FileChannelImpl.java revision fe5da19e0e366286cd4d95f7628fe9442b9062c8
1adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/* 2adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Licensed to the Apache Software Foundation (ASF) under one or more 3adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * contributor license agreements. See the NOTICE file distributed with 4adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * this work for additional information regarding copyright ownership. 5adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * The ASF licenses this file to You under the Apache License, Version 2.0 6adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * (the "License"); you may not use this file except in compliance with 7adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * the License. You may obtain a copy of the License at 8adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * 9adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 10adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * 11adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Unless required by applicable law or agreed to in writing, software 12adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 13adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * See the License for the specific language governing permissions and 15adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * limitations under the License. 16adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 17adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 18ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughespackage java.nio; 19adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 20adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.io.Closeable; 21adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.io.FileDescriptor; 22adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.io.IOException; 23adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.ClosedChannelException; 24adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.FileChannel; 25adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.FileLock; 266ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughesimport java.nio.channels.NonReadableChannelException; 27adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.NonWritableChannelException; 28ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughesimport java.nio.channels.OverlappingFileLockException; 29adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.ReadableByteChannel; 30adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.WritableByteChannel; 31a1603838fe9e865575c87982e32c6343740e464cElliott Hughesimport java.util.Arrays; 32ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughesimport java.util.Comparator; 33ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughesimport java.util.SortedSet; 34ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughesimport java.util.TreeSet; 3552724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughesimport libcore.io.ErrnoException; 3652724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughesimport libcore.io.Libcore; 37fc549a0b0388987b26dea524894d75a63d14783bElliott Hughesimport libcore.io.StructFlock; 388b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughesimport libcore.util.MutableLong; 396ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughesimport static libcore.io.OsConstants.*; 40adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 416fc1a0e1e68dc2e0d12341548e58fa7f1c5dafc4Elliott Hughes/** 426fc1a0e1e68dc2e0d12341548e58fa7f1c5dafc4Elliott Hughes * Our concrete implementation of the abstract FileChannel class. 43adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 446ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughesfinal class FileChannelImpl extends FileChannel { 45ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes private static final Comparator<FileLock> LOCK_COMPARATOR = new Comparator<FileLock>() { 46ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes public int compare(FileLock lock1, FileLock lock2) { 47ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes long position1 = lock1.position(); 48ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes long position2 = lock2.position(); 49ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes return position1 > position2 ? 1 : (position1 < position2 ? -1 : 0); 50ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 51ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes }; 52ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes 536ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes private final Object stream; 5452724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes private final FileDescriptor fd; 556ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes private final int mode; 56adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 57ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes // The set of acquired and pending locks. 58ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes private final SortedSet<FileLock> locks = new TreeSet<FileLock>(LOCK_COMPARATOR); 59adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 60ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes /** 616ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes * Create a new file channel implementation class that wraps the given 626ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes * fd and operates in the specified mode. 63adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 6452724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes public FileChannelImpl(Object stream, FileDescriptor fd, int mode) { 656ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes this.fd = fd; 66adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project this.stream = stream; 676ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes this.mode = mode; 68adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 69adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 706ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes private void checkOpen() throws ClosedChannelException { 71adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (!isOpen()) { 72adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project throw new ClosedChannelException(); 73adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 74adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 75adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 766ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes private void checkReadable() { 776ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if ((mode & O_ACCMODE) == O_WRONLY) { 786ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new NonReadableChannelException(); 796ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 806ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 816ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes 826ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes private void checkWritable() { 836ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if ((mode & O_ACCMODE) == O_RDONLY) { 846ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new NonWritableChannelException(); 856ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 866ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 876ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes 88adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project protected void implCloseChannel() throws IOException { 89adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (stream instanceof Closeable) { 90adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project ((Closeable) stream).close(); 91adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 92adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 93adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 946ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes private FileLock basicLock(long position, long size, boolean shared, boolean wait) throws IOException { 956ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes int accessMode = (mode & O_ACCMODE); 966ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if (accessMode == O_RDONLY) { 976ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if (!shared) { 986ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new NonWritableChannelException(); 996ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 1006ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } else if (accessMode == O_WRONLY) { 1016ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if (shared) { 1026ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new NonReadableChannelException(); 1036ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 1046ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 1056ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes 10603c0a8e681c776fdba0389ab8593282139afc6d6Elliott Hughes if (position < 0 || size < 0) { 1076ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new IllegalArgumentException("position=" + position + " size=" + size); 108adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 109fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes 110adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project FileLock pendingLock = new FileLockImpl(this, position, size, shared); 111ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes addLock(pendingLock); 112adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 113fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes StructFlock flock = new StructFlock(); 114fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes flock.l_type = (short) (shared ? F_RDLCK : F_WRLCK); 115fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes flock.l_whence = (short) SEEK_SET; 116fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes flock.l_start = position; 117fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes flock.l_len = translateLockLength(size); 118adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 1199b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes boolean success = false; 1209b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes try { 1219b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes success = (Libcore.os.fcntlFlock(fd, wait ? F_SETLKW64 : F_SETLK64, flock) != -1); 1229b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes } catch (ErrnoException errnoException) { 1239b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes throw errnoException.rethrowAsIOException(); 1249b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes } finally { 1259b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes if (!success) { 1269b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes removeLock(pendingLock); 1279b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes } 1289b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes } 1299b510df35b57946d843ffc34cf23fdcfc84c5220Elliott Hughes return success ? pendingLock : null; 130fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes } 131fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes 132fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes private static long translateLockLength(long byteCount) { 133fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes // FileChannel uses Long.MAX_VALUE to mean "lock the whole file" where POSIX uses 0. 134fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes return (byteCount == Long.MAX_VALUE) ? 0 : byteCount; 135adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 136adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 137ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes private static final class FileLockImpl extends FileLock { 138ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes private boolean isReleased = false; 139ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes 140ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes public FileLockImpl(FileChannel channel, long position, long size, boolean shared) { 141ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes super(channel, position, size, shared); 142ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 143ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes 1446ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes public boolean isValid() { 145ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes return !isReleased && channel().isOpen(); 146ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 147ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes 1486ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes public void release() throws IOException { 149ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes if (!channel().isOpen()) { 150ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes throw new ClosedChannelException(); 151ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 152ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes if (!isReleased) { 153ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes ((FileChannelImpl) channel()).release(this); 154ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes isReleased = true; 155ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 156ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 157ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 158ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes 159ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes public final FileLock lock(long position, long size, boolean shared) throws IOException { 1606ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 161adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project FileLock resultLock = null; 162adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project { 163adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project boolean completed = false; 164adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project try { 165adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project begin(); 166adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project resultLock = basicLock(position, size, shared, true); 167adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project completed = true; 168adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } finally { 169adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project end(completed); 170adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 171adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 172adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return resultLock; 173adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 174adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 175ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes public final FileLock tryLock(long position, long size, boolean shared) throws IOException { 1766ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 177adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return basicLock(position, size, shared, false); 178adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 179adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 180ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes /** 181adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Non-API method to release a given lock on a file channel. Assumes that 182adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * the lock will mark itself invalid after successful unlocking. 183adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 1846ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes public void release(FileLock lock) throws IOException { 1856ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 186fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes 187fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes StructFlock flock = new StructFlock(); 188fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes flock.l_type = (short) F_UNLCK; 189fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes flock.l_whence = (short) SEEK_SET; 190fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes flock.l_start = lock.position(); 191fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes flock.l_len = translateLockLength(lock.size()); 192fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes try { 193fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes Libcore.os.fcntlFlock(fd, F_SETLKW64, flock); 194fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes } catch (ErrnoException errnoException) { 195fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes throw errnoException.rethrowAsIOException(); 196fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes } 197fc549a0b0388987b26dea524894d75a63d14783bElliott Hughes 198ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes removeLock(lock); 199adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 200adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 2016ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes public void force(boolean metadata) throws IOException { 2026ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 2036ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if ((mode & O_ACCMODE) != O_RDONLY) { 20452724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes try { 20552724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes if (metadata) { 20652724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes Libcore.os.fsync(fd); 20752724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes } else { 20852724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes Libcore.os.fdatasync(fd); 20952724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes } 21052724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes } catch (ErrnoException errnoException) { 211f5333fd2094bdac4d6506177b1964b79afa64d77Elliott Hughes throw errnoException.rethrowAsIOException(); 21252724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes } 2136ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 214adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 215adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 2166ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes public final MappedByteBuffer map(MapMode mapMode, long position, long size) throws IOException { 2176ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 2186ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if (mapMode == null) { 2196ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new NullPointerException("mapMode == null"); 2206ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 2216ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if (position < 0 || size < 0 || size > Integer.MAX_VALUE) { 2226ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new IllegalArgumentException("position=" + position + " size=" + size); 2236ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 2246ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes int accessMode = (mode & O_ACCMODE); 2256ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if (accessMode == O_RDONLY) { 2266ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if (mapMode != MapMode.READ_ONLY) { 2276ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new NonWritableChannelException(); 2286ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 2296ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } else if (accessMode == O_WRONLY) { 2306ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new NonReadableChannelException(); 2316ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes } 232adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (position + size > size()) { 233c03e4ba8cd93513aabda061b00d516b54717c5fbElliott Hughes // We can't defer to FileChannel.truncate because that will only make a file shorter, 234c03e4ba8cd93513aabda061b00d516b54717c5fbElliott Hughes // and we only care about making our backing file longer here. 235c03e4ba8cd93513aabda061b00d516b54717c5fbElliott Hughes try { 236c03e4ba8cd93513aabda061b00d516b54717c5fbElliott Hughes Libcore.os.ftruncate(fd, position + size); 237c03e4ba8cd93513aabda061b00d516b54717c5fbElliott Hughes } catch (ErrnoException errnoException) { 238385c6f4303341beb9b091b6d252811b7ca3b9f42Nick Kralevich // EINVAL can be thrown if we're dealing with non-regular 239385c6f4303341beb9b091b6d252811b7ca3b9f42Nick Kralevich // files, for example, character devices such as /dev/zero. 240385c6f4303341beb9b091b6d252811b7ca3b9f42Nick Kralevich // In those cases, we ignore the failed truncation and 241385c6f4303341beb9b091b6d252811b7ca3b9f42Nick Kralevich // continue on. 242385c6f4303341beb9b091b6d252811b7ca3b9f42Nick Kralevich if (errnoException.errno != EINVAL) { 243385c6f4303341beb9b091b6d252811b7ca3b9f42Nick Kralevich throw errnoException.rethrowAsIOException(); 244385c6f4303341beb9b091b6d252811b7ca3b9f42Nick Kralevich } 245c03e4ba8cd93513aabda061b00d516b54717c5fbElliott Hughes } 246adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 2476fc1a0e1e68dc2e0d12341548e58fa7f1c5dafc4Elliott Hughes long alignment = position - position % Libcore.os.sysconf(_SC_PAGE_SIZE); 248adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int offset = (int) (position - alignment); 2497e25eff38a191d9c19e45093f4fde5102fb09d78Elliott Hughes MemoryBlock block = MemoryBlock.mmap(fd, alignment, size + offset, mapMode); 250fe5da19e0e366286cd4d95f7628fe9442b9062c8Elliott Hughes return new DirectByteBuffer(block, (int) size, offset, (mapMode == MapMode.READ_ONLY), mapMode); 251adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 252adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 253adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public long position() throws IOException { 2546ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 255dedaccdfa07c370a58cba08b096133ad9eec0ec3Elliott Hughes try { 256dedaccdfa07c370a58cba08b096133ad9eec0ec3Elliott Hughes return Libcore.os.lseek(fd, 0L, SEEK_CUR); 257dedaccdfa07c370a58cba08b096133ad9eec0ec3Elliott Hughes } catch (ErrnoException errnoException) { 258dedaccdfa07c370a58cba08b096133ad9eec0ec3Elliott Hughes throw errnoException.rethrowAsIOException(); 259dedaccdfa07c370a58cba08b096133ad9eec0ec3Elliott Hughes } 260adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 261adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 262adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public FileChannel position(long newPosition) throws IOException { 2636ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 264adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (newPosition < 0) { 2656ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new IllegalArgumentException("position: " + newPosition); 266eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson } 267e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes try { 268e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes Libcore.os.lseek(fd, newPosition, SEEK_SET); 269e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } catch (ErrnoException errnoException) { 270e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes throw errnoException.rethrowAsIOException(); 271adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 272adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return this; 273adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 274adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 275adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public int read(ByteBuffer buffer, long position) throws IOException { 276eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson if (position < 0) { 2776ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new IllegalArgumentException("position: " + position); 278adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 