1 /* 2 * Copyright 2018 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 android.media; 18 19 import android.annotation.NonNull; 20 import android.os.ParcelFileDescriptor; 21 import android.util.Log; 22 23 import java.io.IOException; 24 25 /** 26 * Structure of data source descriptor for sources using file descriptor. 27 * 28 * Used by {@link MediaPlayer2#setDataSource}, {@link MediaPlayer2#setNextDataSource} and 29 * {@link MediaPlayer2#setNextDataSources} to set data source for playback. 30 * 31 * <p>Users should use {@link Builder} to create {@link FileDataSourceDesc}. 32 * @hide 33 */ 34 public class FileDataSourceDesc extends DataSourceDesc { 35 private static final String TAG = "FileDataSourceDesc"; 36 37 /** 38 * Used when the length of file descriptor is unknown. 39 * 40 * @see #getLength() 41 */ 42 public static final long FD_LENGTH_UNKNOWN = LONG_MAX; 43 44 private ParcelFileDescriptor mPFD; 45 private long mOffset = 0; 46 private long mLength = FD_LENGTH_UNKNOWN; 47 private int mCount = 0; 48 private boolean mClosed = false; 49 FileDataSourceDesc(String mediaId, long startPositionMs, long endPositionMs, ParcelFileDescriptor pfd, long offset, long length)50 FileDataSourceDesc(String mediaId, long startPositionMs, long endPositionMs, 51 ParcelFileDescriptor pfd, long offset, long length) { 52 super(mediaId, startPositionMs, endPositionMs); 53 mPFD = pfd; 54 mOffset = offset; 55 mLength = length; 56 } 57 58 /** 59 * Releases the resources held by this {@code FileDataSourceDesc} object. 60 */ 61 @Override close()62 void close() { 63 super.close(); 64 decCount(); 65 } 66 67 /** 68 * Decrements usage count by {@link MediaPlayer2}. 69 * If this is the last usage, also releases the file descriptor held by this 70 * {@code FileDataSourceDesc} object. 71 */ decCount()72 void decCount() { 73 synchronized (this) { 74 --mCount; 75 if (mCount > 0) { 76 return; 77 } 78 79 try { 80 mPFD.close(); 81 mClosed = true; 82 } catch (IOException e) { 83 Log.e(TAG, "failed to close pfd: " + e); 84 } 85 } 86 } 87 88 /** 89 * Increments usage count by {@link MediaPlayer2} if PFD has not been closed. 90 */ incCount()91 void incCount() { 92 synchronized (this) { 93 if (!mClosed) { 94 ++mCount; 95 } 96 } 97 } 98 99 /** 100 * Return the status of underline ParcelFileDescriptor 101 * @return true if underline ParcelFileDescriptor is closed, false otherwise. 102 */ isPFDClosed()103 boolean isPFDClosed() { 104 synchronized (this) { 105 return mClosed; 106 } 107 } 108 109 /** 110 * Return the ParcelFileDescriptor of this data source. 111 * @return the ParcelFileDescriptor of this data source 112 */ getParcelFileDescriptor()113 public @NonNull ParcelFileDescriptor getParcelFileDescriptor() { 114 return mPFD; 115 } 116 117 /** 118 * Return the offset associated with the ParcelFileDescriptor of this data source. 119 * It's meaningful only when it has been set by the {@link Builder}. 120 * @return the offset associated with the ParcelFileDescriptor of this data source 121 */ getOffset()122 public long getOffset() { 123 return mOffset; 124 } 125 126 /** 127 * Return the content length associated with the ParcelFileDescriptor of this data source. 128 * {@link #FD_LENGTH_UNKNOWN} means same as the length of source content. 129 * @return the content length associated with the ParcelFileDescriptor of this data source 130 */ getLength()131 public long getLength() { 132 return mLength; 133 } 134 } 135