Package ch.bailu.gtk.gst

Klasse Registry

java.lang.Object
ch.bailu.gtk.type.Type
ch.bailu.gtk.type.Pointer
ch.bailu.gtk.gobject.Object
ch.bailu.gtk.type.PropertyHolder
ch.bailu.gtk.gst.Registry
Alle implementierten Schnittstellen:
PointerInterface
public class Registry extends PropertyHolder
One registry holds the metadata of a set of plugins.

<emphasis role="bold">Design:</emphasis>

The #GstRegistry object is a list of plugins and some functions for dealing
with them. Each #GstPlugin is matched 1-1 with a file on disk, and may or may
not be loaded at a given time.

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 file. The format
and location of the cache file is internal to gstreamer.

On startup, plugins are searched for in the plugin search path. The following
locations are checked in this order:

* location from --gst-plugin-path commandline option.
* the GST_PLUGIN_PATH environment variable.
* the GST_PLUGIN_SYSTEM_PATH environment variable.
* default locations (if GST_PLUGIN_SYSTEM_PATH is not set).
Those default locations are:
`$XDG_DATA_HOME/gstreamer-$GST_API_VERSION/plugins/`
and `$prefix/libs/gstreamer-$GST_API_VERSION/`.
[$XDG_DATA_HOME](http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html) defaults to
`$HOME/.local/share`.

The registry cache file is loaded from
`$XDG_CACHE_HOME/gstreamer-$GST_API_VERSION/registry-$ARCH.bin`
(where $XDG_CACHE_HOME defaults to `$HOME/.cache`) or the file listed in the `GST_REGISTRY`
env var. One 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 "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 initialization.

https://gstreamer.freedesktop.org/documentation/gstreamer/gi-index.html

  • Felddetails

  • Konstruktordetails

  • Methodendetails

    • getClassHandler

      public static ClassHandler getClassHandler()

    • addFeature

      public boolean addFeature(@Nonnull PluginFeature feature)
      Add the feature to the registry. The feature-added signal will be emitted.

      @feature's reference count will be incremented, and any floating
      reference will be removed (see gst_object_ref_sink())
      Parameter:
      feature - the feature to add
      Gibt zurück:
      %TRUE on success. MT safe.

    • addPlugin

      public boolean addPlugin(@Nonnull Plugin plugin)
      Add the plugin to the registry. The plugin-added signal will be emitted.

      @plugin's reference count will be incremented, and any floating
      reference will be removed (see gst_object_ref_sink())
      Parameter:
      plugin - the plugin to add
      Gibt zurück:
      %TRUE on success. MT safe.

    • checkFeatureVersion

      public boolean checkFeatureVersion(@Nonnull Str feature_name, int min_major, int min_minor, int min_micro)
      Checks whether a plugin feature by the given name exists in
      @registry and whether its version is at least the
      version required.
      Parameter:
      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
      Gibt zurück:
      %TRUE if the feature could be found and the version is the same as the required version or newer, and %FALSE otherwise.

    • checkFeatureVersion

      public boolean checkFeatureVersion(String feature_name, int min_major, int min_minor, int min_micro)
      Checks whether a plugin feature by the given name exists in
      @registry and whether its version is at least the
      version required.
      Parameter:
      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
      Gibt zurück:
      %TRUE if the feature could be found and the version is the same as the required version or newer, and %FALSE otherwise.

    • featureFilter

      public List featureFilter(Registry.OnPluginFeatureFilter filter, boolean first, @Nullable Pointer user_data)
      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).
      Parameter:
      filter - the filter to use
      first - only return first match
      user_data - user data passed to the filter function
      Gibt zurück:
      a #GList of #GstPluginFeature. Use gst_plugin_feature_list_free() after usage. MT safe.

    • findFeature

      public PluginFeature findFeature(@Nonnull Str name, long type)
      Find the pluginfeature with the given name and type in the registry.
      Parameter:
      name - the pluginfeature name to find
      type - the pluginfeature type to find
      Gibt zurück:
      the pluginfeature with the given name and type or %NULL if the plugin was not found. gst_object_unref() after usage. MT safe.

    • findFeature

      public PluginFeature findFeature(String name, long type)
      Find the pluginfeature with the given name and type in the registry.
      Parameter:
      name - the pluginfeature name to find
      type - the pluginfeature type to find
      Gibt zurück:
      the pluginfeature with the given name and type or %NULL if the plugin was not found. gst_object_unref() after usage. MT safe.

    • findPlugin

      public Plugin findPlugin(@Nonnull Str name)
      Find the plugin with the given name in the registry.
      The plugin will be reffed; caller is responsible for unreffing.
      Parameter:
      name - the plugin name to find
      Gibt zurück:
      the plugin with the given name or %NULL if the plugin was not found. gst_object_unref() after usage. MT safe.

    • findPlugin

      public Plugin findPlugin(String name)
      Find the plugin with the given name in the registry.
      The plugin will be reffed; caller is responsible for unreffing.
      Parameter:
      name - the plugin name to find
      Gibt zurück:
      the plugin with the given name or %NULL if the plugin was not found. gst_object_unref() after usage. MT safe.

    • getFeatureList

      public List getFeatureList(long type)
      Retrieves a #GList of #GstPluginFeature of @type.
      Parameter:
      type - a #GType.
      Gibt zurück:
      a #GList of #GstPluginFeature of @type. Use gst_plugin_feature_list_free() after use MT safe.

    • getFeatureListByPlugin

      public List getFeatureListByPlugin(@Nonnull Str name)
      Retrieves a #GList of features of the plugin with name @name.
      Parameter:
      name - a plugin name.
      Gibt zurück:
      a #GList of #GstPluginFeature. Use gst_plugin_feature_list_free() after usage.

