gstreamer/gst/gstplugin.h
Tim-Philipp Müller 8c72758ec2 plugin: add release datetime field to GstPluginDesc and set it if GST_PACKAGE_RELEASE_DATETIME is defined
This is a string describing a date and/or date/time in a simple subset of
the ISO-8601 format, namely either "YYYY-MM-DD" or "YYYY-MM-DDTHH:MMZ" (with
'T' the date/time separator and the 'Z' indicating UTC).

The main purpose of this field is to keep track of plugin and element versions
on an absolute timeline, so it's possible to determine which one is newer when
comparing two date time numbers. This will allow us to express 'replaces'-type
relationships betweeen plugins and element factories in future, even across
different modules and plugin merges or splits (source module version numbers
aren't particularly useful here, since they can only meaningfully be compared
within the same module). It also allows applications and libraries to reliably
check that a plugin is recent enough without making assumptions about modules
or module versions.

We use a string here to keep things simple and clear, esp. on the build system
side of things.

https://bugzilla.gnome.org/show_bug.cgi?id=623040
2010-07-23 17:00:56 +01:00

411 lines
15 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstplugin.h: Header for plugin subsystem
*
* 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.
*/
#ifndef __GST_PLUGIN_H__
#define __GST_PLUGIN_H__
#include <gst/gstconfig.h>
#include <time.h> /* time_t */
#include <sys/types.h> /* off_t */
#include <sys/stat.h> /* off_t */
#include <gmodule.h>
#include <gst/gstobject.h>
#include <gst/gstmacros.h>
#include <gst/gststructure.h>
G_BEGIN_DECLS
typedef struct _GstPlugin GstPlugin;
typedef struct _GstPluginClass GstPluginClass;
typedef struct _GstPluginPrivate GstPluginPrivate;
typedef struct _GstPluginDesc GstPluginDesc;
/**
* gst_plugin_error_quark:
*
* Get the error quark.
*
* Returns: The error quark used in GError messages
*/
GQuark gst_plugin_error_quark (void);
/**
* GST_PLUGIN_ERROR:
*
* The error message category quark
*/
#define GST_PLUGIN_ERROR gst_plugin_error_quark ()
/**
* GstPluginError:
* @GST_PLUGIN_ERROR_MODULE: The plugin could not be loaded
* @GST_PLUGIN_ERROR_DEPENDENCIES: The plugin has unresolved dependencies
* @GST_PLUGIN_ERROR_NAME_MISMATCH: The plugin has already be loaded from a different file
*
* The plugin loading errors
*/
typedef enum
{
GST_PLUGIN_ERROR_MODULE,
GST_PLUGIN_ERROR_DEPENDENCIES,
GST_PLUGIN_ERROR_NAME_MISMATCH
} GstPluginError;
/**
* GstPluginFlags:
* @GST_PLUGIN_FLAG_CACHED: Temporarily loaded plugins
* @GST_PLUGIN_FLAG_BLACKLISTED: The plugin won't be scanned (again)
*
* The plugin loading state
*/
typedef enum
{
GST_PLUGIN_FLAG_CACHED = (1<<0),
GST_PLUGIN_FLAG_BLACKLISTED = (1<<1)
} GstPluginFlags;
/**
* GstPluginDependencyFlags:
* @GST_PLUGIN_DEPENDENCY_FLAG_NONE : no special flags
* @GST_PLUGIN_DEPENDENCY_FLAG_RECURSE : recurse into subdirectories
* @GST_PLUGIN_DEPENDENCY_FLAG_PATHS_ARE_DEFAULT_ONLY : use paths
* argument only if none of the environment variables is set
* @GST_PLUGIN_DEPENDENCY_FLAG_FILE_NAME_IS_SUFFIX : interpret
* filename argument as filter suffix and check all matching files in
* the directory
*
* Flags used in connection with gst_plugin_add_dependency().
*
* Since: 0.10.22
*/
typedef enum {
GST_PLUGIN_DEPENDENCY_FLAG_NONE = 0,
GST_PLUGIN_DEPENDENCY_FLAG_RECURSE = (1 << 0),
GST_PLUGIN_DEPENDENCY_FLAG_PATHS_ARE_DEFAULT_ONLY = (1 << 1),
GST_PLUGIN_DEPENDENCY_FLAG_FILE_NAME_IS_SUFFIX = (1 << 2)
} GstPluginDependencyFlags;
/**
* GstPluginInitFunc:
* @plugin: The plugin object
*
* A plugin should provide a pointer to a function of this type in the
* plugin_desc struct.
* This function will be called by the loader at startup. One would then
* register each #GstPluginFeature.
*
* Returns: %TRUE if plugin initialised successfully
*/
/* FIXME 0.11: Make return void */
typedef gboolean (*GstPluginInitFunc) (GstPlugin *plugin);
/**
* GstPluginInitFullFunc:
* @plugin: The plugin object
* @user_data: extra data
*
* A plugin should provide a pointer to a function of either #GstPluginInitFunc
* or this type in the plugin_desc struct.
