1 /* 2 * Copyright (C) 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 package com.android.tv.tuner.exoplayer.buffer; 18 19 import com.google.android.exoplayer.SampleHolder; 20 21 import java.util.LinkedList; 22 23 /** 24 * Pool of samples to recycle ByteBuffers as much as possible. 25 */ 26 public class SamplePool { 27 private final LinkedList<SampleHolder> mSamplePool = new LinkedList<>(); 28 29 /** 30 * Acquires a sample with a buffer larger than size from the pool. Allocate new one or resize 31 * an existing buffer if necessary. 32 */ acquireSample(int size)33 public synchronized SampleHolder acquireSample(int size) { 34 if (mSamplePool.isEmpty()) { 35 SampleHolder sample = new SampleHolder(SampleHolder.BUFFER_REPLACEMENT_MODE_NORMAL); 36 sample.ensureSpaceForWrite(size); 37 return sample; 38 } 39 SampleHolder smallestSufficientSample = null; 40 SampleHolder maxSample = mSamplePool.getFirst(); 41 for (SampleHolder sample : mSamplePool) { 42 // Grab the smallest sufficient sample. 43 if (sample.data.capacity() >= size && (smallestSufficientSample == null 44 || smallestSufficientSample.data.capacity() > sample.data.capacity())) { 45 smallestSufficientSample = sample; 46 } 47 48 // Grab the max size sample. 49 if (maxSample.data.capacity() < sample.data.capacity()) { 50 maxSample = sample; 51 } 52 } 53 SampleHolder sampleFromPool = smallestSufficientSample; 54 55 // If there's no sufficient sample, grab the maximum sample and resize it to size. 56 if (sampleFromPool == null) { 57 sampleFromPool = maxSample; 58 sampleFromPool.ensureSpaceForWrite(size); 59 } 60 mSamplePool.remove(sampleFromPool); 61 return sampleFromPool; 62 } 63 64 /** 65 * Releases the sample back to the pool. 66 */ releaseSample(SampleHolder sample)67 public synchronized void releaseSample(SampleHolder sample) { 68 sample.clearData(); 69 mSamplePool.offerLast(sample); 70 } 71 } 72