88 lines
2.2 KiB
C++
88 lines
2.2 KiB
C++
/*
|
|
* Copyright 2003-2018 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_MUSIC_BUFFER_HXX
|
|
#define MPD_MUSIC_BUFFER_HXX
|
|
|
|
#include "MusicChunkPtr.hxx"
|
|
#include "util/SliceBuffer.hxx"
|
|
#include "thread/Mutex.hxx"
|
|
|
|
/**
|
|
* An allocator for #MusicChunk objects.
|
|
*/
|
|
class MusicBuffer {
|
|
/** a mutex which protects #buffer */
|
|
mutable Mutex mutex;
|
|
|
|
SliceBuffer<MusicChunk> buffer;
|
|
|
|
public:
|
|
/**
|
|
* Creates a new #MusicBuffer object.
|
|
*
|
|
* @param num_chunks the number of #MusicChunk reserved in
|
|
* this buffer
|
|
*/
|
|
explicit MusicBuffer(unsigned num_chunks);
|
|
|
|
#ifndef NDEBUG
|
|
/**
|
|
* Check whether the buffer is empty. This call is not
|
|
* protected with the mutex, and may only be used while this
|
|
* object is inaccessible to other threads.
|
|
*/
|
|
bool IsEmptyUnsafe() const {
|
|
return buffer.empty();
|
|
}
|
|
#endif
|
|
|
|
bool IsFull() const noexcept {
|
|
const std::lock_guard<Mutex> protect(mutex);
|
|
return buffer.IsFull();
|
|
}
|
|
|
|
/**
|
|
* Returns the total number of reserved chunks in this buffer. This
|
|
* is the same value which was passed to the constructor
|
|
* music_buffer_new().
|
|
*/
|
|
gcc_pure
|
|
unsigned GetSize() const noexcept {
|
|
return buffer.GetCapacity();
|
|
}
|
|
|
|
/**
|
|
* Allocates a chunk from the buffer. When it is not used anymore,
|
|
* call Return().
|
|
*
|
|
* @return an empty chunk or nullptr if there are no chunks
|
|
* available
|
|
*/
|
|
MusicChunkPtr Allocate() noexcept;
|
|
|
|
/**
|
|
* Returns a chunk to the buffer. It can be reused by
|
|
* Allocate() then.
|
|
*/
|
|
void Return(MusicChunk *chunk) noexcept;
|
|
};
|
|
|
|
#endif
|