gstreamer_core/gst/gstregistryxml.c
branchRCL_3
changeset 30 7e817e7e631c
parent 0 0e761a78d257
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gstreamer_core/gst/gstregistryxml.c	Wed Sep 01 12:16:41 2010 +0100
@@ -0,0 +1,964 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *                    2005 David A. Schleef <ds@schleef.org>
+ *
+ * gstregistryxml.c: GstRegistry object, support routines
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it ulnder 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <fcntl.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include <gst/gst_private.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/gstregistry.h>
+
+#include <libxml/xmlreader.h>
+
+#include "glib-compat-private.h"
+#include <glib/gstdio.h>
+
+#define BLOCK_SIZE 1024*10
+
+#define GST_CAT_DEFAULT GST_CAT_REGISTRY
+
+#define CLASS(registry)  GST_XML_REGISTRY_CLASS (G_OBJECT_GET_CLASS (registry))
+
+static gboolean
+gst_registry_save (GstRegistry * registry, gchar * format, ...)
+{
+  va_list var_args;
+  gsize written, len;
+  gboolean ret;
+  char *str;
+
+  va_start (var_args, format);
+  str = g_strdup_vprintf (format, var_args);
+  va_end (var_args);
+
+  len = strlen (str);
+
+  written = write (registry->cache_file, str, len);
+
+  if (len == written)
+    ret = TRUE;
+  else {
+    ret = FALSE;
+    GST_ERROR ("Failed to write registry to temporary file: %s",
+        g_strerror (errno));
+  }
+
+  g_free (str);
+
+  return ret;
+}
+
+static void
+add_to_char_array (gchar *** array, gchar * value)
+{
+  gchar **new;
+  gchar **old = *array;
+  gint i = 0;
+
+  /* expensive, but cycles are cheap... */
+  if (old)
+    while (old[i])
+      i++;
+  new = g_new0 (gchar *, i + 2);
+  new[i] = value;
+  while (i > 0) {
+    i--;
+    new[i] = old[i];
+  }
+  g_free (old);
+  *array = new;
+}
+
+/* read a string and copy it into the given location */
+static gboolean
+read_string (xmlTextReaderPtr reader, gchar ** write_to, gboolean allow_blank)
+{
+  int depth = xmlTextReaderDepth (reader);
+  gboolean found = FALSE;
+
+  while (xmlTextReaderRead (reader) == 1) {
+    if (xmlTextReaderDepth (reader) == depth) {
+      if (allow_blank && !found &&
+          xmlTextReaderNodeType (reader) == XML_READER_TYPE_END_ELEMENT) {
+        /* Allow blank strings */
+        *write_to = g_strdup ("");
+        found = TRUE;
+      }
+      return found;
+    }
+    if (xmlTextReaderNodeType (reader) == XML_READER_TYPE_TEXT) {
+      xmlChar *value;
+
+      if (found)
+        return FALSE;
+
+      value = xmlTextReaderValue (reader);
+      *write_to = g_strdup ((gchar *) value);
+      xmlFree (value);
+
+      found = TRUE;
+    }
+  }
+  return FALSE;
+}
+
+static gboolean
+read_const_interned_string (xmlTextReaderPtr reader, const gchar ** write_to,
+    gboolean allow_blank)
+{
+  gchar *s = NULL;
+
+  if (!read_string (reader, &s, allow_blank))
+    return FALSE;
+
+  *write_to = g_intern_string (s);
+  g_free (s);
+  return TRUE;
+}
+
+static gboolean
+read_uint (xmlTextReaderPtr reader, guint * write_to)
+{
+  int depth = xmlTextReaderDepth (reader);
+  gboolean found = FALSE;
+
+  while (xmlTextReaderRead (reader) == 1) {
+    if (xmlTextReaderDepth (reader) == depth)
+      return found;
+    if (xmlTextReaderNodeType (reader) == XML_READER_TYPE_TEXT) {
+      gchar *ret;
+      const gchar *s;
+
+      if (found) {
+        GST_DEBUG ("failed to read uint, multiple text nodes");
+        return FALSE;
+      }
+      s = (const gchar *) xmlTextReaderConstValue (reader);
+      *write_to = strtol (s, &ret, 0);
+      if (s == ret) {
