fix opsArray should be initialized later

Author: Shih-Hao Yeh

evcache-core/src/main/java/com/netflix/evcache/operation/EVCacheBulkGetFuture.java

@@ -51,7 +51,6 @@ public class EVCacheBulkGetFuture<T> extends BulkGetFuture<T> {
     private static final Logger log = LoggerFactory.getLogger(EVCacheBulkGetFuture.class);
     private final Map<String, Future<T>> rvMap;
     private final Collection<Operation> ops;
-    private final Operation[] opsArray;
     private final CountDownLatch latch;
     private final long start;
     private final EVCacheClient client;
@@ -61,7 +60,6 @@ public EVCacheBulkGetFuture(Map<String, Future<T>> m, Collection<Operation> getO
         super(m, getOps, l, service);
         rvMap = m;
         ops = getOps;
-        opsArray = ops.toArray(new Operation[0]);
         latch = l;
         this.start = System.currentTimeMillis();
         this.client = client;
@@ -73,7 +71,7 @@ public Map<String, T> getSome(long to, TimeUnit unit, boolean throwException, bo
         assert operationStates != null;
 
         // Note: The latch here is counterintuitive. Based on the implementation in EVCacheMemcachedClient.asyncGetBulk(),
-        //       the latch count is set to 1 no matter the chunk size and only decrement when pendingChunks counts down to 0.
+        //       the latch count is set to 1 no matter the chunk size (when > 0) and only decrement when pendingChunks counts down to 0.
         boolean allCompleted = latch.await(to, unit);
         if(log.isDebugEnabled()) log.debug("Took " + (System.currentTimeMillis() - start)+ " to fetch " + rvMap.size() + " keys from " + client);
         long pauseDuration = -1;
@@ -130,6 +128,7 @@ public Map<String, T> getSome(long to, TimeUnit unit, boolean throwException, bo
                 if (state == null) {
                     // Operation not yet signaled completion (cancel should still trigger completion) ==> latch timed out
                     // This also indicates allCompleted == false because the latch count wouldn't have drop to 0.
+                    Operation[] opsArray = ops.toArray(new Operation[0]);
                     Operation op = opsArray[i];
                     op.timeOut();
                     MemcachedConnection.opTimedOut(op);
@@ -245,6 +244,7 @@ public void handleBulkException() {
             SingleOperationState state = operationStates.get(i);
 
             if (state == null) {
+                Operation[] opsArray = ops.toArray(new Operation[0]);
                 Operation op = opsArray[i];
                 op.timeOut();
                 MemcachedConnection.opTimedOut(op);
@@ -287,9 +287,10 @@ public Single<Map<String, T>> getSome(long to, TimeUnit units, boolean throwExce
             try {
                 for (int i = 0; i < operationStates.length(); i++) {
                     SingleOperationState state = operationStates.get(i);
-                    Operation op = opsArray[i];
 
                     if (state == null) {
+                        Operation[] opsArray = ops.toArray(new Operation[0]);
+                        Operation op = opsArray[i];
                         op.timeOut();
                         MemcachedConnection.opTimedOut(op);
                         // Should we throw when timeout?
@@ -305,7 +306,6 @@ public Single<Map<String, T>> getSome(long to, TimeUnit units, boolean throwExce
 
                 for (int i = 0; i < operationStates.length(); i++) {
                     SingleOperationState state = operationStates.get(i);
-                    Operation op = opsArray[i];
 
                     // state == null always means timed out and was handled.
                     if (state != null) {