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 <cstring>
18 #include <unistd.h>
19
20
21 #define LOG_TAG "FifoBuffer"
22 //#define LOG_NDEBUG 0
23 #include <utils/Log.h>
24
25 #include <algorithm>
26 #include <memory>
27
28 #include "FifoControllerBase.h"
29 #include "FifoController.h"
30 #include "FifoControllerIndirect.h"
31 #include "FifoBuffer.h"
32
33 using android::FifoBuffer;
34 using android::FifoBufferAllocated;
35 using android::FifoBufferIndirect;
36 using android::fifo_frames_t;
37
FifoBuffer(int32_t bytesPerFrame)38 FifoBuffer::FifoBuffer(int32_t bytesPerFrame)
39 : mBytesPerFrame(bytesPerFrame) {}
40
FifoBufferAllocated(int32_t bytesPerFrame,fifo_frames_t capacityInFrames)41 FifoBufferAllocated::FifoBufferAllocated(int32_t bytesPerFrame, fifo_frames_t capacityInFrames)
42 : FifoBuffer(bytesPerFrame)
43 {
44 mFifo = std::make_unique<FifoController>(capacityInFrames, capacityInFrames);
45 // allocate buffer
46 int32_t bytesPerBuffer = bytesPerFrame * capacityInFrames;
47 mInternalStorage = std::make_unique<uint8_t[]>(bytesPerBuffer);
48 ALOGV("%s() capacityInFrames = %d, bytesPerFrame = %d",
49 __func__, capacityInFrames, bytesPerFrame);
50 }
51
FifoBufferIndirect(int32_t bytesPerFrame,fifo_frames_t capacityInFrames,fifo_counter_t * readIndexAddress,fifo_counter_t * writeIndexAddress,void * dataStorageAddress)52 FifoBufferIndirect::FifoBufferIndirect( int32_t bytesPerFrame,
53 fifo_frames_t capacityInFrames,
54 fifo_counter_t *readIndexAddress,
55 fifo_counter_t *writeIndexAddress,
56 void * dataStorageAddress
57 )
58 : FifoBuffer(bytesPerFrame)
59 , mExternalStorage(static_cast<uint8_t *>(dataStorageAddress))
60 {
61 mFifo = std::make_unique<FifoControllerIndirect>(capacityInFrames,
62 capacityInFrames,
63 readIndexAddress,
64 writeIndexAddress);
65 }
66
convertFramesToBytes(fifo_frames_t frames)67 int32_t FifoBuffer::convertFramesToBytes(fifo_frames_t frames) {
68 return frames * mBytesPerFrame;
69 }
70
fillWrappingBuffer(WrappingBuffer * wrappingBuffer,int32_t framesAvailable,int32_t startIndex)71 void FifoBuffer::fillWrappingBuffer(WrappingBuffer *wrappingBuffer,
72 int32_t framesAvailable,
73 int32_t startIndex) {
74 wrappingBuffer->data[1] = nullptr;
75 wrappingBuffer->numFrames[1] = 0;
76 uint8_t *storage = getStorage();
77 if (framesAvailable > 0) {
78 fifo_frames_t capacity = mFifo->getCapacity();
79 uint8_t *source = &storage[convertFramesToBytes(startIndex)];
80 // Does the available data cross the end of the FIFO?
81 if ((startIndex + framesAvailable) > capacity) {
82 wrappingBuffer->data[0] = source;
83 fifo_frames_t firstFrames = capacity - startIndex;
84 wrappingBuffer->numFrames[0] = firstFrames;
85 wrappingBuffer->data[1] = &storage[0];
86 wrappingBuffer->numFrames[1] = framesAvailable - firstFrames;
87 } else {
88 wrappingBuffer->data[0] = source;
89 wrappingBuffer->numFrames[0] = framesAvailable;
90 }
91 } else {
92 wrappingBuffer->data[0] = nullptr;
93 wrappingBuffer->numFrames[0] = 0;
94 }
95 }
96
getFullDataAvailable(WrappingBuffer * wrappingBuffer)97 fifo_frames_t FifoBuffer::getFullDataAvailable(WrappingBuffer *wrappingBuffer) {
98 // The FIFO might be overfull so clip to capacity.