+        GST_DEBUG ("failed to read uint, text didn't convert to int");
+        return FALSE;
+      }
+      found = TRUE;
+    }
+  }
+  GST_DEBUG ("failed to read uint, no text node");
+  return FALSE;
+}
+
+static gboolean
+read_enum (xmlTextReaderPtr reader, GType enum_type, guint * write_to)
+{
+  int depth = xmlTextReaderDepth (reader);
+  gboolean found = FALSE;
+
+  if (*write_to)
+    return FALSE;
+  while (xmlTextReaderRead (reader) == 1) {
+    if (xmlTextReaderDepth (reader) == depth)
+      return found;
+    if (xmlTextReaderNodeType (reader) == XML_READER_TYPE_TEXT) {
+      GEnumClass *enum_class;
+      GEnumValue *value;
+
+      if (found)
+        return FALSE;
+      enum_class = g_type_class_ref (enum_type);
+      if (!enum_class)
+        return FALSE;
+      value =
+          g_enum_get_value_by_nick (enum_class,
+          (gchar *) xmlTextReaderConstValue (reader));
+      if (value) {
+        *write_to = value->value;
+        found = TRUE;
+      }
+      g_type_class_unref (enum_class);
+    }
+  }
+  return FALSE;
+}
+
+static GstStaticPadTemplate *
+load_pad_template (xmlTextReaderPtr reader)
+{
+  int ret;
+  int depth = xmlTextReaderDepth (reader);
+  const gchar *name = NULL;
+  gchar *caps_str = NULL;
+  guint direction = 0, presence = 0;
+
+  while ((ret = xmlTextReaderRead (reader)) == 1) {
+    if (xmlTextReaderDepth (reader) == depth) {
+      GstStaticPadTemplate *template;
+
+      template = g_new0 (GstStaticPadTemplate, 1);
+      template->name_template = name;   /* must be an interned string! */
+      template->presence = presence;
+      template->direction = direction;
+      template->static_caps.string = caps_str;
+
+      return template;
+    }
+    if (xmlTextReaderNodeType (reader) == XML_READER_TYPE_ELEMENT &&
+        xmlTextReaderDepth (reader) == depth + 1) {
+      const gchar *tag = (gchar *) xmlTextReaderConstName (reader);
+
+      if (g_str_equal (tag, "nametemplate")) {
+        read_const_interned_string (reader, &name, FALSE);
+      } else if (g_str_equal (tag, "direction")) {
+        read_enum (reader, GST_TYPE_PAD_DIRECTION, &direction);
+      } else if (g_str_equal (tag, "presence")) {
+        read_enum (reader, GST_TYPE_PAD_PRESENCE, &presence);
+      } else if (!strncmp (tag, "caps", 4)) {
+        read_string (reader, &caps_str, FALSE);
+      }
+    }
+  }
+  g_free (caps_str);
+
+  return NULL;
+}
+
+static GstPluginFeature *
+load_feature (xmlTextReaderPtr reader)
+{
+  int ret;
+  int depth;
+  xmlChar *feature_name;
+  GstPluginFeature *feature;
+  GType type;
+
+  depth = xmlTextReaderDepth (reader);
+  feature_name = xmlTextReaderGetAttribute (reader, BAD_CAST "typename");
+
+  GST_LOG ("loading feature '%s'", GST_STR_NULL ((const char *) feature_name));
+
+  if (!feature_name)
+    return NULL;
+
+  type = g_type_from_name ((const char *) feature_name);
+  xmlFree (feature_name);
+  feature_name = NULL;
+
+  if (!type) {
+    return NULL;
+  }
+  feature = g_object_new (type, NULL);
+  if (!feature) {
+    return NULL;
+  }
+  if (!GST_IS_PLUGIN_FEATURE (feature)) {
+    /* don't really know what it is */
+    if (GST_IS_OBJECT (feature))
+      gst_object_unref (feature);
+    else
+      g_object_unref (feature);
+    return NULL;
+  }
+  while ((ret = xmlTextReaderRead (reader)) == 1) {
+    if (xmlTextReaderDepth (reader) == depth) {
+      GST_LOG ("loaded feature %p with name %s", feature, feature->name);
+      return feature;
+    }
+    if (xmlTextReaderNodeType (reader) == XML_READER_TYPE_ELEMENT &&
+        xmlTextReaderDepth (reader) == depth + 1) {
