1264 lines
50 KiB
Java
1264 lines
50 KiB
Java
/*
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* Copyright (C) 2014 The Android Open Source Project
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* Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package java.io;
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import dalvik.annotation.optimization.ReachabilitySensitive;
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import java.nio.channels.FileChannel;
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import sun.nio.ch.FileChannelImpl;
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import android.system.Os;
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import android.system.ErrnoException;
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import android.system.OsConstants;
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import dalvik.system.CloseGuard;
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import libcore.io.IoBridge;
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import libcore.io.IoTracker;
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import libcore.io.IoUtils;
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import libcore.io.Libcore;
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import static android.system.OsConstants.*;
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/**
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* Instances of this class support both reading and writing to a
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* random access file. A random access file behaves like a large
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* array of bytes stored in the file system. There is a kind of cursor,
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* or index into the implied array, called the <em>file pointer</em>;
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* input operations read bytes starting at the file pointer and advance
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* the file pointer past the bytes read. If the random access file is
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* created in read/write mode, then output operations are also available;
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* output operations write bytes starting at the file pointer and advance
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* the file pointer past the bytes written. Output operations that write
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* past the current end of the implied array cause the array to be
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* extended. The file pointer can be read by the
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* {@code getFilePointer} method and set by the {@code seek}
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* method.
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* <p>
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* It is generally true of all the reading routines in this class that
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* if end-of-file is reached before the desired number of bytes has been
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* read, an {@code EOFException} (which is a kind of
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* {@code IOException}) is thrown. If any byte cannot be read for
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* any reason other than end-of-file, an {@code IOException} other
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* than {@code EOFException} is thrown. In particular, an
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* {@code IOException} may be thrown if the stream has been closed.
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*
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* @author unascribed
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* @since JDK1.0
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*/
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public class RandomAccessFile implements DataOutput, DataInput, Closeable {
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// BEGIN Android-added: CloseGuard and some helper fields for Android changes in this file.
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@ReachabilitySensitive
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private final CloseGuard guard = CloseGuard.get();
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private final byte[] scratch = new byte[8];
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private static final int FLUSH_NONE = 0;
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private static final int FLUSH_FSYNC = 1;
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private static final int FLUSH_FDATASYNC = 2;
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private int flushAfterWrite = FLUSH_NONE;
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private int mode;
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// END Android-added: CloseGuard and some helper fields for Android changes in this file.
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// Android-added: @ReachabilitySensitive
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@ReachabilitySensitive
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private FileDescriptor fd;
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private FileChannel channel = null;
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private boolean rw;
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/**
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* The path of the referenced file
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* (null if the stream is created with a file descriptor)
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*/
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private final String path;
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private Object closeLock = new Object();
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private volatile boolean closed = false;
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// BEGIN Android-added: IoTracker.
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/**
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* A single tracker to track both read and write. The tracker resets when the operation
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* performed is different from the operation last performed.
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*/
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private final IoTracker ioTracker = new IoTracker();
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// END Android-added: IoTracker.
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/**
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* Creates a random access file stream to read from, and optionally
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* to write to, a file with the specified name. A new
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* {@link FileDescriptor} object is created to represent the
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* connection to the file.
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*
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* <p> The <tt>mode</tt> argument specifies the access mode with which the
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* file is to be opened. The permitted values and their meanings are as
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* specified for the <a
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* href="#mode"><tt>RandomAccessFile(File,String)</tt></a> constructor.
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*
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* <p>
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* If there is a security manager, its {@code checkRead} method
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* is called with the {@code name} argument
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* as its argument to see if read access to the file is allowed.
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* If the mode allows writing, the security manager's
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* {@code checkWrite} method
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* is also called with the {@code name} argument
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* as its argument to see if write access to the file is allowed.
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*
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* @param name the system-dependent filename
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* @param mode the access <a href="#mode">mode</a>
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* @exception IllegalArgumentException if the mode argument is not equal
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* to one of <tt>"r"</tt>, <tt>"rw"</tt>, <tt>"rws"</tt>, or
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* <tt>"rwd"</tt>
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* @exception FileNotFoundException
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* if the mode is <tt>"r"</tt> but the given string does not
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* denote an existing regular file, or if the mode begins with
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* <tt>"rw"</tt> but the given string does not denote an
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* existing, writable regular file and a new regular file of
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* that name cannot be created, or if some other error occurs
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* while opening or creating the file
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* @exception SecurityException if a security manager exists and its
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* {@code checkRead} method denies read access to the file
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* or the mode is "rw" and the security manager's
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* {@code checkWrite} method denies write access to the file
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* @see java.lang.SecurityException
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* @see java.lang.SecurityManager#checkRead(java.lang.String)
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* @see java.lang.SecurityManager#checkWrite(java.lang.String)
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* @revised 1.4
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* @spec JSR-51
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*/
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public RandomAccessFile(String name, String mode)
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throws FileNotFoundException
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{
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this(name != null ? new File(name) : null, mode);
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}
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/**
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* Creates a random access file stream to read from, and optionally to
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* write to, the file specified by the {@link File} argument. A new {@link
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* FileDescriptor} object is created to represent this file connection.
