//
// Copyright (c) Microsoft and contributors. All rights reserved.
//
// 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.
//
'use strict';
var RetryPolicyFilter = require('./retrypolicyfilter');
/**
* Creates a new 'ExponentialRetryPolicyFilter' instance.
* @class
* The ExponentialRetryPolicyFilter allows you to retry operations,
* using an exponential back-off interval between retries.
* To apply a filter to service operations, use `withFilter`
* and specify the filter to be used when creating a service.
* @constructor
* @param {number} [retryCount=3] The client retry count.
* @param {number} [retryInterval=30000] The client retry interval, in milliseconds.
* @param {number} [minRetryInterval=3000] The minimum retry interval, in milliseconds.
* @param {number} [maxRetryInterval=90000] The maximum retry interval, in milliseconds.
*
* @example
* var azure = require('azure-storage');
* var retryOperations = new azure.ExponentialRetryPolicyFilter();
* var blobService = azure.createBlobService().withFilter(retryOperations)
*/
function ExponentialRetryPolicyFilter(retryCount, retryInterval, minRetryInterval, maxRetryInterval) {
this.retryCount = retryCount ? retryCount : ExponentialRetryPolicyFilter.DEFAULT_CLIENT_RETRY_COUNT;
this.retryInterval = retryInterval ? retryInterval : ExponentialRetryPolicyFilter.DEFAULT_CLIENT_RETRY_INTERVAL;
this.minRetryInterval = minRetryInterval ? minRetryInterval : ExponentialRetryPolicyFilter.DEFAULT_CLIENT_MIN_RETRY_INTERVAL;
this.maxRetryInterval = maxRetryInterval ? maxRetryInterval : ExponentialRetryPolicyFilter.DEFAULT_CLIENT_MAX_RETRY_INTERVAL;
}
/**
* Represents the default client retry interval, in milliseconds.
*/
ExponentialRetryPolicyFilter.DEFAULT_CLIENT_RETRY_INTERVAL = 1000 * 30;
/**
* Represents the default client retry count.
*/
ExponentialRetryPolicyFilter.DEFAULT_CLIENT_RETRY_COUNT = 3;
/**
* Represents the default maximum retry interval, in milliseconds.
*/
ExponentialRetryPolicyFilter.DEFAULT_CLIENT_MAX_RETRY_INTERVAL = 1000 * 90;
/**
* Represents the default minimum retry interval, in milliseconds.
*/
ExponentialRetryPolicyFilter.DEFAULT_CLIENT_MIN_RETRY_INTERVAL = 1000 * 3;
/**
* Determines if the operation should be retried and how long to wait until the next retry.
*
* @param {number} statusCode The HTTP status code.
* @param {object} requestOptions The request options.
* @return {retryInfo} Information about whether the operation qualifies for a retry and the retryInterval.
*/
ExponentialRetryPolicyFilter.prototype.shouldRetry = function (statusCode, requestOptions) {
var retryData = (requestOptions && requestOptions.retryContext) ? requestOptions.retryContext : {};
// Adjust retry interval
var incrementDelta = Math.pow(2, retryData.retryCount) - 1;
var boundedRandDelta = this.retryInterval * 0.8 + Math.floor(Math.random() * (this.retryInterval * 1.2 - this.retryInterval * 0.8));
incrementDelta *= boundedRandDelta;
retryData.retryInterval = Math.min(this.minRetryInterval + incrementDelta, this.maxRetryInterval);
retryData.retryable = retryData.retryCount ? retryData.retryCount < this.retryCount : true;
return RetryPolicyFilter._shouldRetryOnError(statusCode, requestOptions);
};
/**
* Handles an operation with an exponential retry policy.
*
* @param {Object} requestOptions The original request options.
* @param {function} next The next filter to be handled.
* @return {undefined}
*/
ExponentialRetryPolicyFilter.prototype.handle = function (requestOptions, next) {
RetryPolicyFilter._handle(this, requestOptions, next);
};
module.exports = ExponentialRetryPolicyFilter;