You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
1018 lines
26 KiB
1018 lines
26 KiB
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 hasAbortSignal = typeof AbortSignal === 'function' |
|
// Some polyfills put this on the AC class, not global |
|
const hasACAbortSignal = typeof AC.AbortSignal === 'function' |
|
const AS = hasAbortSignal |
|
? AbortSignal |
|
: hasACAbortSignal |
|
? AC.AbortController |
|
: 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, |
|
maxEntrySize = 0, |
|
sizeCalculation, |
|
fetchMethod, |
|
fetchContext, |
|
noDeleteOnFetchRejection, |
|
noDeleteOnStaleGet, |
|
} = 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.maxEntrySize = maxEntrySize || this.maxSize |
|
this.sizeCalculation = sizeCalculation || length |
|
if (this.sizeCalculation) { |
|
if (!this.maxSize && !this.maxEntrySize) { |
|
throw new TypeError( |
|
'cannot set sizeCalculation without setting maxSize or maxEntrySize' |
|
) |
|
} |
|
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.fetchContext = fetchContext |
|
if (!this.fetchMethod && fetchContext !== undefined) { |
|
throw new TypeError( |
|
'cannot set fetchContext without fetchMethod' |
|
) |
|
} |
|
|
|
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 |
|
|
|
// NB: maxEntrySize is set to maxSize if it's set |
|
if (this.maxEntrySize !== 0) { |
|
if (this.maxSize !== 0) { |
|
if (!isPosInt(this.maxSize)) { |
|
throw new TypeError( |
|
'maxSize must be a positive integer if specified' |
|
) |
|
} |
|
} |
|
if (!isPosInt(this.maxEntrySize)) { |
|
throw new TypeError( |
|
'maxEntrySize must be a positive integer if specified' |
|
) |
|
} |
|
this.initializeSizeTracking() |
|
} |
|
|
|
this.allowStale = !!allowStale || !!stale |
|
this.noDeleteOnStaleGet = !!noDeleteOnStaleGet |
|
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, start = perf.now()) => { |
|
this.starts[index] = ttl !== 0 ? start : 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, start) {} |
|
isStale(index) { |
|
return false |
|
} |
|
|
|
initializeSizeTracking() { |
|
this.calculatedSize = 0 |
|
this.sizes = new ZeroArray(this.max) |
|
this.removeItemSize = index => { |
|
this.calculatedSize -= this.sizes[index] |
|
this.sizes[index] = 0 |
|
} |
|
this.requireSize = (k, v, size, sizeCalculation) => { |
|
// provisionally accept background fetches. |
|
// actual value size will be checked when they return. |
|
if (this.isBackgroundFetch(v)) { |
|
return 0 |
|
} |
|
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, size) => { |
|
this.sizes[index] = size |
|
if (this.maxSize) { |
|
const maxSize = this.maxSize - this.sizes[index] |
|
while (this.calculatedSize > maxSize) { |
|
this.evict(true) |
|
} |
|
} |
|
this.calculatedSize += this.sizes[index] |
|
} |
|
} |
|
removeItemSize(index) {} |
|
addItemSize(index, size) {} |
|
requireSize(k, v, size, sizeCalculation) { |
|
if (size || sizeCalculation) { |
|
throw new TypeError( |
|
'cannot set size without setting maxSize or maxEntrySize 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({ allowStale: true })) { |
|
const key = this.keyList[i] |
|
const v = this.valList[i] |
|
const value = this.isBackgroundFetch(v) |
|
? v.__staleWhileFetching |
|
: v |
|
const entry = { value } |
|
if (this.ttls) { |
|
entry.ttl = this.ttls[i] |
|
// always dump the start relative to a portable timestamp |
|
// it's ok for this to be a bit slow, it's a rare operation. |
|
const age = perf.now() - this.starts[i] |
|
entry.start = Math.floor(Date.now() - age) |
|
} |
|
if (this.sizes) { |
|
entry.size = this.sizes[i] |
|
} |
|
arr.unshift([key, entry]) |
|
} |
|
return arr |
|
} |
|
|
|
load(arr) { |
|
this.clear() |
|
for (const [key, entry] of arr) { |
