MPD  0.20.15
MusicPipe.hxx
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1 /*
2  * Copyright 2003-2017 The Music Player Daemon Project
3  * http://www.musicpd.org
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
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18  */
19 
20 #ifndef MPD_PIPE_H
21 #define MPD_PIPE_H
22 
23 #include "thread/Mutex.hxx"
24 #include "Compiler.h"
25 
26 #ifndef NDEBUG
27 #include "AudioFormat.hxx"
28 #endif
29 
30 #include <assert.h>
31 
32 struct MusicChunk;
33 class MusicBuffer;
34 
39 class MusicPipe {
41  MusicChunk *head = nullptr;
42 
44  MusicChunk **tail_r = &head;
45 
47  unsigned size = 0;
48 
50  mutable Mutex mutex;
51 
52 #ifndef NDEBUG
53  AudioFormat audio_format = AudioFormat::Undefined();
54 #endif
55 
56 public:
60  MusicPipe() = default;
61 
62  MusicPipe(const MusicPipe &) = delete;
63 
68  assert(head == nullptr);
69  assert(tail_r == &head);
70  }
71 
72  MusicPipe &operator=(const MusicPipe &) = delete;
73 
74 #ifndef NDEBUG
75 
79  gcc_pure
80  bool CheckFormat(AudioFormat other) const noexcept {
81  return !audio_format.IsDefined() ||
82  audio_format == other;
83  }
84 
88  gcc_pure
89  bool Contains(const MusicChunk *chunk) const noexcept;
90 #endif
91 
96  gcc_pure
97  const MusicChunk *Peek() const noexcept {
98  return head;
99  }
100 
104  MusicChunk *Shift() noexcept;
105 
111  void Clear(MusicBuffer &buffer) noexcept;
112 
116  void Push(MusicChunk *chunk) noexcept;
117 
121  gcc_pure
122  unsigned GetSize() const noexcept {
123  return size;
124  }
125 
126  gcc_pure
127  bool IsEmpty() const noexcept {
128  return GetSize() == 0;
129  }
130 };
131 
132 #endif
This structure describes the format of a raw PCM stream.
Definition: AudioFormat.hxx:37
A queue of MusicChunk objects.
Definition: MusicPipe.hxx:39
gcc_pure bool Contains(const MusicChunk *chunk) const noexcept
Checks if the specified chunk is enqueued in the music pipe.
Definition: Mutex.hxx:43
An allocator for MusicChunk objects.
Definition: MusicBuffer.hxx:31
void Clear(MusicBuffer &buffer) noexcept
Clears the whole pipe and returns the chunks to the buffer.
static constexpr AudioFormat Undefined()
Definition: AudioFormat.hxx:75
A chunk of music data.
Definition: MusicChunk.hxx:43
gcc_pure bool IsEmpty() const noexcept
Definition: MusicPipe.hxx:127
~MusicPipe()
Frees the object.
Definition: MusicPipe.hxx:67
MusicPipe()=default
Creates a new MusicPipe object.
gcc_pure bool CheckFormat(AudioFormat other) const noexcept
Checks if the audio format if the chunk is equal to the specified audio_format.
Definition: MusicPipe.hxx:80
constexpr bool IsDefined() const
Checks whether the object has a defined value.
Definition: AudioFormat.hxx:92
MusicPipe & operator=(const MusicPipe &)=delete
void Push(MusicChunk *chunk) noexcept
Pushes a chunk to the tail of the pipe.
gcc_pure unsigned GetSize() const noexcept
Returns the number of chunks currently in this pipe.
Definition: MusicPipe.hxx:122
gcc_pure const MusicChunk * Peek() const noexcept
Returns the first MusicChunk from the pipe.
Definition: MusicPipe.hxx:97
#define gcc_pure
Definition: Compiler.h:116
MusicChunk * Shift() noexcept
Removes the first chunk from the head, and returns it.