Registry

Description One registry holds the metadata of a set of plugins. All registries build the GstRegistryPool. Design: The GstRegistry object is a list of plugins and some functions for dealing with them. GstPlugins are matched 1-1 with a file on disk, and may or may not be loaded at a given time. There may be multiple GstRegistry 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: the cache may not contain information about a given file. the cache may have stale information. the cache may have current 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.

class Registry : ObjectGst {}

Constructors

this
this(GstRegistry* gstRegistry)

Sets our main struct and passes it to the parent class

Members

Functions

addFeature
int addFeature(PluginFeature feature)

Add the feature to the registry. The feature-added signal will be emitted. This function sinks feature.

addOnFeatureAdded
void addOnFeatureAdded(void delegate(void*, Registry) dlg, ConnectFlags connectFlags)

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

addOnPluginAdded
void addOnPluginAdded(void delegate(void*, Registry) dlg, ConnectFlags connectFlags)

Signals that a plugin has been added to the registry (possibly replacing a previously-added one by the same name) See Also GstPlugin, GstPluginFeature

addPlugin
int addPlugin(Plugin plugin)

Add the plugin to the registry. The plugin-added signal will be emitted. This function will sink plugin.

binaryReadCache
int binaryReadCache(string location)

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

binaryWriteCache
int binaryWriteCache(string location)

Write the registry to a cache to file at given location.

featureFilter
ListG featureFilter(GstPluginFeatureFilter filter, int first, void* userData)

Runs a filter against all features of the plugins in the registry and returns a GList with the results. If the first flag is set, only the first match is returned (as a list with a single object).

findFeature
PluginFeature findFeature(string name, GType type)

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

findPlugin
Plugin findPlugin(string name)

Find the plugin with the given name in the registry. The plugin will be reffed; caller is responsible for unreffing.

getFeatureList
ListG getFeatureList(GType type)

Retrieves a GList of GstPluginFeature of type.

getFeatureListByPlugin
ListG getFeatureListByPlugin(string name)

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

getPathList
ListG getPathList()

Get the list of paths for the given registry.

getPluginList
ListG getPluginList()

Get a copy of all plugins registered in the given registry. The refcount of each element in the list in incremented.

getRegistryStruct
GstRegistry* getRegistryStruct()
Undocumented in source. Be warned that the author may not have intended to support it.
getStruct
void* getStruct()

the main Gtk struct as a void*

lookup
Plugin lookup(string filename)

Look up a plugin in the given registry with the given filename. If found, plugin is reffed.

lookupFeature
PluginFeature lookupFeature(string name)

Find a GstPluginFeature with name in registry.

pluginFilter
ListG pluginFilter(GstPluginFilter filter, int first, void* userData)

Runs a filter against all plugins in the registry and returns a GList with the results. If the first flag is set, only the first match is returned (as a list with a single object). Every plugin is reffed; use gst_plugin_list_free() after use, which will unref again.

removeFeature
void removeFeature(PluginFeature feature)

Remove the feature from the registry. MT safe.

removePlugin
void removePlugin(Plugin plugin)

Remove the plugin from the registry. MT safe.

scanPath
int scanPath(string 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.

setStruct
void setStruct(GObject* obj)
Undocumented in source. Be warned that the author may not have intended to support it.
xmlReadCache
int xmlReadCache(string location)

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

xmlWriteCache
int xmlWriteCache(string location)

Write registry in an XML format at the location given by location. Directories are automatically created.

Static functions

callBackFeatureAdded
void callBackFeatureAdded(GstRegistry* registryStruct, void* feature, Registry _registry)
Undocumented in source. Be warned that the author may not have intended to support it.
callBackPluginAdded
void callBackPluginAdded(GstRegistry* registryStruct, void* plugin, Registry _registry)
Undocumented in source. Be warned that the author may not have intended to support it.
defaultRegistryCheckFeatureVersion
int defaultRegistryCheckFeatureVersion(string featureName, uint minMajor, uint minMinor, uint minMicro)

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

getDefault
Registry getDefault()

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

Variables

connectedSignals
int[string] connectedSignals;
gstRegistry
GstRegistry* gstRegistry;

the main Gtk struct

onFeatureAddedListeners
void delegate(void*, Registry)[] onFeatureAddedListeners;
Undocumented in source.
onPluginAddedListeners
void delegate(void*, Registry)[] onPluginAddedListeners;
Undocumented in source.

Inherited Members

From ObjectGst

gstObject
GstObject* gstObject;

the main Gtk struct

getObjectGstStruct
GstObject* getObjectGstStruct()
Undocumented in source. Be warned that the author may not have intended to support it.
getStruct
void* getStruct()

the main Gtk struct as a void*

setStruct
void setStruct(GObject* obj)
Undocumented in source. Be warned that the author may not have intended to support it.
connectedSignals
int[string] connectedSignals;
onDeepNotifyListeners
void delegate(ObjectGst, ParamSpec, ObjectGst)[] onDeepNotifyListeners;
Undocumented in source.
addOnDeepNotify
void addOnDeepNotify(void delegate(ObjectGst, ParamSpec, ObjectGst) dlg, ConnectFlags connectFlags)

The deep notify signal is used to be notified of property changes. It is typically attached to the toplevel bin to receive notifications from all the elements contained in that bin.