+      const gchar *tag = (gchar *) xmlTextReaderConstName (reader);
+
+      if (g_str_equal (tag, "name"))
+        read_string (reader, &feature->name, FALSE);
+      else if (g_str_equal (tag, "rank"))
+        read_uint (reader, &feature->rank);
+
+      if (GST_IS_ELEMENT_FACTORY (feature)) {
+        GstElementFactory *factory = GST_ELEMENT_FACTORY_CAST (feature);
+
+        if (g_str_equal (tag, "longname")) {
+          int ret;
+
+          ret = read_string (reader, &factory->details.longname, TRUE);
+          GST_LOG ("longname ret=%d, name=%s", ret, factory->details.longname);
+        } else if (g_str_equal (tag, "class")) {
+          read_string (reader, &factory->details.klass, TRUE);
+        } else if (g_str_equal (tag, "description")) {
+          read_string (reader, &factory->details.description, TRUE);
+        } else if (g_str_equal (tag, "author")) {
+          read_string (reader, &factory->details.author, TRUE);
+        } else if (g_str_equal (tag, "uri_type")) {
+          gchar *s = NULL;
+
+          if (read_string (reader, &s, FALSE)) {
+            if (g_ascii_strncasecmp (s, "sink", 4) == 0) {
+              factory->uri_type = GST_URI_SINK;
+            } else if (g_ascii_strncasecmp (s, "source", 5) == 0) {
+              factory->uri_type = GST_URI_SRC;
+            }
+            g_free (s);
+          }
+        } else if (g_str_equal (tag, "uri_protocol")) {
+          gchar *s = NULL;
+
+          if (read_string (reader, &s, FALSE))
+            add_to_char_array (&factory->uri_protocols, s);
+        } else if (g_str_equal (tag, "interface")) {
+          gchar *s = NULL;
+
+          if (read_string (reader, &s, FALSE)) {
+            __gst_element_factory_add_interface (factory, s);
+            /* add_interface strdup's s */
+            g_free (s);
+          }
+        } else if (g_str_equal (tag, "padtemplate")) {
+          GstStaticPadTemplate *template = load_pad_template (reader);
+
+          if (template) {
+            GST_LOG ("adding template %s to factory %s",
+                GST_STR_NULL (GST_PAD_TEMPLATE_NAME_TEMPLATE (template)),
+                GST_PLUGIN_FEATURE_NAME (feature));
+            __gst_element_factory_add_static_pad_template (factory, template);
+          }
+        }
+      } else if (GST_IS_TYPE_FIND_FACTORY (feature)) {
+        GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (feature);
+
+        if (g_str_equal (tag, "extension")) {
+          gchar *s = NULL;
+
+          if (read_string (reader, &s, TRUE))
+            add_to_char_array (&factory->extensions, s);
+        } else if (g_str_equal (tag, "caps")) {
+          gchar *s = NULL;
+
+          if (read_string (reader, &s, FALSE)) {
+            factory->caps = gst_caps_from_string (s);
+            g_free (s);
+          }
+        }
+#ifndef GST_DISABLE_INDEX
+      } else if (GST_IS_INDEX_FACTORY (feature)) {
+        GstIndexFactory *factory = GST_INDEX_FACTORY (feature);
+
+        if (g_str_equal (tag, "longdesc"))
+          read_string (reader, &factory->longdesc, TRUE);
+#endif
+      }
+    }
+  }
+
+  GST_WARNING ("Error reading feature from registry: registry corrupt?");
+  return NULL;
+}
+
+static GstPlugin *
+load_plugin (xmlTextReaderPtr reader, GList ** feature_list)
+{
+  int ret;
+  GstPlugin *plugin;
+
+  *feature_list = NULL;
+
+  GST_LOG ("creating new plugin and parsing");
+
+  plugin = g_object_new (GST_TYPE_PLUGIN, NULL);
+
+  plugin->flags |= GST_PLUGIN_FLAG_CACHED;
+  while ((ret = xmlTextReaderRead (reader)) == 1) {
+    if (xmlTextReaderDepth (reader) == 1) {
+      return plugin;
+    }
