mpd/src/PlayerControl.hxx
2014-08-30 00:28:02 +02:00

464 lines
9.1 KiB
C++

/*
* Copyright (C) 2003-2014 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_PLAYER_CONTROL_HXX
#define MPD_PLAYER_CONTROL_HXX
#include "AudioFormat.hxx"
#include "thread/Mutex.hxx"
#include "thread/Cond.hxx"
#include "thread/Thread.hxx"
#include "util/Error.hxx"
#include "CrossFade.hxx"
#include "Chrono.hxx"
#include <stdint.h>
class PlayerListener;
class MultipleOutputs;
class DetachedSong;
enum class PlayerState : uint8_t {
STOP,
PAUSE,
PLAY
};
enum class PlayerCommand : uint8_t {
NONE,
EXIT,
STOP,
PAUSE,
SEEK,
CLOSE_AUDIO,
/**
* At least one AudioOutput.enabled flag has been modified;
* commit those changes to the output threads.
*/
UPDATE_AUDIO,
/** PlayerControl.next_song has been updated */
QUEUE,
/**
* cancel pre-decoding PlayerControl.next_song; if the player
* has already started playing this song, it will completely
* stop
*/
CANCEL,
/**
* Refresh status information in the #PlayerControl struct,
* e.g. elapsed_time.
*/
REFRESH,
};
enum class PlayerError : uint8_t {
NONE,
/**
* The decoder has failed to decode the song.
*/
DECODER,
/**
* The audio output has failed.
*/
OUTPUT,
};
struct player_status {
PlayerState state;
uint16_t bit_rate;
AudioFormat audio_format;
SignedSongTime total_time;
SongTime elapsed_time;
};
struct PlayerControl {
PlayerListener &listener;
MultipleOutputs &outputs;
const unsigned buffer_chunks;
const unsigned buffered_before_play;
/**
* The handle of the player thread.
*/
Thread thread;
/**
* This lock protects #command, #state, #error, #tagged_song.
*/
mutable Mutex mutex;
/**
* Trigger this object after you have modified #command.
*/
Cond cond;
/**
* This object gets signalled when the player thread has
* finished the #command. It wakes up the client that waits
* (i.e. the main thread).
*/
Cond client_cond;
PlayerCommand command;
PlayerState state;
PlayerError error_type;
/**
* The error that occurred in the player thread. This
* attribute is only valid if #error is not
* #PlayerError::NONE. The object must be freed when this
* object transitions back to #PlayerError::NONE.
*/
Error error;
/**
* A copy of the current #DetachedSong after its tags have
* been updated by the decoder (for example, a radio stream
* that has sent a new tag after switching to the next song).
* This shall be used by PlayerListener::OnPlayerTagModified()
* to update the current #DetachedSong in the queue.
*
* Protected by #mutex. Set by the PlayerThread and consumed
* by the main thread.
*/
DetachedSong *tagged_song;
uint16_t bit_rate;
AudioFormat audio_format;
SignedSongTime total_time;
SongTime elapsed_time;
/**
* The next queued song.
*
* This is a duplicate, and must be freed when this attribute
* is cleared.
*/
DetachedSong *next_song;
SongTime seek_time;
CrossFadeSettings cross_fade;
double total_play_time;
/**
* If this flag is set, then the player will be auto-paused at
* the end of the song, before the next song starts to play.
*
* This is a copy of the queue's "single" flag most of the
* time.
*/
bool border_pause;
PlayerControl(PlayerListener &_listener,
MultipleOutputs &_outputs,
unsigned buffer_chunks,
unsigned buffered_before_play);
~PlayerControl();
/**
* Locks the object.
*/
void Lock() const {
mutex.lock();
}
/**
* Unlocks the object.
*/
void Unlock() const {
mutex.unlock();
}
/**
* Signals the object. The object should be locked prior to
* calling this function.
*/
void Signal() {
cond.signal();
}
/**
* Signals the object. The object is temporarily locked by
* this function.
*/
void LockSignal() {
Lock();
Signal();
Unlock();
}
/**
* Waits for a signal on the object. This function is only
* valid in the player thread. The object must be locked
* prior to calling this function.
*/
void Wait() {
assert(thread.IsInside());
cond.wait(mutex);
}
/**
* Wake up the client waiting for command completion.
*
* Caller must lock the object.
