Add support for blob rewrite

gcloud-java-examples/src/main/java/com/google/gcloud/examples/StorageExample.java

@@ -24,6 +24,7 @@
 import com.google.gcloud.storage.BlobId;
 import com.google.gcloud.storage.BlobInfo;
 import com.google.gcloud.storage.BlobReadChannel;
+import com.google.gcloud.storage.CopyWriter;
 import com.google.gcloud.storage.BlobWriteChannel;
 import com.google.gcloud.storage.Bucket;
 import com.google.gcloud.storage.BucketInfo;
@@ -366,8 +367,11 @@ public String params() {
   private static class CopyAction extends StorageAction<CopyRequest> {
     @Override
     public void run(Storage storage, CopyRequest request) {
-      BlobInfo copiedBlobInfo = storage.copy(request);
-      System.out.println("Copied " + copiedBlobInfo);
+      CopyWriter copyWriter = storage.copy(request);
+      while (!copyWriter.isDone()) {
+        copyWriter.copyChunk();
+      }
+      System.out.println("Copied " + copyWriter.result());
     }
 
     @Override

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

@@ -78,6 +78,7 @@ public class DefaultStorageRpc implements StorageRpc {
 
   // see: https://cloud.google.com/storage/docs/concepts-techniques#practices
   private static final Set<Integer> RETRYABLE_CODES = ImmutableSet.of(504, 503, 502, 500, 429, 408);
+  private static final long MEGABYTE = 1024L * 1024L;
 
   public DefaultStorageRpc(StorageOptions options) {
     HttpTransport transport = options.httpTransportFactory().create();
@@ -521,4 +522,46 @@ public String open(StorageObject object, Map<Option, ?> options)
       throw translate(ex);
     }
   }
+
+  @Override
+  public RewriteResponse openRewrite(RewriteRequest rewriteRequest) throws StorageException {
+    return rewrite(rewriteRequest, null);
+  }
+
+  @Override
+  public RewriteResponse continueRewrite(RewriteResponse previousResponse) throws StorageException {
+    return rewrite(previousResponse.rewriteRequest, previousResponse.rewriteToken);
+  }
+
+  private RewriteResponse rewrite(RewriteRequest req, String token) throws StorageException {
+    try {
+      Long maxBytesRewrittenPerCall = req.megabytesRewrittenPerCall != null
+          ? req.megabytesRewrittenPerCall * MEGABYTE : null;
+      com.google.api.services.storage.model.RewriteResponse rewriteReponse = storage.objects()
+          .rewrite(req.source.getBucket(), req.source.getName(), req.target.getBucket(),
+              req.target.getName(), req.target.getContentType() != null ? req.target : null)
+          .setRewriteToken(token)
+          .setMaxBytesRewrittenPerCall(maxBytesRewrittenPerCall)
+          .setProjection(DEFAULT_PROJECTION)
+          .setIfSourceMetagenerationMatch(IF_SOURCE_METAGENERATION_MATCH.getLong(req.sourceOptions))
+          .setIfSourceMetagenerationNotMatch(
+              IF_SOURCE_METAGENERATION_NOT_MATCH.getLong(req.sourceOptions))
+          .setIfSourceGenerationMatch(IF_SOURCE_GENERATION_MATCH.getLong(req.sourceOptions))
+          .setIfSourceGenerationNotMatch(IF_SOURCE_GENERATION_NOT_MATCH.getLong(req.sourceOptions))
+          .setIfMetagenerationMatch(IF_METAGENERATION_MATCH.getLong(req.targetOptions))
+          .setIfMetagenerationNotMatch(IF_METAGENERATION_NOT_MATCH.getLong(req.targetOptions))
+          .setIfGenerationMatch(IF_GENERATION_MATCH.getLong(req.targetOptions))
+          .setIfGenerationNotMatch(IF_GENERATION_NOT_MATCH.getLong(req.targetOptions))
+          .execute();
+      return new RewriteResponse(
+          req,
+          rewriteReponse.getResource(),
+          rewriteReponse.getObjectSize().longValue(),
+          rewriteReponse.getDone(),
+          rewriteReponse.getRewriteToken(),
+          rewriteReponse.getTotalBytesRewritten().longValue());
+    } catch (IOException ex) {
+      throw translate(ex);
+    }
+  }
 }

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

@@ -27,6 +27,7 @@
 import java.io.InputStream;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 public interface StorageRpc {
 
@@ -132,6 +133,89 @@ public BatchResponse(Map<StorageObject, Tuple<Boolean, StorageException>> delete
     }
   }
 
