[kaffe] [PATCH] small NIO slice guilhem forgotten

jserv at linux2.cc.ntu.edu.tw jserv at linux2.cc.ntu.edu.tw
Mon Apr 12 06:16:02 PDT 2004


Hi all,

  I just cvs update to use Guilhem Lavaux's great efforts on NIO merge,
fix for java.text, and cleanup for VMObjectStream. Thanks for his great
work, but I found Guilhem forgot to nio/channels/FileChannelImpl.java
into hist patch. So that, I just copy GNU Classpath's implementation.
The patch is attached.

Thanks,
Jim Huang
-------------- next part --------------
diff -x CVS -urN kaffe/libraries/javalib/gnu/java/nio/channels/FileChannelImpl.java kaffe-nio/libraries/javalib/gnu/java/nio/channels/FileChannelImpl.java
--- kaffe/libraries/javalib/gnu/java/nio/channels/FileChannelImpl.java	1970-01-01 08:00:00.000000000 +0800
+++ kaffe-nio/libraries/javalib/gnu/java/nio/channels/FileChannelImpl.java	2004-04-11 20:02:06.000000000 +0800
@@ -0,0 +1,424 @@
+/* FileChannelImpl.java -- 
+   Copyright (C) 2002, 2004 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath 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 for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package gnu.java.nio.channels;
+
+import gnu.classpath.Configuration;
+import gnu.java.nio.FileLockImpl;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.MappedByteBuffer;
+import java.nio.channels.ClosedChannelException;
+import java.nio.channels.FileChannel;
+import java.nio.channels.FileLock;
+import java.nio.channels.NonReadableChannelException;
+import java.nio.channels.NonWritableChannelException;
+import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.WritableByteChannel;
+
+/**
+ * This file is not user visible !
+ * But alas, Java does not have a concept of friendly packages
+ * so this class is public. 
+ * Instances of this class are created by invoking getChannel
+ * Upon a Input/Output/RandomAccessFile object.
+ */
+
+public final class FileChannelImpl extends FileChannel
+{
+  // These are WHENCE values for seek.
+//   public static final int SET = 0;
+//   public static final int CUR = 1;
+
+  // These are mode values for open().
+  public static final int READ   = 1;
+  public static final int WRITE  = 2;
+  public static final int APPEND = 4;
+
+  // EXCL is used only when making a temp file.
+  public static final int EXCL   = 8;
+  public static final int SYNC   = 16;
+  public static final int DSYNC  = 32;
+
+  private static native void init();
+
+  static
+  {
+    if (Configuration.INIT_LOAD_LIBRARY)
+      {
+        System.loadLibrary("javanio");
+      }
+    
+    init();
+  }
+
+  /**
+   * This is the actual native file descriptor value
+   */
+  // System's notion of file descriptor.  It might seem redundant to
+  // initialize this given that it is reassigned in the constructors.
+  // However, this is necessary because if open() throws an exception
+  // we want to make sure this has the value -1.  This is the most
+  // efficient way to accomplish that.
+  private int fd = -1;
+
+  private int mode;
+
+  public FileChannelImpl ()
+  {
+  }
+
+  /* Open a file.  MODE is a combination of the above mode flags. */
+  public FileChannelImpl (String path, int mode) throws FileNotFoundException
+  {
+    fd = open (path, mode);
+    this.mode = mode;
+  }
+
+  /* Used by init() (native code) */
+  private FileChannelImpl (int fd, int mode)
+  {
+    this.fd = fd;
+    this.mode = mode;
+  }
+
+  public static FileChannelImpl in;
+  public static FileChannelImpl out;
+  public static FileChannelImpl err;
+
+  private native int open (String path, int mode) throws FileNotFoundException;
+
+  public native int available () throws IOException;
+  private native long implPosition () throws IOException;
+  private native void seek (long newPosition) throws IOException;
+  private native void implTruncate (long size) throws IOException;
+  
+  public native void unlock (long pos, long len) throws IOException;
+
+  public native long size () throws IOException;
+    
+  protected native void implCloseChannel() throws IOException;
+
+  public int read (ByteBuffer dst) throws IOException
+  {
+    int result;
+    byte[] buffer = new byte [dst.remaining ()];
+    
+    result = read (buffer, 0, buffer.length);
+
+    if (result > 0)
+      dst.put (buffer, 0, result);
+
+    return result;
+  }
+
+  public int read (ByteBuffer dst, long position)
+    throws IOException
+  {
+    if (position < 0)
+      throw new IllegalArgumentException ();
+    long oldPosition = implPosition ();
+    position (position);
+    int result = read(dst);
+    position (oldPosition);
+    
+    return result;
+  }
+
+  public native int read ()
+    throws IOException;
+
+  public native int read (byte[] buffer, int offset, int length)
+    throws IOException;
+
+  public long read (ByteBuffer[] dsts, int offset, int length)
+    throws IOException
+  {
+    long result = 0;
+
+    for (int i = offset; i < offset + length; i++)
+      {
+        result += read (dsts [i]);
+      }
+
+    return result;
+  }
+
+  public int write (ByteBuffer src) throws IOException
+  {
+    int len = src.remaining ();
+    if (src.hasArray())
+      {
+	byte[] buffer = src.array();
+	write(buffer, src.arrayOffset() + src.position(), len);
+      }
+    else
+      {
+	// Use a more efficient native method! FIXME!
+	byte[] buffer = new byte [len];
+    	src.get (buffer, 0, len);
+	write (buffer, 0, len);
+      }
+    return len;
+  }
+    
+  public int write (ByteBuffer src, long position)
