/* * Copyright (C) 2006 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.os; import dalvik.system.CloseGuard; import java.io.Closeable; import java.io.File; import java.io.FileDescriptor; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.net.DatagramSocket; import java.net.Socket; /** * The FileDescriptor returned by {@link Parcel#readFileDescriptor}, allowing * you to close it when done with it. */ public class ParcelFileDescriptor implements Parcelable, Closeable { private final FileDescriptor mFileDescriptor; /** * Wrapped {@link ParcelFileDescriptor}, if any. Used to avoid * double-closing {@link #mFileDescriptor}. */ private final ParcelFileDescriptor mWrapped; private volatile boolean mClosed; private final CloseGuard mGuard = CloseGuard.get(); /** * For use with {@link #open}: if {@link #MODE_CREATE} has been supplied * and this file doesn't already exist, then create the file with * permissions such that any application can read it. */ public static final int MODE_WORLD_READABLE = 0x00000001; /** * For use with {@link #open}: if {@link #MODE_CREATE} has been supplied * and this file doesn't already exist, then create the file with * permissions such that any application can write it. */ public static final int MODE_WORLD_WRITEABLE = 0x00000002; /** * For use with {@link #open}: open the file with read-only access. */ public static final int MODE_READ_ONLY = 0x10000000; /** * For use with {@link #open}: open the file with write-only access. */ public static final int MODE_WRITE_ONLY = 0x20000000; /** * For use with {@link #open}: open the file with read and write access. */ public static final int MODE_READ_WRITE = 0x30000000; /** * For use with {@link #open}: create the file if it doesn't already exist. */ public static final int MODE_CREATE = 0x08000000; /** * For use with {@link #open}: erase contents of file when opening. */ public static final int MODE_TRUNCATE = 0x04000000; /** * For use with {@link #open}: append to end of file while writing. */ public static final int MODE_APPEND = 0x02000000; /** * Create a new ParcelFileDescriptor accessing a given file. * * @param file The file to be opened. * @param mode The desired access mode, must be one of * {@link #MODE_READ_ONLY}, {@link #MODE_WRITE_ONLY}, or * {@link #MODE_READ_WRITE}; may also be any combination of * {@link #MODE_CREATE}, {@link #MODE_TRUNCATE}, * {@link #MODE_WORLD_READABLE}, and {@link #MODE_WORLD_WRITEABLE}. * * @return Returns a new ParcelFileDescriptor pointing to the given * file. * * @throws FileNotFoundException Throws FileNotFoundException if the given * file does not exist or can not be opened with the requested mode. */ public static ParcelFileDescriptor open(File file, int mode) throws FileNotFoundException { String path = file.getPath(); if ((mode&MODE_READ_WRITE) == 0) { throw new IllegalArgumentException( "Must specify MODE_READ_ONLY, MODE_WRITE_ONLY, or MODE_READ_WRITE"); } FileDescriptor fd = Parcel.openFileDescriptor(path, mode); return fd != null ? new ParcelFileDescriptor(fd) : null; } /** * Create a new ParcelFileDescriptor that is a dup of an existing * FileDescriptor. This obeys standard POSIX semantics, where the * new file descriptor shared state such as file position with the * original file descriptor. */ public static ParcelFileDescriptor dup(FileDescriptor orig) throws IOException { FileDescriptor fd = Parcel.dupFileDescriptor(orig); return fd != null ? new ParcelFileDescriptor(fd) : null; } /** * Create a new ParcelFileDescriptor that is a dup of the existing * FileDescriptor. This obeys standard POSIX semantics, where the * new file descriptor shared state such as file position with the * original file descriptor. */ public ParcelFileDescriptor dup() throws IOException { return dup(getFileDescriptor()); } /** * Create a new ParcelFileDescriptor from a raw native fd. The new * ParcelFileDescriptor holds a dup of the original fd passed in here, * so you must still close that fd as well as the