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PR-URL: https://github.com/nodejs/node/pull/43061 Reviewed-By: Ruy Adorno <ruyadorno@github.com> Reviewed-By: Tobias Nießen <tniessen@tnie.de> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
852 lines
22 KiB
JavaScript
852 lines
22 KiB
JavaScript
const perf = typeof performance === 'object' && performance &&
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typeof performance.now === 'function' ? performance : Date
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const hasAbortController = typeof AbortController === 'function'
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// minimal backwards-compatibility polyfill
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// this doesn't have nearly all the checks and whatnot that
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// actual AbortController/Signal has, but it's enough for
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// our purposes, and if used properly, behaves the same.
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const AC = hasAbortController ? AbortController : Object.assign(
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class AbortController {
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constructor () { this.signal = new AC.AbortSignal }
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abort () {
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this.signal.dispatchEvent('abort')
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}
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},
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{
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AbortSignal: class AbortSignal {
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constructor () {
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this.aborted = false
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this._listeners = []
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}
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dispatchEvent (type) {
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if (type === 'abort') {
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this.aborted = true
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const e = { type, target: this }
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this.onabort(e)
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this._listeners.forEach(f => f(e), this)
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}
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}
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onabort () {}
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addEventListener (ev, fn) {
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if (ev === 'abort') {
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this._listeners.push(fn)
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}
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}
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removeEventListener (ev, fn) {
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if (ev === 'abort') {
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this._listeners = this._listeners.filter(f => f !== fn)
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}
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}
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}
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}
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)
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const warned = new Set()
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const deprecatedOption = (opt, instead) => {
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const code = `LRU_CACHE_OPTION_${opt}`
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if (shouldWarn(code)) {
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warn(code, `${opt} option`, `options.${instead}`, LRUCache)
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}
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}
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const deprecatedMethod = (method, instead) => {
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const code = `LRU_CACHE_METHOD_${method}`
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if (shouldWarn(code)) {
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const { prototype } = LRUCache
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const { get } = Object.getOwnPropertyDescriptor(prototype, method)
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warn(code, `${method} method`, `cache.${instead}()`, get)
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}
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}
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const deprecatedProperty = (field, instead) => {
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const code = `LRU_CACHE_PROPERTY_${field}`
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if (shouldWarn(code)) {
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const { prototype } = LRUCache
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const { get } = Object.getOwnPropertyDescriptor(prototype, field)
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warn(code, `${field} property`, `cache.${instead}`, get)
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}
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}
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const emitWarning = (...a) => {
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typeof process === 'object' &&
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process &&
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typeof process.emitWarning === 'function'
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? process.emitWarning(...a)
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: console.error(...a)
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}
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const shouldWarn = code => !warned.has(code)
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const warn = (code, what, instead, fn) => {
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warned.add(code)
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const msg = `The ${what} is deprecated. Please use ${instead} instead.`
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emitWarning(msg, 'DeprecationWarning', code, fn)
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}
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const isPosInt = n => n && n === Math.floor(n) && n > 0 && isFinite(n)
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/* istanbul ignore next - This is a little bit ridiculous, tbh.
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* The maximum array length is 2^32-1 or thereabouts on most JS impls.
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* And well before that point, you're caching the entire world, I mean,
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* that's ~32GB of just integers for the next/prev links, plus whatever
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* else to hold that many keys and values. Just filling the memory with
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* zeroes at init time is brutal when you get that big.
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* But why not be complete?
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* Maybe in the future, these limits will have expanded. */
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const getUintArray = max => !isPosInt(max) ? null
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: max <= Math.pow(2, 8) ? Uint8Array
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: max <= Math.pow(2, 16) ? Uint16Array
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: max <= Math.pow(2, 32) ? Uint32Array
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: max <= Number.MAX_SAFE_INTEGER ? ZeroArray
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: null
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class ZeroArray extends Array {
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constructor (size) {
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super(size)
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this.fill(0)
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}
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}
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class Stack {
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constructor (max) {
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if (max === 0) {
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return []
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}
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const UintArray = getUintArray(max)
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this.heap = new UintArray(max)
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this.length = 0
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}
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push (n) {
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this.heap[this.length++] = n
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}
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pop () {
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return this.heap[--this.length]
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}
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}
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class LRUCache {
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constructor (options = {}) {
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const {
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max = 0,
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ttl,
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ttlResolution = 1,
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ttlAutopurge,
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updateAgeOnGet,
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updateAgeOnHas,
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allowStale,
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dispose,
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disposeAfter,
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noDisposeOnSet,
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noUpdateTTL,
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maxSize = 0,
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sizeCalculation,
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fetchMethod,
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} = options
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// deprecated options, don't trigger a warning for getting them if
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// the thing being passed in is another LRUCache we're copying.
