JCLOUDS-1543: change FetchBlobMetadata to retain original blob order

blobstore/src/main/java/org/jclouds/blobstore/strategy/internal/FetchBlobMetadata.java

@@ -19,6 +19,9 @@ package org.jclouds.blobstore.strategy.internal;
 import static com.google.common.base.Preconditions.checkState;
 import static org.jclouds.concurrent.FutureIterables.transformParallel;
 
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
 import java.util.concurrent.Callable;
 
 import javax.annotation.Resource;
@@ -79,6 +82,15 @@ public class FetchBlobMetadata implements Function<PageSet<? extends StorageMeta
    public PageSet<? extends StorageMetadata> apply(PageSet<? extends StorageMetadata> in) {
       checkState(container != null, "container name should be initialized");
 
+      if (in == null) {
+         return new PageSetImpl<>(Collections.<StorageMetadata>emptyList(), null);
+      }
+
+      Map<String, StorageMetadata> orderedMap = new LinkedHashMap<>(in.size());
+      for (StorageMetadata storageMetadata : in) {
+         orderedMap.put(storageMetadata.getName(), null);
+      }
+
       Iterable<StorageMetadata> returnv = Lists.newArrayList(transformParallel(in,
           new Function<StorageMetadata, ListenableFuture<? extends StorageMetadata>>() {
 
@@ -88,7 +100,7 @@ public class FetchBlobMetadata implements Function<PageSet<? extends StorageMeta
                return Futures.immediateFuture(from);
             }
             return userExecutor.submit(new Callable<StorageMetadata>() {
-               @Override public StorageMetadata call() throws Exception {
+               @Override public StorageMetadata call() {
                   return blobstore.blobMetadata(container, from.getName());
                }
             });
@@ -96,6 +108,10 @@ public class FetchBlobMetadata implements Function<PageSet<? extends StorageMeta
 
       }, userExecutor, maxTime, logger, String.format("getting metadata from containerName: %s", container)));
 
-      return new PageSetImpl<StorageMetadata>(returnv, in.getNextMarker());
+      for (StorageMetadata storageMetadata : returnv) {
+         orderedMap.put(storageMetadata.getName(), storageMetadata);
+      }
+
+      return new PageSetImpl<>(orderedMap.values(), in.getNextMarker());
    }
 }

blobstore/src/test/java/org/jclouds/blobstore/strategy/internal/FetchBlobMetadataTest.java

@@ -0,0 +1,82 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jclouds.blobstore.strategy.internal;
+
+import com.google.common.collect.Maps;
+import com.google.common.collect.Ordering;
+import com.google.inject.Injector;
+import org.jclouds.ContextBuilder;
+import org.jclouds.blobstore.BlobStore;
+import org.jclouds.blobstore.domain.Blob;
+import org.jclouds.blobstore.domain.PageSet;
+import org.jclouds.blobstore.domain.StorageMetadata;
+import org.jclouds.blobstore.options.ListContainerOptions;
+import org.jclouds.util.Closeables2;
+import org.testng.annotations.AfterClass;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+import java.util.Comparator;
+import java.util.Map;
+
+import static org.testng.Assert.assertNotNull;
+import static org.testng.Assert.assertTrue;
+
+@Test(testName = "FetchBlobMetadataTest", singleThreaded = true)
+public class FetchBlobMetadataTest {
+
+   private static final String CONTAINER_NAME = "container";
+
+   private BlobStore blobStore;
+   private FetchBlobMetadata fetchBlobMetadata;
+
+   @BeforeClass
+   public void setupBlobStore() {
+      Injector injector = ContextBuilder.newBuilder("transient").buildInjector();
+      blobStore = injector.getInstance(BlobStore.class);
+      fetchBlobMetadata = injector.getInstance(FetchBlobMetadata.class);
+      fetchBlobMetadata.setContainerName(CONTAINER_NAME);
+   }
+
+   @AfterClass
+   public void closeBlobSore() {
+      if (blobStore != null) {
+         Closeables2.closeQuietly(blobStore.getContext());
+      }
+   }
+
+   @Test
+   public void testRetainsOriginalOrder() {
+      blobStore.createContainerInLocation(null, CONTAINER_NAME);
+      for (int blobIndex = 0; blobIndex < 20; blobIndex++) {
+         final Blob blob = blobStore.blobBuilder("prefix-" + blobIndex).payload("").build();
+         blobStore.putBlob(CONTAINER_NAME, blob);
+      }
+
+      final PageSet<? extends StorageMetadata> pageSet =
+              blobStore.list(CONTAINER_NAME, ListContainerOptions.Builder.withDetails());
+      final PageSet<? extends StorageMetadata> resultPageSet = fetchBlobMetadata.apply(pageSet);
+      assertNotNull(resultPageSet);
+
+      assertTrue(Ordering.from(new Comparator<StorageMetadata>() {
+         @Override
+         public int compare(StorageMetadata o1, StorageMetadata o2) {
+            return o1.getName().compareTo(o2.getName());
+         }
+      }).isOrdered(resultPageSet));
+   }
+}