84 lines
2.1 KiB
C++
84 lines
2.1 KiB
C++
/*
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* Copyright (C) 2003-2014 The Music Player Daemon Project
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* http://www.musicpd.org
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef MPD_MUSIC_BUFFER_HXX
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#define MPD_MUSIC_BUFFER_HXX
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#include "util/SliceBuffer.hxx"
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#include "thread/Mutex.hxx"
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struct music_chunk;
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/**
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* An allocator for #music_chunk objects.
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*/
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class MusicBuffer {
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/** a mutex which protects #buffer */
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Mutex mutex;
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SliceBuffer<music_chunk> buffer;
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public:
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/**
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* Creates a new #MusicBuffer object.
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*
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* @param num_chunks the number of #music_chunk reserved in
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* this buffer
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*/
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MusicBuffer(unsigned num_chunks);
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#ifndef NDEBUG
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/**
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* Check whether the buffer is empty. This call is not
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* protected with the mutex, and may only be used while this
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* object is inaccessible to other threads.
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*/
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bool IsEmptyUnsafe() const {
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return buffer.IsEmpty();
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}
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#endif
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/**
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* Returns the total number of reserved chunks in this buffer. This
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* is the same value which was passed to the constructor
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* music_buffer_new().
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*/
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gcc_pure
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unsigned GetSize() const {
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return buffer.GetCapacity();
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}
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/**
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* Allocates a chunk from the buffer. When it is not used anymore,
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* call Return().
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*
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* @return an empty chunk or nullptr if there are no chunks
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* available
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*/
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music_chunk *Allocate();
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/**
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* Returns a chunk to the buffer. It can be reused by
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* Allocate() then.
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*/
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void Return(music_chunk *chunk);
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};
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#endif
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