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*
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* <p>The <a name="mode"><tt>mode</tt></a> argument specifies the access mode
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* in which the file is to be opened. The permitted values and their
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* meanings are:
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*
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* <table summary="Access mode permitted values and meanings">
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* <tr><th align="left">Value</th><th align="left">Meaning</th></tr>
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* <tr><td valign="top"><tt>"r"</tt></td>
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* <td> Open for reading only. Invoking any of the <tt>write</tt>
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* methods of the resulting object will cause an {@link
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* java.io.IOException} to be thrown. </td></tr>
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* <tr><td valign="top"><tt>"rw"</tt></td>
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* <td> Open for reading and writing. If the file does not already
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* exist then an attempt will be made to create it. </td></tr>
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* <tr><td valign="top"><tt>"rws"</tt></td>
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* <td> Open for reading and writing, as with <tt>"rw"</tt>, and also
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* require that every update to the file's content or metadata be
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* written synchronously to the underlying storage device. </td></tr>
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* <tr><td valign="top"><tt>"rwd" </tt></td>
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* <td> Open for reading and writing, as with <tt>"rw"</tt>, and also
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* require that every update to the file's content be written
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* synchronously to the underlying storage device. </td></tr>
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* </table>
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*
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* The <tt>"rws"</tt> and <tt>"rwd"</tt> modes work much like the {@link
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* java.nio.channels.FileChannel#force(boolean) force(boolean)} method of
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* the {@link java.nio.channels.FileChannel} class, passing arguments of
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* <tt>true</tt> and <tt>false</tt>, respectively, except that they always
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* apply to every I/O operation and are therefore often more efficient. If
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* the file resides on a local storage device then when an invocation of a
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* method of this class returns it is guaranteed that all changes made to
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* the file by that invocation will have been written to that device. This
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* is useful for ensuring that critical information is not lost in the
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* event of a system crash. If the file does not reside on a local device
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* then no such guarantee is made.
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*
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* <p>The <tt>"rwd"</tt> mode can be used to reduce the number of I/O
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* operations performed. Using <tt>"rwd"</tt> only requires updates to the
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* file's content to be written to storage; using <tt>"rws"</tt> requires
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* updates to both the file's content and its metadata to be written, which
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* generally requires at least one more low-level I/O operation.
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*
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* <p>If there is a security manager, its {@code checkRead} method is
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* called with the pathname of the {@code file} argument as its
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* argument to see if read access to the file is allowed. If the mode
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* allows writing, the security manager's {@code checkWrite} method is
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* also called with the path argument to see if write access to the file is
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* allowed.
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*
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* @param file the file object
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* @param mode the access mode, as described
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* <a href="#mode">above</a>
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* @exception IllegalArgumentException if the mode argument is not equal
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* to one of <tt>"r"</tt>, <tt>"rw"</tt>, <tt>"rws"</tt>, or
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* <tt>"rwd"</tt>
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* @exception FileNotFoundException
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* if the mode is <tt>"r"</tt> but the given file object does
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* not denote an existing regular file, or if the mode begins
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* with <tt>"rw"</tt> but the given file object does not denote
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* an existing, writable regular file and a new regular file of
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* that name cannot be created, or if some other error occurs
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* while opening or creating the file
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* @exception SecurityException if a security manager exists and its
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* {@code checkRead} method denies read access to the file
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* or the mode is "rw" and the security manager's
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* {@code checkWrite} method denies write access to the file
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* @see java.lang.SecurityManager#checkRead(java.lang.String)
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* @see java.lang.SecurityManager#checkWrite(java.lang.String)
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* @see java.nio.channels.FileChannel#force(boolean)
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* @revised 1.4
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* @spec JSR-51
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*/
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public RandomAccessFile(File file, String mode)
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throws FileNotFoundException
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{
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// Android-changed: delegate to constructor which controls O_CLOEXEC.
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this(file, mode, /* setCloExecFlag= */ false);
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}
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/**
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* Identical to {@link #RandomAccessFile(File, String)}, but with a capability to control
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* O_CLOEXEC flag of file descriptor.
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*
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* @param setCloExecFlag if true file descriptor will be opened with O_CLOEXE flag set
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* @hide
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*/
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// Android-changed: added an extra argument to set O_CLOEXEC.
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public RandomAccessFile(File file, String mode, boolean setCloExecFlag)
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throws FileNotFoundException {
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String name = (file != null ? file.getPath() : null);
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int imode = -1;
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if (mode.equals("r")) {
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imode = O_RDONLY;
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} else if (mode.startsWith("rw")) {
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// Android-changed: Added. O_CREAT
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// imode = O_RDWR;
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imode = O_RDWR | O_CREAT;
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rw = true;
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if (mode.length() > 2) {
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if (mode.equals("rws")) {
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// Android-changed: For performance reasons, use fsync after each write.
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// RandomAccessFile.write may result in multiple write syscalls,
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// O_SYNC/O_DSYNC flags will cause a blocking wait on each syscall. Replacing
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// them with single fsync/fdatasync call gives better performance with only
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// minor decrease in reliability.
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// imode |= O_SYNC;
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flushAfterWrite = FLUSH_FSYNC;
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} else if (mode.equals("rwd")) {
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// Android-changed: For performance reasons, use fdatasync after each write.
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// imode |= O_DSYNC;
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flushAfterWrite = FLUSH_FDATASYNC;
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} else {
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imode = -1;
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}
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}
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}
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if (imode < 0) {
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throw new IllegalArgumentException("Illegal mode \"" + mode
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+ "\" must be one of "
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+ "\"r\", \"rw\", \"rws\","
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+ " or \"rwd\"");
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}
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// Android-removed: do not use legacy security code
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/*
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SecurityManager security = System.getSecurityManager();
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if (security != null) {
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security.checkRead(name);
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if (rw) {
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security.checkWrite(name);
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}
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}
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*/
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if (name == null) {
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// Android-changed: different exception message in ctor when file == null.
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// throw new NullPointerException();
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throw new NullPointerException("file == null");
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}
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if (file.isInvalid()) {
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throw new FileNotFoundException("Invalid file path");
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}
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this.path = name;
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// Android-added: set O_CLOEXEC flag if requested.
