google-gax
Version:
Google API Extensions
466 lines • 22.5 kB
JavaScript
"use strict";
/**
* Copyright 2020 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.StreamProxy = exports.StreamType = void 0;
const gax_1 = require("../gax");
const googleError_1 = require("../googleError");
const status_1 = require("../status");
const stream_1 = require("stream");
// eslint-disable-next-line @typescript-eslint/no-var-requires
const duplexify = require('duplexify');
// eslint-disable-next-line @typescript-eslint/no-var-requires
const retryRequest = require('retry-request');
/**
* The type of gRPC streaming.
* @enum {number}
*/
var StreamType;
(function (StreamType) {
/** Client sends a single request, server streams responses. */
StreamType[StreamType["SERVER_STREAMING"] = 1] = "SERVER_STREAMING";
/** Client streams requests, server returns a single response. */
StreamType[StreamType["CLIENT_STREAMING"] = 2] = "CLIENT_STREAMING";
/** Both client and server stream objects. */
StreamType[StreamType["BIDI_STREAMING"] = 3] = "BIDI_STREAMING";
})(StreamType || (exports.StreamType = StreamType = {}));
// In retry-request, you could pass parameters to request using the requestOpts parameter
// when we called retry-request from gax, we always passed null
// passing null here removes an unnecessary parameter from this implementation
const requestOps = null;
class StreamProxy extends duplexify {
type;
_callback;
_isCancelCalled;
stream;
_responseHasSent;
rest;
gaxServerStreamingRetries;
apiCall;
argument;
/**
* StreamProxy is a proxy to gRPC-streaming method.
*
* @private
* @constructor
* @param {StreamType} type - the type of gRPC stream.
* @param {ApiCallback} callback - the callback for further API call.
*/
constructor(type, callback, rest, gaxServerStreamingRetries) {
super(undefined, undefined, {
objectMode: true,
readable: type !== StreamType.CLIENT_STREAMING,
writable: type !== StreamType.SERVER_STREAMING,
});
this.type = type;
this._callback = callback;
this._isCancelCalled = false;
this._responseHasSent = false;
this.rest = rest;
this.gaxServerStreamingRetries = gaxServerStreamingRetries;
}
shouldRetryRequest(error, retry) {
const e = googleError_1.GoogleError.parseGRPCStatusDetails(error);
let shouldRetry = this.defaultShouldRetry(e, retry);
if (retry.shouldRetryFn) {
shouldRetry = retry.shouldRetryFn(e);
}
return shouldRetry;
}
cancel() {
if (this.stream) {
this.stream.cancel();
}
else {
this._isCancelCalled = true;
}
}
/**
* Helper function to handle total timeout + max retry check for server streaming retries
* @param {number} deadline - the current retry deadline
* @param {number} maxRetries - maximum total number of retries
* @param {number} totalTimeoutMillis - total timeout in milliseconds used in timeout calculation
* @param {GoogleError} originalError - underlying error received by the stream
* @param {originalTimeout} originalTimeout - the original Timeout set in backoff settings
* @param {retries} retries - the number of retries the call has made so far
*/
throwIfMaxRetriesOrTotalTimeoutExceeded(deadline, maxRetries, totalTimeoutMillis, originalError, originalTimeout, retries) {
const now = new Date();
const nowTime = now.getTime();
if (originalTimeout &&
(totalTimeoutMillis === 0 ||
totalTimeoutMillis < 0 ||
(deadline && nowTime >= deadline))) {
const error = new googleError_1.GoogleError(`Total timeout of API exceeded ${originalTimeout} milliseconds ${originalError ? `retrying error ${originalError} ` : ''} before any response was received.`);
error.code = status_1.Status.DEADLINE_EXCEEDED;
throw error;
}
if (maxRetries === 0) {
const error = originalError;
error.note = 'Max retries is set to zero.';
throw error;
}
if (retries && retries >= maxRetries) {
const error = new googleError_1.GoogleError('Exceeded maximum number of retries ' +
(originalError ? `retrying error ${originalError} ` : '') +
'before any response was received');
error.code = status_1.Status.DEADLINE_EXCEEDED;
throw error;
}
}
/**
* Forwards events from an API request stream to the user's stream.