new ParcelFileDescriptor. * * @param fd The native fd that the ParcelFileDescriptor should dup. * * @return Returns a new ParcelFileDescriptor holding a FileDescriptor * for a dup of the given fd. */ public static ParcelFileDescriptor fromFd(int fd) throws IOException { FileDescriptor fdesc = getFileDescriptorFromFd(fd); return new ParcelFileDescriptor(fdesc); } // Extracts the file descriptor from the specified socket and returns it untouched private static native FileDescriptor getFileDescriptorFromFd(int fd) throws IOException; /** * Take ownership of a raw native fd in to a new ParcelFileDescriptor. * The returned ParcelFileDescriptor now owns the given fd, and will be * responsible for closing it. You must not close the fd yourself. * * @param fd The native fd that the ParcelFileDescriptor should adopt. * * @return Returns a new ParcelFileDescriptor holding a FileDescriptor * for the given fd. */ public static ParcelFileDescriptor adoptFd(int fd) { FileDescriptor fdesc = getFileDescriptorFromFdNoDup(fd); return new ParcelFileDescriptor(fdesc); } // Extracts the file descriptor from the specified socket and returns it untouched private static native FileDescriptor getFileDescriptorFromFdNoDup(int fd); /** * Create a new ParcelFileDescriptor from the specified Socket. The new * ParcelFileDescriptor holds a dup of the original FileDescriptor in * the Socket, so you must still close the Socket as well as the new * ParcelFileDescriptor. * * @param socket The Socket whose FileDescriptor is used to create * a new ParcelFileDescriptor. * * @return A new ParcelFileDescriptor with the FileDescriptor of the * specified Socket. */ public static ParcelFileDescriptor fromSocket(Socket socket) { FileDescriptor fd = socket.getFileDescriptor$(); return fd != null ? new ParcelFileDescriptor(fd) : null; } /** * Create a new ParcelFileDescriptor from the specified DatagramSocket. * * @param datagramSocket The DatagramSocket whose FileDescriptor is used * to create a new ParcelFileDescriptor. * * @return A new ParcelFileDescriptor with the FileDescriptor of the * specified DatagramSocket. */ public static ParcelFileDescriptor fromDatagramSocket(DatagramSocket datagramSocket) { FileDescriptor fd = datagramSocket.getFileDescriptor$(); return fd != null ? new ParcelFileDescriptor(fd) : null; } /** * Create two ParcelFileDescriptors structured as a data pipe. The first * ParcelFileDescriptor in the returned array is the read side; the second * is the write side. */ public static ParcelFileDescriptor[] createPipe() throws IOException { FileDescriptor[] fds = new FileDescriptor[2]; createPipeNative(fds); ParcelFileDescriptor[] pfds = new ParcelFileDescriptor[2]; pfds[0] = new ParcelFileDescriptor(fds[0]); pfds[1] = new ParcelFileDescriptor(fds[1]); return pfds; } private static native void createPipeNative(FileDescriptor[] outFds) throws IOException; /** * @hide Please use createPipe() or ContentProvider.openPipeHelper(). * Gets a file descriptor for a read-only copy of the given data. * * @param data Data to copy. * @param name Name for the shared memory area that may back the file descriptor. * This is purely informative and may be {@code null}. * @return A ParcelFileDescriptor. * @throws IOException if there is an error while creating the shared memory area. */ @Deprecated public static ParcelFileDescriptor fromData(byte[] data, String name) throws IOException { if (data == null) return null; MemoryFile file = new MemoryFile(name, data.length); if (data.length > 0) { file.writeBytes(data, 0, 0, data.length); } file.deactivate(); FileDescriptor fd = file.getFileDescriptor(); return fd != null ? new ParcelFileDescriptor(fd) : null; } /** * Retrieve the actual FileDescriptor associated with this object. * * @return Returns the FileDescriptor associated with this object. */ public FileDescriptor getFileDescriptor() { return mFileDescriptor; } /** * Return the total size of the file representing this fd, as determined * by stat(). Returns -1 if the fd is not a file. */ public native long getStatSize(); /** * This is needed for implementing AssetFileDescriptor.AutoCloseOutputStream, * and I really don't think we want it to be public. * @hide */ public native long seekTo(long pos); /** * Return the native fd int for this ParcelFileDescriptor. The * ParcelFileDescriptor still owns the fd, and it still must be closed * through this API. */ public int getFd() { if (mClosed) { throw new IllegalStateException("Already closed"); } return getFdNative(); } private native int getFdNative(); /** * Return the native fd int for this ParcelFileDescriptor and detach it * from the object here. You are now responsible for closing the fd in * native code. */ public int detachFd() { if (mClosed) { throw new IllegalStateException("Already closed"); } if (mWrapped != null) { int fd = mWrapped.detachFd(); mClosed = true; mGuard.close(); return fd; } int fd = getFd(); mClosed = true; mGuard.close(); Parcel.clearFileDescriptor(mFileDescriptor); return fd; } /** * Close the ParcelFileDescriptor. This implementation closes the underlying * OS resources allocated to represent this stream. * * @throws IOException * If an error occurs attempting to close this ParcelFileDescriptor. */ @Override public void close() throws IOException { if (mClosed) return; mClosed = true; mGuard.close(); if (mWrapped != null) { // If this is a proxy to another file descriptor, just call through to its // close method. mWrapped.close(); } else { Parcel.closeFileDescriptor(mFileDescriptor); } } /** * An InputStream you can create on a ParcelFileDescriptor, which will * take care of calling {@link ParcelFileDescriptor#close * ParcelFileDescriptor.close()} for you when the stream is closed. */ public static class AutoCloseInputStream extends FileInputStream { private final ParcelFileDescriptor mFd; public AutoCloseInputStream(ParcelFileDescriptor fd) { super(fd.getFileDescriptor()); mFd = fd; } @Override public void close() throws IOException { try { mFd.close(); } finally { super.close(); } } } /** * An OutputStream you can create on a ParcelFileDescriptor, which will * take care of calling {@link ParcelFileDescriptor#close * ParcelFileDescriptor.close()} for you when the stream is closed. */ public static class AutoCloseOutputStream extends FileOutputStream { private final ParcelFileDescriptor mFd; public AutoCloseOutputStream(ParcelFileDescriptor fd) { super(fd.getFileDescriptor()); mFd = fd; } @Override public void close() throws IOException { try { mFd.close(); } finally { super.close(); } } } @Override public String toString() { return "{ParcelFileDescriptor: " + mFileDescriptor + "}"; } @Override protected void finalize() throws Throwable { if (mGuard != null) { mGuard.warnIfOpen(); } try { if (!mClosed) { close(); } } finally { super.finalize(); } } public ParcelFileDescriptor(ParcelFileDescriptor descriptor) { mWrapped = descriptor; mFileDescriptor = mWrapped.mFileDescriptor; mGuard.open("close"); } /** {@hide} */ public ParcelFileDescriptor(FileDescriptor descriptor) { if (descriptor == null) { throw new NullPointerException("descriptor must not be null"); } mWrapped = null; mFileDescriptor = descriptor; mGuard.open("close"); } @Override public int describeContents() { return Parcelable.CONTENTS_FILE_DESCRIPTOR; } /** * {@inheritDoc} * If {@link Parcelable#PARCELABLE_WRITE_RETURN_VALUE} is set in flags, * the file descriptor will be closed after a copy is written to the Parcel. */ @Override public void writeToParcel(Parcel out, int flags) { out.writeFileDescriptor(mFileDescriptor); if ((flags&PARCELABLE_WRITE_RETURN_VALUE) != 0 && !mClosed) { try { close(); } catch (IOException e) { // Empty } } } public static final Parcelable.Creator CREATOR = new Parcelable.Creator() { @Override public ParcelFileDescriptor createFromParcel(Parcel in) { return in.readFileDescriptor(); } @Override public ParcelFileDescriptor[] newArray(int size) { return new ParcelFileDescriptor[size]; } }; }