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imode = setCloExecFlag ? imode | O_CLOEXEC : imode;
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this.mode = imode;
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// BEGIN Android-changed: Use IoBridge.open() instead of open.
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fd = IoBridge.open(name, imode);
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IoUtils.setFdOwner(fd, this);
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maybeSync();
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guard.open("close");
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// END Android-changed: Use IoBridge.open() instead of open.
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}
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// BEGIN Android-added: Sync after rws/rwd write
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private void maybeSync() {
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if (flushAfterWrite == FLUSH_FSYNC) {
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try {
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fd.sync();
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} catch (IOException e) {
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// Ignored
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}
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} else if (flushAfterWrite == FLUSH_FDATASYNC) {
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try {
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Os.fdatasync(fd);
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} catch (ErrnoException e) {
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// Ignored
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}
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}
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}
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// END Android-added: Sync after rws/rwd write
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/**
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* Returns the opaque file descriptor object associated with this
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* stream.
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*
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* @return the file descriptor object associated with this stream.
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* @exception IOException if an I/O error occurs.
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* @see java.io.FileDescriptor
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*/
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public final FileDescriptor getFD() throws IOException {
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if (fd != null) {
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return fd;
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}
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throw new IOException();
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}
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/**
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* Returns the unique {@link java.nio.channels.FileChannel FileChannel}
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* object associated with this file.
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*
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* <p> The {@link java.nio.channels.FileChannel#position()
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* position} of the returned channel will always be equal to
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* this object's file-pointer offset as returned by the {@link
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* #getFilePointer getFilePointer} method. Changing this object's
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* file-pointer offset, whether explicitly or by reading or writing bytes,
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* will change the position of the channel, and vice versa. Changing the
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* file's length via this object will change the length seen via the file
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* channel, and vice versa.
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*
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* @return the file channel associated with this file
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*
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* @since 1.4
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* @spec JSR-51
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*/
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public final FileChannel getChannel() {
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synchronized (this) {
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if (channel == null) {
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channel = FileChannelImpl.open(fd, path, true, rw, this);
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}
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return channel;
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}
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}
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/**
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* Reads a byte of data from this file. The byte is returned as an
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* integer in the range 0 to 255 ({@code 0x00-0x0ff}). This
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* method blocks if no input is yet available.
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* <p>
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* Although {@code RandomAccessFile} is not a subclass of
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* {@code InputStream}, this method behaves in exactly the same
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* way as the {@link InputStream#read()} method of
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* {@code InputStream}.
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*
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* @return the next byte of data, or {@code -1} if the end of the
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* file has been reached.
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* @exception IOException if an I/O error occurs. Not thrown if
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* end-of-file has been reached.
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*/
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public int read() throws IOException {
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// Android-changed: Implement on top of libcore os API.
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// return read0();
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return (read(scratch, 0, 1) != -1) ? scratch[0] & 0xff : -1;
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}
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/**
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* Reads a sub array as a sequence of bytes.
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* @param b the buffer into which the data is read.
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* @param off the start offset of the data.
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* @param len the number of bytes to read.
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* @exception IOException If an I/O error has occurred.
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*/
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private int readBytes(byte b[], int off, int len) throws IOException {
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// Android-changed: Implement on top of libcore os API.
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ioTracker.trackIo(len, IoTracker.Mode.READ);
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return IoBridge.read(fd, b, off, len);
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}
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/**
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* Reads up to {@code len} bytes of data from this file into an
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* array of bytes. This method blocks until at least one byte of input
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* is available.
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* <p>
|
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* Although {@code RandomAccessFile} is not a subclass of
|
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* {@code InputStream}, this method behaves in exactly the
|
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* same way as the {@link InputStream#read(byte[], int, int)} method of
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* {@code InputStream}.
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*
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* @param b the buffer into which the data is read.
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* @param off the start offset in array {@code b}
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* at which the data is written.
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* @param len the maximum number of bytes read.
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* @return the total number of bytes read into the buffer, or
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* {@code -1} if there is no more data because the end of
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* the file has been reached.
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* @exception IOException If the first byte cannot be read for any reason
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* other than end of file, or if the random access file has been closed, or if
|
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* some other I/O error occurs.
|
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* @exception NullPointerException If {@code b} is {@code null}.
|
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* @exception IndexOutOfBoundsException If {@code off} is negative,
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* {@code len} is negative, or {@code len} is greater than
|
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* {@code b.length - off}
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*/
|
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public int read(byte b[], int off, int len) throws IOException {
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return readBytes(b, off, len);
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}
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|
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/**
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* Reads up to {@code b.length} bytes of data from this file
|
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* into an array of bytes. This method blocks until at least one byte
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* of input is available.
|
|
* <p>
|
|
* Although {@code RandomAccessFile} is not a subclass of
|
|
* {@code InputStream}, this method behaves in exactly the
|
|
* same way as the {@link InputStream#read(byte[])} method of
|
|
* {@code InputStream}.
|
|
*
|
|
* @param b the buffer into which the data is read.