* The function will be called by the loader at startup. One would then
* register each #GstPluginFeature. This version allows
* user data to be passed to init function (useful for bindings).
*
* Returns: %TRUE if plugin initialised successfully
*
* Since: 0.10.24
*
*/
/* FIXME 0.11: Merge with GstPluginInitFunc */
typedef gboolean (*GstPluginInitFullFunc) (GstPlugin *plugin, gpointer user_data);
/**
* GstPluginDesc:
* @major_version: the major version number of core that plugin was compiled for
* @minor_version: the minor version number of core that plugin was compiled for
* @name: a unique name of the plugin
* @description: description of plugin
* @plugin_init: pointer to the init function of this plugin.
* @version: version of the plugin
* @license: effective license of plugin
* @source: source module plugin belongs to
* @package: shipped package plugin belongs to
* @origin: URL to provider of plugin
* @release_datetime: date time string in ISO 8601 format (or rather, a
* subset thereof), or NULL. Allowed are the following formats:
* "YYYY-MM-DD" and "YYY-MM-DDTHH:MMZ" (with 'T' a separator and 'Z'
* indicating UTC/Zulu time). This field should be set via the
* GST_PACKAGE_RELEASE_DATETIME preprocessor macro (Since: 0.10.31)
*
* A plugin should export a variable of this type called plugin_desc. The plugin
* loader will use the data provided there to initialize the plugin.
*
* The @licence parameter must be one of: LGPL, GPL, QPL, GPL/QPL, MPL,
* BSD, MIT/X11, Proprietary, unknown.
*/
struct _GstPluginDesc {
gint major_version;
gint minor_version;
const gchar *name;
const gchar *description;
GstPluginInitFunc plugin_init;
const gchar *version;
const gchar *license;
const gchar *source;
const gchar *package;
const gchar *origin;
const gchar *release_datetime;
/*< private >*/
gpointer _gst_reserved[GST_PADDING - 1];
};
#define GST_TYPE_PLUGIN (gst_plugin_get_type())
#define GST_IS_PLUGIN(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_PLUGIN))
#define GST_IS_PLUGIN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_PLUGIN))
#define GST_PLUGIN_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_PLUGIN, GstPluginClass))
#define GST_PLUGIN(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_PLUGIN, GstPlugin))
#define GST_PLUGIN_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_PLUGIN, GstPluginClass))
#define GST_PLUGIN_CAST(obj) ((GstPlugin*)(obj))
/**
* GstPlugin:
*
* The plugin object
*/
struct _GstPlugin {
GstObject object;
/*< private >*/
GstPluginDesc desc;
GstPluginDesc *orig_desc;
unsigned int flags;
gchar * filename;
gchar * basename; /* base name (non-dir part) of plugin path */
GModule * module; /* contains the module if plugin is loaded */
off_t file_size;
time_t file_mtime;
gboolean registered; /* TRUE when the registry has seen a filename
* that matches the plugin's basename */
GstPluginPrivate *priv;
gpointer _gst_reserved[GST_PADDING - 1];
};
struct _GstPluginClass {
GstObjectClass object_class;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
#ifdef GST_PACKAGE_RELEASE_DATETIME
#define __GST_PACKAGE_RELEASE_DATETIME GST_PACKAGE_RELEASE_DATETIME
#else
#define __GST_PACKAGE_RELEASE_DATETIME NULL
#endif
/**
* GST_PLUGIN_DEFINE:
* @major: major version number of the gstreamer-core that plugin was compiled for
* @minor: minor version number of the gstreamer-core that plugin was compiled for
* @name: short, but unique name of the plugin
* @description: information about the purpose of the plugin
* @init: function pointer to the plugin_init method with the signature of <code>static gboolean plugin_init (GstPlugin * plugin)</code>.
* @version: full version string (e.g. VERSION from config.h)
* @license: under which licence the package has been released, e.g. GPL, LGPL.
* @package: the package-name (e.g. PACKAGE_NAME from config.h)
* @origin: a description from where the package comes from (e.g. the homepage URL)
*
* This macro needs to be used to define the entry point and meta data of a
* plugin. One would use this macro to export a plugin, so that it can be used
* by other applications.
*
* The macro uses a define named PACKAGE for the #GstPluginDesc,source field.
* When using autoconf, this is usually set automatically via the AC_INIT
* macro, and set in config.h. If you are not using autoconf, you will need to
* define PACKAGE yourself and set it to a short mnemonic string identifying
* your application/package, e.g. 'someapp' or 'my-plugins-foo.
*
* If defined, the GST_PACKAGE_RELEASE_DATETIME will also be used for the
* #GstPluginDesc,release_datetime field.