279e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes return readImpl(buffer, position); 280adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 281adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 282adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public int read(ByteBuffer buffer) throws IOException { 283e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes return readImpl(buffer, -1); 284e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } 285e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes 286e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes private int readImpl(ByteBuffer buffer, long position) throws IOException { 287e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes buffer.checkWritable(); 2886ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 2896ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkReadable(); 290eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson if (!buffer.hasRemaining()) { 291adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return 0; 292adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 293e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes int bytesRead = 0; 294e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes boolean completed = false; 295e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes try { 296e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes begin(); 29726c7025a7a919044771fb89031161bd26fe03032Elliott Hughes try { 298e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes if (position == -1) { 29926c7025a7a919044771fb89031161bd26fe03032Elliott Hughes bytesRead = Libcore.os.read(fd, buffer); 300e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } else { 301e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes bytesRead = Libcore.os.pread(fd, buffer, position); 302e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } 303e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes if (bytesRead == 0) { 304e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes bytesRead = -1; 305e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } 306e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } catch (ErrnoException errnoException) { 307e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes if (errnoException.errno == EAGAIN) { 308e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes // We don't throw if we try to read from an empty non-blocking pipe. 309e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes bytesRead = 0; 310e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } else { 311e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes throw errnoException.rethrowAsIOException(); 312adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 313adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 314e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes completed = true; 315e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } finally { 316e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes end(completed && bytesRead >= 0); 317e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } 318e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes if (bytesRead > 0) { 319e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes buffer.position(buffer.position() + bytesRead); 320adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 321e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes return bytesRead; 322adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 323adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 324bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes private int transferIoVec(IoVec ioVec) throws IOException { 325bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes if (ioVec.init() == 0) { 326adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return 0; 327adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 328bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes int bytesTransferred = 0; 329bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes boolean completed = false; 330bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes try { 331bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes begin(); 332e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes bytesTransferred = ioVec.doTransfer(fd); 333bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes completed = true; 334bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes } finally { 335bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes end(completed); 336adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 337bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes ioVec.didTransfer(bytesTransferred); 338bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes return bytesTransferred; 339bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes } 340adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 341bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes public long read(ByteBuffer[] buffers, int offset, int length) throws IOException { 342bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes Arrays.checkOffsetAndCount(buffers.length, offset, length); 343bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes checkOpen(); 344bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes checkReadable(); 345bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes return transferIoVec(new IoVec(buffers, offset, length, IoVec.Direction.READV)); 346adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 347adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 348adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public long size() throws IOException { 3496ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 35047cb338d43f75dd998b29caaaa9446c5705217d1Elliott Hughes try { 35147cb338d43f75dd998b29caaaa9446c5705217d1Elliott Hughes return Libcore.os.fstat(fd).st_size; 35247cb338d43f75dd998b29caaaa9446c5705217d1Elliott Hughes } catch (ErrnoException errnoException) { 353f5333fd2094bdac4d6506177b1964b79afa64d77Elliott Hughes throw errnoException.rethrowAsIOException(); 35447cb338d43f75dd998b29caaaa9446c5705217d1Elliott Hughes } 355adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 356adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 3576ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes public long transferFrom(ReadableByteChannel src, long position, long count) throws IOException { 3586ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 359adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (!src.isOpen()) { 360adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project throw new ClosedChannelException(); 361adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 3626ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkWritable(); 363eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson if (position < 0 || count < 0 || count > Integer.MAX_VALUE) { 3646ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new IllegalArgumentException("position=" + position + " count=" + count); 365adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 366eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson if (position > size()) { 367adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return 0; 368adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 369eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson 370e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes // Although sendfile(2) originally supported writing to a regular file. 371e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes // In Linux 2.6 and later, it only supports writing to sockets. 372e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes 373e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes // If our source is a regular file, mmap(2) rather than reading. 