*/
void ClientSignal() {
assert(thread.IsInside());
client_cond.signal();
}
/**
* The client calls this method to wait for command
* completion.
*
* Caller must lock the object.
*/
void ClientWait() {
assert(!thread.IsInside());
client_cond.wait(mutex);
}
/**
* A command has been finished. This method clears the
* command and signals the client.
*
* To be called from the player thread. Caller must lock the
* object.
*/
void CommandFinished() {
assert(command != PlayerCommand::NONE);
command = PlayerCommand::NONE;
ClientSignal();
}
private:
/**
* Wait for the command to be finished by the player thread.
*
* To be called from the main thread. Caller must lock the
* object.
*/
void WaitCommandLocked() {
while (command != PlayerCommand::NONE)
ClientWait();
}
/**
* Send a command to the player thread and synchronously wait
* for it to finish.
*
* To be called from the main thread. Caller must lock the
* object.
*/
void SynchronousCommand(PlayerCommand cmd) {
assert(command == PlayerCommand::NONE);
command = cmd;
Signal();
WaitCommandLocked();
}
/**
* Send a command to the player thread and synchronously wait
* for it to finish.
*
* To be called from the main thread. This method locks the
* object.
*/
void LockSynchronousCommand(PlayerCommand cmd) {
Lock();
SynchronousCommand(cmd);
Unlock();
}
public:
/**
* @param song the song to be queued; the given instance will
* be owned and freed by the player
*/
void Play(DetachedSong *song);
/**
* see PlayerCommand::CANCEL
*/
void Cancel();
void SetPause(bool pause_flag);
private:
void PauseLocked();
public:
void Pause();
/**
* Set the player's #border_pause flag.
*/
void SetBorderPause(bool border_pause);
void Kill();
gcc_pure
player_status GetStatus();
PlayerState GetState() const {
return state;
}
/**
* Set the error. Discards any previous error condition.
*
* Caller must lock the object.
*
* @param type the error type; must not be #PlayerError::NONE
* @param error detailed error information; must be defined.
*/
void SetError(PlayerError type, Error &&error);
/**
* Checks whether an error has occurred, and if so, returns a
* copy of the #Error object.
*
* Caller must lock the object.
*/
gcc_pure
Error GetError() const {
Error result;
if (error_type != PlayerError::NONE)
result.Set(error);
return result;
}
/**
* Like GetError(), but locks and unlocks the object.
*/
gcc_pure
Error LockGetError() const {
Lock();
Error result = GetError();
Unlock();
return result;
}
void ClearError();
PlayerError GetErrorType() const {
return error_type;
}
/**
* Set the #tagged_song attribute to a newly allocated copy of
* the given #DetachedSong. Locks and unlocks the object.
*/
void LockSetTaggedSong(const DetachedSong &song);
void ClearTaggedSong();
/**
* Read and clear the #tagged_song attribute.
*
* Caller must lock the object.
*/
DetachedSong *ReadTaggedSong() {
DetachedSong *result = tagged_song;
tagged_song = nullptr;
return result;
}
/**
* Like ReadTaggedSong(), but locks and unlocks the object.
*/
DetachedSong *LockReadTaggedSong() {
Lock();
DetachedSong *result = ReadTaggedSong();
Unlock();
return result;
}
void Stop();
void UpdateAudio();
private:
void EnqueueSongLocked(DetachedSong *song) {
assert(song != nullptr);
assert(next_song == nullptr);
next_song = song;
SynchronousCommand(PlayerCommand::QUEUE);
}
public:
/**
* @param song the song to be queued; the given instance will be owned
* and freed by the player
*/
void EnqueueSong(DetachedSong *song);
/**
* Makes the player thread seek the specified song to a position.
*
* @param song the song to be queued; the given instance will be owned
* and freed by the player
* @return true on success, false on failure (e.g. if MPD isn't
* playing currently)
*/
bool Seek(DetachedSong *song, SongTime t);
void SetCrossFade(float cross_fade_seconds);
float GetCrossFade() const {
return cross_fade.duration;
}
void SetMixRampDb(float mixramp_db);
float GetMixRampDb() const {
return cross_fade.mixramp_db;
}
void SetMixRampDelay(float mixramp_delay_seconds);
float GetMixRampDelay() const {
return cross_fade.mixramp_delay;
}
double GetTotalPlayTime() const {
return total_play_time;
}
};
#endif