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|
* @return the total number of bytes read into the buffer, or
|
|
* {@code -1} if there is no more data because the end of
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* this file has been reached.
|
|
* @exception IOException If the first byte cannot be read for any reason
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|
* other than end of file, or if the random access file has been closed, or if
|
|
* some other I/O error occurs.
|
|
* @exception NullPointerException If {@code b} is {@code null}.
|
|
*/
|
|
public int read(byte b[]) throws IOException {
|
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return readBytes(b, 0, b.length);
|
|
}
|
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|
|
/**
|
|
* Reads {@code b.length} bytes from this file into the byte
|
|
* array, starting at the current file pointer. This method reads
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|
* repeatedly from the file until the requested number of bytes are
|
|
* read. This method blocks until the requested number of bytes are
|
|
* read, the end of the stream is detected, or an exception is thrown.
|
|
*
|
|
* @param b the buffer into which the data is read.
|
|
* @exception EOFException if this file reaches the end before reading
|
|
* all the bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final void readFully(byte b[]) throws IOException {
|
|
readFully(b, 0, b.length);
|
|
}
|
|
|
|
/**
|
|
* Reads exactly {@code len} bytes from this file into the byte
|
|
* array, starting at the current file pointer. This method reads
|
|
* repeatedly from the file until the requested number of bytes are
|
|
* read. This method blocks until the requested number of bytes are
|
|
* read, the end of the stream is detected, or an exception is thrown.
|
|
*
|
|
* @param b the buffer into which the data is read.
|
|
* @param off the start offset of the data.
|
|
* @param len the number of bytes to read.
|
|
* @exception EOFException if this file reaches the end before reading
|
|
* all the bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final void readFully(byte b[], int off, int len) throws IOException {
|
|
int n = 0;
|
|
do {
|
|
int count = this.read(b, off + n, len - n);
|
|
if (count < 0)
|
|
throw new EOFException();
|
|
n += count;
|
|
} while (n < len);
|
|
}
|
|
|
|
/**
|
|
* Attempts to skip over {@code n} bytes of input discarding the
|
|
* skipped bytes.
|
|
* <p>
|
|
*
|
|
* This method may skip over some smaller number of bytes, possibly zero.
|
|
* This may result from any of a number of conditions; reaching end of
|
|
* file before {@code n} bytes have been skipped is only one
|
|
* possibility. This method never throws an {@code EOFException}.
|
|
* The actual number of bytes skipped is returned. If {@code n}
|
|
* is negative, no bytes are skipped.
|
|
*
|
|
* @param n the number of bytes to be skipped.
|
|
* @return the actual number of bytes skipped.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public int skipBytes(int n) throws IOException {
|
|
long pos;
|
|
long len;
|
|
long newpos;
|
|
|
|
if (n <= 0) {
|
|
return 0;
|
|
}
|
|
pos = getFilePointer();
|
|
len = length();
|
|
newpos = pos + n;
|
|
if (newpos > len) {
|
|
newpos = len;
|
|
}
|
|
seek(newpos);
|
|
|
|
/* return the actual number of bytes skipped */
|
|
return (int) (newpos - pos);
|
|
}
|
|
|
|
// 'Write' primitives
|
|
|
|
/**
|
|
* Writes the specified byte to this file. The write starts at
|
|
* the current file pointer.
|
|
*
|
|
* @param b the {@code byte} to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public void write(int b) throws IOException {
|
|
// BEGIN Android-changed: Implement on top of libcore os API.
|
|
// write0(b);
|
|
scratch[0] = (byte) (b & 0xff);
|
|
write(scratch, 0, 1);
|
|
// END Android-changed: Implement on top of libcore os API.
|
|
}
|
|
|
|
/**
|
|
* 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
|
|
* @exception IOException If an I/O error has occurred.
|
|
*/
|
|
private void writeBytes(byte b[], int off, int len) throws IOException {
|
|
// BEGIN Android-changed: Implement on top of libcore os API.
|
|
ioTracker.trackIo(len, IoTracker.Mode.WRITE);
|
|
IoBridge.write(fd, b, off, len);
|
|
maybeSync();
|
|
// END Android-changed: Implement on top of libcore os API.
|
|
}
|
|
|
|
/**
|
|
* Writes {@code b.length} bytes from the specified byte array
|
|
* to this file, starting at the current file pointer.
|
|
*
|
|
* @param b the data.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public void write(byte b[]) throws IOException {
|
|
writeBytes(b, 0, b.length);
|
|
}
|
|
|
|
/**
|
|
* Writes {@code len} bytes from the specified byte array
|
|
* starting at offset {@code off} to this file.
|
|
*
|
|
* @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 {
|
|
writeBytes(b, off, len);
|
|
}
|
|
|
|
// 'Random access' stuff
|
|
|
|
/**
|
|
* Returns the current offset in this file.
|
|
*
|
|
* @return the offset from the beginning of the file, in bytes,
|
|
* at which the next read or write occurs.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public long getFilePointer() throws IOException {
|
|
// BEGIN Android-changed: Implement on top of libcore os API.
|
|
try {
|
|
return Libcore.os.lseek(fd, 0L, SEEK_CUR);
|
|
} catch (ErrnoException errnoException) {
|
|
throw errnoException.rethrowAsIOException();
|
|
}
|
|
// END Android-changed: Implement on top of libcore os API.
|
|
}
|
|
|
|
/**
|
|
* Sets the file-pointer offset, measured from the beginning of this
|
|
* file, at which the next read or write occurs. The offset may be
|
|
* set beyond the end of the file. Setting the offset beyond the end
|
|
* of the file does not change the file length. The file length will
|
|
* change only by writing after the offset has been set beyond the end
|
|
* of the file.
|
|
*
|
|
* @param pos the offset position, measured in bytes from the
|
|
* beginning of the file, at which to set the file
|
|
* pointer.
|
|
* @exception IOException if {@code pos} is less than
|
|
* {@code 0} or if an I/O error occurs.
|
|
*/
|
|
public void seek(long pos) throws IOException {
|
|
if (pos < 0) {
|
|
// Android-changed: different exception message for seek(-1).
|
|
// throw new IOException("Negative seek offset");
|
|
throw new IOException("offset < 0: " + pos);
|
|
} else {
|
|
// BEGIN Android-changed: Implement on top of libcore os API.
|
|
// seek0(pos);
|
|
try {
|
|
Libcore.os.lseek(fd, pos, SEEK_SET);
|
|
ioTracker.reset();
|
|
} catch (ErrnoException errnoException) {
|
|
throw errnoException.rethrowAsIOException();
|
|
}
|
|
// END Android-changed: Implement on top of libcore os API.
