From 50c1987265f8ddaf5032a7ace07b2462aba4f09b Mon Sep 17 00:00:00 2001
From: Jonathan Ellis <jbellis@apache.org>
Date: Fri, 10 Apr 2009 19:08:27 +0000
Subject: [PATCH] fix getCompactionBuckets -- something is broken in
 NonBlockingHashMap when removing and re-adding the same collection
 mid-iteration; it ends up with multiple references to that collection.  going
 back to ConcurrentHashMap fixes the problem.  (any additional overhead from
 CHM is negligible here.)  patch by jbellis; reviewed by Eric Evans for #57

git-svn-id: https://svn.apache.org/repos/asf/incubator/cassandra/trunk@764004 13f79535-47bb-0310-9956-ffa450edef68
---
 .../cassandra/db/ColumnFamilyStore.java       |  4 ++--
 .../cassandra/db/ColumnFamilyStoreTest.java   | 20 +++++++++++++++++--
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/org/apache/cassandra/db/ColumnFamilyStore.java b/src/org/apache/cassandra/db/ColumnFamilyStore.java
index c81a353f86..a1f286650c 100644
--- a/src/org/apache/cassandra/db/ColumnFamilyStore.java
+++ b/src/org/apache/cassandra/db/ColumnFamilyStore.java
@@ -30,6 +30,7 @@ import java.util.Set;
 import java.util.StringTokenizer;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
@@ -50,7 +51,6 @@ import org.apache.cassandra.service.IPartitioner;
 import org.apache.cassandra.utils.BloomFilter;
 import org.apache.cassandra.utils.FileUtils;
 import org.apache.cassandra.utils.LogUtil;
-import org.cliffc.high_scale_lib.NonBlockingHashMap;
 
 /**
  * Author : Avinash Lakshman ( alakshman@facebook.com) & Prashant Malik ( pmalik@facebook.com )
@@ -694,7 +694,7 @@ public class ColumnFamilyStore
      */
     static Set<List<String>> getCompactionBuckets(List<String> files, long min)
     {
-    	Map<List<String>, Long> buckets = new NonBlockingHashMap<List<String>, Long>();
+    	Map<List<String>, Long> buckets = new ConcurrentHashMap<List<String>, Long>();
     	for(String fname : files)
     	{
     		File f = new File(fname);
diff --git a/test/org/apache/cassandra/db/ColumnFamilyStoreTest.java b/test/org/apache/cassandra/db/ColumnFamilyStoreTest.java
index 652cf2b32b..5089f45ef2 100644
--- a/test/org/apache/cassandra/db/ColumnFamilyStoreTest.java
+++ b/test/org/apache/cassandra/db/ColumnFamilyStoreTest.java
@@ -15,6 +15,7 @@ import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 
 import org.apache.commons.lang.ArrayUtils;
+import org.apache.commons.lang.StringUtils;
 
 import org.apache.cassandra.ServerTest;
 import org.testng.annotations.Test;
@@ -285,8 +286,23 @@ public class ColumnFamilyStoreTest extends ServerTest
         }
 
         Set<List<String>> buckets = ColumnFamilyStore.getCompactionBuckets(all, 50);
-        assert buckets.contains(small);
-        assert buckets.contains(med);
+        assert buckets.size() == 2 : bucketString(buckets);
+        Iterator<List<String>> iter = buckets.iterator();
+        List<String> bucket1 = iter.next();
+        List<String> bucket2 = iter.next();
+        assert bucket1.size() + bucket2.size() == all.size() : bucketString(buckets) + " does not match [" + StringUtils.join(all, ", ") + "]";
+        assert buckets.contains(small) : bucketString(buckets) + " does not contain {" + StringUtils.join(small, ", ") + "}";
+        assert buckets.contains(med) : bucketString(buckets) + " does not contain {" + StringUtils.join(med, ", ") + "}";
+    }
+
+    private static String bucketString(Set<List<String>> buckets)
+    {
+        ArrayList<String> pieces = new ArrayList<String>();
+        for (List<String> bucket : buckets)
+        {
+            pieces.add("[" + StringUtils.join(bucket, ", ") + "]");
+        }
+        return "{" + StringUtils.join(pieces, ", ") + "}";
     }
 
     private String createFile(int nBytes) throws IOException