MPD: util/DynamicFifoBuffer.hxx Source File

MPD 0.20.18

DynamicFifoBuffer.hxx
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1 /*
2 * Copyright (C) 2003-2015 Max Kellermann <max.kellermann@gmail.com>
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the
14 * distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
19 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
20 * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27 * OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #ifndef DYNAMIC_FIFO_BUFFER_HXX
31 #define DYNAMIC_FIFO_BUFFER_HXX
32
33 #include "ForeignFifoBuffer.hxx"
34
40 template<typename T>
41 class DynamicFifoBuffer : protected ForeignFifoBuffer<T> {
42 public:
43 typedef typename ForeignFifoBuffer<T>::size_type size_type;
44 typedef typename ForeignFifoBuffer<T>::pointer_type pointer_type;
45 typedef typename ForeignFifoBuffer<T>::const_pointer_type const_pointer_type;
46 typedef typename ForeignFifoBuffer<T>::Range Range;
47
48 explicit DynamicFifoBuffer(size_type _capacity)
49 :ForeignFifoBuffer<T>(new T[_capacity], _capacity) {}
50 ~DynamicFifoBuffer() {
51 delete[] GetBuffer();
52 }
53
54 DynamicFifoBuffer(const DynamicFifoBuffer &) = delete;
55
56 using ForeignFifoBuffer<T>::GetCapacity;
57 using ForeignFifoBuffer<T>::Clear;
58 using ForeignFifoBuffer<T>::IsEmpty;
59 using ForeignFifoBuffer<T>::IsFull;
60 using ForeignFifoBuffer<T>::GetAvailable;
61 using ForeignFifoBuffer<T>::Read;
62 using ForeignFifoBuffer<T>::Consume;
63 using ForeignFifoBuffer<T>::Write;
64 using ForeignFifoBuffer<T>::Append;
65
66 void Grow(size_type new_capacity) {
67 assert(new_capacity > GetCapacity());
68
69 T *old_data = GetBuffer();
70 T *new_data = new T[new_capacity];
71 ForeignFifoBuffer<T>::MoveBuffer(new_data, new_capacity);
72 delete[] old_data;
73 }
74
75 void WantWrite(size_type n) {
76 if (ForeignFifoBuffer<T>::WantWrite(n))
77 /* we already have enough space */
78 return;
79
80 const size_type in_use = GetAvailable();
81 const size_type required_capacity = in_use + n;
82 size_type new_capacity = GetCapacity();
83 do {
84 new_capacity <<= 1;
85 } while (new_capacity < required_capacity);
86
87 Grow(new_capacity);
88 }
89
94 pointer_type Write(size_type n) {
95 WantWrite(n);
96 return Write().data;
97 }
98
102 void Append(const_pointer_type p, size_type n) {
103 std::copy_n(p, n, Write(n));
104 Append(n);
105 }
106
107 protected:
108 using ForeignFifoBuffer<T>::GetBuffer;
109 };
110
111 #endif
DynamicFifoBuffer::DynamicFifoBuffer
DynamicFifoBuffer(size_type _capacity)
Definition: DynamicFifoBuffer.hxx:48
ForeignFifoBuffer::MoveBuffer
void MoveBuffer(T *new_data, size_type new_capacity)
Definition: ForeignFifoBuffer.hxx:123
ForeignFifoBuffer::pointer_type
Range::pointer_type pointer_type
Definition: ForeignFifoBuffer.hxx:56
WritableBuffer
A reference to a memory area that is writable.
Definition: Silence.hxx:27
DynamicFifoBuffer::~DynamicFifoBuffer
~DynamicFifoBuffer()
Definition: DynamicFifoBuffer.hxx:50
ForeignFifoBuffer::GetCapacity
constexpr size_type GetCapacity() const
Definition: ForeignFifoBuffer.hxx:104
DynamicFifoBuffer::Range
ForeignFifoBuffer< T >::Range Range
Definition: DynamicFifoBuffer.hxx:46
ForeignFifoBuffer::const_pointer_type
Range::const_pointer_type const_pointer_type
Definition: ForeignFifoBuffer.hxx:57
ForeignFifoBuffer::Write
Range Write()
Prepares writing.
Definition: ForeignFifoBuffer.hxx:149
ForeignFifoBuffer::size_type
size_t size_type
Definition: ForeignFifoBuffer.hxx:54
ForeignFifoBuffer
A first-in-first-out buffer: you can append data at the end, and read data from the beginning...
Definition: ForeignFifoBuffer.hxx:52
WritableBuffer::data
pointer_type data
Definition: WritableBuffer.hxx:90
DynamicFifoBuffer::const_pointer_type
ForeignFifoBuffer< T >::const_pointer_type const_pointer_type
Definition: DynamicFifoBuffer.hxx:45
DynamicFifoBuffer::Write
pointer_type Write(size_type n)
Write data to the buffer, growing it as needed.
Definition: DynamicFifoBuffer.hxx:94
ForeignFifoBuffer::GetAvailable
constexpr size_type GetAvailable() const
Definition: ForeignFifoBuffer.hxx:185
DynamicFifoBuffer::size_type
ForeignFifoBuffer< T >::size_type size_type
Definition: DynamicFifoBuffer.hxx:43
ForeignFifoBuffer.hxx
DynamicFifoBuffer::pointer_type
ForeignFifoBuffer< T >::pointer_type pointer_type
Definition: DynamicFifoBuffer.hxx:44
DynamicFifoBuffer
A first-in-first-out buffer: you can append data at the end, and read data from the beginning...
Definition: DynamicFifoBuffer.hxx:41
DynamicFifoBuffer::Grow
void Grow(size_type new_capacity)
Definition: DynamicFifoBuffer.hxx:66
ForeignFifoBuffer::GetBuffer
T * GetBuffer()
Definition: ForeignFifoBuffer.hxx:100
DynamicFifoBuffer::WantWrite
void WantWrite(size_type n)
Definition: DynamicFifoBuffer.hxx:75
DynamicFifoBuffer::Append
void Append(const_pointer_type p, size_type n)
Append data to the buffer, growing it as needed.
Definition: DynamicFifoBuffer.hxx:102