99 fifo_frames_t framesAvailable = std::min(mFifo->getFullFramesAvailable(),
100 mFifo->getCapacity());
101 fifo_frames_t startIndex = mFifo->getReadIndex();
102 fillWrappingBuffer(wrappingBuffer, framesAvailable, startIndex);
103 return framesAvailable;
104 }
105
getEmptyRoomAvailable(WrappingBuffer * wrappingBuffer)106 fifo_frames_t FifoBuffer::getEmptyRoomAvailable(WrappingBuffer *wrappingBuffer) {
107 // The FIFO might have underrun so clip to capacity.
108 fifo_frames_t framesAvailable = std::min(mFifo->getEmptyFramesAvailable(),
109 mFifo->getCapacity());
110 fifo_frames_t startIndex = mFifo->getWriteIndex();
111 fillWrappingBuffer(wrappingBuffer, framesAvailable, startIndex);
112 return framesAvailable;
113 }
114
read(void * buffer,fifo_frames_t numFrames)115 fifo_frames_t FifoBuffer::read(void *buffer, fifo_frames_t numFrames) {
116 WrappingBuffer wrappingBuffer;
117 uint8_t *destination = (uint8_t *) buffer;
118 fifo_frames_t framesLeft = numFrames;
119
120 getFullDataAvailable(&wrappingBuffer);
121
122 // Read data in one or two parts.
123 int partIndex = 0;
124 while (framesLeft > 0 && partIndex < WrappingBuffer::SIZE) {
125 fifo_frames_t framesToRead = framesLeft;
126 fifo_frames_t framesAvailable = wrappingBuffer.numFrames[partIndex];
127 if (framesAvailable > 0) {
128 if (framesToRead > framesAvailable) {
129 framesToRead = framesAvailable;
130 }
131 int32_t numBytes = convertFramesToBytes(framesToRead);
132 memcpy(destination, wrappingBuffer.data[partIndex], numBytes);
133
134 destination += numBytes;
135 framesLeft -= framesToRead;
136 } else {
137 break;
138 }
139 partIndex++;
140 }
141 fifo_frames_t framesRead = numFrames - framesLeft;
142 mFifo->advanceReadIndex(framesRead);
143 return framesRead;
144 }
145
write(const void * buffer,fifo_frames_t numFrames)146 fifo_frames_t FifoBuffer::write(const void *buffer, fifo_frames_t numFrames) {
147 WrappingBuffer wrappingBuffer;
148 uint8_t *source = (uint8_t *) buffer;
149 fifo_frames_t framesLeft = numFrames;
150
151 getEmptyRoomAvailable(&wrappingBuffer);
152
153 // Read data in one or two parts.
154 int partIndex = 0;
155 while (framesLeft > 0 && partIndex < WrappingBuffer::SIZE) {
156 fifo_frames_t framesToWrite = framesLeft;
157 fifo_frames_t framesAvailable = wrappingBuffer.numFrames[partIndex];
158 if (framesAvailable > 0) {
159 if (framesToWrite > framesAvailable) {
160 framesToWrite = framesAvailable;
161 }
162 int32_t numBytes = convertFramesToBytes(framesToWrite);
163 memcpy(wrappingBuffer.data[partIndex], source, numBytes);
164
165 source += numBytes;
166 framesLeft -= framesToWrite;
167 } else {
168 break;
169 }
170 partIndex++;
171 }
172 fifo_frames_t framesWritten = numFrames - framesLeft;
173 mFifo->advanceWriteIndex(framesWritten);
174 return framesWritten;
175 }
176
getThreshold()177 fifo_frames_t FifoBuffer::getThreshold() {
178 return mFifo->getThreshold();
179 }
180
setThreshold(fifo_frames_t threshold)181 void FifoBuffer::setThreshold(fifo_frames_t threshold) {
182 mFifo->setThreshold(threshold);
183 }
184
getBufferCapacityInFrames()185 fifo_frames_t FifoBuffer::getBufferCapacityInFrames() {
186 return mFifo->getCapacity();
187 }
188
eraseMemory()189 void FifoBuffer::eraseMemory() {
190 int32_t numBytes = convertFramesToBytes(getBufferCapacityInFrames());
191 if (numBytes > 0) {
192 memset(getStorage(), 0, (size_t) numBytes);
193 }
194 }
195