+    if (xmlTextReaderNodeType (reader) == XML_READER_TYPE_ELEMENT &&
+        xmlTextReaderDepth (reader) == 2) {
+      const gchar *tag = (gchar *) xmlTextReaderConstName (reader);
+
+      if (g_str_equal (tag, "name")) {
+        int ret;
+
+        ret = read_const_interned_string (reader, &plugin->desc.name, FALSE);
+        GST_LOG ("name ret=%d, name=%s", ret, plugin->desc.name);
+        if (!ret)
+          break;
+      } else if (g_str_equal (tag, "description")) {
+        if (!read_string (reader, &plugin->desc.description, TRUE)) {
+          GST_WARNING ("description field was invalid in registry");
+          break;
+        }
+        GST_LOG ("description %s", plugin->desc.description);
+      } else if (g_str_equal (tag, "filename")) {
+        if (!read_string (reader, &plugin->filename, FALSE)) {
+          GST_WARNING ("filename field was invalid in registry");
+          break;
+        }
+        GST_LOG ("filename %s", plugin->filename);
+        plugin->basename = g_path_get_basename (plugin->filename);
+      } else if (g_str_equal (tag, "version")) {
+        if (!read_const_interned_string (reader, &plugin->desc.version, TRUE)) {
+          GST_WARNING ("version field was invalid in registry");
+          break;
+        }
+        GST_LOG ("version %s", plugin->desc.version);
+      } else if (g_str_equal (tag, "license")) {
+        if (!read_const_interned_string (reader, &plugin->desc.license, TRUE)) {
+          GST_WARNING ("license field was invalid in registry");
+          break;
+        }
+        GST_LOG ("license %s", plugin->desc.license);
+      } else if (g_str_equal (tag, "source")) {
+        if (!read_const_interned_string (reader, &plugin->desc.source, TRUE)) {
+          GST_WARNING ("source field was invalid in registry");
+          break;
+        }
+        GST_LOG ("source %s", plugin->desc.source);
+      } else if (g_str_equal (tag, "package")) {
+        if (!read_const_interned_string (reader, &plugin->desc.package, TRUE)) {
+          GST_WARNING ("package field was invalid in registry");
+          break;
+        }
+        GST_LOG ("package %s", plugin->desc.package);
+      } else if (g_str_equal (tag, "origin")) {
+        if (!read_const_interned_string (reader, &plugin->desc.origin, TRUE)) {
+          GST_WARNING ("failed to read origin");
+          break;
+        }
+      } else if (g_str_equal (tag, "m32p")) {
+        char *s;
+
+        if (!read_string (reader, &s, FALSE)) {
+          GST_WARNING ("failed to read mtime");
+          break;
+        }
+        plugin->file_mtime = strtol (s, NULL, 0);
+        GST_LOG ("mtime %d", (int) plugin->file_mtime);
+        g_free (s);
+      } else if (g_str_equal (tag, "size")) {
+        unsigned int x;
+
+        if (read_uint (reader, &x)) {
+          plugin->file_size = x;
+          GST_LOG ("file_size %" G_GINT64_FORMAT, (gint64) plugin->file_size);
+        } else {
+          GST_WARNING ("failed to read size");
+        }
+      } else if (g_str_equal (tag, "feature")) {
+        GstPluginFeature *feature = load_feature (reader);
+
+        if (feature) {
+          feature->plugin_name = plugin->desc.name;     /* interned string */
+          *feature_list = g_list_prepend (*feature_list, feature);
+        }
+      } else {
+        GST_WARNING ("unknown tag %s", tag);
+      }
+    }
+  }
+  gst_object_unref (plugin);
+
+  GST_WARNING ("problem reading plugin");
+
+  return NULL;
+}
+
+/**
+ * gst_registry_xml_read_cache:
+ * @registry: a #GstRegistry
+ * @location: a filename
+ *
+ * Read the contents of the XML cache file at @location into @registry.
