A streamable hash map.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@2616 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/util/StreamableHashMap.java

@@ -0,0 +1,66 @@
+//
+// $Id: StreamableHashMap.java,v 1.1 2003/05/27 22:48:31 mdb Exp $
+
+package com.threerings.util;
+
+import java.io.IOException;
+import java.util.Iterator;
+import java.util.HashMap;
+
+import com.threerings.io.ObjectInputStream;
+import com.threerings.io.ObjectOutputStream;
+import com.threerings.io.Streamable;
+
+/**
+ * A {@link HashMap} extension that can be streamed. The keys and values
+ * in the map must also be of streamable types.
+ *
+ * @see Streamable
+ */
+public class StreamableHashMap extends HashMap
+{
+    /**
+     * Constructs an empty hash map with the specified number of hash
+     * buckets.
+     */
+    public StreamableHashMap (int buckets, float loadFactor)
+    {
+        super(buckets, loadFactor);
+    }
+
+    /**
+     * Constructs an empty hash map with the default number of hash
+     * buckets.
+     */
+    public StreamableHashMap ()
+    {
+        super();
+    }
+
+    /**
+     * Writes our custom streamable fields.
+     */
+    public void writeObject (ObjectOutputStream out)
+        throws IOException
+    {
+        int ecount = size();
+        out.writeInt(ecount);
+        for (Iterator iter = keySet().iterator(); iter.hasNext(); ) {
+            Object key = iter.next();
+            out.writeObject(key);
+            out.writeObject(get(key));
+        }
+    }
+
+    /**
+     * Reads our custom streamable fields.
+     */
+    public void readObject (ObjectInputStream in)
+        throws IOException, ClassNotFoundException
+    {
+        int ecount = in.readInt();
+        for (int ii = 0; ii < ecount; ii++) {
+            put(in.readObject(), in.readObject());
+        }
+    }
+}