com.google.cloud.storage

Class CopyWriter

java.lang.Object

com.google.cloud.storage.CopyWriter

All Implemented Interfaces:

com.google.cloud.Restorable<CopyWriter>

Direct Known Subclasses:

HttpCopyWriter

public abstract class CopyWriter
extends Object
implements com.google.cloud.Restorable<CopyWriter>

Google Storage blob copy writer. A CopyWriter object allows to copy both blob's data and information. To override source blob's information supply a BlobInfo to the CopyRequest using either Storage.CopyRequest.Builder.setTarget(BlobInfo, Storage.BlobTargetOption...) or Storage.CopyRequest.Builder.setTarget(BlobInfo, Iterable).

This class holds the result of a copy request. If source and destination blobs share the same location and storage class the copy is completed in one RPC call otherwise one or more copyChunk() calls are necessary to complete the copy. In addition, getResult() can be used to automatically complete the copy and return information on the newly created blob.

See Also:

Rewrite

Method Summary

Modifier and Type	Method and Description
abstract com.google.cloud.RestorableState<CopyWriter>	capture()
abstract void	copyChunk() Copies the next chunk of the blob.
abstract long	getBlobSize() Returns the size of the blob being copied.
abstract Blob	getResult() Returns the updated information for the written blob.
abstract long	getTotalBytesCopied() Returns the number of bytes copied.
abstract boolean	isDone() Returns true if blob copy has finished, false otherwise.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getResult

public abstract Blob getResult()

Returns the updated information for the written blob. Calling this method when isDone() is false will block until all pending chunks are copied.

This method has the same effect of doing:

 while (!copyWriter.isDone()) {
    copyWriter.copyChunk();
 }
 

Throws:

StorageException - upon failure

getBlobSize

public abstract long getBlobSize()

Returns the size of the blob being copied.

isDone

public abstract boolean isDone()

Returns true if blob copy has finished, false otherwise.

getTotalBytesCopied

public abstract long getTotalBytesCopied()

Returns the number of bytes copied.

copyChunk

public abstract void copyChunk()

Copies the next chunk of the blob. An RPC is issued only if copy has not finished yet (isDone() returns false).

Throws:

StorageException - upon failure

capture

public abstract com.google.cloud.RestorableState<CopyWriter> capture()

Specified by:

capture in interface com.google.cloud.Restorable<CopyWriter>