BundleExecutor.java

/*
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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package com.google.api.gax.grpc;

import com.google.api.gax.bundling.ThresholdBundleReceiver;
import com.google.common.base.Preconditions;

import java.util.ArrayList;
import java.util.List;

/**
 * A bundle receiver which uses a provided bundling descriptor to merge the items from the bundle
 * into a single request, invoke the callable from the bundling context to issue the request, split
 * the bundle response into the components matching each incoming request, and finally send the
 * result back to the listener for each request.
 *
 * <p>Package-private for internal use.
 */
class BundleExecutor<RequestT, ResponseT>
    implements ThresholdBundleReceiver<BundlingContext<RequestT, ResponseT>> {

  private final BundlingDescriptor<RequestT, ResponseT> bundlingDescriptor;
  private final String partitionKey;

  public BundleExecutor(
      BundlingDescriptor<RequestT, ResponseT> bundlingDescriptor, String partitionKey) {
    this.bundlingDescriptor = Preconditions.checkNotNull(bundlingDescriptor);
    this.partitionKey = Preconditions.checkNotNull(partitionKey);
  }

  @Override
  public void validateItem(BundlingContext<RequestT, ResponseT> item) {
    String itemPartitionKey = bundlingDescriptor.getBundlePartitionKey(item.getRequest());
    if (!itemPartitionKey.equals(partitionKey)) {
      String requestClassName = item.getRequest().getClass().getSimpleName();
      throw new IllegalArgumentException(
          String.format(
              "For type %s, invalid partition key: %s, should be: %s",
              requestClassName,
              itemPartitionKey,
              partitionKey));
    }
  }

  @Override
  public void processBundle(List<BundlingContext<RequestT, ResponseT>> bundle) {
    List<RequestT> requests = new ArrayList<>(bundle.size());
    for (BundlingContext<RequestT, ResponseT> message : bundle) {
      requests.add(message.getRequest());
    }
    RequestT bundleRequest = bundlingDescriptor.mergeRequests(requests);
    UnaryCallable<RequestT, ResponseT> callable = bundle.get(0).getCallable();

    try {
      ResponseT bundleResponse = callable.call(bundleRequest);
      bundlingDescriptor.splitResponse(bundleResponse, bundle);
    } catch (Throwable exception) {
      bundlingDescriptor.splitException(exception, bundle);
    }

    for (BundlingContext<RequestT, ResponseT> message : bundle) {
      message.sendResult();
    }
  }
}