*/
#define GST_PLUGIN_DEFINE(major,minor,name,description,init,version,license,package,origin) \
G_BEGIN_DECLS \
GST_PLUGIN_EXPORT GstPluginDesc gst_plugin_desc = { \
major, \
minor, \
name, \
(gchar *) description, \
init, \
version, \
license, \
PACKAGE, \
package, \
origin, \
__GST_PACKAGE_RELEASE_DATETIME, \
GST_PADDING_INIT \
}; \
G_END_DECLS
/**
* GST_PLUGIN_DEFINE_STATIC:
* @major: major version number of the gstreamer-core that plugin was compiled for
* @minor: minor version number of the gstreamer-core that plugin was compiled for
* @name: short, but unique name of the plugin
* @description: information about the purpose of the plugin
* @init: function pointer to the plugin_init method with the signature of <code>static gboolean plugin_init (GstPlugin * plugin)</code>.
* @version: full version string (e.g. VERSION from config.h)
* @license: under which licence the package has been released, e.g. GPL, LGPL.
* @package: the package-name (e.g. PACKAGE_NAME from config.h)
* @origin: a description from where the package comes from (e.g. the homepage URL)
*
* This macro needs to be used to define the entry point and meta data of a
* local plugin. One would use this macro to define a local plugin that can only
* be used by the own application.
*
* The macro uses a define named PACKAGE for the #GstPluginDesc.source field.
*
* Deprecated: Use gst_plugin_register_static() instead. This macro was
* deprecated because it uses constructors, which is a compiler feature not
* available on all compilers.
*
*/
/* We don't have deprecation guards here on purpose, it's enough to have
* deprecation guards around _gst_plugin_register_static(), and will result in
* much better error messages when compiling with -DGST_DISABLE_DEPRECATED */
#define GST_PLUGIN_DEFINE_STATIC(major,minor,name,description,init,version,license,package,origin) \
static void GST_GNUC_CONSTRUCTOR \
_gst_plugin_static_init__ ##init (void) \
{ \
static GstPluginDesc plugin_desc_ = { \
major, \
minor, \
name, \
(gchar *) description, \
init, \
version, \
license, \
PACKAGE, \
package, \
origin, \
NULL, \
GST_PADDING_INIT \
}; \
_gst_plugin_register_static (&plugin_desc_); \
}
/**
* GST_LICENSE_UNKNOWN:
*
* To be used in GST_PLUGIN_DEFINE or GST_PLUGIN_DEFINE_STATIC if usure about
* the licence.
*/
#define GST_LICENSE_UNKNOWN "unknown"
/* function for filters */
/**
* GstPluginFilter:
* @plugin: the plugin to check
* @user_data: the user_data that has been passed on e.g. gst_registry_plugin_filter()
*
* A function that can be used with e.g. gst_registry_plugin_filter()
* to get a list of plugins that match certain criteria.
*
* Returns: TRUE for a positive match, FALSE otherwise
*/
typedef gboolean (*GstPluginFilter) (GstPlugin *plugin,
gpointer user_data);
GType gst_plugin_get_type (void);
#ifndef GST_DISABLE_DEPRECATED
void _gst_plugin_register_static (GstPluginDesc *desc);
#endif
gboolean gst_plugin_register_static (gint major_version,
gint minor_version,
const gchar *name,
const gchar *description,
GstPluginInitFunc init_func,
const gchar *version,
const gchar *license,
const gchar *source,
const gchar *package,
const gchar *origin);
gboolean gst_plugin_register_static_full (gint major_version,
gint minor_version,
const gchar *name,
const gchar *description,
GstPluginInitFullFunc init_full_func,
const gchar *version,
const gchar *license,
const gchar *source,
const gchar *package,
const gchar *origin,
gpointer user_data);
G_CONST_RETURN gchar* gst_plugin_get_name (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_description (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_filename (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_version (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_license (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_source (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_package (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_origin (GstPlugin *plugin);
G_CONST_RETURN GstStructure* gst_plugin_get_cache_data (GstPlugin * plugin);
void gst_plugin_set_cache_data (GstPlugin * plugin, GstStructure *cache_data);
GModule * gst_plugin_get_module (GstPlugin *plugin);
gboolean gst_plugin_is_loaded (GstPlugin *plugin);
gboolean gst_plugin_name_filter (GstPlugin *plugin, const gchar *name);
GstPlugin * gst_plugin_load_file (const gchar *filename, GError** error);
GstPlugin * gst_plugin_load (GstPlugin *plugin);
GstPlugin * gst_plugin_load_by_name (const gchar *name);
void gst_plugin_add_dependency (GstPlugin * plugin,
const gchar ** env_vars,
const gchar ** paths,
const gchar ** names,
GstPluginDependencyFlags flags);
void gst_plugin_add_dependency_simple (GstPlugin * plugin,
const gchar * env_vars,
const gchar * paths,
const gchar * names,
GstPluginDependencyFlags flags);
void gst_plugin_list_free (GList *list);
G_END_DECLS
#endif /* __GST_PLUGIN_H__ */