content: /*
   * Copyright (C) 2014 The Android Open Source Project
   * Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package java.io;
  
  import static android.system.OsConstants.O_APPEND;
  import static android.system.OsConstants.O_CREAT;
  import static android.system.OsConstants.O_TRUNC;
  import static android.system.OsConstants.O_WRONLY;
  
  import java.nio.channels.FileChannel;
  
  import dalvik.annotation.optimization.ReachabilitySensitive;
  import dalvik.system.BlockGuard;
  import dalvik.system.CloseGuard;
  import sun.nio.ch.FileChannelImpl;
  import libcore.io.IoBridge;
  import libcore.io.IoTracker;
  import libcore.io.IoUtils;
  
  /**
   * A file output stream is an output stream for writing data to a
   * <code>File</code> or to a <code>FileDescriptor</code>. Whether or not
   * a file is available or may be created depends upon the underlying
   * platform.  Some platforms, in particular, allow a file to be opened
   * for writing by only one <tt>FileOutputStream</tt> (or other
   * file-writing object) at a time.  In such situations the constructors in
   * this class will fail if the file involved is already open.
   *
   * <p><code>FileOutputStream</code> is meant for writing streams of raw bytes
   * such as image data. For writing streams of characters, consider using
   * <code>FileWriter</code>.
   *
   * @author  Arthur van Hoff
   * @see     File
   * @see     FileDescriptor
   * @see     FileInputStream
   * @see     java.nio.file.Files#newOutputStream
   * @since   JDK1.0
   */
  public
  class FileOutputStream extends OutputStream
  {
      /**
       * The system dependent file descriptor.
       */
      // Android-added: @ReachabilitySensitive
      @ReachabilitySensitive
      private final FileDescriptor fd;
  
      /**
       * True if the file is opened for append.
       */
      private final boolean append;
  
      /**
       * The associated channel, initialized lazily.
       */
      private FileChannel channel;
  
      /**
       * The path of the referenced file
       * (null if the stream is created with a file descriptor)
       */
      private final String path;
  
      private final Object closeLock = new Object();
      private volatile boolean closed = false;
  
      // Android-added: CloseGuard support: Log if the stream is not closed.
      @ReachabilitySensitive
      private final CloseGuard guard = CloseGuard.get();
  
      // Android-added: Field for tracking whether the stream owns the underlying FileDescriptor.
      private final boolean isFdOwner;
  
      // Android-added: Tracking of unbuffered I/O.
      private final IoTracker tracker = new IoTracker();
  
      /**
       * Creates a file output stream to write to the file with the
       * specified name. A new <code>FileDescriptor</code> object is
       * created to represent this file connection.
       * <p>
       * First, if there is a security manager, its <code>checkWrite</code>
       * method is called with <code>name</code> as its argument.
       * <p>
       * If the file exists but is a directory rather than a regular file, does
       * not exist but cannot be created, or cannot be opened for any other
       * reason then a <code>FileNotFoundException</code> is thrown.
       *
       * @param      name   the system-dependent filename
       * @exception  FileNotFoundException  if the file exists but is a directory
       *                   rather than a regular file, does not exist but cannot
       *                   be created, or cannot be opened for any other reason
       * @exception  SecurityException  if a security manager exists and its
       *               <code>checkWrite</code> method denies write access
       *               to the file.
       * @see        SecurityManager#checkWrite(String)
       */
      public FileOutputStream(String name) throws FileNotFoundException {
          this(name != null ? new File(name) : null, false);
      }
  
