1 files changed, 137 insertions, 0 deletions
diff --git a/libjava/java/nio/channels/FileLock.java b/libjava/java/nio/channels/FileLock.java
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+++ b/libjava/java/nio/channels/FileLock.java
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+/* FileLock.java -- 
+   Copyright (C) 2002 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 java.nio.channels;
+
+import java.io.IOException;
+
+/**
+ * @since 1.4
+ */
+public abstract class FileLock
+{
+  FileChannel channel;
+  long position;
+  long size;
+  boolean shared;
+  
+  /**
+   * Initializes the file lock.
+   *
+   * @exception IllegalArgumentException If the preconditions on the parameters do not hold
+   */
+  protected FileLock (FileChannel channel, long position, long size,
+                      boolean shared)
+  {
+    if (position < 0 ||
+        size < 0)
+      throw new IllegalArgumentException ();
+
+    this.channel = channel;
+    this.position = position;
+    this.size = size;
+    this.shared = shared;
+  }
+ 
+  /**
+   * Tells whether or not this lock is valid.
+   */
+  public abstract boolean isValid();
+ 
+  /**
+   * Releases this lock.
+   *
+   * @exception IOException If an error occurs
+   * @exception ClosedChannelException If the locked channel is no longer open.
+   */
+  public abstract void release () throws IOException;
+  
+  /**
+   * Returns the file channel upon whose file this lock is held.
+   */
+  public final FileChannel channel ()
+  {
+    return channel;
+  }
+
+  /**
+   * Tells whether this lock is shared.
+   */
+  public final boolean isShared ()
+  {
+    return shared;
+  }    
+
+  /**
+   * Tells whether or not this lock overlaps the given lock range.
+   */
+  public final boolean overlaps (long position, long size)
+  {
+    if (position > this.position +this.size)
+      return false;
+
+    if (position + size < this.position)
+      return false;
+
+    return true;
+  }
+
+  /**
+   * Returns the position within the file of the first byte of the
+   * locked region.
+   */
+  public final long position ()
+  {
+    return position;
+  }
+    
+  /**
+   * Returns the size of the locked region in bytes.
+   */
+  public final long size ()
+  {
+    return size;
+  }
+
+  /**
+   * Returns a string describing the range, type, and validity of this lock.
+   */
+  public final String toString ()
+  {
+    return "file-lock:pos=" + position + "size=" + size;
+  }
+}