Added size(), fixed two bugs in internal array expansion: one was that it

was doubling the size of the internal array every time add() was called,
whether it needed to or not, the other was that unserializing an empty set
caused expand() to be called with -1 as the index from which mayhem would
ensue.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@463 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/presents/dobj/DSet.java

@@ -1,5 +1,5 @@
 //
-// $Id: DSet.java,v 1.10 2001/10/12 20:11:00 mdb Exp $
+// $Id: DSet.java,v 1.11 2001/10/16 16:43:20 mdb Exp $
 
 package com.threerings.presents.dobj;
 
@@ -105,6 +105,14 @@ public class DSet
         }
     }
 
+    /**
+     * Returns the number of elements in this set.
+     */
+    public int size ()
+    {
+        return _size;
+    }
+
     /**
      * Returns true if the set contains an element whose
      * <code>getKey()</code> method returns a key that
@@ -219,7 +227,9 @@ public class DSet
         }
 
         // expand the array if necessary
-        expand(index);
+        if (index >= _elements.length) {
+            expand(index);
+        }
 
         // insert the item
         _elements[index] = elem;
@@ -328,7 +338,7 @@ public class DSet
         _size = in.readInt();
 
         // make sure we can fit _size elements
-        expand(_size-1);
+        expand(_size);
 
         for (int i = 0; i < _size; i++) {
             Element elem = newElement();
@@ -372,17 +382,30 @@ public class DSet
 
     protected void expand (int index)
     {
-        int elength = _elements.length;
+        // sanity check
+        if (index < 0) {
+            Log.warning("Requested to expand to accomodate bogus index! " +
+                        "[index=" + index + "].");
+            Thread.dumpStack();
+            index = 0;
+        }
 
         // increase our length in powers of two until we're big enough
-        int tlength = elength*2;
+        int tlength = _elements.length;
         while (index >= tlength) {
             tlength *= 2;
         }
 
+        // further sanity checks
+        if (tlength > 4096) {
+            Log.warning("Requested to expand to questionably large size " +
+                        "[index=" + index + ", tlength=" + tlength + "].");
+            Thread.dumpStack();
+        }
+
         // create a new array and copy our data into it
         Element[] elems = new Element[tlength];
-        System.arraycopy(_elements, 0, elems, 0, elength);
+        System.arraycopy(_elements, 0, elems, 0, _elements.length);
         _elements = elems;
     }