Add batch get, update, delete methods to Storage and Blob

gcloud-java-storage/src/main/java/com/google/gcloud/spi/StorageRpc.java

@@ -16,6 +16,8 @@
 
 package com.google.gcloud.spi;
 
+import static com.google.common.base.MoreObjects.firstNonNull;
+
 import com.google.api.services.storage.model.Bucket;
 import com.google.api.services.storage.model.StorageObject;
 import com.google.common.collect.ImmutableList;
@@ -106,9 +108,12 @@ class BatchRequest {
     public BatchRequest(Iterable<Tuple<StorageObject, Map<Option, ?>>> toDelete,
         Iterable<Tuple<StorageObject, Map<Option, ?>>> toUpdate,
         Iterable<Tuple<StorageObject, Map<Option, ?>>> toGet) {
-      this.toDelete = ImmutableList.copyOf(toDelete);
-      this.toUpdate = ImmutableList.copyOf(toUpdate);
-      this.toGet = ImmutableList.copyOf(toGet);
+      this.toDelete = ImmutableList.copyOf(
+          firstNonNull(toDelete, ImmutableList.<Tuple<StorageObject, Map<Option, ?>>>of()));
+      this.toUpdate = ImmutableList.copyOf(
+          firstNonNull(toUpdate, ImmutableList.<Tuple<StorageObject, Map<Option, ?>>>of()));
+      this.toGet = ImmutableList.copyOf(
+          firstNonNull(toGet, ImmutableList.<Tuple<StorageObject, Map<Option, ?>>>of()));
     }
   }
 

gcloud-java-storage/src/main/java/com/google/gcloud/storage/Blob.java

@@ -20,12 +20,17 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.gcloud.storage.Blob.BlobSourceOption.convert;
 
+import com.google.common.base.Function;
+import com.google.common.collect.Lists;
 import com.google.gcloud.spi.StorageRpc;
 import com.google.gcloud.storage.Storage.BlobTargetOption;
 import com.google.gcloud.storage.Storage.CopyRequest;
 import com.google.gcloud.storage.Storage.SignUrlOption;
 
 import java.net.URL;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
 import java.util.Objects;
 
 /**
@@ -256,4 +261,87 @@ public URL signUrl(long expirationTimeInSeconds, SignUrlOption... options) {
   public Storage storage() {
     return storage;
   }
+
+  /**
+   * Gets the requested blobs. If {@code infos.length == 0} an empty list is returned. If
+   * {@code infos.length > 1} a batch request is used to fetch blobs.
+   *
+   * @param storage the storage service used to issue the request
+   * @param infos the blobs to get
+   * @return an immutable list of {@code Blob} objects. If a blob does not exist or access to it has
+   * been denied the corresponding item in the list is {@code null}.
+   */
+  public static List<Blob> get(final Storage storage, BlobInfo... infos) {
+    checkNotNull(storage);
+    checkNotNull(infos);
+    int length = infos.length;
+    switch (length) {
+      case 0:
+        return Collections.emptyList();
+      case 1:
+        return Collections.singletonList(
+            new Blob(storage, storage.get(infos[0].bucket(), infos[0].name())));
+      default:
+        return Collections.unmodifiableList(Lists.transform(storage.get(infos),
+            new Function<BlobInfo, Blob>() {
+              @Override
+              public Blob apply(BlobInfo f) {
+                return f != null ? new Blob(storage, f) : null;
+              }
+            }));
+    }
+  }
+
+  /**
+   * Updates the requested blobs. If {@code infos.length == 0} an empty list is returned. If
+   * {@code infos.length > 1} a batch request is used to update blobs.
+   *
+   * @param storage the storage service used to issue the request
+   * @param infos the blobs to update
+   * @return an immutable list of {@code Blob} objects. If a blob does not exist or access to it has
+   * been denied the corresponding item in the list is {@code null}.
+   */
+  public static List<Blob> update(final Storage storage, BlobInfo... infos) {
+    checkNotNull(storage);
+    checkNotNull(infos);
+    int length = infos.length;
+    switch (length) {
+      case 0:
+        return Collections.emptyList();
+      case 1:
+        return Collections.singletonList(new Blob(storage, storage.update(infos[0])));
+      default:
+        return Collections.unmodifiableList(Lists.transform(storage.update(infos),
+            new Function<BlobInfo, Blob>() {
+              @Override
+              public Blob apply(BlobInfo f) {
+                return f != null ? new Blob(storage, f) : null;
+              }
+            }));
+    }
+  }
+
+  /**
+   * Deletes the requested blobs. If {@code infos.length == 0} an empty list is returned. If
+   * {@code infos.length > 1} a batch request is used to delete blobs.
+   *
+   * @param storage the storage service used to issue the request
+   * @param infos the blobs to delete
+   * @return an immutable list of booleans. If a blob has been deleted the corresponding item in the
+   * list is {@code true}. If deletion failed or access to the resource was denied the item is
+   * {@code false}.
+   */
+  public static List<Boolean> delete(Storage storage, BlobInfo... infos) {
+    checkNotNull(storage);
+    checkNotNull(infos);
+    int length = infos.length;
+    switch (length) {
+      case 0:
+        return Collections.emptyList();
+      case 1:
+        return Collections.singletonList(storage.delete(infos[0].bucket(), infos[0].name()));
+      default:
+        return Collections.unmodifiableList(storage.delete(infos));
+    }
+  }
 }

