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/*
* Copyright 2003-2021 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_DECODER_PLUGIN_HXX
#define MPD_DECODER_PLUGIN_HXX
#include <forward_list> // IWYU pragma: export
#include <set>
#include <string>
#include <string_view>
struct ConfigBlock;
class InputStream;
class TagHandler;
class Path;
class DecoderClient;
class DetachedSong;
struct DecoderPlugin {
const char *name;
/**
* Initialize the decoder plugin. Optional method.
*
* @param param 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
*/
bool (*init)(const ConfigBlock &block) = nullptr;
/**
* Deinitialize a decoder plugin which was initialized
* successfully. Optional method.
*/
void (*finish)() noexcept = nullptr;
/**
* Return a set of supported protocols.
*/
std::set<std::string> (*protocols)() noexcept = nullptr;
/**
* Decode an URI with a protocol listed in protocols().
*/
void (*uri_decode)(DecoderClient &client, const char *uri) = nullptr;
/**
* Decode a stream (data read from an #InputStream object).
*
* Either implement this method or file_decode(). If
* possible, it is recommended to implement this method,
* because it is more versatile.
*/
void (*stream_decode)(DecoderClient &client, InputStream &is) = nullptr;
/**
* Decode a local file.
*
* Either implement this method or stream_decode().
*/
void (*file_decode)(DecoderClient &client, Path path_fs) = nullptr;
/**
* Scan metadata of a file.
*
* Throws on I/O error.
*
* @return false if the file was not recognized
*/
bool (*scan_file)(Path path_fs, TagHandler &handler) = nullptr;
/**
* Scan metadata of a stream.
*
* Throws on I/O error.
*
* @return false if the stream was not recognized
*/
bool (*scan_stream)(InputStream &is, TagHandler &handler) = nullptr;
/**
* @brief Return a "virtual" filename for subtracks in
* container formats like flac
* @param path_fs full pathname for the file on fs
*
* @return an empty list if there are no multiple files
* a filename for every single track;
* do not include full pathname here, just the "virtual" file
*/
std::forward_list<DetachedSong> (*container_scan)(Path path_fs) = nullptr;
/* last element in these arrays must always be a nullptr: */
const char *const*suffixes = nullptr;
const char *const*mime_types = nullptr;
constexpr DecoderPlugin(const char *_name,
void (*_file_decode)(DecoderClient &client,
Path path_fs),
bool (*_scan_file)(Path path_fs,
TagHandler &handler)) noexcept
:name(_name),
file_decode(_file_decode), scan_file(_scan_file) {}
constexpr DecoderPlugin(const char *_name,
void (*_stream_decode)(DecoderClient &client,
InputStream &is),
bool (*_scan_stream)(InputStream &is, TagHandler &handler)) noexcept
:name(_name),
stream_decode(_stream_decode),
scan_stream(_scan_stream) {}
constexpr DecoderPlugin(const char *_name,
void (*_stream_decode)(DecoderClient &client,
InputStream &is),
bool (*_scan_stream)(InputStream &is, TagHandler &handler),
void (*_file_decode)(DecoderClient &client,
Path path_fs),
bool (*_scan_file)(Path path_fs,
TagHandler &handler)) noexcept
:name(_name),
stream_decode(_stream_decode),
file_decode(_file_decode),
scan_file(_scan_file),
scan_stream(_scan_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 WithContainer(std::forward_list<DetachedSong> (*_container_scan)(Path path_fs)) const noexcept {
auto copy = *this;
copy.container_scan = _container_scan;
return copy;
}
constexpr auto WithProtocols(std::set<std::string> (*_protocols)() noexcept,
void (*_uri_decode)(DecoderClient &client, const char *uri)) const noexcept {
auto copy = *this;
copy.protocols = _protocols;
copy.uri_decode = _uri_decode;
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;
}
/**
* Initialize a decoder plugin.
*
* @param block a configuration block for this plugin
* @return true if the plugin was initialized successfully, false if
* the plugin is not available
*/
bool Init(const ConfigBlock &block) const {
return init != nullptr
? init(block)
: true;
}
/**
* Deinitialize a decoder plugin which was initialized successfully.
*/
void Finish() const {
if (finish != nullptr)
finish();
}
/**
* Decode a stream.
*/
void StreamDecode(DecoderClient &client, InputStream &is) const {
stream_decode(client, is);
}
/**
* Decode an URI which is supported (check SupportsUri()).
*/
void UriDecode(DecoderClient &client, const char *uri) const {
uri_decode(client, uri);
}
/**
* Decode a file.
*/
template<typename P>
void FileDecode(DecoderClient &client, P path_fs) const {
file_decode(client, path_fs);
}
/**
* Read the tag of a file.
*/
template<typename P>
bool ScanFile(P path_fs, TagHandler &handler) const {
return scan_file != nullptr
? scan_file(path_fs, handler)
: false;
}
/**
* Read the tag of a stream.
*/
bool ScanStream(InputStream &is, TagHandler &handler) const {
return scan_stream != nullptr
? scan_stream(is, handler)
: false;
}
/**
* return "virtual" tracks in a container
*/
template<typename P>
char *ContainerScan(P path, const unsigned int tnum) const {
return container_scan(path, tnum);
}
[[gnu::pure]]
bool SupportsUri(const char *uri) 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;
bool SupportsContainerSuffix(std::string_view suffix) const noexcept {
return container_scan != nullptr && SupportsSuffix(suffix);
}
};
#endif