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.mtp; 18 19 import android.os.ParcelFileDescriptor; 20 import android.util.Log; 21 22 import java.io.IOException; 23 import java.util.concurrent.ExecutorService; 24 import java.util.concurrent.Executors; 25 import java.util.concurrent.TimeUnit; 26 27 class PipeManager { 28 /** 29 * Milliseconds we wait for background thread when pausing. 30 */ 31 private final static long AWAIT_TERMINATION_TIMEOUT = 2000; 32 33 final ExecutorService mExecutor; 34 final MtpDatabase mDatabase; 35 36 PipeManager(MtpDatabase database) { 37 this(database, Executors.newSingleThreadExecutor()); 38 } 39 40 PipeManager(MtpDatabase database, ExecutorService executor) { 41 this.mDatabase = database; 42 this.mExecutor = executor; 43 } 44 45 ParcelFileDescriptor readDocument(MtpManager model, Identifier identifier) throws IOException { 46 final Task task = new ImportFileTask(model, identifier); 47 mExecutor.execute(task); 48 return task.getReadingFileDescriptor(); 49 } 50 51 ParcelFileDescriptor readThumbnail(MtpManager model, Identifier identifier) throws IOException { 52 final Task task = new GetThumbnailTask(model, identifier); 53 mExecutor.execute(task); 54 return task.getReadingFileDescriptor(); 55 } 56 57 private static abstract class Task implements Runnable { 58 protected final MtpManager mManager; 59 protected final Identifier mIdentifier; 60 protected final ParcelFileDescriptor[] mDescriptors; 61 62 Task(MtpManager manager, Identifier identifier) throws IOException { 63 mManager = manager; 64 mIdentifier = identifier; 65 mDescriptors = ParcelFileDescriptor.createReliablePipe(); 66 } 67 68 ParcelFileDescriptor getReadingFileDescriptor() { 69 return mDescriptors[0]; 70 } 71 } 72 73 private static class ImportFileTask extends Task { 74 ImportFileTask(MtpManager model, Identifier identifier) throws IOException { 75 super(model, identifier); 76 } 77 78 @Override 79 public void run() { 80 try { 81 mManager.importFile( 82 mIdentifier.mDeviceId, mIdentifier.mObjectHandle, mDescriptors[1]); 83 mDescriptors[1].close(); 84 } catch (IOException error) { 85 try { 86 mDescriptors[1].closeWithError("Failed to stream a file."); 87 } catch (IOException closeError) { 88 Log.w(MtpDocumentsProvider.TAG, closeError.getMessage()); 89 } 90 } 91 } 92 } 93 94 private static class GetThumbnailTask extends Task { 95 GetThumbnailTask(MtpManager model, Identifier identifier) throws IOException { 96 super(model, identifier); 97 } 98 99 @Override 100 public void run() { 101 try { 102 try (final ParcelFileDescriptor.AutoCloseOutputStream stream = 103 new ParcelFileDescriptor.AutoCloseOutputStream(mDescriptors[1])) { 104 try { 105 stream.write(mManager.getThumbnail( 106 mIdentifier.mDeviceId, mIdentifier.mObjectHandle)); 107 } catch (IOException error) { 108 mDescriptors[1].closeWithError("Failed to stream a thumbnail."); 109 } 110 } 111 } catch (IOException closeError) { 112 Log.w(MtpDocumentsProvider.TAG, closeError.getMessage()); 113 } 114 } 115 } 116 117 boolean close() throws InterruptedException { 118 mExecutor.shutdownNow(); 119 return mExecutor.awaitTermination(AWAIT_TERMINATION_TIMEOUT, TimeUnit.MILLISECONDS); 120 } 121 } 122