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#ifndef FIFO_FIFO_BUFFER_H
18#define FIFO_FIFO_BUFFER_H
19
20#include <stdint.h>
21
22#include "FifoControllerBase.h"
23
24namespace android {
25
26/**
27 * Structure that represents a region in a circular buffer that might be at the
28 * end of the array and split in two.
29 */
30struct WrappingBuffer {
31    enum {
32        SIZE = 2
33    };
34    void *data[SIZE];
35    int32_t numFrames[SIZE];
36};
37
38class FifoBuffer {
39public:
40    FifoBuffer(int32_t bytesPerFrame, fifo_frames_t capacityInFrames);
41
42    FifoBuffer(int32_t bytesPerFrame,
43               fifo_frames_t capacityInFrames,
44               fifo_counter_t *readCounterAddress,
45               fifo_counter_t *writeCounterAddress,
46               void *dataStorageAddress);
47
48    ~FifoBuffer();
49
50    int32_t convertFramesToBytes(fifo_frames_t frames);
51
52    fifo_frames_t read(void *destination, fifo_frames_t framesToRead);
53
54    fifo_frames_t write(const void *source, fifo_frames_t framesToWrite);
55
56    fifo_frames_t getThreshold();
57
58    void setThreshold(fifo_frames_t threshold);
59
60    fifo_frames_t getBufferCapacityInFrames();
61
62    /**
63     * Return pointer to available full frames in data1 and set size in numFrames1.
64     * if the data is split across the end of the FIFO then set data2 and numFrames2.
65     * Other wise set them to null
66     * @param wrappingBuffer
67     * @return total full frames available
68     */
69    fifo_frames_t getFullDataAvailable(WrappingBuffer *wrappingBuffer);
70
71    /**
72     * Return pointer to available empty frames in data1 and set size in numFrames1.
73     * if the room is split across the end of the FIFO then set data2 and numFrames2.
74     * Other wise set them to null
75     * @param wrappingBuffer
76     * @return total empty frames available
77     */
78    fifo_frames_t getEmptyRoomAvailable(WrappingBuffer *wrappingBuffer);
79
80    /**
81     * Copy data from the FIFO into the buffer.
82     * @param buffer
83     * @param numFrames
84     * @return
85     */
86    fifo_frames_t readNow(void *buffer, fifo_frames_t numFrames);
87
88    int64_t getNextReadTime(int32_t frameRate);
89
90    int32_t getUnderrunCount() const { return mUnderrunCount; }
91
92    FifoControllerBase *getFifoControllerBase() { return mFifo; }
93
94    int32_t getBytesPerFrame() {
95        return mBytesPerFrame;
96    }
97
98    fifo_counter_t getReadCounter() {
99        return mFifo->getReadCounter();
100    }
101
102    void setReadCounter(fifo_counter_t n) {
103        mFifo->setReadCounter(n);
104    }
105
106    fifo_counter_t getWriteCounter() {
107        return mFifo->getWriteCounter();
108    }
109
110    void setWriteCounter(fifo_counter_t n) {
111        mFifo->setWriteCounter(n);
112    }
113
114    /*
115     * This is generally only called before or after the buffer is used.
116     */
117    void eraseMemory();
118
119private:
120
121    void fillWrappingBuffer(WrappingBuffer *wrappingBuffer,
122                            int32_t framesAvailable, int32_t startIndex);
123
124    const fifo_frames_t mFrameCapacity;
125    const int32_t mBytesPerFrame;
126    uint8_t *mStorage;
127    bool mStorageOwned; // did this object allocate the storage?
128    FifoControllerBase *mFifo;
129    fifo_counter_t mFramesReadCount;
130    fifo_counter_t mFramesUnderrunCount;
131    int32_t mUnderrunCount; // need? just use frames
132    int32_t mLastReadSize;
133};
134
135}  // android
136
137#endif //FIFO_FIFO_BUFFER_H
138