From dd8e9e293093ef73b6cbd20afe3f09765b9bec59 Mon Sep 17 00:00:00 2001
From: fjy <fangjin@metamarkets.com>
Date: Tue, 8 Apr 2014 16:23:24 -0700
Subject: [PATCH] fix concurrent modification exceptions in local cache

---
 .../java/io/druid/client/cache/MapCache.java     | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/server/src/main/java/io/druid/client/cache/MapCache.java b/server/src/main/java/io/druid/client/cache/MapCache.java
index fd03fac61d7..5221fd0ca91 100644
--- a/server/src/main/java/io/druid/client/cache/MapCache.java
+++ b/server/src/main/java/io/druid/client/cache/MapCache.java
@@ -77,7 +77,10 @@ public class MapCache implements Cache
   @Override
   public byte[] get(NamedKey key)
   {
-    final byte[] retVal = baseMap.get(computeKey(getNamespaceId(key.namespace), key.key));
+    final byte[] retVal;
+    synchronized (clearLock) {
+      retVal = baseMap.get(computeKey(getNamespaceId(key.namespace), key.key));
+    }
     if (retVal == null) {
       missCount.incrementAndGet();
     } else {
@@ -90,7 +93,7 @@ public class MapCache implements Cache
   public void put(NamedKey key, byte[] value)
   {
     synchronized (clearLock) {
-        baseMap.put(computeKey(getNamespaceId(key.namespace), key.key), value);
+      baseMap.put(computeKey(getNamespaceId(key.namespace), key.key), value);
     }
   }
 
@@ -98,7 +101,7 @@ public class MapCache implements Cache
   public Map<NamedKey, byte[]> getBulk(Iterable<NamedKey> keys)
   {
     Map<NamedKey, byte[]> retVal = Maps.newHashMap();
-    for(NamedKey key : keys) {
+    for (NamedKey key : keys) {
       retVal.put(key, get(key));
     }
     return retVal;
@@ -110,7 +113,9 @@ public class MapCache implements Cache
     byte[] idBytes;
     synchronized (namespaceId) {
       idBytes = getNamespaceId(namespace);
-      if(idBytes == null) return;
+      if (idBytes == null) {
+        return;
+      }
 
       namespaceId.remove(namespace);
     }
@@ -150,7 +155,8 @@ public class MapCache implements Cache
     return retVal;
   }
 
-  public boolean isLocal() {
+  public boolean isLocal()
+  {
     return true;
   }
 }