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Diffstat (limited to 'together/node_modules/lru-cache/index.js')
| -rw-r--r-- | together/node_modules/lru-cache/index.js | 334 |
1 files changed, 0 insertions, 334 deletions
diff --git a/together/node_modules/lru-cache/index.js b/together/node_modules/lru-cache/index.js deleted file mode 100644 index 573b6b8..0000000 --- a/together/node_modules/lru-cache/index.js +++ /dev/null @@ -1,334 +0,0 @@ -'use strict' - -// A linked list to keep track of recently-used-ness -const Yallist = require('yallist') - -const MAX = Symbol('max') -const LENGTH = Symbol('length') -const LENGTH_CALCULATOR = Symbol('lengthCalculator') -const ALLOW_STALE = Symbol('allowStale') -const MAX_AGE = Symbol('maxAge') -const DISPOSE = Symbol('dispose') -const NO_DISPOSE_ON_SET = Symbol('noDisposeOnSet') -const LRU_LIST = Symbol('lruList') -const CACHE = Symbol('cache') -const UPDATE_AGE_ON_GET = Symbol('updateAgeOnGet') - -const naiveLength = () => 1 - -// lruList is a yallist where the head is the youngest -// item, and the tail is the oldest. the list contains the Hit -// objects as the entries. -// Each Hit object has a reference to its Yallist.Node. This -// never changes. -// -// cache is a Map (or PseudoMap) that matches the keys to -// the Yallist.Node object. -class LRUCache { - constructor (options) { - if (typeof options === 'number') - options = { max: options } - - if (!options) - options = {} - - if (options.max && (typeof options.max !== 'number' || options.max < 0)) - throw new TypeError('max must be a non-negative number') - // Kind of weird to have a default max of Infinity, but oh well. - const max = this[MAX] = options.max || Infinity - - const lc = options.length || naiveLength - this[LENGTH_CALCULATOR] = (typeof lc !== 'function') ? naiveLength : lc - this[ALLOW_STALE] = options.stale || false - if (options.maxAge && typeof options.maxAge !== 'number') - throw new TypeError('maxAge must be a number') - this[MAX_AGE] = options.maxAge || 0 - this[DISPOSE] = options.dispose - this[NO_DISPOSE_ON_SET] = options.noDisposeOnSet || false - this[UPDATE_AGE_ON_GET] = options.updateAgeOnGet || false - this.reset() - } - - // resize the cache when the max changes. - set max (mL) { - if (typeof mL !== 'number' || mL < 0) - throw new TypeError('max must be a non-negative number') - - this[MAX] = mL || Infinity - trim(this) - } - get max () { - return this[MAX] - } - - set allowStale (allowStale) { - this[ALLOW_STALE] = !!allowStale - } - get allowStale () { - return this[ALLOW_STALE] - } - - set maxAge (mA) { - if (typeof mA !== 'number') - throw new TypeError('maxAge must be a non-negative number') - - this[MAX_AGE] = mA - trim(this) - } - get maxAge () { - return this[MAX_AGE] - } - - // resize the cache when the lengthCalculator changes. - set lengthCalculator (lC) { - if (typeof lC !== 'function') - lC = naiveLength - - if (lC !== this[LENGTH_CALCULATOR]) { - this[LENGTH_CALCULATOR] = lC - this[LENGTH] = 0 - this[LRU_LIST].forEach(hit => { - hit.length = this[LENGTH_CALCULATOR](hit.value, hit.key) - this[LENGTH] += hit.length - }) - } - trim(this) - } - get lengthCalculator () { return this[LENGTH_CALCULATOR] } - - get length () { return this[LENGTH] } - get itemCount () { return this[LRU_LIST].length } - - rforEach (fn, thisp) { - thisp = thisp || this - for (let walker = this[LRU_LIST].tail; walker !== null;) { - const prev = walker.prev - forEachStep(this, fn, walker, thisp) - walker = prev - } - } - - forEach (fn, thisp) { - thisp = thisp || this - for (let walker = this[LRU_LIST].head; walker !== null;) { - const next = walker.next - forEachStep(this, fn, walker, thisp) - walker = next - } - } - - keys () { - return this[LRU_LIST].toArray().map(k => k.key) - } - - values () { - return this[LRU_LIST].toArray().map(k => k.value) - } - - reset () { - if (this[DISPOSE] && - this[LRU_LIST] && - this[LRU_LIST].length) { - this[LRU_LIST].forEach(hit => this[DISPOSE](hit.key, hit.value)) - } - - this[CACHE] = new Map() // hash of items by key - this[LRU_LIST] = new Yallist() // list of items in order of use recency - this[LENGTH] = 0 // length of items in the list - } - - dump () { - return this[LRU_LIST].map(hit => - isStale(this, hit) ? false : { - k: hit.key, - v: hit.value, - e: hit.now + (hit.maxAge || 0) - }).toArray().filter(h => h) - } - - dumpLru () { - return this[LRU_LIST] - } - - set (key, value, maxAge) { - maxAge = maxAge || this[MAX_AGE] - - if (maxAge && typeof maxAge !