gcloud-java-storage/src/main/java/com/google/gcloud/storage/Bucket.java

@@ -25,6 +25,7 @@
 import com.google.gcloud.storage.Storage.BucketTargetOption;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 
@@ -146,21 +147,26 @@ public Blob get(String blob, BlobSourceOption... options) {
   /**
    * Returns a list of requested blobs in this bucket. Blobs that do not exist are null.
    * 
-   * @param blobNames names of the requested blobs
+   * @param blobName1 first blob to get
+   * @param blobName2 second blob to get
+   * @param blobNames other blobs to get
+   * @return an immutable list of {@code Blob} objects.
    * @throws StorageException upon failure
    */
-  public List<Blob> getAll(String... blobNames) {
+  public List<Blob> get(String blobName1, String blobName2, String... blobNames) {
     BatchRequest.Builder batch = BatchRequest.builder();
-    for (String blobName : blobNames) {
-      batch.get(info.name(), blobName);
+    batch.get(info.name(), blobName1);
+    batch.get(info.name(), blobName2);
+    for (String name : blobNames) {
+      batch.get(info.name(), name);
     }
     List<Blob> blobs = new ArrayList<>(blobNames.length);
     BatchResponse response = storage.apply(batch.build());
     for (BatchResponse.Result<BlobInfo> result : response.gets()) {
       BlobInfo blobInfo = result.get();
       blobs.add(blobInfo != null ? new Blob(storage, blobInfo) : null);
     }
-    return blobs;
+    return Collections.unmodifiableList(blobs);
   }
 
   /**

gcloud-java-storage/src/main/java/com/google/gcloud/storage/Storage.java

@@ -563,6 +563,14 @@ public static Builder builder() {
    */
   BlobInfo update(BlobInfo blobInfo, BlobTargetOption... options);
 