+ *
+ * Returns: %TRUE on success.
+ */
+gboolean
+gst_registry_xml_read_cache (GstRegistry * registry, const char *location)
+{
+  GMappedFile *mapped = NULL;
+  GTimer *timer;
+  gdouble seconds;
+  xmlTextReaderPtr reader = NULL;
+  int ret;
+  gboolean in_registry = FALSE;
+  FILE *file = NULL;
+
+  /* make sure these types exist */
+  GST_TYPE_ELEMENT_FACTORY;
+  GST_TYPE_TYPE_FIND_FACTORY;
+#ifndef GST_DISABLE_INDEX
+  GST_TYPE_INDEX_FACTORY;
+#endif
+
+  timer = g_timer_new ();
+
+  mapped = g_mapped_file_new (location, FALSE, NULL);
+  if (mapped) {
+    reader = xmlReaderForMemory (g_mapped_file_get_contents (mapped),
+        g_mapped_file_get_length (mapped), NULL, NULL, 0);
+    if (reader == NULL) {
+      g_mapped_file_free (mapped);
+      mapped = NULL;
+    }
+  }
+
+  if (reader == NULL) {
+    file = fopen (location, "r");
+    if (file == NULL) {
+      g_timer_destroy (timer);
+      return FALSE;
+    }
+
+    reader = xmlReaderForFd (fileno (file), NULL, NULL, 0);
+    if (!reader) {
+      fclose (file);
+      g_timer_destroy (timer);
+      return FALSE;
+    }
+  }
+
+  while ((ret = xmlTextReaderRead (reader)) == 1) {
+    if (xmlTextReaderDepth (reader) == 0) {
+      in_registry = xmlTextReaderNodeType (reader) == XML_READER_TYPE_ELEMENT &&
+          g_str_equal ("GST-PluginRegistry", xmlTextReaderConstName (reader));
+    } else if (in_registry) {
+      if (xmlTextReaderDepth (reader) == 1 &&
+          xmlTextReaderNodeType (reader) == XML_READER_TYPE_ELEMENT) {
+        const gchar *tag = (const gchar *) xmlTextReaderConstName (reader);
+
+        if (g_str_equal (tag, "plugin")) {
+          GList *feature_list;
+          GstPlugin *plugin = load_plugin (reader, &feature_list);
+
+          if (plugin) {
+            GList *g;
+
+            gst_registry_add_plugin (registry, plugin);
+            for (g = feature_list; g; g = g_list_next (g)) {
+              gst_registry_add_feature (registry,
+                  GST_PLUGIN_FEATURE_CAST (g->data));
+            }
+            g_list_free (feature_list);
+          }
+        }
+      }
+    }
+  }
+  xmlFreeTextReader (reader);
+  if (ret != 0) {
+    GST_ERROR ("parsing registry cache: %s", location);
+    if (mapped)
+      g_mapped_file_free (mapped);
+    if (file)
+      fclose (file);
+    g_timer_destroy (timer);
+    return FALSE;
+  }
+
+  g_timer_stop (timer);
+  seconds = g_timer_elapsed (timer, NULL);
+  g_timer_destroy (timer);
+
+  GST_INFO ("loaded %s in %lf seconds", location, seconds);
+
+  if (mapped)
+    g_mapped_file_free (mapped);
+
+  if (file)
+    fclose (file);
+
+  return TRUE;
+}
+
+/*
+ * Save
+ */
+static gboolean
+gst_registry_save_escaped (GstRegistry * registry, const char *prefix,
+    const char *tag, const char *value)
+{
+  gboolean ret = TRUE;
+
+  if (value) {
+    gchar *v;
+
+    if (g_utf8_validate (value, -1, NULL)) {
+      v = g_markup_escape_text (value, -1);
+    } else {
+      g_warning ("Invalid UTF-8 while saving registry tag '%s'", tag);
+      v = g_strdup ("[ERROR: invalid UTF-8]");
+    }
+
+    ret = gst_registry_save (registry, "%s<%s>%s</%s>\n", prefix, tag, v, tag);
+    g_free (v);
+  }
+
+  return ret;
+}
+
+
+static gboolean
+gst_registry_xml_save_caps (GstRegistry * registry, const GstCaps * caps)
+{