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const {
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length,
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maxAge,
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stale,
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} = options instanceof LRUCache ? {} : options
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if (max !== 0 && !isPosInt(max)) {
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throw new TypeError('max option must be a nonnegative integer')
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}
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const UintArray = max ? getUintArray(max) : Array
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if (!UintArray) {
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throw new Error('invalid max value: ' + max)
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}
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this.max = max
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this.maxSize = maxSize
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this.sizeCalculation = sizeCalculation || length
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if (this.sizeCalculation) {
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if (!this.maxSize) {
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throw new TypeError('cannot set sizeCalculation without setting maxSize')
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}
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if (typeof this.sizeCalculation !== 'function') {
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throw new TypeError('sizeCalculation set to non-function')
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}
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}
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this.fetchMethod = fetchMethod || null
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if (this.fetchMethod && typeof this.fetchMethod !== 'function') {
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throw new TypeError('fetchMethod must be a function if specified')
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}
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this.keyMap = new Map()
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this.keyList = new Array(max).fill(null)
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this.valList = new Array(max).fill(null)
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this.next = new UintArray(max)
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this.prev = new UintArray(max)
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this.head = 0
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this.tail = 0
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this.free = new Stack(max)
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this.initialFill = 1
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this.size = 0
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if (typeof dispose === 'function') {
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this.dispose = dispose
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}
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if (typeof disposeAfter === 'function') {
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this.disposeAfter = disposeAfter
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this.disposed = []
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} else {
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this.disposeAfter = null
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this.disposed = null
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}
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this.noDisposeOnSet = !!noDisposeOnSet
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this.noUpdateTTL = !!noUpdateTTL
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if (this.maxSize !== 0) {
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if (!isPosInt(this.maxSize)) {
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throw new TypeError('maxSize must be a positive integer if specified')
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}
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this.initializeSizeTracking()
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}
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this.allowStale = !!allowStale || !!stale
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this.updateAgeOnGet = !!updateAgeOnGet
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this.updateAgeOnHas = !!updateAgeOnHas
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this.ttlResolution = isPosInt(ttlResolution) || ttlResolution === 0
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? ttlResolution : 1
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this.ttlAutopurge = !!ttlAutopurge
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this.ttl = ttl || maxAge || 0
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if (this.ttl) {
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if (!isPosInt(this.ttl)) {
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throw new TypeError('ttl must be a positive integer if specified')
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}
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this.initializeTTLTracking()
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}
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// do not allow completely unbounded caches
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if (this.max === 0 && this.ttl === 0 && this.maxSize === 0) {
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throw new TypeError('At least one of max, maxSize, or ttl is required')
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}
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if (!this.ttlAutopurge && !this.max && !this.maxSize) {
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const code = 'LRU_CACHE_UNBOUNDED'
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if (shouldWarn(code)) {
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warned.add(code)
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const msg = 'TTL caching without ttlAutopurge, max, or maxSize can ' +
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'result in unbounded memory consumption.'
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emitWarning(msg, 'UnboundedCacheWarning', code, LRUCache)
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}
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}
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if (stale) {
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deprecatedOption('stale', 'allowStale')
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}
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if (maxAge) {
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deprecatedOption('maxAge', 'ttl')
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}
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if (length) {
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deprecatedOption('length', 'sizeCalculation')
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}
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}
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getRemainingTTL (key) {
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return this.has(key, { updateAgeOnHas: false }) ? Infinity : 0
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}
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initializeTTLTracking () {
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this.ttls = new ZeroArray(this.max)
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this.starts = new ZeroArray(this.max)
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this.setItemTTL = (index, ttl) => {
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this.starts[index] = ttl !== 0 ? perf.now() : 0
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this.ttls[index] = ttl
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if (ttl !== 0 && this.ttlAutopurge) {
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const t = setTimeout(() => {
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if (this.isStale(index)) {
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this.delete(this.keyList[index])
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}
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}, ttl + 1)
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/* istanbul ignore else - unref() not supported on all platforms */
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if (t.unref) {
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t.unref()
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}
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}
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}
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this.updateItemAge = (index) => {
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this.starts[index] = this.ttls[index] !== 0 ? perf.now() : 0
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}
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// debounce calls to perf.now() to 1s so we're not hitting
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// that costly call repeatedly.