374e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes // Callers should only be using transferFrom for large transfers, 375e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes // so the mmap(2) overhead isn't a concern. 376e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes if (src instanceof FileChannel) { 377e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes FileChannel fileSrc = (FileChannel) src; 378e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes long size = fileSrc.size(); 379e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes long filePosition = fileSrc.position(); 380e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes count = Math.min(count, size - filePosition); 381e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes ByteBuffer buffer = fileSrc.map(MapMode.READ_ONLY, filePosition, count); 382e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes try { 383adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project fileSrc.position(filePosition + count); 384e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes return write(buffer, position); 385e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes } finally { 386e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes NioUtils.freeDirectBuffer(buffer); 387adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 388adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 389e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes 390e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes // For non-file channels, all we can do is read and write via userspace. 391e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes ByteBuffer buffer = ByteBuffer.allocate((int) count); 392e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes src.read(buffer); 393e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes buffer.flip(); 394e3d7539b3cb1e763f1ed5832120684468e635d94Elliott Hughes return write(buffer, position); 395adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 396adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 3972cff86c0c10588a35036fe5bbca83b07f53e1b1dElliott Hughes public long transferTo(long position, long count, WritableByteChannel target) throws IOException { 3986ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 399adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (!target.isOpen()) { 400adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project throw new ClosedChannelException(); 401adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 4022cff86c0c10588a35036fe5bbca83b07f53e1b1dElliott Hughes checkReadable(); 4036ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes if (target instanceof FileChannelImpl) { 4046ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes ((FileChannelImpl) target).checkWritable(); 405adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 406eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson if (position < 0 || count < 0) { 4076ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes throw new IllegalArgumentException("position=" + position + " count=" + count); 408adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 409eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson 410adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (count == 0 || position >= size()) { 411adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return 0; 412adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 413adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project count = Math.min(count, size() - position); 4148b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes 4158b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes // Try sendfile(2) first... 4168b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes boolean completed = false; 417adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (target instanceof SocketChannelImpl) { 4188b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes FileDescriptor outFd = ((SocketChannelImpl) target).getFD(); 4198b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes try { 4208b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes begin(); 4218b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes try { 4228b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes MutableLong offset = new MutableLong(position); 4238b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes long rc = Libcore.os.sendfile(outFd, fd, offset, count); 4248b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes completed = true; 4258b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes return rc; 4268b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes } catch (ErrnoException errnoException) { 4278b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes // If the OS doesn't support what we asked for, we want to fall through and 4288b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes // try a different approach. If it does support it, but it failed, we're done. 4298b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes if (errnoException.errno != ENOSYS && errnoException.errno != EINVAL) { 4308b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes throw errnoException.rethrowAsIOException(); 4318b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes } 4328b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes } 4338b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes } finally { 4348b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes end(completed); 4358b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes } 436adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 4378b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes // ...fall back to write(2). 4388b15dcc5890963edad4dfcf558cc16027c7985e5Elliott Hughes ByteBuffer buffer = null; 439adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project try { 440adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project buffer = map(MapMode.READ_ONLY, position, count); 441adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return target.write(buffer); 442adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } finally { 443c73a5be50cdd804ff3c12e7b43da08c33cdd6f21Elliott Hughes NioUtils.freeDirectBuffer(buffer); 444adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 445adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 446adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 447adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public FileChannel truncate(long size) throws IOException { 4486ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 449adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (size < 0) { 450126ab1b546c71137a97cef68cc89267e7f7be634Elliott Hughes throw new IllegalArgumentException("size < 0: " + size); 451adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 4526ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkWritable(); 453adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (size < size()) { 454f5333fd2094bdac4d6506177b1964b79afa64d77Elliott Hughes try { 455f5333fd2094bdac4d6506177b1964b79afa64d77Elliott Hughes Libcore.os.ftruncate(fd, size); 456f5333fd2094bdac4d6506177b1964b79afa64d77Elliott Hughes } catch (ErrnoException errnoException) { 457f5333fd2094bdac4d6506177b1964b79afa64d77Elliott Hughes throw errnoException.rethrowAsIOException(); 458adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 459adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 460adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return this; 461adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 462adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 463adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public int write(ByteBuffer buffer, long position) throws IOException { 464eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson if (position < 0) { 465126ab1b546c71137a97cef68cc89267e7f7be634Elliott Hughes throw new IllegalArgumentException("position < 0: " + position); 466adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 