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns the length of this file.
|
|
*
|
|
* @return the length of this file, measured in bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public long length() throws IOException {
|
|
// BEGIN Android-changed: Implement on top of libcore os API.
|
|
try {
|
|
return Libcore.os.fstat(fd).st_size;
|
|
} catch (ErrnoException errnoException) {
|
|
throw errnoException.rethrowAsIOException();
|
|
}
|
|
// END Android-changed: Implement on top of libcore os API.
|
|
}
|
|
|
|
/**
|
|
* Sets the length of this file.
|
|
*
|
|
* <p> If the present length of the file as returned by the
|
|
* {@code length} method is greater than the {@code newLength}
|
|
* argument then the file will be truncated. In this case, if the file
|
|
* offset as returned by the {@code getFilePointer} method is greater
|
|
* than {@code newLength} then after this method returns the offset
|
|
* will be equal to {@code newLength}.
|
|
*
|
|
* <p> If the present length of the file as returned by the
|
|
* {@code length} method is smaller than the {@code newLength}
|
|
* argument then the file will be extended. In this case, the contents of
|
|
* the extended portion of the file are not defined.
|
|
*
|
|
* @param newLength The desired length of the file
|
|
* @exception IOException If an I/O error occurs
|
|
* @since 1.2
|
|
*/
|
|
public void setLength(long newLength) throws IOException {
|
|
// BEGIN Android-changed: Implement on top of libcore os API.
|
|
if (newLength < 0) {
|
|
throw new IllegalArgumentException("newLength < 0");
|
|
}
|
|
try {
|
|
Libcore.os.ftruncate(fd, newLength);
|
|
} catch (ErrnoException errnoException) {
|
|
throw errnoException.rethrowAsIOException();
|
|
}
|
|
|
|
long filePointer = getFilePointer();
|
|
if (filePointer > newLength) {
|
|
seek(newLength);
|
|
}
|
|
maybeSync();
|
|
// END Android-changed: Implement on top of libcore os API.
|
|
}
|
|
|
|
|
|
/**
|
|
* Closes this random access file stream and releases any system
|
|
* resources associated with the stream. A closed random access
|
|
* file cannot perform input or output operations and cannot be
|
|
* reopened.
|
|
*
|
|
* <p> If this file 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 {
|
|
guard.close();
|
|
synchronized (closeLock) {
|
|
if (closed) {
|
|
return;
|
|
}
|
|
closed = true;
|
|
}
|
|
|
|
// BEGIN Android-changed: Implement on top of libcore os API.
|
|
if (channel != null && channel.isOpen()) {
|
|
channel.close();
|
|
}
|
|
IoBridge.closeAndSignalBlockedThreads(fd);
|
|
// END Android-changed: Implement on top of libcore os API.
|
|
}
|
|
|
|
//
|
|
// Some "reading/writing Java data types" methods stolen from
|
|
// DataInputStream and DataOutputStream.
|
|
//
|
|
|
|
/**
|
|
* Reads a {@code boolean} from this file. This method reads a
|
|
* single byte from the file, starting at the current file pointer.
|
|
* A value of {@code 0} represents
|
|
* {@code false}. Any other value represents {@code true}.
|
|
* This method blocks until the byte is read, the end of the stream
|
|
* is detected, or an exception is thrown.
|
|
*
|
|
* @return the {@code boolean} value read.
|
|
* @exception EOFException if this file has reached the end.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final boolean readBoolean() throws IOException {
|
|
int ch = this.read();
|
|
if (ch < 0)
|
|
throw new EOFException();
|
|
return (ch != 0);
|
|
}
|
|
|
|
/**
|
|
* Reads a signed eight-bit value from this file. This method reads a
|
|
* byte from the file, starting from the current file pointer.
|
|
* If the byte read is {@code b}, where
|
|
* <code>0 <= b <= 255</code>,
|
|
* then the result is:
|
|
* <blockquote><pre>
|
|
* (byte)(b)
|
|
* </pre></blockquote>
|
|
* <p>
|
|
* This method blocks until the byte is read, the end of the stream
|
|
* is detected, or an exception is thrown.
|
|
*
|
|
* @return the next byte of this file as a signed eight-bit
|
|
* {@code byte}.
|
|
* @exception EOFException if this file has reached the end.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final byte readByte() throws IOException {
|
|
int ch = this.read();
|
|
if (ch < 0)
|
|
throw new EOFException();
|
|
return (byte)(ch);
|
|
}
|
|
|
|
/**
|
|
* Reads an unsigned eight-bit number from this file. This method reads
|
|
* a byte from this file, starting at the current file pointer,
|
|
* and returns that byte.
|
|
* <p>
|
|
* This method blocks until the byte is read, the end of the stream
|
|
* is detected, or an exception is thrown.
|
|
*
|
|
* @return the next byte of this file, interpreted as an unsigned
|
|
* eight-bit number.
|
|
* @exception EOFException if this file has reached the end.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final int readUnsignedByte() throws IOException {
|
|
int ch = this.read();
|
|
if (ch < 0)
|
|
throw new EOFException();
|
|
return ch;
|
|
}
|
|
|
|
/**
|
|
* Reads a signed 16-bit number from this file. The method reads two
|
|
* bytes from this file, starting at the current file pointer.