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let cachedNow = 0
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const getNow = () => {
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const n = perf.now()
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if (this.ttlResolution > 0) {
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cachedNow = n
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const t = setTimeout(() => cachedNow = 0, this.ttlResolution)
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/* istanbul ignore else - not available on all platforms */
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if (t.unref) {
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t.unref()
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}
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}
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return n
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}
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this.getRemainingTTL = (key) => {
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const index = this.keyMap.get(key)
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if (index === undefined) {
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return 0
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}
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return this.ttls[index] === 0 || this.starts[index] === 0 ? Infinity
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: ((this.starts[index] + this.ttls[index]) - (cachedNow || getNow()))
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}
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this.isStale = (index) => {
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return this.ttls[index] !== 0 && this.starts[index] !== 0 &&
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((cachedNow || getNow()) - this.starts[index] > this.ttls[index])
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}
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}
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updateItemAge (index) {}
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setItemTTL (index, ttl) {}
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isStale (index) { return false }
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initializeSizeTracking () {
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this.calculatedSize = 0
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this.sizes = new ZeroArray(this.max)
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this.removeItemSize = index => this.calculatedSize -= this.sizes[index]
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this.requireSize = (k, v, size, sizeCalculation) => {
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if (!isPosInt(size)) {
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if (sizeCalculation) {
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if (typeof sizeCalculation !== 'function') {
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throw new TypeError('sizeCalculation must be a function')
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}
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size = sizeCalculation(v, k)
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if (!isPosInt(size)) {
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throw new TypeError('sizeCalculation return invalid (expect positive integer)')
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}
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} else {
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throw new TypeError('invalid size value (must be positive integer)')
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}
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}
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return size
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}
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this.addItemSize = (index, v, k, size) => {
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this.sizes[index] = size
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const maxSize = this.maxSize - this.sizes[index]
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while (this.calculatedSize > maxSize) {
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this.evict(true)
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}
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this.calculatedSize += this.sizes[index]
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}
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}
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removeItemSize (index) {}
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addItemSize (index, v, k, size) {}
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requireSize (k, v, size, sizeCalculation) {
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if (size || sizeCalculation) {
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throw new TypeError('cannot set size without setting maxSize on cache')
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}
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}
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*indexes ({ allowStale = this.allowStale } = {}) {
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if (this.size) {
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for (let i = this.tail; true; ) {
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if (!this.isValidIndex(i)) {
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break
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}
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if (allowStale || !this.isStale(i)) {
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yield i
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}
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if (i === this.head) {
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break
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} else {
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i = this.prev[i]
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}
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}
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}
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}
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*rindexes ({ allowStale = this.allowStale } = {}) {
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if (this.size) {
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for (let i = this.head; true; ) {
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if (!this.isValidIndex(i)) {
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break
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}
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if (allowStale || !this.isStale(i)) {
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yield i
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}
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if (i === this.tail) {