+  /* we copy the caps here so we can simplify them before saving. This is a lot
+   * faster when loading them later on */
+  char *s;
+  GstCaps *copy = gst_caps_copy (caps);
+  gboolean ret;
+
+  gst_caps_do_simplify (copy);
+  s = gst_caps_to_string (copy);
+  gst_caps_unref (copy);
+
+  ret = gst_registry_save_escaped (registry, "  ", "caps", s);
+  g_free (s);
+  return ret;
+}
+
+static gboolean
+gst_registry_xml_save_pad_template (GstRegistry * registry,
+    GstStaticPadTemplate * template)
+{
+  gchar *presence;
+
+  if (!gst_registry_save_escaped (registry, "   ", "nametemplate",
+          template->name_template))
+    return FALSE;
+
+  if (!gst_registry_save (registry,
+          "   <direction>%s</direction>\n",
+          (template->direction == GST_PAD_SINK ? "sink" : "src")))
+    return FALSE;
+
+  switch (template->presence) {
+    case GST_PAD_ALWAYS:
+      presence = "always";
+      break;
+    case GST_PAD_SOMETIMES:
+      presence = "sometimes";
+      break;
+    case GST_PAD_REQUEST:
+      presence = "request";
+      break;
+    default:
+      presence = "unknown";
+      break;
+  }
+  if (!gst_registry_save (registry, "   <presence>%s</presence>\n", presence))
+    return FALSE;
+
+  if (template->static_caps.string) {
+    if (!gst_registry_save (registry, "   <caps>%s</caps>\n",
+            template->static_caps.string))
+      return FALSE;
+  }
+  return TRUE;
+}
+
+static gboolean
+gst_registry_xml_save_feature (GstRegistry * registry,
+    GstPluginFeature * feature)
+{
+  if (!gst_registry_save_escaped (registry, "  ", "name", feature->name))
+    return FALSE;
+
+  if (feature->rank > 0) {
+    gint rank = feature->rank;
+
+    if (!gst_registry_save (registry, "  <rank>%d</rank>\n", rank))
+      return FALSE;
+  }
+
+  if (GST_IS_ELEMENT_FACTORY (feature)) {
+    GstElementFactory *factory = GST_ELEMENT_FACTORY (feature);
+    GList *walk;
+
+    if (!gst_registry_save_escaped (registry, "  ", "longname",
+            factory->details.longname))
+      return FALSE;
+    if (!gst_registry_save_escaped (registry, "  ", "class",
+            factory->details.klass))
+      return FALSE;
+    if (!gst_registry_save_escaped (registry, "  ", "description",
+            factory->details.description))
+      return FALSE;
+    if (!gst_registry_save_escaped (registry, "  ", "author",
+            factory->details.author))
+      return FALSE;
+
+    walk = factory->staticpadtemplates;
+
+    while (walk) {
+      GstStaticPadTemplate *template = walk->data;
+
+      if (!gst_registry_save (registry, "  <padtemplate>\n"))
+        return FALSE;
+      if (!gst_registry_xml_save_pad_template (registry, template))
+        return FALSE;
+      if (!gst_registry_save (registry, "  </padtemplate>\n"))
+        return FALSE;
+
+      walk = g_list_next (walk);
+    }
+
+    walk = factory->interfaces;
+    while (walk) {
+      if (!gst_registry_save_escaped (registry, "  ", "interface",
+              (gchar *) walk->data))
+        return FALSE;
+      walk = g_list_next (walk);
+    }
+
+    if (GST_URI_TYPE_IS_VALID (factory->uri_type)) {
+      if (!gst_registry_save_escaped (registry, "  ", "uri_type",
+              factory->uri_type == GST_URI_SINK ? "sink" : "source"))
+        return FALSE;
+      if (factory->uri_protocols) {
