com.google.api.gax.batching

Interface BatchingDescriptor<ElementT,ElementResultT,RequestT,ResponseT>

Type Parameters:

ElementT - The type of each individual element to be batched

ElementResultT - The type of the result for each individual element

RequestT - The type of the request that will contain the accumulated elements

ResponseT - The type of the response that will be unpacked into individual element results

@BetaApi(value="The surface for batching is not stable yet and may change in the future.")
 @InternalApi(value="For google-cloud-java client use only.")
public interface BatchingDescriptor<ElementT,ElementResultT,RequestT,ResponseT>

An adapter that packs and unpacks the elements in and out of batch requests and responses.

This interface should be implemented by either a service specific client or autogenerated by gapic-generator.

Example implementation:

 class ListDescriptor implements BatchingDescriptor<String, String, List<String>, List<String>> {

   RequestBuilder<String, List<String>> newRequestBuilder(List<String> prototype) {
     return new RequestBuilder<String, List<String>>() {

       void add(String element) {
         list.add(element);
       }

       List<String> build() {
         return list.clone();
       }
     };
   }

   void splitResponse(List<String> callableResponse, List<SettableApiFuture<String>> batch) {
     for (int i = 0; i < batchResponse.size(); i++) {
       batch.get(i).set(batchResponse.get(i);
     }
   }

   void splitException(Throwable throwable, List<SettableApiFuture<String>> batch) {
     for (SettableApiFuture<String> result : batch) {
       result.setException(throwable);
     }
   }

   long countBytes(String element) {
     return element.length();
   }
 }
 

Method Summary

Modifier and Type	Method and Description
long	countBytes(ElementT element) Returns the size of the passed element object in bytes.
BatchingRequestBuilder<ElementT,RequestT>	newRequestBuilder(RequestT prototype) Creates a new wrapper for the underlying request builder.
void	splitException(Throwable throwable, List<BatchEntry<ElementT,ElementResultT>> batch) Unpacks the batch response error into individual element errors.
void	splitResponse(ResponseT batchResponse, List<BatchEntry<ElementT,ElementResultT>> batch) Unpacks the batch response into individual elements results.

Method Detail

newRequestBuilder

BatchingRequestBuilder<ElementT,RequestT> newRequestBuilder(RequestT prototype)

Creates a new wrapper for the underlying request builder. It's used to pack the current batch request with elements.

splitResponse

void splitResponse(ResponseT batchResponse,
                   List<BatchEntry<ElementT,ElementResultT>> batch)

Unpacks the batch response into individual elements results.

splitException

void splitException(Throwable throwable,
                    List<BatchEntry<ElementT,ElementResultT>> batch)

Unpacks the batch response error into individual element errors.

countBytes

long countBytes(ElementT element)

Returns the size of the passed element object in bytes.