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break
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} else {
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i = this.next[i]
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}
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}
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}
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}
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isValidIndex (index) {
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return this.keyMap.get(this.keyList[index]) === index
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}
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*entries () {
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for (const i of this.indexes()) {
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yield [this.keyList[i], this.valList[i]]
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}
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}
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*rentries () {
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for (const i of this.rindexes()) {
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yield [this.keyList[i], this.valList[i]]
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}
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}
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*keys () {
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for (const i of this.indexes()) {
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yield this.keyList[i]
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}
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}
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*rkeys () {
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for (const i of this.rindexes()) {
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yield this.keyList[i]
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}
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}
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*values () {
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for (const i of this.indexes()) {
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yield this.valList[i]
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}
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}
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*rvalues () {
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for (const i of this.rindexes()) {
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yield this.valList[i]
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}
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}
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[Symbol.iterator] () {
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return this.entries()
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}
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find (fn, getOptions = {}) {
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for (const i of this.indexes()) {
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if (fn(this.valList[i], this.keyList[i], this)) {
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return this.get(this.keyList[i], getOptions)
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}
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}
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}
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forEach (fn, thisp = this) {
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for (const i of this.indexes()) {
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fn.call(thisp, this.valList[i], this.keyList[i], this)
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}
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}
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rforEach (fn, thisp = this) {
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for (const i of this.rindexes()) {
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fn.call(thisp, this.valList[i], this.keyList[i], this)
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}
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}
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get prune () {
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deprecatedMethod('prune', 'purgeStale')
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return this.purgeStale
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}
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purgeStale () {
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let deleted = false
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for (const i of this.rindexes({ allowStale: true })) {
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if (this.isStale(i)) {
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this.delete(this.keyList[i])
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deleted = true
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}
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}
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return deleted
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}
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dump () {
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const arr = []
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for (const i of this.indexes()) {
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const key = this.keyList[i]
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const value = this.valList[i]
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const entry = { value }
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if (this.ttls) {
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entry.ttl = this.ttls[i]
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}
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if (this.sizes) {
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entry.size = this.sizes[i]
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}
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arr.unshift([key, entry])
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}
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return arr
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}
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load (arr) {
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this.clear()
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for (const [key, entry] of arr) {
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this.set(key, entry.value, entry)
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}
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}
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dispose (v, k, reason) {}
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set (k, v, {
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ttl = this.ttl,
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noDisposeOnSet = this.noDisposeOnSet,
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size = 0,