|
if (entry.start) { |
|
// entry.start is a portable timestamp, but we may be using |
|
// node's performance.now(), so calculate the offset. |
|
// it's ok for this to be a bit slow, it's a rare operation. |
|
const age = Date.now() - entry.start |
|
entry.start = perf.now() - age |
|
} |
|
this.set(key, entry.value, entry) |
|
} |
|
} |
|
|
|
dispose(v, k, reason) {} |
|
|
|
set( |
|
k, |
|
v, |
|
{ |
|
ttl = this.ttl, |
|
start, |
|
noDisposeOnSet = this.noDisposeOnSet, |
|
size = 0, |
|
sizeCalculation = this.sizeCalculation, |
|
noUpdateTTL = this.noUpdateTTL, |
|
} = {} |
|
) { |
|
size = this.requireSize(k, v, size, sizeCalculation) |
|
// if the item doesn't fit, don't do anything |
|
// NB: maxEntrySize set to maxSize by default |
|
if (this.maxEntrySize && size > this.maxEntrySize) { |
|
// have to delete, in case a background fetch is there already. |
|
// in non-async cases, this is a no-op |
|
this.delete(k) |
|
return this |
|
} |
|
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, 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, size) |
|
} |
|
this.moveToTail(index) |
|
} |
|
if (ttl !== 0 && this.ttl === 0 && !this.ttls) { |
|
this.initializeTTLTracking() |
|
} |
|
if (!noUpdateTTL) { |
|
this.setItemTTL(index, ttl, start) |
|
} |
|
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))) { |
|
const v = this.valList[index] |
|
// either stale and allowed, or forcing a refresh of non-stale value |
|
return this.isBackgroundFetch(v) ? v.__staleWhileFetching : v |
|
} |
|
} |
|
|
|
backgroundFetch(k, index, options, context) { |
|
const v = index === undefined ? undefined : this.valList[index] |
|
if (this.isBackgroundFetch(v)) { |
|
return v |
|
} |
|
const ac = new AC() |
|
const fetchOpts = { |
|
signal: ac.signal, |
|
options, |
|
context, |
|
} |
|
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, |
|
noDeleteOnStaleGet = this.noDeleteOnStaleGet, |
|
// set options |
|
ttl = this.ttl, |
|
noDisposeOnSet = this.noDisposeOnSet, |
|
size = 0, |
|
sizeCalculation = this.sizeCalculation, |
|
noUpdateTTL = this.noUpdateTTL, |
|
// fetch exclusive options |
|
noDeleteOnFetchRejection = this.noDeleteOnFetchRejection, |
|
fetchContext = this.fetchContext, |
|
forceRefresh = false, |
|
} = {} |
|
) { |
|
if (!this.fetchMethod) { |
|
return this.get(k, { |
|
allowStale, |
|
updateAgeOnGet, |
|
noDeleteOnStaleGet, |
|
}) |
|
} |
|
|
|
const options = { |
|
allowStale, |
|
updateAgeOnGet, |
|
noDeleteOnStaleGet, |
|
ttl, |
|
noDisposeOnSet, |
|
size, |
|
sizeCalculation, |
|
noUpdateTTL, |
|
noDeleteOnFetchRejection, |
|
} |
|
|
|
let index = this.keyMap.get(k) |
|
if (index === undefined) { |
|
const p = this.backgroundFetch(k, index, options, fetchContext) |
|
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 we force a refresh, that means do NOT serve the cached value, |
|
// unless we are already in the process of refreshing the cache. |
|
if (!forceRefresh && !this.isStale(index)) { |
|
this.moveToTail(index) |
|
if (updateAgeOnGet) { |
|
this.updateItemAge(index) |
|
} |
|
return v |
|
} |
|
|
|
// ok, it is stale or a forced refresh, and not already fetching. |
|
// refresh the cache. |
|
const p = this.backgroundFetch(k, index, options, fetchContext) |
|
return allowStale && p.__staleWhileFetching !== undefined |
|
? p.__staleWhileFetching |
|
: (p.__returned = p) |
|
} |
|
} |
|
|
|
get( |
|
k, |
|
{ |
|
allowStale = this.allowStale, |
|
updateAgeOnGet = this.updateAgeOnGet, |
|
noDeleteOnStaleGet = this.noDeleteOnStaleGet, |
|
} = {} |
|
) { |
|
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) { |
|
if (!noDeleteOnStaleGet) { |
|
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
|
|
|