+  class RewriteRequest {
+
+    public final StorageObject source;
+    public final Map<StorageRpc.Option, ?> sourceOptions;
+    public final StorageObject target;
+    public final Map<StorageRpc.Option, ?> targetOptions;
+    public final Long megabytesRewrittenPerCall;
+
+    public RewriteRequest(StorageObject source, Map<StorageRpc.Option, ?> sourceOptions,
+        StorageObject target, Map<StorageRpc.Option, ?> targetOptions,
+        Long megabytesRewrittenPerCall) {
+      this.source = source;
+      this.sourceOptions = sourceOptions;
+      this.target = target;
+      this.targetOptions = targetOptions;
+      this.megabytesRewrittenPerCall = megabytesRewrittenPerCall;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+      if (obj == null) {
+        return false;
+      }
+      if (!(obj instanceof RewriteRequest)) {
+        return false;
+      }
+      final RewriteRequest other = (RewriteRequest) obj;
+      return Objects.equals(this.source, other.source)
+          && Objects.equals(this.sourceOptions, other.sourceOptions)
+          && Objects.equals(this.target, other.target)
+          && Objects.equals(this.targetOptions, other.targetOptions)
+          && Objects.equals(this.megabytesRewrittenPerCall, other.megabytesRewrittenPerCall);
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(source, sourceOptions, target, targetOptions, megabytesRewrittenPerCall);
+    }
+  }
+
+  class RewriteResponse {
+
+    public final RewriteRequest rewriteRequest;
+    public final StorageObject result;
+    public final Long blobSize;
+    public final Boolean isDone;
+    public final String rewriteToken;
+    public final Long totalBytesRewritten;
+
+    public RewriteResponse(RewriteRequest rewriteRequest, StorageObject result, Long blobSize,
+        Boolean isDone, String rewriteToken, Long totalBytesRewritten) {
+      this.rewriteRequest = rewriteRequest;
+      this.result = result;
+      this.blobSize = blobSize;
+      this.isDone = isDone;
+      this.rewriteToken = rewriteToken;
+      this.totalBytesRewritten = totalBytesRewritten;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+      if (obj == null) {
+        return false;
+      }
+      if (!(obj instanceof RewriteResponse)) {
+        return false;
+      }
+      final RewriteResponse other = (RewriteResponse) obj;
+      return Objects.equals(this.rewriteRequest, other.rewriteRequest)
+          && Objects.equals(this.result, other.result)
+          && Objects.equals(this.rewriteToken, other.rewriteToken)
+          && Objects.equals(this.blobSize, other.blobSize)
+          && Objects.equals(this.isDone, other.isDone)
+          && Objects.equals(this.totalBytesRewritten, other.totalBytesRewritten);
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(rewriteRequest, result, blobSize, isDone, rewriteToken,
+          totalBytesRewritten);
+    }
+  }
+
   Bucket create(Bucket bucket, Map<Option, ?> options) throws StorageException;
 
   StorageObject create(StorageObject object, InputStream content, Map<Option, ?> options)
@@ -174,4 +258,8 @@ byte[] read(StorageObject from, Map<Option, ?> options, long position, int bytes
 
   void write(String uploadId, byte[] toWrite, int toWriteOffset, StorageObject dest,
       long destOffset, int length, boolean last) throws StorageException;
+
+  RewriteResponse openRewrite(RewriteRequest rewriteRequest) throws StorageException;
+
+  RewriteResponse continueRewrite(RewriteResponse previousResponse) throws StorageException;
 }

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

@@ -213,19 +213,20 @@ public Blob update(BlobInfo blobInfo, BlobTargetOption... options) {
   }
 
   /**
-   * Copies this blob to the specified target. Possibly copying also some of the metadata
-   * (e.g. content-type).
+   * Sends a copy request for the current blob to the target blob. Possibly also some of the
+   * metadata are copied (e.g. content-type).
    *
    * @param targetBlob target blob's id
    * @param options source blob options
-   * @return the copied blob
+   * @return a {@link CopyWriter} object that can be used to get information on the newly created
+   *     blob or to complete the copy if more than one RPC request is needed
    * @throws StorageException upon failure
    */
-  public Blob copyTo(BlobId targetBlob, BlobSourceOption... options) {
+  public CopyWriter copyTo(BlobId targetBlob, BlobSourceOption... options) {
     BlobInfo updatedInfo = info.toBuilder().blobId(targetBlob).build();
     CopyRequest copyRequest = CopyRequest.builder().source(info.bucket(), info.name())
         .sourceOptions(convert(info, options)).target(updatedInfo).build();
-    return new Blob(storage, storage.copy(copyRequest));
+    return storage.copy(copyRequest);
   }
 
   /**
@@ -240,33 +241,35 @@ public boolean delete(BlobSourceOption... options) {
   }
 
   /**
-   * Copies this blob to the target bucket, preserving its name. Possibly copying also some of the
-   * metadata (e.g. content-type).
+   * Sends a copy request for the current blob to the target bucket, preserving its name. Possibly
+   * copying also some of the metadata (e.g. content-type).
    *
    * @param targetBucket target bucket's name
    * @param options source blob options
-   * @return the copied blob
+   * @return a {@link CopyWriter} object that can be used to get information on the newly created
+   *     blob or to complete the copy if more than one RPC request is needed
    * @throws StorageException upon failure
    */
-  public Blob copyTo(String targetBucket, BlobSourceOption... options) {
+  public CopyWriter copyTo(String targetBucket, BlobSourceOption... options) {
     return copyTo(targetBucket, info.name(), options);
   }
 
   /**
-   * Copies this blob to the target bucket with a new name. Possibly copying also some of the
-   * metadata (e.g. content-type).
+   * Sends a copy request for the current blob to the target blob. Possibly also some of the
+   * metadata are copied (e.g. content-type).
    *
    * @param targetBucket target bucket's name
    * @param targetBlob target blob's name
    * @param options source blob options
-   * @return the copied blob
+   * @return a {@link CopyWriter} object that can be used to get information on the newly created
+   *     blob or to complete the copy if more than one RPC request is needed
    * @throws StorageException upon failure
    */
-  public Blob copyTo(String targetBucket, String targetBlob, BlobSourceOption... options) {
+  public CopyWriter copyTo(String targetBucket, String targetBlob, BlobSourceOption... options) {
     BlobInfo updatedInfo = info.toBuilder().blobId(BlobId.of(targetBucket, targetBlob)).build();
     CopyRequest copyRequest = CopyRequest.builder().source(info.bucket(), info.name())
         .sourceOptions(convert(info, options)).target(updatedInfo).build();
-    return new Blob(storage, storage.copy(copyRequest));
+    return storage.copy(copyRequest);
   }
 
   /**