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sizeCalculation = this.sizeCalculation,
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noUpdateTTL = this.noUpdateTTL,
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} = {}) {
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size = this.requireSize(k, v, size, sizeCalculation)
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let index = this.size === 0 ? undefined : this.keyMap.get(k)
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if (index === undefined) {
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// addition
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index = this.newIndex()
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this.keyList[index] = k
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this.valList[index] = v
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this.keyMap.set(k, index)
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this.next[this.tail] = index
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this.prev[index] = this.tail
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this.tail = index
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this.size ++
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this.addItemSize(index, v, k, size)
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noUpdateTTL = false
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} else {
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// update
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const oldVal = this.valList[index]
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if (v !== oldVal) {
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if (this.isBackgroundFetch(oldVal)) {
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oldVal.__abortController.abort()
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} else {
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if (!noDisposeOnSet) {
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this.dispose(oldVal, k, 'set')
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if (this.disposeAfter) {
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this.disposed.push([oldVal, k, 'set'])
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}
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}
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}
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this.removeItemSize(index)
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this.valList[index] = v
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this.addItemSize(index, v, k, size)
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}
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this.moveToTail(index)
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}
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if (ttl !== 0 && this.ttl === 0 && !this.ttls) {
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this.initializeTTLTracking()
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}
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if (!noUpdateTTL) {
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this.setItemTTL(index, ttl)
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}
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if (this.disposeAfter) {
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|
while (this.disposed.length) {
|
|
this.disposeAfter(...this.disposed.shift())
|
|
}
|
|
}
|
|
return this
|
|
}
|
|
|
|
newIndex () {
|
|
if (this.size === 0) {
|
|
return this.tail
|
|
}
|
|
if (this.size === this.max && this.max !== 0) {
|
|
return this.evict(false)
|
|
}
|
|
if (this.free.length !== 0) {
|
|
return this.free.pop()
|
|
}
|
|
// initial fill, just keep writing down the list
|
|
return this.initialFill++
|
|
}
|
|
|
|
pop () {
|
|
if (this.size) {
|
|
const val = this.valList[this.head]
|
|
this.evict(true)
|
|
return val
|
|
}
|
|
}
|
|
|
|
evict (free) {
|
|
const head = this.head
|
|
const k = this.keyList[head]
|
|
const v = this.valList[head]
|
|
if (this.isBackgroundFetch(v)) {
|
|
v.__abortController.abort()
|
|
} else {
|
|
this.dispose(v, k, 'evict')
|
|
if (this.disposeAfter) {
|
|
this.disposed.push([v, k, 'evict'])
|
|
}
|
|
}
|
|
this.removeItemSize(head)
|
|
// if we aren't about to use the index, then null these out
|
|
if (free) {
|
|
this.keyList[head] = null
|
|
this.valList[head] = null
|
|
this.free.push(head)
|
|
}
|
|
this.head = this.next[head]
|
|
this.keyMap.delete(k)
|
|
this.size --
|
|
return head
|
|
}
|
|
|
|
has (k, { updateAgeOnHas = this.updateAgeOnHas } = {}) {
|
|
const index = this.keyMap.get(k)
|
|
if (index !== undefined) {
|
|
if (!this.isStale(index)) {
|
|
if (updateAgeOnHas) {
|
|
this.updateItemAge(index)
|
|
}
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
// like get(), but without any LRU updating or TTL expiration
|
|
peek (k, { allowStale = this.allowStale } = {}) {
|
|
const index = this.keyMap.get(k)
|
|
if (index !== undefined && (allowStale || !this.isStale(index))) {
|
|
return this.valList[index]
|
|
}
|
|
}
|
|
|
|
backgroundFetch (k, index, options) {
|
|
const v = index === undefined ? undefined : this.valList[index]
|
|
if (this.isBackgroundFetch(v)) {
|
|
return v
|
|
}
|
|
const ac = new AC()
|
|
const fetchOpts = {
|
|
signal: ac.signal,
|
|
options,
|
|
}
|
|
const p = Promise.resolve(this.fetchMethod(k, v, fetchOpts)).then(v => {
|
|
if (!ac.signal.aborted) {
|
|
this.set(k, v, fetchOpts.options)
|
|
}
|
|
return v
|
|
})
|
|
p.__abortController = ac
|
|
p.__staleWhileFetching = v
|
|
if (index === undefined) {
|
|
this.set(k, p, fetchOpts.options)
|
|
index = this.keyMap.get(k)
|
|
} else {
|
|
this.valList[index] = p
|
|
}
|
|
return p
|
|
}
|
|
|
|
isBackgroundFetch (p) {
|
|
return p && typeof p === 'object' && typeof p.then === 'function' &&
|
|
Object.prototype.hasOwnProperty.call(p, '__staleWhileFetching')
|
|
}
|
|
|
|
// this takes the union of get() and set() opts, because it does both
|
|
async fetch (k, {
|
|
allowStale = this.allowStale,
|
|
updateAgeOnGet = this.updateAgeOnGet,
|
|
ttl = this.ttl,
|
|
noDisposeOnSet = this.noDisposeOnSet,
|
|
size = 0,
|
|
sizeCalculation = this.sizeCalculation,
|
|
noUpdateTTL = this.noUpdateTTL,
|
|
} = {}) {
|
|
if (!this.fetchMethod) {
|
|
return this.get(k, {allowStale, updateAgeOnGet})
|
|
}
|
|
|
|
const options = {
|
|
allowStale,
|
|
updateAgeOnGet,
|
|
ttl,
|
|
noDisposeOnSet,
|
|
size,
|
|
sizeCalculation,
|
|
noUpdateTTL,
|
|
}
|
|
|
|
let index = this.keyMap.get(k)
|
|
if (index === undefined) {
|
|
return this.backgroundFetch(k, index, options)
|
|
} else {
|
|
// in cache, maybe already fetching
|
|
const v = this.valList[index]
|
|
if (this.isBackgroundFetch(v)) {
|
|
return allowStale && v.__staleWhileFetching !== undefined
|
|
? v.__staleWhileFetching : v
|
|
}
|
|
|
|
if (!this.isStale(index)) {
|
|
this.moveToTail(index)
|
|
if (updateAgeOnGet) {
|
|
this.updateItemAge(index)
|
|
}
|
|
return v
|
|
}
|
|
|
|
// ok, it is stale, and not already fetching
|
|
// refresh the cache.
