Package 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
    @InternalApi("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();
   }
 }