+        gchar **protocol;
+
+        protocol = factory->uri_protocols;
+        while (*protocol) {
+          if (!gst_registry_save_escaped (registry, "  ", "uri_protocol",
+                  *protocol))
+            return FALSE;
+          protocol++;
+        }
+      } else {
+        g_warning ("GStreamer feature '%s' is URI handler but does not provide"
+            " any protocols it can handle", feature->name);
+      }
+    }
+  } else if (GST_IS_TYPE_FIND_FACTORY (feature)) {
+    GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (feature);
+    gint i = 0;
+
+    if (factory->caps) {
+      if (!gst_registry_xml_save_caps (registry, factory->caps))
+        return FALSE;
+    }
+    if (factory->extensions) {
+      while (factory->extensions[i]) {
+        if (!gst_registry_save_escaped (registry, "  ", "extension",
+                factory->extensions[i]))
+          return FALSE;
+        i++;
+      }
+    }
+#ifndef GST_DISABLE_INDEX
+  } else if (GST_IS_INDEX_FACTORY (feature)) {
+    if (!gst_registry_save_escaped (registry, "  ", "longdesc",
+            GST_INDEX_FACTORY (feature)->longdesc))
+      return FALSE;
+#endif
+  }
+  return TRUE;
+}
+
+static gboolean
+gst_registry_xml_save_plugin (GstRegistry * registry, GstPlugin * plugin)
+{
+  GList *list;
+  GList *walk;
+  char s[100];
+
+  if (!gst_registry_save_escaped (registry, " ", "name", plugin->desc.name))
+    return FALSE;
+  if (!gst_registry_save_escaped (registry, " ", "description",
+          plugin->desc.description))
+    return FALSE;
+  if (!gst_registry_save_escaped (registry, " ", "filename", plugin->filename))
+    return FALSE;
+
+  sprintf (s, "%d", (int) plugin->file_size);
+  if (!gst_registry_save_escaped (registry, " ", "size", s))
+    return FALSE;
+
+  sprintf (s, "%d", (int) plugin->file_mtime);
+  if (!gst_registry_save_escaped (registry, " ", "m32p", s))
+    return FALSE;
+
+  if (!gst_registry_save_escaped (registry, " ", "version",
+          plugin->desc.version))
+    return FALSE;
+  if (!gst_registry_save_escaped (registry, " ", "license",
+          plugin->desc.license))
+    return FALSE;
+  if (!gst_registry_save_escaped (registry, " ", "source", plugin->desc.source))
+    return FALSE;
+  if (!gst_registry_save_escaped (registry, " ", "package",
+          plugin->desc.package))
+    return FALSE;
+  if (!gst_registry_save_escaped (registry, " ", "origin", plugin->desc.origin))
+    return FALSE;
+
+  list = gst_registry_get_feature_list_by_plugin (registry, plugin->desc.name);
+
+  for (walk = list; walk; walk = g_list_next (walk)) {
+    GstPluginFeature *feature = GST_PLUGIN_FEATURE (walk->data);
+
+    if (!gst_registry_save (registry,
+            " <feature typename=\"%s\">\n",
+            g_type_name (G_OBJECT_TYPE (feature))))
+      goto fail;
+    if (!gst_registry_xml_save_feature (registry, feature))
+      goto fail;
+    if (!gst_registry_save (registry, " </feature>\n"))
+      goto fail;
+  }
+
+  gst_plugin_feature_list_free (list);
+  return TRUE;
+
+fail:
+  gst_plugin_feature_list_free (list);
+  return FALSE;
+
+}
+
+/**
+ * gst_registry_xml_write_cache:
+ * @registry: a #GstRegistry
+ * @location: a filename
+ *
+ * Write @registry in an XML format at the location given by
+ * @location. Directories are automatically created.
