[Mulgara-svn] r860 - projects/xa2/object-pool/src

[andrae at mulgara.org]

Author: andrae
Date: 2008-04-28 03:57:20 -0700 (Mon, 28 Apr 2008)
New Revision: 860

Modified:
   projects/xa2/object-pool/src/CompMemTrie.java
Log:
Removed more control-flow exceptions.

I wish java supported continuations.



Modified: projects/xa2/object-pool/src/CompMemTrie.java
===================================================================
--- projects/xa2/object-pool/src/CompMemTrie.java	2008-04-28 08:58:12 UTC (rev 859)
+++ projects/xa2/object-pool/src/CompMemTrie.java	2008-04-28 10:57:20 UTC (rev 860)
@@ -39,9 +39,7 @@
     if (root == null) {
       root = new TrieLeaf(key, value);
     } else {
-      try {
-        root.insert(key, value);
-      } catch (TrieNode.InsertAbove k) {
+      if (!root.insert(key, value)) {
         root = new TrieBranch(root, key, value);
       }
     }
@@ -124,10 +122,6 @@
   }
 
   protected abstract static class TrieNode {
-    @SuppressWarnings("serial")
-    protected static class InsertAbove extends Exception {} ;
-    protected static final InsertAbove cont = new InsertAbove();
-
     protected TrieLeaf aLeaf;
     /**
      * Offset into block of this TrieNode.
@@ -135,8 +129,11 @@
      */
     protected short location = 0;
 
-    public void insert(byte[] key, long value) throws InsertAbove {
-      insert(new TrieLeaf(key, value), 0);
+    /**
+     * @return false if we need to insert key above this node.
+     */
+    public boolean insert(byte[] key, long value) {
+      return insert(new TrieLeaf(key, value), 0);
     }
 
     public long lookup(byte[] key) throws NotFound {
@@ -153,7 +150,7 @@
     protected abstract void write(ByteBuffer index, FileChannel data) throws IOException;
     protected abstract int totalIndexSize();
     protected abstract int totalDataSize();
-    protected abstract void insert(TrieLeaf node, int parentLcd) throws InsertAbove;
+    protected abstract boolean insert(TrieLeaf node, int parentLcd);
     protected abstract long lookup(byte[] key, int parentLcd) throws NotFound;
 
     protected static boolean regionMatches(byte[] lhs, int lhsOff, byte[] rhs, int rhsOff, int len) {
@@ -305,9 +302,9 @@
       }
     }
 
-    protected void insert(TrieLeaf node, int parentLcp) throws InsertAbove {
+    protected boolean insert(TrieLeaf node, int parentLcp) {
       if (!regionMatches(aLeaf.key, parentLcp, node.key, parentLcp, offset - parentLcp)) {
-        throw cont;
+        return false;
       } else {
         // new node matches the lcp of this node.
         if (node.key.length == offset) {
@@ -315,7 +312,7 @@
           if (term == null) {
             term = node;
           } else {
-            term.insert(node, offset);
+            return term.insert(node, offset);
           }
         } else {
           // new node is expected to terminate in one of this nodes children.
@@ -324,14 +321,14 @@
             // this is the first node to be inserted on this branching key.
             children.insert(node.key[offset], node);
           } else {
-            try {
-              // there is an existing child node branching on this branching key.
-              child.insert(node, offset);
-            } catch (InsertAbove k) {
-                children.insert(node.key[offset], new TrieBranch(child, node));
+            // there is an existing child node branching on this branching key.
+            if (!child.insert(node, offset)) {
+              children.insert(node.key[offset], new TrieBranch(child, node));
             }
           }
         }
+
+        return true;
       }
     }
 
@@ -395,13 +392,13 @@
       this.aLeaf = this;
     }
 
-    protected void insert(TrieLeaf node, int parentLcp) throws InsertAbove {
+    protected boolean insert(TrieLeaf node, int parentLcp) {
       if (key.length != node.key.length) {
-        throw cont;
+        return false;
       } else if (!regionMatches(key, parentLcp, node.key, parentLcp, key.length - parentLcp)) {
-        throw cont;
+        return false;
       } else if (value == node.value) {
-        return; // Duplicate key/value pair.
+        return true; // Duplicate key/value pair.
       } else {
         throw new IllegalArgumentException("Attempt to insert multiple values for same key");
       }