From a33d6684eb8913cd79403ed1b9d45912e9fc9318 Mon Sep 17 00:00:00 2001
From: "Hiram R. Chirino" <chirino@apache.org>
Date: Thu, 21 Jan 2010 16:37:37 +0000
Subject: [PATCH] Adding a isEmpty() method to the btree indexes..  related to
 the fix created for AMQ-2512

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@901763 13f79535-47bb-0310-9956-ffa450edef68
---
 .../org/apache/activemq/store/kahadb/KahaDBStore.java     | 8 +-------
 .../src/main/java/org/apache/kahadb/index/BTreeIndex.java | 4 ++++
 .../src/main/java/org/apache/kahadb/index/BTreeNode.java  | 4 ++++
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/activemq-core/src/main/java/org/apache/activemq/store/kahadb/KahaDBStore.java b/activemq-core/src/main/java/org/apache/activemq/store/kahadb/KahaDBStore.java
index e43853e872..1dddef7963 100644
--- a/activemq-core/src/main/java/org/apache/activemq/store/kahadb/KahaDBStore.java
+++ b/activemq-core/src/main/java/org/apache/activemq/store/kahadb/KahaDBStore.java
@@ -207,13 +207,7 @@ public class KahaDBStore extends MessageDatabase implements PersistenceAdapter {
                     public Boolean execute(Transaction tx) throws IOException {
                         // Iterate through all index entries to get a count of messages in the destination.
                         StoredDestination sd = getStoredDestination(dest, tx);
-                        boolean result = true;
-                        for (Iterator<Entry<Location, Long>> iterator = sd.locationIndex.iterator(tx); iterator.hasNext();) {
-                            iterator.next();
-                            result = false;
-                            break;
-                        }
-                        return result;
+                        return sd.locationIndex.isEmpty(tx);
                     }
                 });
             }
diff --git a/kahadb/src/main/java/org/apache/kahadb/index/BTreeIndex.java b/kahadb/src/main/java/org/apache/kahadb/index/BTreeIndex.java
index 4cba413a87..350a654ce2 100644
--- a/kahadb/src/main/java/org/apache/kahadb/index/BTreeIndex.java
+++ b/kahadb/src/main/java/org/apache/kahadb/index/BTreeIndex.java
@@ -220,6 +220,10 @@ public class BTreeIndex<Key,Value> implements Index<Key,Value> {
         pw.flush();
     }
 
+    synchronized public boolean isEmpty(final Transaction tx) throws IOException {
+        return getRoot(tx).isEmpty(tx);
+    }
+
     synchronized public Iterator<Map.Entry<Key,Value>> iterator(final Transaction tx) throws IOException {
         return getRoot(tx).iterator(tx);
     }
diff --git a/kahadb/src/main/java/org/apache/kahadb/index/BTreeNode.java b/kahadb/src/main/java/org/apache/kahadb/index/BTreeNode.java
index 372f430223..a32de749ce 100644
--- a/kahadb/src/main/java/org/apache/kahadb/index/BTreeNode.java
+++ b/kahadb/src/main/java/org/apache/kahadb/index/BTreeNode.java
@@ -507,6 +507,10 @@ public final class BTreeNode<Key,Value> {
         }
     }
     
+    public boolean isEmpty(final Transaction tx) throws IOException {
+        return keys.length==0;
+    }
+
     public void visit(Transaction tx, BTreeVisitor<Key, Value> visitor) throws IOException {
         if (visitor == null) {
             throw new IllegalArgumentException("Visitor cannot be null");