wallet-core/node_modules/fbjs/lib/fetchWithRetries.js.flow
2017-10-14 18:40:54 +02:00

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/**
* Copyright (c) 2013-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @providesModule fetchWithRetries
* @typechecks
* @flow
*/
'use strict';
const ExecutionEnvironment = require('./ExecutionEnvironment');
const sprintf = require('./sprintf');
const fetch = require('./fetch');
const warning = require('./warning');
export type InitWithRetries = {
body?: mixed;
cache?: ?string;
credentials?: ?string;
fetchTimeout?: ?number;
headers?: mixed;
method?: ?string;
mode?: ?string;
retryDelays?: ?Array<number>;
};
const DEFAULT_TIMEOUT = 15000;
const DEFAULT_RETRIES = [1000, 3000];
/**
* Makes a POST request to the server with the given data as the payload.
* Automatic retries are done based on the values in `retryDelays`.
*/
function fetchWithRetries(uri: string, initWithRetries?: ?InitWithRetries): Promise<any> {
const { fetchTimeout, retryDelays, ...init } = initWithRetries || {};
const _fetchTimeout = fetchTimeout != null ? fetchTimeout : DEFAULT_TIMEOUT;
const _retryDelays = retryDelays != null ? retryDelays : DEFAULT_RETRIES;
let requestsAttempted = 0;
let requestStartTime = 0;
return new Promise((resolve, reject) => {
/**
* Sends a request to the server that will timeout after `fetchTimeout`.
* If the request fails or times out a new request might be scheduled.
*/
function sendTimedRequest(): void {
requestsAttempted++;
requestStartTime = Date.now();
let isRequestAlive = true;
const request = fetch(uri, init);
const requestTimeout = setTimeout(() => {
isRequestAlive = false;
if (shouldRetry(requestsAttempted)) {
warning(false, 'fetchWithRetries: HTTP timeout, retrying.');
retryRequest();
} else {
reject(new Error(sprintf('fetchWithRetries(): Failed to get response from server, ' + 'tried %s times.', requestsAttempted)));
}
}, _fetchTimeout);
request.then(response => {
clearTimeout(requestTimeout);
if (isRequestAlive) {
// We got a response, we can clear the timeout.
if (response.status >= 200 && response.status < 300) {
// Got a response code that indicates success, resolve the promise.
resolve(response);
} else if (shouldRetry(requestsAttempted)) {
// Fetch was not successful, retrying.
// TODO(#7595849): Only retry on transient HTTP errors.
warning(false, 'fetchWithRetries: HTTP error, retrying.'), retryRequest();
} else {
// Request was not successful, giving up.
const error: any = new Error(sprintf('fetchWithRetries(): Still no successful response after ' + '%s retries, giving up.', requestsAttempted));
error.response = response;
reject(error);
}
}
}).catch(error => {
clearTimeout(requestTimeout);
if (shouldRetry(requestsAttempted)) {
retryRequest();
} else {
reject(error);
}
});
}
/**
* Schedules another run of sendTimedRequest based on how much time has
* passed between the time the last request was sent and now.
*/
function retryRequest(): void {
const retryDelay = _retryDelays[requestsAttempted - 1];
const retryStartTime = requestStartTime + retryDelay;
// Schedule retry for a configured duration after last request started.
setTimeout(sendTimedRequest, retryStartTime - Date.now());
}
/**
* Checks if another attempt should be done to send a request to the server.
*/
function shouldRetry(attempt: number): boolean {
return ExecutionEnvironment.canUseDOM && attempt <= _retryDelays.length;
}
sendTimedRequest();
});
}
module.exports = fetchWithRetries;