin of registry and is updated on each read */
  in = contents;
  GST_DEBUG ("File data at address %p", in);
  if (size < sizeof (GstBinaryRegistryMagic)) {
    GST_ERROR ("No or broken registry header");
    goto Error;
  }

  /* check if header is valid */
  if ((check_magic_result = gst_registry_binary_check_magic (&in, size)) < 0) {

    if (check_magic_result == -1)
      GST_ERROR
          ("Binary registry type not recognized (invalid magic) for file at %s",
          location);
    goto Error;
  }

  /* check if there are plugins in the file */
  if (!(((gsize) in + sizeof (GstBinaryPluginElement)) <
          (gsize) contents + size)) {
    GST_INFO ("No binary plugins structure to read");
    /* empty file, this is not an error */
  } else {
    gchar *end = contents + size;
    /* read as long as we still have space for a GstBinaryPluginElement */
    for (;
        ((gsize) in + sizeof (GstBinaryPluginElement)) <
        (gsize) contents + size;) {
      GST_DEBUG ("reading binary registry %" G_GSIZE_FORMAT "(%x)/%"
          G_GSIZE_FORMAT, (gsize) in - (gsize) contents,
          (guint) ((gsize) in - (gsize) contents), size);
      if (!gst_registry_binary_load_plugin (registry, &in, end)) {
        GST_ERROR ("Problem while reading binary registry %s", location);
        goto Error;
      }
    }
  }

#ifndef GST_DISABLE_GST_DEBUG
  g_timer_stop (timer);
  seconds = g_timer_elapsed (timer, NULL);
#endif

  GST_INFO ("loaded %s in %lf seconds", location, seconds);

  res = TRUE;
  /* TODO: once we re-use the pointers to registry contents, return here */

Error:
#ifndef GST_DISABLE_GST_DEBUG
  g_timer_destroy (timer);
#endif
  if (mapped) {
    g_mapped_file_free (mapped);
  } else {
    g_free (contents);
  }
  return res;
}


/* FIXME 0.11: these are here for backwards compatibility */

gboolean
gst_registry_xml_read_cache (GstRegistry * registry, const char *location)
{
  return FALSE;
}

gboolean
gst_registry_xml_write_cache (GstRegistry * registry, const char *location)
{
  return FALSE;
}