1 /*
2 * Copyright 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <algorithm>
18 #include <memory.h>
19 #include <stdint.h>
20
21 #include "fifo/FifoControllerBase.h"
22 #include "fifo/FifoController.h"
23 #include "fifo/FifoControllerIndirect.h"
24 #include "fifo/FifoBuffer.h"
25
26 namespace oboe {
27
FifoBuffer(uint32_t bytesPerFrame,uint32_t capacityInFrames)28 FifoBuffer::FifoBuffer(uint32_t bytesPerFrame, uint32_t capacityInFrames)
29 : mBytesPerFrame(bytesPerFrame)
30 , mStorage(nullptr)
31 , mFramesReadCount(0)
32 , mFramesUnderrunCount(0)
33 {
34 mFifo = std::make_unique<FifoController>(capacityInFrames);
35 // allocate buffer
36 int32_t bytesPerBuffer = bytesPerFrame * capacityInFrames;
37 mStorage = new uint8_t[bytesPerBuffer];
38 mStorageOwned = true;
39 }
40
FifoBuffer(uint32_t bytesPerFrame,uint32_t capacityInFrames,std::atomic<uint64_t> * readCounterAddress,std::atomic<uint64_t> * writeCounterAddress,uint8_t * dataStorageAddress)41 FifoBuffer::FifoBuffer( uint32_t bytesPerFrame,
42 uint32_t capacityInFrames,
43 std::atomic<uint64_t> *readCounterAddress,
44 std::atomic<uint64_t> *writeCounterAddress,
45 uint8_t *dataStorageAddress
46 )
47 : mBytesPerFrame(bytesPerFrame)
48 , mStorage(dataStorageAddress)
49 , mFramesReadCount(0)
50 , mFramesUnderrunCount(0)
51 {
52 mFifo = std::make_unique<FifoControllerIndirect>(capacityInFrames,
53 readCounterAddress,
54 writeCounterAddress);
55 mStorage = dataStorageAddress;
56 mStorageOwned = false;
57 }
58
~FifoBuffer()59 FifoBuffer::~FifoBuffer() {
60 if (mStorageOwned) {
61 delete[] mStorage;
62 }
63 }
64
convertFramesToBytes(int32_t frames)65 int32_t FifoBuffer::convertFramesToBytes(int32_t frames) {
66 return frames * mBytesPerFrame;
67 }
68
read(void * buffer,int32_t numFrames)69 int32_t FifoBuffer::read(void *buffer, int32_t numFrames) {
70 if (numFrames <= 0) {
71 return 0;
72 }
73 // safe because numFrames is guaranteed positive
74 uint32_t framesToRead = static_cast<uint32_t>(numFrames);
75 uint32_t framesAvailable = mFifo->getFullFramesAvailable();
76 framesToRead = std::min(framesToRead, framesAvailable);
77
78 uint32_t readIndex = mFifo->getReadIndex(); // ranges 0 to capacity
79 uint8_t *destination = reinterpret_cast<uint8_t *>(buffer);
80 uint8_t *source = &mStorage[convertFramesToBytes(readIndex)];
81 if ((readIndex + framesToRead) > mFifo->getFrameCapacity()) {
82 // read in two parts, first part here is at the end of the mStorage buffer
83 int32_t frames1 = static_cast<int32_t>(mFifo->getFrameCapacity() - readIndex);
84 int32_t numBytes = convertFramesToBytes(frames1);
85 if (numBytes < 0) {
86 return static_cast<int32_t>(Result::ErrorOutOfRange);
87 }
88 memcpy(destination, source, static_cast<size_t>(numBytes));
89 destination += numBytes;
90 // read second part, which is at the beginning of mStorage
91 source = &mStorage[0];
92 int32_t frames2 = static_cast<uint32_t>(framesToRead - frames1);
93 numBytes = convertFramesToBytes(frames2);
94 if (numBytes < 0) {
95 return static_cast<int32_t>(Result::ErrorOutOfRange);
96 }
97 memcpy(destination, source, static_cast<size_t>(numBytes));
98 } else {
99 // just read in one shot
100 int32_t numBytes = convertFramesToBytes(framesToRead);
101 if (numBytes < 0) {
102 return static_cast<int32_t>(Result::ErrorOutOfRange);
103 }
104 memcpy(destination, source, static_cast<size_t>(numBytes));
105 }
106 mFifo->advanceReadIndex(framesToRead);
107
108 return framesToRead;
109 }
110
write(const void * buffer,int32_t numFrames)111 int32_t FifoBuffer::write(const void *buffer, int32_t numFrames) {
112 if (numFrames <= 0) {
113 return 0;
114 }
115 // Guaranteed positive.
116 uint32_t framesToWrite = static_cast<uint32_t>(numFrames);
117 uint32_t framesAvailable = mFifo->getEmptyFramesAvailable();
118 framesToWrite = std::min(framesToWrite, framesAvailable);
119
120 uint32_t writeIndex = mFifo->getWriteIndex();
121 int byteIndex = convertFramesToBytes(writeIndex);
122 const uint8_t *source = reinterpret_cast<const uint8_t *>(buffer);
123 uint8_t *destination = &mStorage[byteIndex];
124 if ((writeIndex + framesToWrite) > mFifo->getFrameCapacity()) {
125 // write in two parts, first part here
126 int32_t frames1 = static_cast<uint32_t>(mFifo->getFrameCapacity() - writeIndex);
127 int32_t numBytes = convertFramesToBytes(frames1);
128 if (numBytes < 0) {
129 return static_cast<int32_t>(Result::ErrorOutOfRange);
130 }
131 memcpy(destination, source, static_cast<size_t>(numBytes));
132 // read second part
133 source += convertFramesToBytes(frames1);
134 destination = &mStorage[0];
135 int frames2 = static_cast<uint32_t>(framesToWrite - frames1);
136 numBytes = convertFramesToBytes(frames2);
137 if (numBytes < 0) {
138 return static_cast<int32_t>(Result::ErrorOutOfRange);
139 }
140 memcpy(destination, source, static_cast<size_t>(numBytes));
141 } else {
142 // just write in one shot
143 int32_t numBytes = convertFramesToBytes(framesToWrite);
144 if (numBytes < 0) {
145 return static_cast<int32_t>(Result::ErrorOutOfRange);
146 }
147 memcpy(destination, source, static_cast<size_t>(numBytes));
148 }
149 mFifo->advanceWriteIndex(framesToWrite);
150
151 return framesToWrite;
152 }
153
readNow(void * buffer,int32_t numFrames)154 int32_t FifoBuffer::readNow(void *buffer, int32_t numFrames) {
155 int32_t framesRead = read(buffer, numFrames);
156 if (framesRead < 0) {
157 return framesRead;
158 }
159 int32_t framesLeft = numFrames - framesRead;
160 mFramesReadCount += framesRead;
161 mFramesUnderrunCount += framesLeft;
162 // Zero out any samples we could not set.
163 if (framesLeft > 0) {
164 uint8_t *destination = reinterpret_cast<uint8_t *>(buffer);
165 destination += convertFramesToBytes(framesRead); // point to first byte not set
166 int32_t bytesToZero = convertFramesToBytes(framesLeft);
167 memset(destination, 0, static_cast<size_t>(bytesToZero));
168 }
169
170 return framesRead;
171 }
172
173
getBufferCapacityInFrames() const174 uint32_t FifoBuffer::getBufferCapacityInFrames() const {
175 return mFifo->getFrameCapacity();
176 }
177
178 } // namespace oboe
179