* @param {Stream} stream - The API request stream.
*/
eventForwardHelper(stream) {
const eventsToForward = ['metadata', 'response', 'status'];
eventsToForward.forEach(event => {
stream.on(event, this.emit.bind(this, event));
});
}
/**
* Helper function that emits a response on the stream after either a 'metadata'
* or a 'status' event - this helps streams to behave more like http consumers expect
* @param {Stream} stream - The API request stream.
*/
statusMetadataHelper(stream) {
// gRPC is guaranteed emit the 'status' event but not 'metadata', and 'status' is the last event to emit.
// Emit the 'response' event if stream has no 'metadata' event.
// This avoids the stream swallowing the other events, such as 'end'.
stream.on('status', () => {
if (!this._responseHasSent) {
stream.emit('response', {
code: 200,
details: '',
message: 'OK',
});
}
});
// We also want to supply the status data as 'response' event to support
// the behavior of google-cloud-node expects.
// see:
// https://github.com/GoogleCloudPlatform/google-cloud-node/pull/1775#issuecomment-259141029
// https://github.com/GoogleCloudPlatform/google-cloud-node/blob/116436fa789d8b0f7fc5100b19b424e3ec63e6bf/packages/common/src/grpc-service.js#L355
stream.on('metadata', metadata => {
// Create a response object with succeeds.
// TODO: unify this logic with the decoration of gRPC response when it's
// added. see: https://github.com/googleapis/gax-nodejs/issues/65
stream.emit('response', {
code: 200,
details: '',
message: 'OK',
metadata,
});
this._responseHasSent = true;
});
}
/**
* Forward events from an API request stream to the user's stream.
* gRPC is guaranteed emit the 'status' event but not 'metadata'
* 'status' is the last event to emit; if 'metadata' emits, it will
* be the first event to emit. It should only emit once; if it emits
* more than once, unexpected side effects will occur.
*
* @param {Stream} stream - The API request stream.
* @param {RetryOptions} retry - Configures the exceptions upon which the
* function should retry, and the parameters to the exponential backoff retry
* algorithm.
*/
forwardEvents(stream) {
this.eventForwardHelper(stream);
this.statusMetadataHelper(stream);
stream.on('error', error => {
googleError_1.GoogleError.parseGRPCStatusDetails(error);
});
}
/**
* Default mechanism for determining whether a streaming call should retry
* If a user passes in a "shouldRetryFn", this will not be used
* @param {GoogleError} errpr - The error we need to determine is retryable or not
* @param {RetryOptions} retry - Configures the exceptions upon which the
* function should retry, and the parameters to the exponential backoff retry
* algorithm.
*/
defaultShouldRetry(error, retry) {
if ((retry.retryCodes.length > 0 &&
retry.retryCodes.indexOf(error.code) < 0) ||
retry.retryCodes.length === 0) {
return false;
}
return true;
}
/**
* Specifies the target stream.
* @param {ApiCall} apiCall - the API function to be called.
* @param {Object} argument - the argument to be passed to the apiCall.
* @param {RetryOptions} retry - Configures the exceptions upon which the
* function should retry, and the parameters to the exponential backoff retry
* algorithm.