      /**
       * Creates a file output stream to write to the file with the specified
       * name.  If the second argument is <code>true</code>, then
       * bytes will be written to the end of the file rather than the beginning.
       * A new <code>FileDescriptor</code> object is created to represent this
       * file connection.
       * <p>
       * First, if there is a security manager, its <code>checkWrite</code>
       * method is called with <code>name</code> as its argument.
       * <p>
       * If the file exists but is a directory rather than a regular file, does
       * not exist but cannot be created, or cannot be opened for any other
       * reason then a <code>FileNotFoundException</code> is thrown.
       *
       * @param     name        the system-dependent file name
       * @param     append      if <code>true</code>, then bytes will be written
       *                   to the end of the file rather than the beginning
       * @exception  FileNotFoundException  if the file exists but is a directory
       *                   rather than a regular file, does not exist but cannot
       *                   be created, or cannot be opened for any other reason.
       * @exception  SecurityException  if a security manager exists and its
       *               <code>checkWrite</code> method denies write access
       *               to the file.
       * @see        SecurityManager#checkWrite(String)
       * @since     JDK1.1
       */
      public FileOutputStream(String name, boolean append)
          throws FileNotFoundException
      {
          this(name != null ? new File(name) : null, append);
      }
  
      /**
       * Creates a file output stream to write to the file represented by
       * the specified <code>File</code> object. A new
       * <code>FileDescriptor</code> object is created to represent this
       * file connection.
       * <p>
       * First, if there is a security manager, its <code>checkWrite</code>
       * method is called with the path represented by the <code>file</code>
       * argument as its argument.
       * <p>
       * If the file exists but is a directory rather than a regular file, does
       * not exist but cannot be created, or cannot be opened for any other
       * reason then a <code>FileNotFoundException</code> is thrown.
       *
       * @param      file               the file to be opened for writing.
       * @exception  FileNotFoundException  if the file exists but is a directory
       *                   rather than a regular file, does not exist but cannot
       *                   be created, or cannot be opened for any other reason
       * @exception  SecurityException  if a security manager exists and its
       *               <code>checkWrite</code> method denies write access
       *               to the file.
       * @see        File#getPath()
       * @see        SecurityException
       * @see        SecurityManager#checkWrite(String)
       */
      public FileOutputStream(File file) throws FileNotFoundException {
          this(file, false);
      }
  
      /**
       * Creates a file output stream to write to the file represented by
       * the specified <code>File</code> object. If the second argument is
       * <code>true</code>, then bytes will be written to the end of the file
       * rather than the beginning. A new <code>FileDescriptor</code> object is
       * created to represent this file connection.
       * <p>
       * First, if there is a security manager, its <code>checkWrite</code>
       * method is called with the path represented by the <code>file</code>
       * argument as its argument.
       * <p>
       * If the file exists but is a directory rather than a regular file, does
       * not exist but cannot be created, or cannot be opened for any other
       * reason then a <code>FileNotFoundException</code> is thrown.
       *
       * @param      file               the file to be opened for writing.
       * @param     append      if <code>true</code>, then bytes will be written
       *                   to the end of the file rather than the beginning
       * @exception  FileNotFoundException  if the file exists but is a directory
       *                   rather than a regular file, does not exist but cannot
       *                   be created, or cannot be opened for any other reason
       * @exception  SecurityException  if a security manager exists and its
       *               <code>checkWrite</code> method denies write access
       *               to the file.
       * @see        File#getPath()
       * @see        SecurityException
       * @see        SecurityManager#checkWrite(String)
       * @since 1.4
       */
      public FileOutputStream(File file, boolean append)
          throws FileNotFoundException
      {
          String name = (file != null ? file.getPath() : null);
          SecurityManager security = System.getSecurityManager();
          if (security != null) {
              security.checkWrite(name);
          }
          if (name == null) {
              throw new NullPointerException();
          }
          if (file.isInvalid()) {
              throw new FileNotFoundException("Invalid file path");
          }
          // BEGIN Android-changed: Open files using IoBridge to share BlockGuard & StrictMode logic.
          // http://b/111268862
          // this.fd = new FileDescriptor();
          int flags = O_WRONLY | O_CREAT | (append ? O_APPEND : O_TRUNC);
          this.fd = IoBridge.open(name, flags);
          // END Android-changed: Open files using IoBridge to share BlockGuard & StrictMode logic.
  
