1 /* 2 * Copyright (C) 2014 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.camera.one.v2.sharedimagereader.ringbuffer; 18 19 import com.android.camera.async.BufferQueue; 20 import com.android.camera.async.BufferQueueController; 21 import com.android.camera.async.Lifetime; 22 import com.android.camera.async.Observable; 23 import com.android.camera.one.v2.camera2proxy.ImageProxy; 24 import com.android.camera.one.v2.sharedimagereader.ticketpool.TicketPool; 25 import com.google.common.util.concurrent.MoreExecutors; 26 27 /* 28 * Creates a dynamic ring buffer of images. 29 * <p> 30 * The ring buffer is implicitly defined by an input and an output. 31 * <p> 32 * The size of the ring-buffer is dictated by how many tickets it can retrieve from the root 33 * ticket pool. As tickets become available, the ring-buffer expands. 34 * <p> 35 * The ring buffer also provides its own ticket pool. When tickets are requested from this pool, 36 * the ring buffer shrinks. 37 * <p> 38 * Images which cannot be held in the ring-buffer are released immediately. 39 */ 40 public class DynamicRingBufferFactory { 41 private final TicketPool mOutputTicketPool; 42 private final BufferQueueController<ImageProxy> mRingBufferInput; 43 private final BufferQueue<ImageProxy> mRingBufferOutput; 44 DynamicRingBufferFactory(Lifetime lifetime, TicketPool rootTicketPool, final Observable<Integer> maxRingBufferSize)45 public DynamicRingBufferFactory(Lifetime lifetime, TicketPool rootTicketPool, 46 final Observable<Integer> maxRingBufferSize) { 47 final DynamicRingBuffer ringBuffer = new DynamicRingBuffer(rootTicketPool); 48 lifetime.add(ringBuffer); 49 lifetime.add(maxRingBufferSize.addCallback(new Runnable() { 50 @Override 51 public void run() { 52 ringBuffer.setMaxSize(Math.max(0, maxRingBufferSize.get())); 53 } 54 }, MoreExecutors.sameThreadExecutor())); 55 ringBuffer.setMaxSize(Math.max(0, maxRingBufferSize.get())); 56 57 mOutputTicketPool = ringBuffer; 58 mRingBufferInput = ringBuffer; 59 mRingBufferOutput = ringBuffer; 60 } 61 provideTicketPool()62 public TicketPool provideTicketPool() { 63 return mOutputTicketPool; 64 } 65 provideRingBufferInput()66 public BufferQueueController<ImageProxy> provideRingBufferInput() { 67 return mRingBufferInput; 68 } 69 provideRingBufferOutput()70 public BufferQueue<ImageProxy> provideRingBufferOutput() { 71 return mRingBufferOutput; 72 } 73 } 74