91 lines
2.8 KiB
JavaScript
91 lines
2.8 KiB
JavaScript
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import retry from 'retry';
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const defaultRetryOptions = {
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retries: process.env.DICOMWEB_CLIENT_RETRY_RETRIES || 5,
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factor: process.env.DICOMWEB_CLIENT_RETRY_FACTOR || 3,
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minTimeout: process.env.DICOMWEB_CLIENT_RETRY_MIN_TIMEOUT || 1 * 1000,
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maxTimeout: process.env.DICOMWEB_CLIENT_RETRY_MAX_TIMEOUT || 60 * 1000,
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randomize: process.env.DICOMWEB_CLIENT_RETRY_RANDOMIZE || true,
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};
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let retryOptions = { ...defaultRetryOptions };
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/**
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* Request hook used to add retry functionality to XHR requests.
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*
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* @param {XMLHttpRequest} request XHR request instance
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* @param {object} metadata Metadata about the request
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* @param {object} metadata.url URL
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* @param {object} metadata.method HTTP method
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* @returns {XMLHttpRequest} request instance optionally modified
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*/
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const xhrRetryRequestHook = (request, metadata) => {
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const { url, method } = metadata;
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function faultTolerantRequestSend(...args) {
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const operation = retry.operation(retryOptions);
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operation.attempt(function operationAttempt(currentAttempt) {
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const originalOnReadyStateChange = request.onreadystatechange;
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request.onreadystatechange = function onReadyStateChange() {
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originalOnReadyStateChange.call(request);
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if (request.status === 429 || request.status >= 500) {
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const errorMessage = `Attempt to request ${url} failed.`;
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const attemptFailedError = new Error(errorMessage);
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operation.retry(attemptFailedError);
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}
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};
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console.warn(`Requesting ${url}... (attempt: ${currentAttempt})`);
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request.open(method, url, true);
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originalRequestSend.call(request, ...args);
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});
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}
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const originalRequestSend = request.send;
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request.send = faultTolerantRequestSend;
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return request;
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};
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/**
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* Returns a configured retry request hook function
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* that can be used to add retry functionality to XHR request.
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*
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* Default options:
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* retries: 5
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* factor: 3
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* minTimeout: 1 * 1000
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* maxTimeout: 60 * 1000
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* randomize: true
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*
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* @param {*} options
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* @param {*} options.retires number of retries
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* @param {*} options.factor factor
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* @param {*} options.minTimeout the min timeout
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* @param {*} options.maxTimeout the max timeout
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* @param {*} options.randomize randomize
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* @returns {function} the configured retry request function
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*/
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export const getXHRRetryRequestHook = (options = {}) => {
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retryOptions = { ...defaultRetryOptions };
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if ('retries' in options) {
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retryOptions.retries = options.retries;
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}
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if ('factor' in options) {
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retryOptions.factor = options.factor;
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}
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if ('minTimeout' in options) {
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retryOptions.minTimeout = options.minTimeout;
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}
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if ('maxTimeout' in options) {
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retryOptions.maxTimeout = options.maxTimeout;
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}
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if ('randomize' in options) {
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retryOptions.randomize = options.randomize;
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}
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return xhrRetryRequestHook;
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};
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export default getXHRRetryRequestHook;
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