|
|
* If the two bytes read, in order, are
|
|
* {@code b1} and {@code b2}, where each of the two values is
|
|
* between {@code 0} and {@code 255}, inclusive, then the
|
|
* result is equal to:
|
|
* <blockquote><pre>
|
|
* (short)((b1 << 8) | b2)
|
|
* </pre></blockquote>
|
|
* <p>
|
|
* This method blocks until the two bytes are read, the end of the
|
|
* stream is detected, or an exception is thrown.
|
|
*
|
|
* @return the next two bytes of this file, interpreted as a signed
|
|
* 16-bit number.
|
|
* @exception EOFException if this file reaches the end before reading
|
|
* two bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final short readShort() throws IOException {
|
|
int ch1 = this.read();
|
|
int ch2 = this.read();
|
|
if ((ch1 | ch2) < 0)
|
|
throw new EOFException();
|
|
return (short)((ch1 << 8) + (ch2 << 0));
|
|
}
|
|
|
|
/**
|
|
* Reads an unsigned 16-bit number from this file. This method reads
|
|
* two bytes from the file, starting at the current file pointer.
|
|
* If the bytes read, in order, are
|
|
* {@code b1} and {@code b2}, where
|
|
* <code>0 <= b1, b2 <= 255</code>,
|
|
* then the result is equal to:
|
|
* <blockquote><pre>
|
|
* (b1 << 8) | b2
|
|
* </pre></blockquote>
|
|
* <p>
|
|
* This method blocks until the two bytes are read, the end of the
|
|
* stream is detected, or an exception is thrown.
|
|
*
|
|
* @return the next two bytes of this file, interpreted as an unsigned
|
|
* 16-bit integer.
|
|
* @exception EOFException if this file reaches the end before reading
|
|
* two bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final int readUnsignedShort() throws IOException {
|
|
int ch1 = this.read();
|
|
int ch2 = this.read();
|
|
if ((ch1 | ch2) < 0)
|
|
throw new EOFException();
|
|
return (ch1 << 8) + (ch2 << 0);
|
|
}
|
|
|
|
/**
|
|
* Reads a character from this file. This method reads two
|
|
* bytes from the file, starting at the current file pointer.
|
|
* If the bytes read, in order, are
|
|
* {@code b1} and {@code b2}, where
|
|
* <code>0 <= b1, b2 <= 255</code>,
|
|
* then the result is equal to:
|
|
* <blockquote><pre>
|
|
* (char)((b1 << 8) | b2)
|
|
* </pre></blockquote>
|
|
* <p>
|
|
* This method blocks until the two bytes are read, the end of the
|
|
* stream is detected, or an exception is thrown.
|
|
*
|
|
* @return the next two bytes of this file, interpreted as a
|
|
* {@code char}.
|
|
* @exception EOFException if this file reaches the end before reading
|
|
* two bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final char readChar() throws IOException {
|
|
int ch1 = this.read();
|
|
int ch2 = this.read();
|
|
if ((ch1 | ch2) < 0)
|
|
throw new EOFException();
|
|
return (char)((ch1 << 8) + (ch2 << 0));
|
|
}
|
|
|
|
/**
|
|
* Reads a signed 32-bit integer from this file. This method reads 4
|
|
* bytes from the file, starting at the current file pointer.
|
|
* If the bytes read, in order, are {@code b1},
|
|
* {@code b2}, {@code b3}, and {@code b4}, where
|
|
* <code>0 <= b1, b2, b3, b4 <= 255</code>,
|
|
* then the result is equal to:
|
|
* <blockquote><pre>
|
|
* (b1 << 24) | (b2 << 16) + (b3 << 8) + b4
|
|
* </pre></blockquote>
|
|
* <p>
|
|
* This method blocks until the four bytes are read, the end of the
|
|
* stream is detected, or an exception is thrown.
|
|
*
|
|
* @return the next four bytes of this file, interpreted as an
|
|
* {@code int}.
|
|
* @exception EOFException if this file reaches the end before reading
|
|
* four bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final int readInt() throws IOException {
|
|
int ch1 = this.read();
|
|
int ch2 = this.read();
|
|
int ch3 = this.read();
|
|
int ch4 = this.read();
|
|
if ((ch1 | ch2 | ch3 | ch4) < 0)
|
|
throw new EOFException();
|
|
return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0));
|
|
}
|
|
|
|
/**
|
|
* Reads a signed 64-bit integer from this file. This method reads eight
|
|
* bytes from the file, starting at the current file pointer.
|
|
* If the bytes read, in order, are
|
|
* {@code b1}, {@code b2}, {@code b3},
|
|
* {@code b4}, {@code b5}, {@code b6},
|
|
* {@code b7}, and {@code b8,} where:
|
|
* <blockquote><pre>
|
|
* 0 <= b1, b2, b3, b4, b5, b6, b7, b8 <=255,
|
|
* </pre></blockquote>
|
|
* <p>
|
|
* then the result is equal to:
|
|
* <blockquote><pre>
|
|
* ((long)b1 << 56) + ((long)b2 << 48)
|
|
* + ((long)b3 << 40) + ((long)b4 << 32)
|
|
* + ((long)b5 << 24) + ((long)b6 << 16)
|
|
* + ((long)b7 << 8) + b8
|
|
* </pre></blockquote>
|
|
* <p>
|
|
* This method blocks until the eight bytes are read, the end of the
|
|
* stream is detected, or an exception is thrown.
|
|
*
|
|
* @return the next eight bytes of this file, interpreted as a
|
|
* {@code long}.
|
|
* @exception EOFException if this file reaches the end before reading
|
|
* eight bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final long readLong() throws IOException {
|
|
return ((long)(readInt()) << 32) + (readInt() & 0xFFFFFFFFL);
|
|
}
|
|
|
|
/**
|
|
* Reads a {@code float} from this file. This method reads an
|
|
* {@code int} value, starting at the current file pointer,
|
|
* as if by the {@code readInt} method
|
|
* and then converts that {@code int} to a {@code float}
|
|
* using the {@code intBitsToFloat} method in class
|
|
* {@code Float}.