|
|
const p = this.backgroundFetch(k, index, options)
|
|
return allowStale && p.__staleWhileFetching !== undefined
|
|
? p.__staleWhileFetching : p
|
|
}
|
|
}
|
|
|
|
get (k, {
|
|
allowStale = this.allowStale,
|
|
updateAgeOnGet = this.updateAgeOnGet,
|
|
} = {}) {
|
|
const index = this.keyMap.get(k)
|
|
if (index !== undefined) {
|
|
const value = this.valList[index]
|
|
const fetching = this.isBackgroundFetch(value)
|
|
if (this.isStale(index)) {
|
|
// delete only if not an in-flight background fetch
|
|
if (!fetching) {
|
|
this.delete(k)
|
|
return allowStale ? value : undefined
|
|
} else {
|
|
return allowStale ? value.__staleWhileFetching : undefined
|
|
}
|
|
} else {
|
|
// if we're currently fetching it, we don't actually have it yet
|
|
// it's not stale, which means this isn't a staleWhileRefetching,
|
|
// so we just return undefined
|
|
if (fetching) {
|
|
return undefined
|
|
}
|
|
this.moveToTail(index)
|
|
if (updateAgeOnGet) {
|
|
this.updateItemAge(index)
|
|
}
|
|
return value
|
|
}
|
|
}
|
|
}
|
|
|
|
connect (p, n) {
|
|
this.prev[n] = p
|
|
this.next[p] = n
|
|
}
|
|
|
|
moveToTail (index) {
|
|
// if tail already, nothing to do
|
|
// if head, move head to next[index]
|
|
// else
|
|
// move next[prev[index]] to next[index] (head has no prev)
|
|
// move prev[next[index]] to prev[index]
|
|
// prev[index] = tail
|
|
// next[tail] = index
|
|
// tail = index
|
|
if (index !== this.tail) {
|
|
if (index === this.head) {
|
|
this.head = this.next[index]
|
|
} else {
|
|
this.connect(this.prev[index], this.next[index])
|
|
}
|
|
this.connect(this.tail, index)
|
|
this.tail = index
|
|
}
|
|
}
|
|
|
|
get del () {
|
|
deprecatedMethod('del', 'delete')
|
|
return this.delete
|
|
}
|
|
|
|
delete (k) {
|
|
let deleted = false
|
|
if (this.size !== 0) {
|
|
const index = this.keyMap.get(k)
|
|
if (index !== undefined) {
|
|
deleted = true
|
|
if (this.size === 1) {
|
|
this.clear()
|
|
} else {
|
|
this.removeItemSize(index)
|
|
const v = this.valList[index]
|
|
if (this.isBackgroundFetch(v)) {
|
|
v.__abortController.abort()
|
|
} else {
|
|
this.dispose(v, k, 'delete')
|
|
if (this.disposeAfter) {
|
|
this.disposed.push([v, k, 'delete'])
|
|
}
|
|
}
|
|
this.keyMap.delete(k)
|
|
this.keyList[index] = null
|
|
this.valList[index] = null
|
|
if (index === this.tail) {
|
|
this.tail = this.prev[index]
|
|
} else if (index === this.head) {
|
|
this.head = this.next[index]
|
|
} else {
|
|
this.next[this.prev[index]] = this.next[index]
|
|
this.prev[this.next[index]] = this.prev[index]
|
|
}
|
|
this.size --
|
|
this.free.push(index)
|
|
}
|
|
}
|
|
}
|
|
if (this.disposed) {
|
|
while (this.disposed.length) {
|
|
this.disposeAfter(...this.disposed.shift())
|
|
}
|
|
}
|
|
return deleted
|
|
}
|
|
|
|
clear () {
|
|
for (const index of this.rindexes({ allowStale: true })) {
|
|
const v = this.valList[index]
|
|
if (this.isBackgroundFetch(v)) {
|
|
v.__abortController.abort()
|
|
} else {
|
|
const k = this.keyList[index]
|
|
this.dispose(v, k, 'delete')
|
|
if (this.disposeAfter) {
|
|
this.disposed.push([v, k, 'delete'])
|
|
}
|
|
}
|
|
}
|
|
|
|
this.keyMap.clear()
|
|
this.valList.fill(null)
|
|
this.keyList.fill(null)
|
|
if (this.ttls) {
|
|
this.ttls.fill(0)
|
|
this.starts.fill(0)
|
|
}
|
|
if (this.sizes) {
|
|
this.sizes.fill(0)
|
|
}
|
|
this.head = 0
|
|
this.tail = 0
|
|
this.initialFill = 1
|
|
this.free.length = 0
|
|
this.calculatedSize = 0
|
|
this.size = 0
|
|
if (this.disposed) {
|
|
while (this.disposed.length) {
|
|
this.disposeAfter(...this.disposed.shift())
|
|
}
|
|
}
|
|
}
|
|
|
|
get reset () {
|
|
deprecatedMethod('reset', 'clear')
|
|
return this.clear
|
|
}
|
|
|
|
get length () {
|
|
deprecatedProperty('length', 'size')
|
|
return this.size
|
|
}
|
|
|
|
static get AbortController () {
|
|
return AC
|
|
}
|
|
}
|
|
|
|
module.exports = LRUCache
|