+ *
+ * Returns: TRUE on success.
+ */
+gboolean
+gst_registry_xml_write_cache (GstRegistry * registry, const char *location)
+{
+  GList *walk;
+  char *tmp_location;
+
+  g_return_val_if_fail (GST_IS_REGISTRY (registry), FALSE);
+
+  tmp_location = g_strconcat (location, ".tmpXXXXXX", NULL);
+  registry->cache_file = g_mkstemp (tmp_location);
+  if (registry->cache_file == -1) {
+    char *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 (tmp_location);
+    tmp_location = g_strconcat (location, ".tmpXXXXXX", NULL);
+    registry->cache_file = g_mkstemp (tmp_location);
+
+    if (registry->cache_file == -1) {
+      GST_DEBUG ("g_mkstemp() failed: %s", g_strerror (errno));
+      g_free (tmp_location);
+      return FALSE;
+    }
+  }
+
+  if (!gst_registry_save (registry, "<?xml version=\"1.0\"?>\n"))
+    goto fail;
+  if (!gst_registry_save (registry, "<GST-PluginRegistry>\n"))
+    goto fail;
+
+
+  for (walk = g_list_last (registry->plugins); walk;
+      walk = g_list_previous (walk)) {
+    GstPlugin *plugin = GST_PLUGIN_CAST (walk->data);
+
+    if (!plugin->filename)
+      continue;
+
+    if (plugin->flags & GST_PLUGIN_FLAG_CACHED) {
+      int ret;
+      struct stat statbuf;
+
+      ret = g_stat (plugin->filename, &statbuf);
+      if (ret < 0)
+        continue;
+      if (plugin->file_mtime != statbuf.st_mtime ||
+          plugin->file_size != statbuf.st_size) {
+        continue;
+      }
+    }
+
+    if (!gst_registry_save (registry, "<plugin>\n"))
+      goto fail;
+    if (!gst_registry_xml_save_plugin (registry, plugin))
+      goto fail;
+    if (!gst_registry_save (registry, "</plugin>\n"))
+      goto fail;
+  }
+  if (!gst_registry_save (registry, "</GST-PluginRegistry>\n"))
+    goto fail;
+
+  /* check return value of close(), write errors may only get reported here */
+  if (close (registry->cache_file) < 0)
+    goto close_failed;
+
+  if (g_file_test (tmp_location, G_FILE_TEST_EXISTS)) {
+#ifdef WIN32
+    g_remove (location);
+#endif
+    if (g_rename (tmp_location, location) < 0)
+      goto rename_failed;
+  } else {
+    /* FIXME: shouldn't we return FALSE here? */
+  }
+
+  g_free (tmp_location);
+  GST_INFO ("Wrote XML registry cache");
+  return TRUE;
+
+/* ERRORS */
+fail:
+  {
+    (void) close (registry->cache_file);
+    /* fall through */
+  }
+fail_after_close:
+  {
+    g_remove (tmp_location);
+    g_free (tmp_location);
+    return FALSE;
+  }
+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;
+  }
+}