--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/gov/nasa/jpf/vm/Allocation.java	Fri Jan 23 10:14:01 2015 -0800
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2014, United States Government, as represented by the
+ * Administrator of the National Aeronautics and Space Administration.
+ * All rights reserved.
+ *
+ * The Java Pathfinder core (jpf-core) platform is licensed under the
+ * Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ * 
+ *        http://www.apache.org/licenses/LICENSE-2.0. 
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and 
+ * limitations under the License.
+ */
+package gov.nasa.jpf.vm;
+
+import gov.nasa.jpf.util.OATHash;
+
+/**
+ * helper class for search global object id (SGOID) computation. This
+ * captures both allocation context and count.
+ * 
+ * NOTE: this is used as a key for associative arrays, but we do
+ * allow destructive updates via init() in order to enable key
+ * caching for lookups that don't lead to new entries. 
+ * THE CALLER HAS TO MAKE SURE init() IS NEVER CALLED ON A STORED KEY !!
+ */
+public class Allocation {
+  
+  final AllocationContext context;
+  final int count;
+  final int hash;
+  
+  public Allocation (AllocationContext context, int count){
+    this.context = context;
+    this.count = count;
+    this.hash = OATHash.hash(context.hashCode(), count);
+  }
+  
+  @Override
+  public boolean equals (Object o) {
+    if (o instanceof Allocation) {
+      Allocation other = (Allocation)o;
+      
+      if (other.hash == hash) {
+        if (other.context.equals(context)) {
+          return true;
+        }
+      }
+    }
+    
+    return false;
+  }
+  
+  @Override
+  public int hashCode() {
+    return hash;
+  }
+}