com.google.cloud.hadoop.gcsio

Class BatchHelper

java.lang.Object

com.google.cloud.hadoop.gcsio.BatchHelper

public class BatchHelper
extends Object

BatchHelper abstracts out the logic for maximum requests per batch, and also allows a workaround for the fact that BatchRequest was made a "final class" for some reason, making it impossible to unittest. Instead, batch interactions with a Storage API client will be funneled through this class, while unittests can inject a mock batch helper.

This class is thread-safe, because if numThreads is greater than 0, request callbacks will be executed on a different thread(s) than a client thread that queues requests.

Expected usage is to create a new BatchHelper instance per client operation (copy, rename, delete, etc.) that represent logical grouping of requests.

Instance of this class can not be used again after flush() method call.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BatchHelper.Factory Since each BatchHelper instance should be tied to a particular related set of requests, use cases will generally interact via an injectable BatchHelper.Factory.
protected static interface	BatchHelper.QueueRequestCallback Callback that causes a single StorageRequest to be added to the BatchRequest.

Method Summary

Modifier and Type	Method and Description
void	flush() Sends any currently remaining requests in the batch; should be called at the end of any series of batched requests to ensure everything has been sent.
boolean	isEmpty() Returns true if there are no currently queued entries in the batch helper.
<T> void	queue(com.google.api.services.storage.StorageRequest<T> req, com.google.api.client.googleapis.batch.json.JsonBatchCallback<T> callback) Adds an additional request to the batch, and possibly flushes the current contents of the batch if maxRequestsPerBatch has been reached.

Methods inherited from class java.lang.Object

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

Method Detail

queue

public <T> void queue(com.google.api.services.storage.StorageRequest<T> req,
                      com.google.api.client.googleapis.batch.json.JsonBatchCallback<T> callback)
               throws IOException

Adds an additional request to the batch, and possibly flushes the current contents of the batch if maxRequestsPerBatch has been reached.

Throws:

IOException

flush

public void flush()
           throws IOException

Sends any currently remaining requests in the batch; should be called at the end of any series of batched requests to ensure everything has been sent.

Throws:

IOException

isEmpty

public boolean isEmpty()

Returns true if there are no currently queued entries in the batch helper.