*/
setStream(apiCall, argument, retryRequestOptions = {}, retry) {
this.apiCall = apiCall;
this.argument = argument;
if (this.type === StreamType.SERVER_STREAMING) {
if (this.rest) {
const stream = apiCall(argument, this._callback);
this.stream = stream;
this.setReadable(stream);
}
else if (this.gaxServerStreamingRetries) {
const request = () => {
if (this._isCancelCalled) {
if (this.stream) {
this.stream.cancel();
}
return;
}
const stream = apiCall(argument, this._callback);
return stream;
};
const retryStream = this.newStreamingRetryRequest({ request, retry });
this.stream = retryStream;
this.eventForwardHelper(retryStream);
this.setReadable(retryStream);
}
else {
const retryStream = retryRequest(null, {
objectMode: true,
request: () => {
if (this._isCancelCalled) {
if (this.stream) {
this.stream.cancel();
}
return;
}
const stream = apiCall(argument, this._callback);
this.stream = stream;
this.forwardEvents(stream);
return stream;
},
retries: retryRequestOptions.retries,
currentRetryAttempt: retryRequestOptions.currentRetryAttempt,
noResponseRetries: retryRequestOptions.noResponseRetries,
shouldRetryFn: retryRequestOptions.shouldRetryFn,
});
this.setReadable(retryStream);
}
return;
}
const stream = apiCall(argument, this._callback);
this.stream = stream;
this.forwardEvents(stream);
if (this.type === StreamType.CLIENT_STREAMING) {
this.setWritable(stream);
}
if (this.type === StreamType.BIDI_STREAMING) {
this.setReadable(stream);
this.setWritable(stream);
}
if (this._isCancelCalled && this.stream) {
this.stream.cancel();
}
}
/**
* Creates a new retry request stream -
*inner arrow function "newMakeRequest" handles retrying and resumption
* @param {streamingRetryRequestOptions} opts
* {request} - the request to be made if the stream errors
* {retry} - the retry options associated with the call
* @returns {CancellableStream} - the stream that handles retry logic
*/
newStreamingRetryRequest(opts) {
// at this point, it would be unexpected if retry were undefined
// but if it is, provide a logical default so we don't run into trouble
const retry = opts.retry ?? {
retryCodes: [],
backoffSettings: (0, gax_1.createDefaultBackoffSettings)(),
};
let retries = 0;
const retryStream = new stream_1.PassThrough({
objectMode: true,
});
const totalTimeout = retry.backoffSettings.totalTimeoutMillis ?? undefined;
const maxRetries = retry.backoffSettings.maxRetries ?? undefined;
let timeout = retry.backoffSettings.initialRpcTimeoutMillis ?? undefined;
let now = new Date();
let deadline = 0;
if (totalTimeout) {
deadline = now.getTime() + totalTimeout;
}
const transientErrorHelper = (error, requestStream) => {
const e = googleError_1.GoogleError.parseGRPCStatusDetails(error);
e.note =
'Exception occurred in retry method that was ' +
'not classified as transient';
// clean up the request stream and retryStreams, silently destroy it on the request stream
// but do raise it on destructin of the retryStream so the consumer can see it
requestStream.destroy();
retryStream.destroy(e);
return retryStream;
};
const newMakeRequest = (newopts) => {
let dataEnd = false;
let statusReceived = false;
let enteredError = false;
// make the request
const requestStream = newopts.request(requestOps);
retryStream.cancel = requestStream.cancel; // make sure the retryStream is also cancellable by the user
const eventsToForward = ['metadata', 'response', 'status'];
eventsToForward.forEach(event => {
requestStream.on(event, retryStream.emit.bind(retryStream, event));
});
this.statusMetadataHelper(requestStream);
// TODO - b/353262542 address buffer stuff
requestStream.on('data', (data) => {
retries = 0;
this.emit.bind(this, 'data')(data);
});
/* in retry-request, which previously handled retries,
* "end" could be emitted on a request stream before other gRPC events.
* To ensure it doesn't reach the consumer stream prematurely, retry-request piped
* two streams together (delayStream and retryStream)
* to ensure that "end" only emitted after a "response" event
*
* We are consciously NOT using pipeline or .pipe as part of similar logic here
* because we want more control over what happens during event handoff and we want to
* avoid the undesired behavior that can happen with error events
* if consumers in client libraries are also using pipes
*
* Since "status" is guaranteed to be the last event emitted by gRPC.
* If we have seen an "end" event, the dataEnd boolean will be true and we can safely
* end the stream.