|
|
* <p>
|
|
* This method blocks until the four bytes are read, the end of the
|
|
* stream is detected, or an exception is thrown.
|
|
*
|
|
* @return the next four bytes of this file, interpreted as a
|
|
* {@code float}.
|
|
* @exception EOFException if this file reaches the end before reading
|
|
* four bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
* @see java.io.RandomAccessFile#readInt()
|
|
* @see java.lang.Float#intBitsToFloat(int)
|
|
*/
|
|
public final float readFloat() throws IOException {
|
|
return Float.intBitsToFloat(readInt());
|
|
}
|
|
|
|
/**
|
|
* Reads a {@code double} from this file. This method reads a
|
|
* {@code long} value, starting at the current file pointer,
|
|
* as if by the {@code readLong} method
|
|
* and then converts that {@code long} to a {@code double}
|
|
* using the {@code longBitsToDouble} method in
|
|
* class {@code Double}.
|
|
* <p>
|
|
* This method blocks until the eight bytes are read, the end of the
|
|
* stream is detected, or an exception is thrown.
|
|
*
|
|
* @return the next eight bytes of this file, interpreted as a
|
|
* {@code double}.
|
|
* @exception EOFException if this file reaches the end before reading
|
|
* eight bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
* @see java.io.RandomAccessFile#readLong()
|
|
* @see java.lang.Double#longBitsToDouble(long)
|
|
*/
|
|
public final double readDouble() throws IOException {
|
|
return Double.longBitsToDouble(readLong());
|
|
}
|
|
|
|
/**
|
|
* Reads the next line of text from this file. This method successively
|
|
* reads bytes from the file, starting at the current file pointer,
|
|
* until it reaches a line terminator or the end
|
|
* of the file. Each byte is converted into a character by taking the
|
|
* byte's value for the lower eight bits of the character and setting the
|
|
* high eight bits of the character to zero. This method does not,
|
|
* therefore, support the full Unicode character set.
|
|
*
|
|
* <p> A line of text is terminated by a carriage-return character
|
|
* ({@code '\u005Cr'}), a newline character ({@code '\u005Cn'}), a
|
|
* carriage-return character immediately followed by a newline character,
|
|
* or the end of the file. Line-terminating characters are discarded and
|
|
* are not included as part of the string returned.
|
|
*
|
|
* <p> This method blocks until a newline character is read, a carriage
|
|
* return and the byte following it are read (to see if it is a newline),
|
|
* the end of the file is reached, or an exception is thrown.
|
|
*
|
|
* @return the next line of text from this file, or null if end
|
|
* of file is encountered before even one byte is read.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
|
|
public final String readLine() throws IOException {
|
|
StringBuffer input = new StringBuffer();
|
|
int c = -1;
|
|
boolean eol = false;
|
|
|
|
while (!eol) {
|
|
switch (c = read()) {
|
|
case -1:
|
|
case '\n':
|
|
eol = true;
|
|
break;
|
|
case '\r':
|
|
eol = true;
|
|
long cur = getFilePointer();
|
|
if ((read()) != '\n') {
|
|
seek(cur);
|
|
}
|
|
break;
|
|
default:
|
|
input.append((char)c);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if ((c == -1) && (input.length() == 0)) {
|
|
return null;
|
|
}
|
|
return input.toString();
|
|
}
|
|
|
|
/**
|
|
* Reads in a string from this file. The string has been encoded
|
|
* using a
|
|
* <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
|
|
* format.
|
|
* <p>
|
|
* The first two bytes are read, starting from the current file
|
|
* pointer, as if by
|
|
* {@code readUnsignedShort}. This value gives the number of
|
|
* following bytes that are in the encoded string, not
|
|
* the length of the resulting string. The following bytes are then
|
|
* interpreted as bytes encoding characters in the modified UTF-8 format
|
|
* and are converted into characters.
|
|
* <p>
|
|
* This method blocks until all the bytes are read, the end of the
|
|
* stream is detected, or an exception is thrown.
|
|
*
|
|
* @return a Unicode string.
|
|
* @exception EOFException if this file reaches the end before
|
|
* reading all the bytes.
|
|
* @exception IOException if an I/O error occurs.
|
|
* @exception UTFDataFormatException if the bytes do not represent
|
|
* valid modified UTF-8 encoding of a Unicode string.
|
|
* @see java.io.RandomAccessFile#readUnsignedShort()
|
|
*/
|
|
public final String readUTF() throws IOException {
|
|
return DataInputStream.readUTF(this);
|
|
}
|
|
|
|
/**
|
|
* Writes a {@code boolean} to the file as a one-byte value. The
|
|
* value {@code true} is written out as the value
|
|
* {@code (byte)1}; the value {@code false} is written out
|
|
* as the value {@code (byte)0}. The write starts at
|
|
* the current position of the file pointer.
|
|
*
|
|
* @param v a {@code boolean} value to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final void writeBoolean(boolean v) throws IOException {
|
|
write(v ? 1 : 0);
|
|
//written++;
|
|
}
|
|
|
|
/**
|
|
* Writes a {@code byte} to the file as a one-byte value. The
|
|
* write starts at the current position of the file pointer.
|
|
*
|
|
* @param v a {@code byte} value to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final void writeByte(int v) throws IOException {
|
|
write(v);
|
|
//written++;
|
|
}
|
|
|
|
/**
|
|
* Writes a {@code short} to the file as two bytes, high byte first.
|
|
* The write starts at the current position of the file pointer.
