apiCaller.ts

/*
 * Copyright 2019, Google LLC
 * All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 *
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 * notice, this list of conditions and the following disclaimer.
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 * in the documentation and/or other materials provided with the
 * distribution.
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 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */

import {APICallback, CancellableStream, GRPCCall, ResultTuple, SimpleCallbackFunction} from './apitypes';
import {CancellablePromise, OngoingCall, OngoingCallPromise} from './call';
import {Descriptor} from './descriptor';
import {CallSettings} from './gax';
import {GoogleError} from './googleError';
import {NormalApiCaller} from './normalCalls/normalApiCaller';
import {StreamProxy} from './streamingCalls/streaming';

export interface ApiCallerSettings {
  promise: PromiseConstructor;
}

/**
 * An interface for all kinds of API callers (normal, that just calls API, and
 * all special ones: long-running, paginated, bundled, streaming).
 */
export interface APICaller {
  init(settings: ApiCallerSettings, callback?: APICallback): OngoingCallPromise
      |OngoingCall|StreamProxy;
  wrap(func: GRPCCall): GRPCCall;
  call(
      apiCall: SimpleCallbackFunction, argument: {}, settings: {},
      canceller: OngoingCallPromise|OngoingCall|StreamProxy): void;
  fail(
      canceller: OngoingCallPromise|OngoingCall|CancellableStream,
      err: GoogleError): void;
  result(canceller: OngoingCallPromise|OngoingCall|
         CancellableStream): CancellablePromise<ResultTuple>|CancellableStream;
}

export function createAPICaller(
    settings: CallSettings, descriptor: Descriptor|undefined): APICaller {
  if (!descriptor) {
    return new NormalApiCaller();
  }
  return descriptor.getApiCaller(settings);
}