Gst::Registry Class Reference

Gst::Registry — Abstract base class for management of Gst::Plugin objects. More...

#include <registry.h>

Inheritance diagram for Gst::Registry:

Gst::Object

List of all members.

Public Member Functions

virtual ~Registry ()
GstRegistry* gobj ()
 Provides access to the underlying C GObject.
const GstRegistry* gobj () const
 Provides access to the underlying C GObject.
GstRegistry* gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
Glib::ListHandle< Glib::RefPtr
<Gst::PluginFeature >> 
get_feature_list (GType type)
 Retrieves a List of Gst::PluginFeature of type.
Glib::ListHandle< Glib::RefPtr
<Gst::PluginFeature >> 
get_feature_list (const Glib::ustring& name)
 Retrieves a List of features of the plugin with name name.
Glib::ListHandle<Glib::ustring> get_path_list ()
 Get the list of paths for the given registry.
Glib::ListHandle< Glib::RefPtr
<Gst::Plugin >> 
get_plugin_list ()
 Get a copy of all plugins registered in the given registry.
bool add_plugin (const Glib::RefPtr<Gst::Plugin>& plugin)
 Add the plugin to the registry.
void remove_plugin (const Glib::RefPtr<Gst::Plugin>& plugin)
 Remove the plugin from the registry.
Glib::ListHandle< Glib::RefPtr
<Gst::Plugin >> 
get_plugin_list (const Plugin::SlotFilter& filter, bool first)
 Runs a filter against all plugins in the registry and returns a List with the results.
Glib::ListHandle< Glib::RefPtr
<Gst::PluginFeature >> 
get_feature_list (const PluginFeature::SlotFilter& filter, bool first)
 Runs a filter against all features of the plugins in the registry and returns a List with the results.
Glib::RefPtr<Gst::Pluginfind_plugin (const Glib::ustring& name)
 Find the plugin with the given name in the registry.
Glib::RefPtr<Gst::PluginFeaturefind_feature (const Glib::ustring& name, GType type)
 Find the pluginfeature with the given name and type in the registry.
Glib::RefPtr<Gst::PluginFeaturelookup_feature (const Glib::ustring& name)
 Find a Gst::PluginFeature with name in registry.
void add_path (const Glib::ustring& path)
 Add the given path to the registry.
void scan_path (const Glib::ustring& path)
 Add the given path to the registry.
bool xml_read_cache (const Glib::ustring& location)
 Read the contents of the XML cache file at location into registry.
bool xml_write_cache (const Glib::ustring& location)
 Write registry in an XML format at the location given by location.
Glib::RefPtr<Gst::Pluginlookup (const Glib::ustring& filename)
 Look up a plugin in the given registry with the given filename.
void remove_feature (const Glib::RefPtr<Gst::PluginFeature>& feature)
 Remove the feature from the registry.
void add_feature (const Glib::RefPtr<Gst::PluginFeature>& feature)
 Add the feature to the registry.
Glib::SignalProxy1< void,
const Glib::RefPtr
<Gst::PluginFeature >&> 
signal_feature_added ()
 Signals that a feature has been added to the registry (possibly replacing a previously-added one by the same name).
Glib::SignalProxy1< void,
const Glib::RefPtr
<Gst::Plugin >&> 
signal_plugin_added ()
 Signals that a plugin has been added to the registry (possibly replacing a previously-added one by the same name).

Static Public Member Functions

static Glib::RefPtr
<Gst::Registry
get_default ()
 Retrieves the default registry.
static bool check_feature_version (const Glib::ustring& feature_name, guint min_major, guint min_minor, guint min_micro)
 Checks whether a plugin feature by the given name exists in the default registry and whether its version is at least the version required.

Protected Member Functions

virtual void on_feature_added (const Glib::RefPtr<Gst::PluginFeature>& feature)
virtual void on_plugin_added (const Glib::RefPtr<Gst::Plugin>& plugin)

Related Functions

(Note that these are not member functions.)

Glib::RefPtr<Gst::Registrywrap (GstRegistry* object, bool take_copy=false)
 A Glib::wrap() method for this object.


Detailed Description

Gst::Registry — Abstract base class for management of Gst::Plugin objects.

One registry holds the metadata of a set of plugins. All registries build the GstRegistryPool.

Design:

The Gst::Registry object is a list of plugins and some functions for dealing with them. Gst::Plugins are matched 1-1 with a file on disk, and may or may not be loaded at a given time. There may be multiple Gst::Registry objects, but the "default registry" is the only object that has any meaning to the core.

The registry.xml file is actually a cache of plugin information. This is unlike versions prior to 0.10, where the registry file was the primary source of plugin information, and was created by the gst-register command.

