mirror of git://gcc.gnu.org/git/gcc.git
98 lines
3.1 KiB
Java
98 lines
3.1 KiB
Java
// FileDescriptor.java - Open file or device
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/* Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation
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This file is part of libgcj.
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This software is copyrighted work licensed under the terms of the
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Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
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details. */
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package java.io;
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/**
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* @author Tom Tromey <tromey@cygnus.com>
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* @date September 24, 1998
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*/
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/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
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* "The Java Language Specification", ISBN 0-201-63451-1
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* Status: Complete to 1.1
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*/
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// For now we assume a POSIXy file system. This can be changed later
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// if need be.
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public final class FileDescriptor
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{
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public static final FileDescriptor in = new FileDescriptor (0);
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public static final FileDescriptor out = new FileDescriptor (1);
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public static final FileDescriptor err = new FileDescriptor (2);
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public native void sync () throws SyncFailedException;
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public native boolean valid ();
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// These are mode values for open().
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static final int READ = 1;
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static final int WRITE = 2;
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static final int APPEND = 4;
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// EXCL is used only when making a temp file.
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static final int EXCL = 8;
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// These are WHENCE values for seek.
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static final int SET = 0;
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static final int CUR = 1;
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// This constructor is specified to create an invalid descriptor.
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public FileDescriptor ()
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{
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}
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// Open a file. MODE is a combination of the above mode flags.
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FileDescriptor (String path, int mode) throws FileNotFoundException
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{
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fd = open (path, mode);
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}
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native int open (String path, int mode) throws FileNotFoundException;
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native void write (int b) throws IOException;
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native void write (byte[] b, int offset, int len)
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throws IOException, NullPointerException, IndexOutOfBoundsException;
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native void close () throws IOException;
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// EOF_TRUNC is true if a request to seek past the end of file
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// should actually stop at the end of file. If false, then a seek
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// past the end is ok (and if a subsequent write occurs the file
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// will grow).
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native int seek (long pos, int whence, boolean eof_trunc) throws IOException;
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native long length () throws IOException;
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native long getFilePointer () throws IOException;
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native int read () throws IOException;
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native int read (byte[] bytes, int offset, int len) throws IOException;
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native int available () throws IOException;
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// When collected, close.
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protected void finalize () throws IOException
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{
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if (valid ())
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close ();
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}
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// Attach to an already-opened file. This is not private because we
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// need access to it from other packages, for instance java.net.
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// Ordinarily that wouldn't work, either, but in our case we know
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// the access comes from C++, where "package private" is translated
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// into "public". Eww.
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FileDescriptor (int desc)
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{
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fd = desc;
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}
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// System's notion of file descriptor. It might seem redundant to
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// initialize this given that it is reassigned in the constructors.
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// However, this is necessary because if open() throws an exception
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// we want to make sure this has the value -1. This is the most
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// efficient way to accomplish that.
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private int fd = -1;
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}
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