== 'number') - throw new TypeError('maxAge must be a number') - - const now = maxAge ? Date.now() : 0 - const len = this[LENGTH_CALCULATOR](value, key) - - if (this[CACHE].has(key)) { - if (len > this[MAX]) { - del(this, this[CACHE].get(key)) - return false - } - - const node = this[CACHE].get(key) - const item = node.value - - // dispose of the old one before overwriting - // split out into 2 ifs for better coverage tracking - if (this[DISPOSE]) { - if (!this[NO_DISPOSE_ON_SET]) - this[DISPOSE](key, item.value) - } - - item.now = now - item.maxAge = maxAge - item.value = value - this[LENGTH] += len - item.length - item.length = len - this.get(key) - trim(this) - return true - } - - const hit = new Entry(key, value, len, now, maxAge) - - // oversized objects fall out of cache automatically. - if (hit.length > this[MAX]) { - if (this[DISPOSE]) - this[DISPOSE](key, value) - - return false - } - - this[LENGTH] += hit.length - this[LRU_LIST].unshift(hit) - this[CACHE].set(key, this[LRU_LIST].head) - trim(this) - return true - } - - has (key) { - if (!this[CACHE].has(key)) return false - const hit = this[CACHE].get(key).value - return !isStale(this, hit) - } - - get (key) { - return get(this, key, true) - } - - peek (key) { - return get(this, key, false) - } - - pop () { - const node = this[LRU_LIST].tail - if (!node) - return null - - del(this, node) - return node.value - } - - del (key) { - del(this, this[CACHE].get(key)) - } - - load (arr) { - // reset the cache - this.reset() - - const now = Date.now() - // A previous serialized cache has the most recent items first - for (let l = arr.length - 1; l >= 0; l--) { - const hit = arr[l] - const expiresAt = hit.e || 0 - if (expiresAt === 0) - // the item was created without expiration in a non aged cache - this.set(hit.k, hit.v) - else { - const maxAge = expiresAt - now - // dont add already expired items - if (maxAge > 0) { - this.set(hit.k, hit.v, maxAge) - } - } - } - } - - prune () { - this[CACHE].forEach((value, key) => get(this, key, false)) - } -} - -const get = (self, key, doUse) => { - const node = self[CACHE].get(key) - if (node) { - const hit = node.value - if (isStale(self, hit)) { - del(self, node) - if (!self[ALLOW_STALE]) - return undefined - } else { - if (doUse) { - if (self[UPDATE_AGE_ON_GET]) - node.value.now = Date.now() - self[LRU_LIST].unshiftNode(node) - } - } - return hit.value - } -} - -const isStale = (self, hit) => { - if (!hit || (!hit.maxAge && !self[MAX_AGE])) - return false - - const diff = Date.now() - hit.now - return hit.maxAge ? diff > hit.maxAge - : self[MAX_AGE] && (diff > self[MAX_AGE]) -} - -const trim = self => { - if (self[LENGTH] > self[MAX]) { - for (let walker = self[LRU_LIST].tail; - self[LENGTH] > self[MAX] && walker !== null;) { - // We know that we're about to delete this one, and also - // what the next least recently used key will be, so just - // go ahead and set it now. - const prev = walker.prev - del(self, walker) - walker = prev - } - } -} - -const del = (self, node) => { - if (node) { - const hit = node.value - if (self[DISPOSE]) - self[DISPOSE](hit.key, hit.value) - - self[LENGTH] -= hit.length - self[CACHE].delete(hit.key) - self[LRU_LIST].removeNode(node) - } -} - -class Entry { - constructor (key, value, length, now, maxAge) { - this.key = key - this.value = value - this.length = length - this.now = now - this.maxAge = maxAge || 0 - } -} - -const forEachStep = (self, fn, node, thisp) => { - let hit = node.value - if (isStale(self, hit)) { - del(self, node) - if (!self[ALLOW_STALE]) - hit = undefined - } - if (hit) - fn.call(thisp, hit.value, hit.key, self) -} - -module.exports = LRUCache |