          // Android-changed: Tracking mechanism for FileDescriptor sharing.
          // fd.attach(this);
          this.isFdOwner = true;
  
          this.append = append;
          this.path = name;
  
          // Android-removed: Open files using IoBridge to share BlockGuard & StrictMode logic.
          // open(name, append);
  
          // Android-added: File descriptor ownership tracking.
          IoUtils.setFdOwner(this.fd, this);
  
          // Android-added: CloseGuard support.
          guard.open("close");
      }
  
      // Android-removed: Documentation around SecurityException. Not thrown on Android.
      /**
       * Creates a file output stream to write to the specified file
       * descriptor, which represents an existing connection to an actual
       * file in the file system.
       * <p>
       * First, if there is a security manager, its <code>checkWrite</code>
       * method is called with the file descriptor <code>fdObj</code>
       * argument as its argument.
       * <p>
       * If <code>fdObj</code> is null then a <code>NullPointerException</code>
       * is thrown.
       * <p>
       * This constructor does not throw an exception if <code>fdObj</code>
       * is {@link FileDescriptor#valid() invalid}.
       * However, if the methods are invoked on the resulting stream to attempt
       * I/O on the stream, an <code>IOException</code> is thrown.
       *
       * @param      fdObj   the file descriptor to be opened for writing
       */
      public FileOutputStream(FileDescriptor fdObj) {
          // Android-changed: Delegate to added hidden constructor.
          this(fdObj, false /* isOwner */);
      }
  
      // Android-added: Internal/hidden constructor for specifying FileDescriptor ownership.
      // Android-removed: SecurityManager calls.
      /**
       * Internal constructor for {@code FileOutputStream} objects where the file descriptor
       * is owned by this tream.
       *
       * @hide
       */
      public FileOutputStream(FileDescriptor fdObj, boolean isFdOwner) {
          if (fdObj == null) {
              // Android-changed: Improved NullPointerException message.
              throw new NullPointerException("fdObj == null");
          }
  
          this.fd = fdObj;
          this.append = false;
          this.path = null;
  
          // Android-changed: FileDescriptor ownership tracking mechanism.
          // fd.attach(this);
          this.isFdOwner = isFdOwner;
      }
  
      // BEGIN Android-changed: Open files using IoBridge to share BlockGuard & StrictMode logic.
      // http://b/112107427
      /*
      /**
       * Opens a file, with the specified name, for overwriting or appending.
       * @param name name of file to be opened
       * @param append whether the file is to be opened in append mode
       *
      private native void open0(String name, boolean append)
          throws FileNotFoundException;
  
      // wrap native call to allow instrumentation
      /**
       * Opens a file, with the specified name, for overwriting or appending.
       * @param name name of file to be opened
       * @param append whether the file is to be opened in append mode
       *
      private void open(String name, boolean append)
          throws FileNotFoundException {
          open0(name, append);
      }
      */
      // END Android-changed: Open files using IoBridge to share BlockGuard & StrictMode logic.
  
      // Android-removed: write(int, boolean), use IoBridge instead.
      /*
      /**
       * Writes the specified byte to this file output stream.
       *
       * @param   b   the byte to be written.
       * @param   append   {@code true} if the write operation first
       *     advances the position to the end of file
       *
      private native void write(int b, boolean append) throws IOException;
      */
  
      /**
       * Writes the specified byte to this file output stream. Implements
       * the <code>write</code> method of <code>OutputStream</code>.
       *
       * @param      b   the byte to be written.
       * @exception  IOException  if an I/O error occurs.
       */
      public void write(int b) throws IOException {
          // Android-changed: Write methods delegate to write(byte[],int,int) to share Android logic.
          write(new byte[] { (byte) b }, 0, 1);
      }
  
      // Android-removed: Write methods delegate to write(byte[],int,int) to share Android logic.
      /*
      /**
       * Writes a sub array as a sequence of bytes.
       * @param b the data to be written
       * @param off the start offset in the data
       * @param len the number of bytes that are written
       * @param append {@code true} to first advance the position to the
       *     end of file
       * @exception IOException If an I/O error has occurred.
       *
      private native void writeBytes(byte b[], int off, int len, boolean append)
          throws IOException;
      */
  
