HttpJsonCallableFactory.java

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

import com.google.api.core.BetaApi;
import com.google.api.core.InternalApi;
import com.google.api.gax.longrunning.OperationSnapshot;
import com.google.api.gax.rpc.BatchingCallSettings;
import com.google.api.gax.rpc.Callables;
import com.google.api.gax.rpc.ClientContext;
import com.google.api.gax.rpc.LongRunningClient;
import com.google.api.gax.rpc.OperationCallSettings;
import com.google.api.gax.rpc.OperationCallable;
import com.google.api.gax.rpc.PagedCallSettings;
import com.google.api.gax.rpc.UnaryCallSettings;
import com.google.api.gax.rpc.UnaryCallable;
import com.google.api.gax.tracing.SpanName;
import com.google.api.gax.tracing.TracedUnaryCallable;
import com.google.common.base.Preconditions;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.annotation.Nonnull;

/** Class with utility methods to create http/json-based direct callables. */
@BetaApi
public class HttpJsonCallableFactory {
  // Used to extract service and method name from a grpc MethodDescriptor.
  // fullMethodName has the format: service.resource.action
  // For example: compute.instances.addAccessConfig
  private static final Pattern FULL_METHOD_NAME_REGEX = Pattern.compile("^(.+)\\.(.+)$");

  private HttpJsonCallableFactory() {}

  private static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createDirectUnaryCallable(
      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings) {
    return new HttpJsonDirectCallable<RequestT, ResponseT>(
        httpJsonCallSettings.getMethodDescriptor(), httpJsonCallSettings.getTypeRegistry());
  }

  static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
      UnaryCallable<RequestT, ResponseT> innerCallable,
      UnaryCallSettings<?, ?> callSettings,
      ClientContext clientContext) {
    UnaryCallable<RequestT, ResponseT> callable =
        new HttpJsonExceptionCallable<>(innerCallable, callSettings.getRetryableCodes());
    callable = Callables.retrying(callable, callSettings, clientContext);
    return callable.withDefaultCallContext(clientContext.getDefaultCallContext());
  }

  /**
   * Create a Unary callable object with minimal http/json-specific functionality. Designed for use
   * by generated code.
   *
   * @param httpJsonCallSettings the gRPC call settings
   * @param callSettings the unary call settings
   * @param clientContext {@link ClientContext} to use to connect to the service.
   */
  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBaseUnaryCallable(
      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
      UnaryCallSettings<?, ?> callSettings,
      ClientContext clientContext) {
    UnaryCallable<RequestT, ResponseT> callable = createDirectUnaryCallable(httpJsonCallSettings);
    callable = new HttpJsonExceptionCallable<>(callable, callSettings.getRetryableCodes());
    callable = Callables.retrying(callable, callSettings, clientContext);

    return callable;
  }

  /**
   * Create a callable object with http/json-specific functionality. Designed for use by generated
   * code.
   *
   * @param httpJsonCallSettings the http/json call settings
   * @param callSettings {@link UnaryCallSettings} to configure the method-level settings with.
   * @param clientContext {@link ClientContext} to use to connect to the service.
   * @return {@link UnaryCallable} callable object.
   */
  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
      UnaryCallSettings<RequestT, ResponseT> callSettings,
      ClientContext clientContext) {
    UnaryCallable<RequestT, ResponseT> innerCallable =
        createDirectUnaryCallable(httpJsonCallSettings);

    innerCallable =
        new TracedUnaryCallable<>(
            innerCallable,
            clientContext.getTracerFactory(),
            getSpanName(httpJsonCallSettings.getMethodDescriptor()));

    return createUnaryCallable(innerCallable, callSettings, clientContext);
  }

  /**
   * Create a paged callable object that represents a paged API method. Designed for use by
   * generated code.
   *
   * @param httpJsonCallSettings the http/json call settings
   * @param pagedCallSettings {@link PagedCallSettings} to configure the paged settings with.
   * @param clientContext {@link ClientContext} to use to connect to the service.
   * @return {@link UnaryCallable} callable object.
   */
  public static <RequestT, ResponseT, PagedListResponseT>
      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
          HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> pagedCallSettings,
          ClientContext clientContext) {
    UnaryCallable<RequestT, ResponseT> callable = createDirectUnaryCallable(httpJsonCallSettings);
    callable = createUnaryCallable(callable, pagedCallSettings, clientContext);
    UnaryCallable<RequestT, PagedListResponseT> pagedCallable =
        Callables.paged(callable, pagedCallSettings);
    return pagedCallable.withDefaultCallContext(clientContext.getDefaultCallContext());
  }

  /**
   * Create a callable object that represents a batching API method. Designed for use by generated
   * code.
   *
   * @param httpJsonCallSettings the http/json call settings
   * @param batchingCallSettings {@link BatchingCallSettings} to configure the batching related
   *     settings with.
   * @param clientContext {@link ClientContext} to use to connect to the service.
   * @return {@link UnaryCallable} callable object.
   */
  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
      BatchingCallSettings<RequestT, ResponseT> batchingCallSettings,
      ClientContext clientContext) {
    UnaryCallable<RequestT, ResponseT> callable = createDirectUnaryCallable(httpJsonCallSettings);
    callable = createUnaryCallable(callable, batchingCallSettings, clientContext);
    callable = Callables.batching(callable, batchingCallSettings, clientContext);
    return callable.withDefaultCallContext(clientContext.getDefaultCallContext());
  }

  @BetaApi(
      "The surface for long-running operations is not stable yet and may change in the future.")
  public static <RequestT, ResponseT, MetadataT>
      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
          OperationCallSettings<RequestT, ResponseT, MetadataT> operationCallSettings,
          ClientContext clientContext,
          LongRunningClient longRunningClient,
          UnaryCallable<RequestT, OperationSnapshot> operationSnapshotCallable) {
    OperationCallable<RequestT, ResponseT, MetadataT> operationCallable =
        Callables.longRunningOperation(
            operationSnapshotCallable, operationCallSettings, clientContext, longRunningClient);
    return operationCallable.withDefaultCallContext(clientContext.getDefaultCallContext());
  }

  @InternalApi("Visible for testing")
  static SpanName getSpanName(@Nonnull ApiMethodDescriptor<?, ?> methodDescriptor) {
    Matcher matcher = FULL_METHOD_NAME_REGEX.matcher(methodDescriptor.getFullMethodName());

    Preconditions.checkArgument(matcher.matches(), "Invalid fullMethodName");
    return SpanName.of(matcher.group(1), matcher.group(2));
  }
}