The primary source, at all times, of plugin information is each plugin file itself. Thus, if an application wants information about a particular plugin, or wants to search for a feature that satisfies given criteria, the primary means of doing so is to load every plugin and look at the resulting information that is gathered in the default registry. Clearly, this is a time consuming process, so we cache information in the registry.xml file.

On startup, plugins are searched for in the plugin search path. This path can be set directly using the GST_PLUGIN_PATH environment variable. The registry file is loaded from ~/.gstreamer-$GST_MAJORMINOR/registry-$ARCH.xml or the file listed in the GST_REGISTRY env var. The only reason to change the registry location is for testing.

For each plugin that is found in the plugin search path, there could be 3 possibilities for cached information:

In the first two cases, the plugin is loaded and the cache updated. In addition to these cases, the cache may have entries for plugins that are not relevant to the current process. These are marked as not available to the current process. If the cache is updated for whatever reason, it is marked dirty.

A dirty cache is written out at the end of initialization. Each entry is checked to make sure the information is minimally valid. If not, the entry is simply dropped.

Implementation notes:

The "cache" and "default registry" are different concepts and can represent different sets of plugins. For various reasons, at init time, the cache is stored in the default registry, and plugins not relevant to the current process are marked with the GST_PLUGIN_FLAG_CACHED bit. These plugins are removed at the end of intitialization.


Constructor & Destructor Documentation

virtual Gst::Registry::~Registry (  )  [virtual]


Member Function Documentation

void Gst::Registry::add_feature ( const Glib::RefPtr<Gst::PluginFeature>&  feature  ) 

Add the feature to the registry.

The feature-added signal will be emitted. This function sinks feature.

Parameters:
feature The feature to add.
Returns:
true on success.
MT safe.

void Gst::Registry::add_path ( const Glib::ustring &  path  ) 

Add the given path to the registry.

The syntax of the path is specific to the registry. If the path has already been added, do nothing.

Parameters:
path The path to add to the registry.

bool Gst::Registry::add_plugin ( const Glib::RefPtr<Gst::Plugin>&  plugin  ) 

Add the plugin to the registry.

The plugin-added signal will be emitted. This function will sink plugin.

Parameters:
plugin The plugin to add.
Returns:
true on success.
MT safe.

static bool Gst::Registry::check_feature_version ( const Glib::ustring &  feature_name,
guint  min_major,
guint  min_minor,
guint  min_micro 
) [static]

Checks whether a plugin feature by the given name exists in the default registry and whether its version is at least the version required.

Parameters:
feature_name The name of the feature (e.g. "oggdemux").
min_major The minimum major version number.
min_minor The minimum minor version number.
min_micro The minimum micro version number.
Returns:
#true if the feature could be found and the version is the same as the required version or newer, and #false otherwise.

Glib::RefPtr<Gst::PluginFeature> Gst::Registry::find_feature ( const Glib::ustring &  name,
GType  type 
)

Find the pluginfeature with the given name and type in the registry.

Parameters:
name The pluginfeature name to find.
type The pluginfeature type to find.
Returns:
The pluginfeature with the given name and type or 0 if the plugin was not found. Gst::Object::unref() after usage.
MT safe.

Glib::RefPtr<Gst::Plugin> Gst::Registry::find_plugin ( const Glib::ustring &  name  ) 

Find the plugin with the given name in the registry.

The plugin will be reffed; caller is responsible for unreffing.

Parameters:
name The plugin name to find.
Returns:
The plugin with the given name or 0 if the plugin was not found. Gst::Object::unref() after usage.
MT safe.

static Glib::RefPtr<Gst::Registry> Gst::Registry::get_default (  )  [static]

Retrieves the default registry.

The caller does not own a reference on the registry, as it is alive as long as GStreamer is initialized.

Returns:
The default Gst::Registry.

Glib::ListHandle<Glib::RefPtr<Gst::PluginFeature>> Gst::Registry::get_feature_list ( const PluginFeature::SlotFilter filter,
bool  first 
)

Runs a filter against all features of the plugins in the registry and returns a List with the results.

If the first flag is set, only the first match is returned (as a list with a single object).

Parameters:
registry Registry to query.
filter The filter to use.
first Only return first match.
Returns:
A list of Gst::PluginFeature. MT safe.

Glib::ListHandle<Glib::RefPtr<Gst::PluginFeature>> Gst::Registry::get_feature_list ( const Glib::ustring &  name  ) 

Retrieves a List of features of the plugin with name name.

Parameters:
name A plugin name.
Returns:
A List of Gst::PluginFeature. Use Gst::PluginFeature::list_free() after usage.

Glib::ListHandle<Glib::RefPtr<Gst::PluginFeature>> Gst::Registry::get_feature_list ( GType  type  ) 

Retrieves a List of Gst::PluginFeature of type.

