Package com.google.cloud.storage

Interface BlobAppendableUpload.AppendableUploadWriteableByteChannel

All Superinterfaces:

AutoCloseable, Channel, Closeable, WritableByteChannel

Enclosing interface:

BlobAppendableUpload

@BetaApi
@InternalExtensionOnly
public static interface BlobAppendableUpload.AppendableUploadWriteableByteChannel
extends WritableByteChannel

The WritableByteChannel returned from BlobAppendableUpload.open().

This interface allows writing bytes to an Appendable Upload, and provides methods to close this channel -- optionally finalizing the upload.

The write(ByteBuffer) method of this channel is non-blocking.

Since:

2.51.0 This new api is in preview and is subject to breaking changes.

Method Summary

Modifier and Type	Method	Description
void	close()	This method is blocking
void	closeWithoutFinalizing()	This method is blocking
void	finalizeAndClose()	This method is blocking
void	flush()	This method is blocking
int	write(ByteBuffer src)	This method is non-blocking

Methods inherited from interface java.nio.channels.Channel

isOpen

Method Details

write

int write(ByteBuffer src)
   throws IOException

This method is non-blocking

Consume as many bytes as can fit in the underlying outbound queue. The size of the outbound queue is determined from BlobAppendableUploadConfig.getFlushPolicy() .getMaxPendingBytes(). If the outbound queue is full, and can not fit more bytes, this method will return 0.

If your application needs to empty its ByteBuffer before progressing, use our helper method StorageChannelUtils.blockingEmptyTo(ByteBuffer, WritableByteChannel) like so:

 try (AppendableUploadWriteableByteChannel channel = session.open()) {
   int written = StorageChannelUtils.blockingEmptyTo(byteBuffer, channel);
 }
 

Specified by:

write in interface WritableByteChannel

Parameters:

src - The buffer from which bytes are to be retrieved

Returns:

The number of bytes written, possibly zero

Throws:

ClosedChannelException - If this channel is closed

IOException - If some other I/O error occurs

flush

@BetaApi
void flush()
    throws IOException

This method is blocking

Block the invoking thread, waiting until the number of bytes written so far has been acknowledged by Google Cloud Storage.

Throws:

IOException - if an error happens while waiting for the flush to complete

InterruptedIOException - if the current thread is interrupted while waiting

Since:

2.56.0 This new api is in preview and is subject to breaking changes.

finalizeAndClose

@BetaApi
void finalizeAndClose()
               throws IOException

This method is blocking

Finalize the upload and close this instance to further write(ByteBuffer)ing. This will close any underlying stream and release any releasable resources once out of scope.

Once this method is called, and returns no more writes to the object will be allowed by GCS.

This method and close() are mutually exclusive. If one of the other methods are called before this method, this method will be a no-op.

Throws:

IOException

Since:

2.51.0 This new api is in preview and is subject to breaking changes.

See Also:

• Storage.blobAppendableUpload(BlobInfo, BlobAppendableUploadConfig, BlobWriteOption...)
• BlobAppendableUploadConfig.CloseAction.FINALIZE_WHEN_CLOSING
• BlobAppendableUploadConfig.getCloseAction()
• BlobAppendableUploadConfig.withCloseAction(CloseAction)

closeWithoutFinalizing

@BetaApi
void closeWithoutFinalizing()
                     throws IOException

This method is blocking

Close this instance to further write(ByteBuffer)ing without finalizing the upload. This will close any underlying stream and release any releasable resources once out of scope.

This method, finalizeAndClose() and close() are mutually exclusive. If one of the other methods are called before this method, this method will be a no-op.

Throws:

IOException

Since:

2.51.0 This new api is in preview and is subject to breaking changes.

See Also:

• Storage.blobAppendableUpload(BlobInfo, BlobAppendableUploadConfig, BlobWriteOption...)
• BlobAppendableUploadConfig.CloseAction.CLOSE_WITHOUT_FINALIZING
• BlobAppendableUploadConfig.getCloseAction()
• BlobAppendableUploadConfig.withCloseAction(CloseAction)

close

@BetaApi
void close()
    throws IOException

This method is blocking

Close this instance to further write(ByteBuffer)ing.

Whether the upload is finalized during this depends on the BlobAppendableUploadConfig.getCloseAction() provided to create the BlobAppendableUpload. If BlobAppendableUploadConfig.getCloseAction()== BlobAppendableUploadConfig.CloseAction.FINALIZE_WHEN_CLOSING, finalizeAndClose() will be called. If BlobAppendableUploadConfig.getCloseAction()== BlobAppendableUploadConfig.CloseAction.CLOSE_WITHOUT_FINALIZING, closeWithoutFinalizing() will be called.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Specified by:

close in interface Closeable

Throws:

IOException

Since:

2.51.0 This new api is in preview and is subject to breaking changes.

See Also:

• Storage.blobAppendableUpload(BlobInfo, BlobAppendableUploadConfig, BlobWriteOption...)
• BlobAppendableUploadConfig.getCloseAction()
• BlobAppendableUploadConfig.withCloseAction(CloseAction)