callBackDeepNotify
void callBackDeepNotify(GstObject* gstobjectStruct, GstObject* propObject, GParamSpec* prop, ObjectGst _objectGst)
Undocumented in source. Be warned that the author may not have intended to support it.
onObjectSavedListeners
void delegate(void*, ObjectGst)[] onObjectSavedListeners;
Undocumented in source.
addOnObjectSaved
void addOnObjectSaved(void delegate(void*, ObjectGst) dlg, ConnectFlags connectFlags)

Trigered whenever a new object is saved to XML. You can connect to this signal to insert custom XML tags into the core XML.

callBackObjectSaved
void callBackObjectSaved(GstObject* gstobjectStruct, void* xmlNode, ObjectGst _objectGst)
Undocumented in source. Be warned that the author may not have intended to support it.
onParentSetListeners
void delegate(ObjectG, ObjectGst)[] onParentSetListeners;
Undocumented in source.
addOnParentSet
void addOnParentSet(void delegate(ObjectG, ObjectGst) dlg, ConnectFlags connectFlags)

Emitted when the parent of an object is set.

callBackParentSet
void callBackParentSet(GstObject* gstobjectStruct, GObject* parent, ObjectGst _objectGst)
Undocumented in source. Be warned that the author may not have intended to support it.
onParentUnsetListeners
void delegate(ObjectG, ObjectGst)[] onParentUnsetListeners;
Undocumented in source.
addOnParentUnset
void addOnParentUnset(void delegate(ObjectG, ObjectGst) dlg, ConnectFlags connectFlags)

Emitted when the parent of an object is unset.

callBackParentUnset
void callBackParentUnset(GstObject* gstobjectStruct, GObject* parent, ObjectGst _objectGst)
Undocumented in source. Be warned that the author may not have intended to support it.
setName
int setName(string name)

Sets the name of object, or gives object a guaranteed unique name (if name is NULL). This function makes a copy of the provided name, so the caller retains ownership of the name it sent.

getName
string getName()

Returns a copy of the name of object. Caller should g_free() the return value after usage. For a nameless object, this returns NULL, which you can safely g_free() as well.

setParent
int setParent(ObjectGst parent)

Sets the parent of object to parent. The object's reference count will be incremented, and any floating reference will be removed (see gst_object_sink()). This function causes the parent-set signal to be emitted when the parent was successfully set.

getParent
ObjectGst getParent()

Returns the parent of object. This function increases the refcount of the parent object so you should gst_object_unref() it after usage.

unparent
void unparent()

Clear the parent of object, removing the associated reference. This function decreases the refcount of object. MT safe. Grabs and releases object's lock.

getNamePrefix
string getNamePrefix()

Returns a copy of the name prefix of object. Caller should g_free() the return value after usage. For a prefixless object, this returns NULL, which you can safely g_free() as well.

setNamePrefix
void setNamePrefix(string namePrefix)

Sets the name prefix of object to name_prefix. This function makes a copy of the provided name prefix, so the caller retains ownership of the name prefix it sent. MT safe. This function grabs and releases object's LOCK.

defaultDeepNotify
void defaultDeepNotify(ObjectG object, ObjectGst orig, ParamSpec pspec, string[] excludedProps)

A default deep_notify signal callback for an object. The user data should contain a pointer to an array of strings that should be excluded from the notify. The default handler will print the new value of the property using g_print. MT safe. This function grabs and releases object's LOCK for getting its path string.

defaultError
void defaultError(ErrorG error, string dbug)

A default error function. The default handler will simply print the error string using g_print.

checkUniqueness
int checkUniqueness(ListG list, string name)

Checks to see if there is any object named name in list. This function does not do any locking of any kind. You might want to protect the provided list with the lock of the owner of the list. This function will lock each GstObject in the list to compare the name, so be carefull when passing a list with a locked object.

hasAncestor
int hasAncestor(ObjectGst ancestor)

Check if object has an ancestor ancestor somewhere up in the hierarchy.

doref
void* doref(void* object)

Increments the refence count on object. This function does not take the lock on object because it relies on atomic refcounting. This object returns the input parameter to ease writing

unref
void unref(void* object)

Decrements the refence count on object. If reference count hits zero, destroy object. This function does not take the lock on object as it relies on atomic refcounting. The unref method should never be called with the LOCK held since this might deadlock the dispose function.

sink
void sink(void* object)

If object was floating, the GST_OBJECT_FLOATING flag is removed and object is unreffed. When object was not floating, this function does nothing. Any newly created object has a refcount of 1 and is floating. This function should be used when creating a new object to symbolically 'take ownership' of object. This done by first doing a gst_object_ref() to keep a reference to object and then gst_object_sink() to remove and unref any floating references to object. Use gst_object_set_parent() to have this done for you. MT safe. This function grabs and releases object lock.

replace
void replace(ObjectGst oldobj, ObjectGst newobj)

Unrefs the GstObject pointed to by oldobj, refs newobj and puts newobj in *oldobj. Be carefull when calling this function, it does not take any locks. You might want to lock the object owning oldobj pointer before calling this function. Make sure not to LOCK oldobj because it might be unreffed which could cause a deadlock when it is disposed.

getPathString
string getPathString()

Generates a string describing the path of object in the object hierarchy. Only useful (or used) for debugging.

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