467e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes return writeImpl(buffer, position); 468e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } 469e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes 470e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes public int write(ByteBuffer buffer) throws IOException { 471e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes return writeImpl(buffer, -1); 472e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } 473e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes 474e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes private int writeImpl(ByteBuffer buffer, long position) throws IOException { 4756ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 4766ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkWritable(); 477e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes if (buffer == null) { 478e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes throw new NullPointerException("buffer == null"); 479e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } 480eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson if (!buffer.hasRemaining()) { 481adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return 0; 482adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 483adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int bytesWritten = 0; 484e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes boolean completed = false; 485e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes try { 486e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes begin(); 48778c7cc547101002b9f9043cf3845970719d1bda8Elliott Hughes try { 488e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes if (position == -1) { 48978c7cc547101002b9f9043cf3845970719d1bda8Elliott Hughes bytesWritten = Libcore.os.write(fd, buffer); 490e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } else { 491e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes bytesWritten = Libcore.os.pwrite(fd, buffer, position); 492adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 493e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } catch (ErrnoException errnoException) { 494e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes throw errnoException.rethrowAsIOException(); 495adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 496e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes completed = true; 497e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } finally { 498e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes end(completed); 499adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 500e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes if (bytesWritten > 0) { 501e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes buffer.position(buffer.position() + bytesWritten); 502e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes } 503e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes return bytesWritten; 504adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 505adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 5062620ff9a08ce7fc6d66b60784b1eecd78eb001baElliott Hughes public long write(ByteBuffer[] buffers, int offset, int length) throws IOException { 507a1603838fe9e865575c87982e32c6343740e464cElliott Hughes Arrays.checkOffsetAndCount(buffers.length, offset, length); 5086ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkOpen(); 5096ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes checkWritable(); 510bbac92e691de7d570928ddfba639067978e55b06Elliott Hughes return transferIoVec(new IoVec(buffers, offset, length, IoVec.Direction.WRITEV)); 511adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 512eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson 5132620ff9a08ce7fc6d66b60784b1eecd78eb001baElliott Hughes /** 5142620ff9a08ce7fc6d66b60784b1eecd78eb001baElliott Hughes * @param copyingIn true if we're copying data into the buffers (typically 5152620ff9a08ce7fc6d66b60784b1eecd78eb001baElliott Hughes * because the caller is a file/network read operation), false if we're 5162620ff9a08ce7fc6d66b60784b1eecd78eb001baElliott Hughes * copying data out of the buffers (for a file/network write operation). 5172620ff9a08ce7fc6d66b60784b1eecd78eb001baElliott Hughes */ 5182620ff9a08ce7fc6d66b60784b1eecd78eb001baElliott Hughes static int calculateTotalRemaining(ByteBuffer[] buffers, int offset, int length, boolean copyingIn) { 519d85168bd730e513cb0bd561030da3f7ea5044725Elliott Hughes int count = 0; 520d85168bd730e513cb0bd561030da3f7ea5044725Elliott Hughes for (int i = offset; i < offset + length; ++i) { 521d85168bd730e513cb0bd561030da3f7ea5044725Elliott Hughes count += buffers[i].remaining(); 5222620ff9a08ce7fc6d66b60784b1eecd78eb001baElliott Hughes if (copyingIn) { 523e3b6fa2bf357f2712ab2ee9e8487f157595ea0c7Elliott Hughes buffers[i].checkWritable(); 5242620ff9a08ce7fc6d66b60784b1eecd78eb001baElliott Hughes } 525d85168bd730e513cb0bd561030da3f7ea5044725Elliott Hughes } 526d85168bd730e513cb0bd561030da3f7ea5044725Elliott Hughes return count; 527d85168bd730e513cb0bd561030da3f7ea5044725Elliott Hughes } 528d85168bd730e513cb0bd561030da3f7ea5044725Elliott Hughes 52952724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes public FileDescriptor getFD() { 5306ab5999b58777725b4556e4d81bdec56b6d6c182Elliott Hughes return fd; 531adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 532ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes 533ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes /** 534ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes * Add a new pending lock to the manager. Throws an exception if the lock 535ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes * would overlap an existing lock. Once the lock is acquired it remains in 536ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes * this set as an acquired lock. 537ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes */ 538ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes private synchronized void addLock(FileLock lock) throws OverlappingFileLockException { 539ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes long lockEnd = lock.position() + lock.size(); 540ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes for (FileLock existingLock : locks) { 541ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes if (existingLock.position() > lockEnd) { 542ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes // This, and all remaining locks, start beyond our end (so 543ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes // cannot overlap). 544ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes break; 545ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 546ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes if (existingLock.overlaps(lock.position(), lock.size())) { 547ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes throw new OverlappingFileLockException(); 548ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 549ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 550ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes locks.add(lock); 551ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 552ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes 553ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes /** 554ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes * Removes an acquired lock from the lock manager. If the lock did not exist 555ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes * in the lock manager the operation is a no-op. 556ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes */ 557ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes private synchronized void removeLock(FileLock lock) { 558ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes locks.remove(lock); 559ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes } 560adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project} 561