*
* The "statusReceived" boolean covers the opposite case - that we receive the "status" event before
* a successful stream end event - this signals the .on('end') event handler that it's okay to end the stream
*
*
*/
requestStream.on('status', () => {
statusReceived = true;
if (dataEnd) {
retryStream.end();
}
return retryStream;
});
requestStream.on('end', () => {
if (!enteredError) {
dataEnd = true;
// in this case, we've already received "status"
// which is the last event from gRPC, so it's cool to end the stream
if (statusReceived) {
retryStream.end();
}
}
return retryStream;
// there is no else case because if enteredError
// is true, we will handle stream destruction as part of
// either retrying (where we don't want to end the stream)
// or as part of error handling, which will take care of stream destruction
});
requestStream.on('error', (error) => {
enteredError = true;
// type check for undefined instead of for truthiness in case maxRetries or timeout is equal to zero
if (typeof maxRetries !== undefined ||
typeof totalTimeout !== undefined) {
if (this.shouldRetryRequest(error, retry)) {
if (maxRetries && totalTimeout) {
const newError = new googleError_1.GoogleError('Cannot set both totalTimeoutMillis and maxRetries ' +
'in backoffSettings.');
newError.code = status_1.Status.INVALID_ARGUMENT;
// clean up the request stream and retryStreams, silently destroy it on the request stream
// but do raise it on destructin of the retryStream so the consumer can see it
requestStream.destroy();
retryStream.destroy(newError);
return retryStream;
}
else {
// check for exceeding timeout or max retries
try {
this.throwIfMaxRetriesOrTotalTimeoutExceeded(deadline, maxRetries, timeout, error, totalTimeout, retries);
}
catch (error) {
const e = googleError_1.GoogleError.parseGRPCStatusDetails(error);
// clean up the request stream and retryStreams, silently destroy it on the request stream
// but do raise it on destruction of the retryStream so the consumer can see it
requestStream.destroy();
retryStream.destroy(e);
return retryStream;
}
const delayMult = retry.backoffSettings.retryDelayMultiplier;
const maxDelay = retry.backoffSettings.maxRetryDelayMillis;
const timeoutMult = retry.backoffSettings.rpcTimeoutMultiplier;
const maxTimeout = retry.backoffSettings.maxRpcTimeoutMillis;
let delay = retry.backoffSettings.initialRetryDelayMillis;
// calculate new deadlines
const toSleep = Math.random() * delay;
const calculateTimeoutAndResumptionFunction = () => {
setTimeout(() => {
// only do timeout calculations if not using maxRetries
if (timeout) {
now = new Date();
delay = Math.min(delay * delayMult, maxDelay);
const timeoutCal = timeout && timeoutMult ? timeout * timeoutMult : 0;
const rpcTimeout = maxTimeout ? maxTimeout : 0;
const newDeadline = deadline ? deadline - now.getTime() : 0;
timeout = Math.min(timeoutCal, rpcTimeout, newDeadline);
}
retries++;
let retryArgument = this.argument;
// if resumption logic is passed, use it to determined the
// new argument for the new request made to the server
// otherwise, the original argument will be passed
if (retry.getResumptionRequestFn !== undefined) {
retryArgument = retry.getResumptionRequestFn(retryArgument);
}
const newRequest = () => {
if (this._isCancelCalled) {
if (this.stream) {
this.stream.cancel();
}
return;
}
const newStream = this.apiCall(retryArgument, this._callback);
return newStream;
};
opts.request = newRequest;
// make a request with the updated parameters
// based on the resumption strategy
return newMakeRequest(opts);
}, toSleep);
};
return calculateTimeoutAndResumptionFunction();
}
}
else {
// non retryable error
return transientErrorHelper(error, requestStream);
}
}
else {
// neither timeout nor maxRetries are defined, surface the error to the caller
return transientErrorHelper(error, requestStream);
}
});
// return the stream if we didn't return it as
// part of an error state
return retryStream;
};
// this is the first make request call with the options the user passed in
return newMakeRequest(opts);
}
}
exports.StreamProxy = StreamProxy;
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