Parameters:
type A Type.
Returns:
A List of Gst::PluginFeature of type. Use Gst::PluginFeature::list_free() after usage.
MT safe.

Glib::ListHandle< Glib::ustring > Gst::Registry::get_path_list (  ) 

Get the list of paths for the given registry.

Returns:
A Glist of paths as strings. g_list_free after use.
MT safe.

Glib::ListHandle<Glib::RefPtr<Gst::Plugin>> Gst::Registry::get_plugin_list ( const Plugin::SlotFilter filter,
bool  first 
)

Runs a filter against all plugins in the registry and returns a List with the results.

If the first flag is set, only the first match is returned (as a list with a single object).

Parameters:
filter The filter to use.
first Only return first match.
Returns:
A list of Gst::Plugin. MT safe.

Glib::ListHandle<Glib::RefPtr<Gst::Plugin>> Gst::Registry::get_plugin_list (  ) 

Get a copy of all plugins registered in the given registry.

The refcount of each element in the list in incremented.

Returns:
A List of Gst::Plugin. Use Gst::Plugin::list_free() after usage.
MT safe.

const GstRegistry* Gst::Registry::gobj (  )  const [inline]

Provides access to the underlying C GObject.

Reimplemented from Gst::Object.

GstRegistry* Gst::Registry::gobj (  )  [inline]

Provides access to the underlying C GObject.

Reimplemented from Gst::Object.

GstRegistry* Gst::Registry::gobj_copy (  ) 

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

Reimplemented from Gst::Object.

Glib::RefPtr<Gst::Plugin> Gst::Registry::lookup ( const Glib::ustring &  filename  ) 

Look up a plugin in the given registry with the given filename.

If found, plugin is reffed.

Parameters:
filename The name of the file to look up.
Returns:
The Gst::Plugin if found, or 0 if not. Gst::Object::unref() after usage.

Glib::RefPtr<Gst::PluginFeature> Gst::Registry::lookup_feature ( const Glib::ustring &  name  ) 

Find a Gst::PluginFeature with name in registry.

Parameters:
name A Gst::PluginFeature name.
Returns:
A Gst::PluginFeature with its refcount incremented, use Gst::Object::unref() after usage.
MT safe.

virtual void Gst::Registry::on_feature_added ( const Glib::RefPtr<Gst::PluginFeature>&  feature  )  [protected, virtual]

virtual void Gst::Registry::on_plugin_added ( const Glib::RefPtr<Gst::Plugin>&  plugin  )  [protected, virtual]

void Gst::Registry::remove_feature ( const Glib::RefPtr<Gst::PluginFeature>&  feature  ) 

Remove the feature from the registry.

MT safe.

Parameters:
feature The feature to remove.

void Gst::Registry::remove_plugin ( const Glib::RefPtr<Gst::Plugin>&  plugin  ) 

Remove the plugin from the registry.

MT safe.

Parameters:
plugin The plugin to remove.

void Gst::Registry::scan_path ( const Glib::ustring &  path  ) 

Add the given path to the registry.

The syntax of the path is specific to the registry. If the path has already been added, do nothing.

Parameters:
path The path to add to the registry.
Returns:
true if registry changed.

Glib::SignalProxy1<void,const Glib::RefPtr<Gst::PluginFeature>&> Gst::Registry::signal_feature_added (  ) 

Signals that a feature has been added to the registry (possibly replacing a previously-added one by the same name).

Prototype:
void on_my_feature_added(const Glib::RefPtr<Gst::PluginFeature>& feature)

Glib::SignalProxy1<void,const Glib::RefPtr<Gst::Plugin>&> Gst::Registry::signal_plugin_added (  ) 

Signals that a plugin has been added to the registry (possibly replacing a previously-added one by the same name).

Prototype:
void on_my_plugin_added(const Glib::RefPtr<Gst::Plugin>& plugin)

bool Gst::Registry::xml_read_cache ( const Glib::ustring &  location  ) 

Read the contents of the XML cache file at location into registry.

Parameters:
location A filename.
Returns:
true on success.

bool Gst::Registry::xml_write_cache ( const Glib::ustring &  location  ) 

Write registry in an XML format at the location given by location.

Directories are automatically created.

Parameters:
location A filename.
Returns:
true on success.


Friends And Related Function Documentation

Glib::RefPtr<Gst::Registry> wrap ( GstRegistry *  object,
bool  take_copy = false 
) [related]

A Glib::wrap() method for this object.

Parameters:
object The C instance.
take_copy False if the result should take ownership of the C instance. True if it should take a new copy or ref.
Returns:
A C++ instance that wraps this C instance.


The documentation for this class was generated from the following file:

Generated on Thu Jan 15 09:33:13 2009 for gstreamermm by  doxygen 1.5.7.1