|
|
*
|
|
* @param v a {@code short} to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final void writeShort(int v) throws IOException {
|
|
write((v >>> 8) & 0xFF);
|
|
write((v >>> 0) & 0xFF);
|
|
//written += 2;
|
|
}
|
|
|
|
/**
|
|
* Writes a {@code char} to the file as a two-byte value, high
|
|
* byte first. The write starts at the current position of the
|
|
* file pointer.
|
|
*
|
|
* @param v a {@code char} value to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final void writeChar(int v) throws IOException {
|
|
write((v >>> 8) & 0xFF);
|
|
write((v >>> 0) & 0xFF);
|
|
//written += 2;
|
|
}
|
|
|
|
/**
|
|
* Writes an {@code int} to the file as four bytes, high byte first.
|
|
* The write starts at the current position of the file pointer.
|
|
*
|
|
* @param v an {@code int} to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final void writeInt(int v) throws IOException {
|
|
write((v >>> 24) & 0xFF);
|
|
write((v >>> 16) & 0xFF);
|
|
write((v >>> 8) & 0xFF);
|
|
write((v >>> 0) & 0xFF);
|
|
//written += 4;
|
|
}
|
|
|
|
/**
|
|
* Writes a {@code long} to the file as eight bytes, high byte first.
|
|
* The write starts at the current position of the file pointer.
|
|
*
|
|
* @param v a {@code long} to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final void writeLong(long v) throws IOException {
|
|
write((int)(v >>> 56) & 0xFF);
|
|
write((int)(v >>> 48) & 0xFF);
|
|
write((int)(v >>> 40) & 0xFF);
|
|
write((int)(v >>> 32) & 0xFF);
|
|
write((int)(v >>> 24) & 0xFF);
|
|
write((int)(v >>> 16) & 0xFF);
|
|
write((int)(v >>> 8) & 0xFF);
|
|
write((int)(v >>> 0) & 0xFF);
|
|
//written += 8;
|
|
}
|
|
|
|
/**
|
|
* Converts the float argument to an {@code int} using the
|
|
* {@code floatToIntBits} method in class {@code Float},
|
|
* and then writes that {@code int} value to the file as a
|
|
* four-byte quantity, high byte first. The write starts at the
|
|
* current position of the file pointer.
|
|
*
|
|
* @param v a {@code float} value to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
* @see java.lang.Float#floatToIntBits(float)
|
|
*/
|
|
public final void writeFloat(float v) throws IOException {
|
|
writeInt(Float.floatToIntBits(v));
|
|
}
|
|
|
|
/**
|
|
* Converts the double argument to a {@code long} using the
|
|
* {@code doubleToLongBits} method in class {@code Double},
|
|
* and then writes that {@code long} value to the file as an
|
|
* eight-byte quantity, high byte first. The write starts at the current
|
|
* position of the file pointer.
|
|
*
|
|
* @param v a {@code double} value to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
* @see java.lang.Double#doubleToLongBits(double)
|
|
*/
|
|
public final void writeDouble(double v) throws IOException {
|
|
writeLong(Double.doubleToLongBits(v));
|
|
}
|
|
|
|
/**
|
|
* Writes the string to the file as a sequence of bytes. Each
|
|
* character in the string is written out, in sequence, by discarding
|
|
* its high eight bits. The write starts at the current position of
|
|
* the file pointer.
|
|
*
|
|
* @param s a string of bytes to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
@SuppressWarnings("deprecation")
|
|
public final void writeBytes(String s) throws IOException {
|
|
int len = s.length();
|
|
byte[] b = new byte[len];
|
|
s.getBytes(0, len, b, 0);
|
|
writeBytes(b, 0, len);
|
|
}
|
|
|
|
/**
|
|
* Writes a string to the file as a sequence of characters. Each
|
|
* character is written to the data output stream as if by the
|
|
* {@code writeChar} method. The write starts at the current
|
|
* position of the file pointer.
|
|
*
|
|
* @param s a {@code String} value to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
* @see java.io.RandomAccessFile#writeChar(int)
|
|
*/
|
|
public final void writeChars(String s) throws IOException {
|
|
int clen = s.length();
|
|
int blen = 2*clen;
|
|
byte[] b = new byte[blen];
|
|
char[] c = new char[clen];
|
|
s.getChars(0, clen, c, 0);
|
|
for (int i = 0, j = 0; i < clen; i++) {
|
|
b[j++] = (byte)(c[i] >>> 8);
|
|
b[j++] = (byte)(c[i] >>> 0);
|
|
}
|
|
writeBytes(b, 0, blen);
|
|
}
|
|
|
|
/**
|
|
* Writes a string to the file using
|
|
* <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
|
|
* encoding in a machine-independent manner.
|
|
* <p>
|
|
* First, two bytes are written to the file, starting at the
|
|
* current file pointer, as if by the
|
|
* {@code writeShort} method giving the number of bytes to
|
|
* follow. This value is the number of bytes actually written out,
|
|
* not the length of the string. Following the length, each character
|
|
* of the string is output, in sequence, using the modified UTF-8 encoding
|
|
* for each character.
|
|
*
|
|
* @param str a string to be written.
|
|
* @exception IOException if an I/O error occurs.
|
|
*/
|
|
public final void writeUTF(String str) throws IOException {
|
|
DataOutputStream.writeUTF(str, this);
|
|
}
|
|
|
|
// Android-added: use finalize() to detect if not close()d.
|
|
@Override protected void finalize() throws Throwable {
|
|
try {
|
|
if (guard != null) {
|
|
guard.warnIfOpen();
|
|
}
|
|
close();
|
|
} finally {
|
|
super.finalize();
|
|
}
|
|
}
|
|
}
|