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