mpd/src/playlist/PlaylistPlugin.hxx
2024-05-15 20:02:12 +02:00

150 lines
3.7 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#ifndef MPD_PLAYLIST_PLUGIN_HXX
#define MPD_PLAYLIST_PLUGIN_HXX
#include "input/Ptr.hxx"
#include "thread/Mutex.hxx"
#include <string_view>
struct ConfigBlock;
struct Tag;
class SongEnumerator;
struct PlaylistPlugin {
const char *name;
/**
* Initialize the plugin. Optional method.
*
* @param block a configuration block for this plugin (may be
* empty if none is configured)
* @return true if the plugin was initialized successfully,
* false if the plugin is not available
*/
bool (*init)(const ConfigBlock &block) = nullptr;
/**
* Deinitialize a plugin which was initialized successfully.
* Optional method.
*/
void (*finish)() noexcept = nullptr;
/**
* Opens the playlist on the specified URI. This URI has
* either matched one of the schemes or one of the suffixes.
*/
std::unique_ptr<SongEnumerator> (*open_uri)(const char *uri,
Mutex &mutex) = nullptr;
/**
* Opens the playlist in the specified input stream. It has
* either matched one of the suffixes or one of the MIME
* types.
*
* @parm is the input stream; the pointer will not be
* invalidated when the function returns nullptr
*/
std::unique_ptr<SongEnumerator> (*open_stream)(InputStreamPtr &&is) = nullptr;
const char *const*schemes = nullptr;
const char *const*suffixes = nullptr;
const char *const*mime_types = nullptr;
/**
* If true, then playlists of this type are shown in the
* database as folders.
*/
bool as_folder = false;
constexpr PlaylistPlugin(const char *_name,
std::unique_ptr<SongEnumerator> (*_open_uri)(const char *uri,
Mutex &mutex)) noexcept
:name(_name), open_uri(_open_uri) {}
constexpr PlaylistPlugin(const char *_name,
std::unique_ptr<SongEnumerator> (*_open_stream)(InputStreamPtr &&is)) noexcept
:name(_name), open_stream(_open_stream) {}
constexpr auto WithInit(bool (*_init)(const ConfigBlock &block),
void (*_finish)() noexcept = nullptr) const noexcept {
auto copy = *this;
copy.init = _init;
copy.finish = _finish;
return copy;
}
constexpr auto WithSchemes(const char *const*_schemes) const noexcept {
auto copy = *this;
copy.schemes = _schemes;
return copy;
}
constexpr auto WithSuffixes(const char *const*_suffixes) const noexcept {
auto copy = *this;
copy.suffixes = _suffixes;
return copy;
}
constexpr auto WithMimeTypes(const char *const*_mime_types) const noexcept {
auto copy = *this;
copy.mime_types = _mime_types;
return copy;
}
constexpr auto WithAsFolder(bool value=true) const noexcept {
auto copy = *this;
copy.as_folder = value;
return copy;
}
/**
* Does the plugin announce the specified URI scheme?
*/
[[gnu::pure]]
bool SupportsScheme(std::string_view scheme) const noexcept;
/**
* Does the plugin announce the specified file name suffix?
*/
[[gnu::pure]]
bool SupportsSuffix(std::string_view suffix) const noexcept;
/**
* Does the plugin announce the specified MIME type?
*/
[[gnu::pure]]
bool SupportsMimeType(std::string_view mime_type) const noexcept;
};
/**
* Initialize a plugin.
*
* @param block a configuration block for this plugin, or nullptr if none
* is configured
* @return true if the plugin was initialized successfully, false if
* the plugin is not available
*/
static inline bool
playlist_plugin_init(const PlaylistPlugin *plugin,
const ConfigBlock &block)
{
return plugin->init != nullptr
? plugin->init(block)
: true;
}
/**
* Deinitialize a plugin which was initialized successfully.
*/
static inline void
playlist_plugin_finish(const PlaylistPlugin *plugin) noexcept
{
if (plugin->finish != nullptr)
plugin->finish();
}
#endif