      /**
       * Writes <code>b.length</code> bytes from the specified byte array
       * to this file output stream.
       *
       * @param      b   the data.
       * @exception  IOException  if an I/O error occurs.
       */
      public void write(byte b[]) throws IOException {
          // Android-changed: Write methods delegate to write(byte[],int,int) to share Android logic.
          write(b, 0, b.length);
      }
  
      /**
       * Writes <code>len</code> bytes from the specified byte array
       * starting at offset <code>off</code> to this file output stream.
       *
       * @param      b     the data.
       * @param      off   the start offset in the data.
       * @param      len   the number of bytes to write.
       * @exception  IOException  if an I/O error occurs.
       */
      public void write(byte b[], int off, int len) throws IOException {
          // Android-added: close() check before I/O.
          if (closed && len > 0) {
              throw new IOException("Stream Closed");
          }
  
          // Android-added: Tracking of unbuffered I/O.
          tracker.trackIo(len);
  
          // Android-changed: Use IoBridge instead of calling native method.
          IoBridge.write(fd, b, off, len);
      }
  
      /**
       * Closes this file output stream and releases any system resources
       * associated with this stream. This file output stream may no longer
       * be used for writing bytes.
       *
       * <p> If this stream has an associated channel then the channel is closed
       * as well.
       *
       * @exception  IOException  if an I/O error occurs.
       *
       * @revised 1.4
       * @spec JSR-51
       */
      public void close() throws IOException {
          synchronized (closeLock) {
              if (closed) {
                  return;
              }
              closed = true;
          }
  
          // Android-added: CloseGuard support.
          guard.close();
  
          if (channel != null) {
              channel.close();
          }
  
          // BEGIN Android-changed: Close handling / notification of blocked threads.
          if (isFdOwner) {
              IoBridge.closeAndSignalBlockedThreads(fd);
          }
          // END Android-changed: Close handling / notification of blocked threads.
      }
  
      /**
       * Returns the file descriptor associated with this stream.
       *
       * @return  the <code>FileDescriptor</code> object that represents
       *          the connection to the file in the file system being used
       *          by this <code>FileOutputStream</code> object.
       *
       * @exception  IOException  if an I/O error occurs.
       * @see        FileDescriptor
       */
       // Android-added: @ReachabilitySensitive
       @ReachabilitySensitive
       public final FileDescriptor getFD()  throws IOException {
          if (fd != null) {
              return fd;
          }
          throw new IOException();
       }
  
      /**
       * Returns the unique {@link FileChannel FileChannel}
       * object associated with this file output stream.
       *
       * <p> The initial {@link FileChannel#position()
       * position} of the returned channel will be equal to the
       * number of bytes written to the file so far unless this stream is in
       * append mode, in which case it will be equal to the size of the file.
       * Writing bytes to this stream will increment the channel's position
       * accordingly.  Changing the channel's position, either explicitly or by
       * writing, will change this stream's file position.
       *
       * @return  the file channel associated with this file output stream
       *
       * @since 1.4
       * @spec JSR-51
       */
      public FileChannel getChannel() {
          synchronized (this) {
              if (channel == null) {
                  channel = FileChannelImpl.open(fd, path, false, true, append, this);
              }
              return channel;
          }
      }
  
      /**
       * Cleans up the connection to the file, and ensures that the
       * <code>close</code> method of this file output stream is
       * called when there are no more references to this stream.
       *
       * @exception  IOException  if an I/O error occurs.
       * @see        FileInputStream#close()
       */
      protected void finalize() throws IOException {
          // Android-added: CloseGuard support.
          if (guard != null) {
              guard.warnIfOpen();
          }
  
          if (fd != null) {
              if (fd == FileDescriptor.out || fd == FileDescriptor.err) {
                  flush();
              } else {
                  // Android-removed: Obsoleted comment about shared FileDescriptor handling.
                  close();
              }
          }
      }
  
      // BEGIN Android-removed: Unused code.
      /*
      private native void close0() throws IOException;
  
      private static native void initIDs();
  
      static {
          initIDs();
      }
      */
      // END Android-removed: Unused code.
  
  }
  