Convert Narya (most of the way) over to a Maven Ant task based build. The

ActionScript bits remain belligerent, but the Java stuff is mostly shipshape.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@6222 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/main/java/com/threerings/io/ArrayMask.java

@@ -0,0 +1,91 @@
+//
+// $Id$
+//
+// Narya library - tools for developing networked games
+// Copyright (C) 2002-2010 Three Rings Design, Inc., All Rights Reserved
+// http://code.google.com/p/narya/
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library 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
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.threerings.io;
+
+import java.io.IOException;
+
+/**
+ * Used to keep track of which entries in an array are null and which are
+ * not. <em>Note:</em> only arrays up to 262,144 elements in length can be
+ * handled by this class.
+ */
+public class ArrayMask
+{
+    /**
+     * Creates an array mask suitable for unserializing.
+     */
+    public ArrayMask ()
+    {
+    }
+
+    /**
+     * Creates an array mask for an array of the specified length.
+     */
+    public ArrayMask (int length)
+    {
+        int mlength = length/8;
+        if (length % 8 != 0) {
+            mlength++;
+        }
+        _mask = new byte[mlength];
+    }
+
+    /**
+     * Sets the bit indicating that the specified array index is non-null.
+     */
+    public void set (int index)
+    {
+        _mask[index/8] |= (1 << (index%8));
+    }
+
+    /**
+     * Returns true if the specified array index should be non-null.
+     */
+    public boolean isSet (int index)
+    {
+        return (_mask[index/8] & (1 << (index%8))) != 0;
+    }
+
+    /**
+     * Writes this mask to the specified output stream.
+     */
+    public void writeTo (ObjectOutputStream out)
+        throws IOException
+    {
+        out.writeShort(_mask.length);
+        out.write(_mask);
+    }
+
+    /**
+     * Reads this mask from the specified input stream.
+     */
+    public void readFrom (ObjectInputStream in)
+        throws IOException
+    {
+        int length = in.readShort();
+        _mask = new byte[length];
+        in.read(_mask);
+    }
+
+    /** A byte array with bits for every entry in the source array. */
+    protected byte[] _mask;
+}