+    throws IOException
+  {
+    if (position < 0)
+      throw new IllegalArgumentException ();
+
+    if (!isOpen ())
+      throw new ClosedChannelException ();
+    
+    if ((mode & WRITE) == 0)
+       throw new NonWritableChannelException ();
+
+    int result;
+    long oldPosition;
+
+    oldPosition = implPosition ();
+    seek (position);
+    result = write(src);
+    seek (oldPosition);
+    
+    return result;
+  }
+
+  public native void write (byte[] buffer, int offset, int length)
+    throws IOException;
+  
+  public native void write (int b) throws IOException;
+
+  public long write(ByteBuffer[] srcs, int offset, int length)
+    throws IOException
+  {
+    long result = 0;
+
+    for (int i = offset;i < offset + length;i++)
+      {
+        result += write (srcs[i]);
+      }
+    
+    return result;
+  }
+				   
+  public native MappedByteBuffer mapImpl (char mode, long position, int size)
+    throws IOException;
+
+  public MappedByteBuffer map (FileChannel.MapMode mode,
+			       long position, long size)
+    throws IOException
+  {
+    char nmode = 0;
+    if (mode == MapMode.READ_ONLY)
+      {
+	nmode = 'r';
+	if ((this.mode & READ) == 0)
+	  throw new NonReadableChannelException();
+      }
+    else if (mode == MapMode.READ_WRITE || mode == MapMode.PRIVATE)
+      {
+	nmode = mode == MapMode.READ_WRITE ? '+' : 'c';
+	if ((this.mode & (READ|WRITE)) != (READ|WRITE))
+	  throw new NonWritableChannelException();
+      }
+    else
+      throw new IllegalArgumentException ();
+    
+    if (position < 0 || size < 0 || size > Integer.MAX_VALUE)
+      throw new IllegalArgumentException ();
+    return mapImpl(nmode, position, (int) size);
+  }
+
+  /**
+   * msync with the disk
+   */
+  public void force (boolean metaData) throws IOException
+  {
+    if (!isOpen ())
+      throw new ClosedChannelException ();
+  }
+
+  public long transferTo (long position, long count, WritableByteChannel target)
+    throws IOException
+  {
+    if (position < 0
+        || count < 0)
+      throw new IllegalArgumentException ();
+
+    if (!isOpen ())
+      throw new ClosedChannelException ();
+
+    if ((mode & READ) == 0)
+       throw new NonReadableChannelException ();
+   
+    // XXX: count needs to be casted from long to int. Dataloss ?
+    ByteBuffer buffer = ByteBuffer.allocate ((int) count);
+    read (buffer, position);
+    buffer.flip();
+    return target.write (buffer);
+  }
+
+  public long transferFrom (ReadableByteChannel src, long position, long count)
+    throws IOException
+  {
+    if (position < 0
+        || count < 0)
+      throw new IllegalArgumentException ();
+
+    if (!isOpen ())
+      throw new ClosedChannelException ();
+
+    if ((mode & WRITE) == 0)
+       throw new NonWritableChannelException ();
+
+    // XXX: count needs to be casted from long to int. Dataloss ?
+    ByteBuffer buffer = ByteBuffer.allocate ((int) count);
+    src.read (buffer);
+    buffer.flip();
+    return write (buffer, position);
+  }
+
+  public FileLock tryLock (long position, long size, boolean shared)
+    throws IOException
+  {
+    if (position < 0
+        || size < 0)
+      throw new IllegalArgumentException ();
+
+    if (!isOpen ())
+      throw new ClosedChannelException ();
+
+    if (shared && (mode & READ) == 0)
+      throw new NonReadableChannelException ();
+	
+    if (!shared && (mode & WRITE) == 0)
+      throw new NonWritableChannelException ();
+	
+    boolean completed = false;
+    
+    try
+      {
+	begin();
+        lock(position, size, shared, true);
+	completed = true;
+	return new FileLockImpl(this, position, size, shared);
+      }
+    finally
+      {
+	end(completed);
+      }
+  }
+
+  /** Try to acquire a lock at the given position and size.
+   * On success return true.
+   * If wait as specified, block until we can get it.
+   * Otherwise return false.
+   */
+  private native boolean lock(long position, long size,
+			      boolean shared, boolean wait) throws IOException;
+  
+  public FileLock lock (long position, long size, boolean shared)
+    throws IOException
+  {
+    if (position < 0
+        || size < 0)
+      throw new IllegalArgumentException ();
+
+    if (!isOpen ())
+      throw new ClosedChannelException ();
+
+    boolean completed = false;
+
+    try
+      {
+	boolean lockable = lock(position, size, shared, false);
+	completed = true;
+	return (lockable
+		? new FileLockImpl(this, position, size, shared)
+		: null);
+      }
+    finally
+      {
+	end(completed);
+      }
+  }
+
+  public long position ()
+    throws IOException
+  {
+    if (!isOpen ())
+      throw new ClosedChannelException ();
+
+    return implPosition ();
+  }
+  
+  public FileChannel position (long newPosition)
+    throws IOException
+  {
+    if (newPosition < 0)
+      throw new IllegalArgumentException ();
+
+    if (!isOpen ())
+      throw new ClosedChannelException ();
+
+    // FIXME note semantics if seeking beyond eof.
+    // We should seek lazily - only on a write.
+    seek (newPosition);
+    return this;
+  }
+  
+  public FileChannel truncate (long size)
+    throws IOException
+  {
+    if (size < 0)
+      throw new IllegalArgumentException ();
+
+    if (!isOpen ())
+      throw new ClosedChannelException ();
+
+    if ((mode & WRITE) == 0)
+       throw new NonWritableChannelException ();
+
+    implTruncate (size);
+    return this;
+  }
+}


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