    • getFeatureListByPlugin

      public List getFeatureListByPlugin(String name)
      Retrieves a #GList of features of the plugin with name @name.
      Parameter:
      name - a plugin name.
      Gibt zurück:
      a #GList of #GstPluginFeature. Use gst_plugin_feature_list_free() after usage.

    • getFeatureListCookie

      public int getFeatureListCookie()
      Returns the registry's feature list cookie. This changes
      every time a feature is added or removed from the registry.
      Gibt zurück:
      the feature list cookie.

    • getPluginList

      public List getPluginList()
      Get a copy of all plugins registered in the given registry. The refcount
      of each element in the list in incremented.
      Gibt zurück:
      a #GList of #GstPlugin. Use gst_plugin_list_free() after usage. MT safe.

    • lookup

      public Plugin lookup(@Nonnull Str filename)
      Look up a plugin in the given registry with the given filename.
      If found, plugin is reffed.
      Parameter:
      filename - the name of the file to look up
      Gibt zurück:
      the #GstPlugin if found, or %NULL if not. gst_object_unref() after usage.

    • lookup

      public Plugin lookup(String filename)
      Look up a plugin in the given registry with the given filename.
      If found, plugin is reffed.
      Parameter:
      filename - the name of the file to look up
      Gibt zurück:
      the #GstPlugin if found, or %NULL if not. gst_object_unref() after usage.

    • lookupFeature

      public PluginFeature lookupFeature(@Nonnull Str name)
      Find a #GstPluginFeature with @name in @registry.
      Parameter:
      name - a #GstPluginFeature name
      Gibt zurück:
      a #GstPluginFeature with its refcount incremented, use gst_object_unref() after usage. MT safe.

    • lookupFeature

      public PluginFeature lookupFeature(String name)
      Find a #GstPluginFeature with @name in @registry.
      Parameter:
      name - a #GstPluginFeature name
      Gibt zurück:
      a #GstPluginFeature with its refcount incremented, use gst_object_unref() after usage. MT safe.

    • pluginFilter

      public List pluginFilter(Registry.OnPluginFilter filter, boolean first, @Nullable Pointer user_data)
      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.
      Parameter:
      filter - the filter to use
      first - only return first match
      user_data - user data passed to the filter function
      Gibt zurück:
      a #GList of #GstPlugin. Use gst_plugin_list_free() after usage. MT safe.

    • removeFeature

      public void removeFeature(@Nonnull PluginFeature feature)
      Remove the feature from the registry.

      MT safe.
      Parameter:
      feature - the feature to remove

    • removePlugin

      public void removePlugin(@Nonnull Plugin plugin)
      Remove the plugin from the registry.

      MT safe.
      Parameter:
      plugin - the plugin to remove

    • scanPath

      public boolean scanPath(@Nonnull Str path)
      Scan the given path for plugins to add to the registry. The syntax of the
      path is specific to the registry.
      Parameter:
      path - the path to scan
      Gibt zurück:
      %TRUE if registry changed

    • scanPath

      public boolean scanPath(String path)
      Scan the given path for plugins to add to the registry. The syntax of the
      path is specific to the registry.
      Parameter:
      path - the path to scan
      Gibt zurück:
      %TRUE if registry changed

    • onFeatureAdded

      public SignalHandler onFeatureAdded(Registry.OnFeatureAdded signal)
      Connect to signal "feature-added".
      See Registry.OnFeatureAdded.onFeatureAdded(ch.bailu.gtk.gst.PluginFeature) for signal description.
      Field SIGNAL_ON_FEATURE_ADDED contains original signal name and can be used as resource reference.
      Parameter:
      signal - callback function (lambda).
      Gibt zurück:
      SignalHandler. Can be used to disconnect signal and to release callback function.

    • onPluginAdded

      public SignalHandler onPluginAdded(Registry.OnPluginAdded signal)
      Connect to signal "plugin-added".
      See Registry.OnPluginAdded.onPluginAdded(ch.bailu.gtk.gst.Plugin) for signal description.
      Field SIGNAL_ON_PLUGIN_ADDED contains original signal name and can be used as resource reference.
      Parameter:
      signal - callback function (lambda).
      Gibt zurück:
      SignalHandler. Can be used to disconnect signal and to release callback function.

    • forkIsEnabled

      public static boolean forkIsEnabled()
      By default GStreamer will perform scanning and rebuilding of the
      registry file using a helper child process.

      Applications might want to disable this behaviour with the
      gst_registry_fork_set_enabled() function, in which case new plugins
      are scanned (and loaded) into the application process.
      Gibt zurück:
      %TRUE if GStreamer will use the child helper process when rebuilding the registry.

    • forkSetEnabled

      public static void forkSetEnabled(boolean enabled)
      Applications might want to disable/enable spawning of a child helper process
      when rebuilding the registry. See gst_registry_fork_is_enabled() for more
      information.
      Parameter:
      enabled - whether rebuilding the registry can use a temporary child helper process.

    • get

      public static Registry get()
      Retrieves the singleton plugin registry. The caller does not own a
      reference on the registry, as it is alive as long as GStreamer is
      initialized.
      Gibt zurück:
      the #GstRegistry.

    • getTypeID

      public static long getTypeID()

    • getParentTypeID

      public static long getParentTypeID()

    • getTypeSize

      public static TypeSystem.TypeSize getTypeSize()

    • getParentTypeSize

      public static TypeSystem.TypeSize getParentTypeSize()

    • getInstanceSize

      public static int getInstanceSize()