| 1 | {"version":3,"file":"delayFunction.js","sourceRoot":"","sources":["../../../src/link/retry/delayFunction.ts"],"names":[],"mappings":"AA2CA,MAAM,UAAU,kBAAkB,CAChC,YAAmC;IAE7B,IAAA,KAAmD,YAAY,IAAI,EAAE,EAAnE,eAAa,EAAb,OAAO,mBAAG,GAAG,KAAA,EAAE,cAAa,EAAb,MAAM,mBAAG,IAAI,KAAA,EAAE,WAAc,EAAd,GAAG,mBAAG,QAAQ,KAAuB,CAAC;IAK5E,IAAM,SAAS,GAAG,MAAM,CAAC,CAAC,CAAC,OAAO,CAAC,CAAC,CAAC,OAAO,GAAG,CAAC,CAAC;IAEjD,OAAO,SAAS,aAAa,CAAC,KAAa;QACzC,IAAI,KAAK,GAAG,IAAI,CAAC,GAAG,CAAC,GAAG,EAAE,SAAS,GAAG,SAAA,CAAC,EAAI,KAAK,CAAA,CAAC,CAAC;QAClD,IAAI,MAAM,EAAE;YAGV,KAAK,GAAG,IAAI,CAAC,MAAM,EAAE,GAAG,KAAK,CAAC;SAC/B;QAED,OAAO,KAAK,CAAC;IACf,CAAC,CAAC;AACJ,CAAC","sourcesContent":["import { Operation } from '../core';\n\n/**\n * Advanced mode: a function that implements the strategy for calculating delays\n * for particular responses.\n */\nexport interface DelayFunction {\n (count: number, operation: Operation, error: any): number;\n}\n\nexport interface DelayFunctionOptions {\n /**\n * The number of milliseconds to wait before attempting the first retry.\n *\n * Delays will increase exponentially for each attempt. E.g. if this is\n * set to 100, subsequent retries will be delayed by 200, 400, 800, etc,\n * until they reach maxDelay.\n *\n * Note that if jittering is enabled, this is the _average_ delay.\n *\n * Defaults to 300.\n */\n initial?: number;\n\n /**\n * The maximum number of milliseconds that the link should wait for any\n * retry.\n *\n * Defaults to Infinity.\n */\n max?: number;\n\n /**\n * Whether delays between attempts should be randomized.\n *\n * This helps avoid thundering herd type situations by better distributing\n * load during major outages.\n *\n * Defaults to true.\n */\n jitter?: boolean;\n}\n\nexport function buildDelayFunction(\n delayOptions?: DelayFunctionOptions,\n): DelayFunction {\n const { initial = 300, jitter = true, max = Infinity } = delayOptions || {};\n // If we're jittering, baseDelay is half of the maximum delay for that\n // attempt (and is, on average, the delay we will encounter).\n // If we're not jittering, adjust baseDelay so that the first attempt\n // lines up with initialDelay, for everyone's sanity.\n const baseDelay = jitter ? initial : initial / 2;\n\n return function delayFunction(count: number) {\n let delay = Math.min(max, baseDelay * 2 ** count);\n if (jitter) {\n // We opt for a full jitter approach for a mostly uniform distribution,\n // but bound it within initialDelay and delay for everyone's sanity.\n delay = Math.random() * delay;\n }\n\n return delay;\n };\n}\n"]} |