+  /**
+   * Update blob information.
+   *
+   * @return the updated blob
+   * @throws StorageException upon failure
+   */
+  BlobInfo update(BlobInfo blobInfo);
+
   /**
    * Delete the requested bucket.
    *
@@ -638,4 +646,32 @@ public static Builder builder() {
    * @see <a href="https://cloud.google.com/storage/docs/access-control#Signed-URLs">Signed-URLs</a>
    */
   URL signUrl(BlobInfo blobInfo, long expirationTimeInSeconds, SignUrlOption... options);
+
+  /**
+   * Gets the requested blobs. A batch request is used to perform this call.
+   *
+   * @param blobInfos blobs to get
+   * @return an immutable list of {@code BlobInfo} objects. If a blob does not exist or access to it
+   * has been denied the corresponding item in the list is {@code null}.
+   */
+  List<BlobInfo> get(BlobInfo... blobInfos);
+
+  /**
+   * Updates the requested blobs. A batch request is used to perform this call.
+   *
+   * @param blobInfos blobs to update
+   * @return an immutable list of {@code BlobInfo} objects. If a blob does not exist or access to it
+   * has been denied the corresponding item in the list is {@code null}.
+   */
+  List<BlobInfo> update(BlobInfo... blobInfos);
+
+  /**
+   * Deletes the requested blobs. A batch request is used to perform this call.
+   *
+   * @param blobInfos blobs to delete
+   * @return an immutable list of booleans. If a blob has been deleted the corresponding item in the
+   * list is {@code true}. If deletion failed or access to the resource was denied the item is
+   * {@code false}.
+   */
+  List<Boolean> delete(BlobInfo... blobInfos);
 }

gcloud-java-storage/src/main/java/com/google/gcloud/storage/StorageImpl.java

@@ -62,6 +62,7 @@
 import java.security.Signature;
 import java.security.SignatureException;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.EnumMap;
 import java.util.List;
 import java.util.Map;
@@ -348,6 +349,11 @@ public StorageObject call() {
     }
   }
 
+  @Override
+  public BlobInfo update(BlobInfo blobInfo) {
+    return update(blobInfo, new BlobTargetOption[0]);
+  }
+
   @Override
   public boolean delete(String bucket, BucketSourceOption... options) {
     final com.google.api.services.storage.model.Bucket bucketPb = BucketInfo.of(bucket).toPb();
@@ -577,6 +583,46 @@ public URL signUrl(BlobInfo blobInfo, long expiration, SignUrlOption... options)
     }
   }
 
+  @Override
+  public List<BlobInfo> get(BlobInfo... blobInfos) {
+    BatchRequest.Builder requestBuilder = BatchRequest.builder();
+    for (BlobInfo blobInfo : blobInfos) {
+      requestBuilder.get(blobInfo.bucket(), blobInfo.name());
+    }
+    BatchResponse response = apply(requestBuilder.build());
+    return Collections.unmodifiableList(transformResultList(response.gets(), null));
+  }
+
+  @Override
+  public List<BlobInfo> update(BlobInfo... blobInfos) {
+    BatchRequest.Builder requestBuilder = BatchRequest.builder();
+    for (BlobInfo blobInfo : blobInfos) {
+      requestBuilder.update(blobInfo);
+    }
+    BatchResponse response = apply(requestBuilder.build());
+    return Collections.unmodifiableList(transformResultList(response.updates(), null));
+  }
+
+  @Override
+  public List<Boolean> delete(BlobInfo... blobInfos) {
+    BatchRequest.Builder requestBuilder = BatchRequest.builder();
+    for (BlobInfo blobInfo : blobInfos) {
+      requestBuilder.delete(blobInfo.bucket(), blobInfo.name());
+    }
+    BatchResponse response = apply(requestBuilder.build());
+    return Collections.unmodifiableList(transformResultList(response.deletes(), Boolean.FALSE));
+  }
+
+  private static <T extends Serializable> List<T> transformResultList(
+      List<BatchResponse.Result<T>> results, final T errorValue) {
+    return Lists.transform(results, new Function<BatchResponse.Result<T>, T>() {
+      @Override
+      public T apply(BatchResponse.Result<T> f) {
+        return f.failed() ? errorValue : f.get();
+      }
+    });
+  }
+
   private Map<StorageRpc.Option, ?> optionMap(Long generation, Long metaGeneration,
       Iterable<? extends Option> options) {
     return optionMap(generation, metaGeneration, options, false);