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shrine-medco/shrine-webclient/src/main/html/node_modules/lru-cache/lib/lru-cache.js
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lru-cache.js
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;(function () { // closure for web browsers
if (typeof module === 'object' && module.exports) {
module.exports = LRUCache
} else {
// just set the global for non-node platforms.
this.LRUCache = LRUCache
}
function hOP (obj, key) {
return Object.prototype.hasOwnProperty.call(obj, key)
}
function naiveLength () { return 1 }
var didTypeWarning = false
function typeCheckKey(key) {
if (!didTypeWarning && typeof key !== 'string' && typeof key !== 'number') {
didTypeWarning = true
console.error(new TypeError("LRU: key must be a string or number. Almost certainly a bug! " + typeof key).stack)
}
}
function LRUCache (options) {
if (!(this instanceof LRUCache))
return new LRUCache(options)
if (typeof options === 'number')
options = { max: options }
if (!options)
options = {}
this._max = options.max
// Kind of weird to have a default max of Infinity, but oh well.
if (!this._max || !(typeof this._max === "number") || this._max <= 0 )
this._max = Infinity
this._lengthCalculator = options.length || naiveLength
if (typeof this._lengthCalculator !== "function")
this._lengthCalculator = naiveLength
this._allowStale = options.stale || false
this._maxAge = options.maxAge || null
this._dispose = options.dispose
this.reset()
}
// resize the cache when the max changes.
Object.defineProperty(LRUCache.prototype, "max",
{ set : function (mL) {
if (!mL || !(typeof mL === "number") || mL <= 0 ) mL = Infinity
this._max = mL
if (this._length > this._max) trim(this)
}
, get : function () { return this._max }
, enumerable : true
})
// resize the cache when the lengthCalculator changes.
Object.defineProperty(LRUCache.prototype, "lengthCalculator",
{ set : function (lC) {
if (typeof lC !== "function") {
this._lengthCalculator = naiveLength
this._length = this._itemCount
for (var key in this._cache) {
this._cache[key].length = 1
}
} else {
this._lengthCalculator = lC
this._length = 0
for (var key in this._cache) {
this._cache[key].length = this._lengthCalculator(this._cache[key].value)
this._length += this._cache[key].length
}
}
if (this._length > this._max) trim(this)
}
, get : function () { return this._lengthCalculator }
, enumerable : true
})
Object.defineProperty(LRUCache.prototype, "length",
{ get : function () { return this._length }
, enumerable : true
})
Object.defineProperty(LRUCache.prototype, "itemCount",
{ get : function () { return this._itemCount }
, enumerable : true
})
LRUCache.prototype.forEach = function (fn, thisp) {
thisp = thisp || this
var i = 0
var itemCount = this._itemCount
for (var k = this._mru - 1; k >= 0 && i < itemCount; k--) if (this._lruList[k]) {
i++
var hit = this._lruList[k]
if (isStale(this, hit)) {
del(this, hit)
if (!this._allowStale) hit = undefined
}
if (hit) {
fn.call(thisp, hit.value, hit.key, this)
}
}
}
LRUCache.prototype.keys = function () {
var keys = new Array(this._itemCount)
var i = 0
for (var k = this._mru - 1; k >= 0 && i < this._itemCount; k--) if (this._lruList[k]) {
var hit = this._lruList[k]
keys[i++] = hit.key
}
return keys
}
LRUCache.prototype.values = function () {
var values = new Array(this._itemCount)
var i = 0
for (var k = this._mru - 1; k >= 0 && i < this._itemCount; k--) if (this._lruList[k]) {
var hit = this._lruList[k]
values[i++] = hit.value
}
return values
}
LRUCache.prototype.reset = function () {
if (this._dispose && this._cache) {
for (var k in this._cache) {
this._dispose(k, this._cache[k].value)
}
}
this._cache = Object.create(null) // hash of items by key
this._lruList = Object.create(null) // list of items in order of use recency
this._mru = 0 // most recently used
this._lru = 0 // least recently used
this._length = 0 // number of items in the list
this._itemCount = 0
}
LRUCache.prototype.dump = function () {
var arr = []
var i = 0
for (var k = this._mru - 1; k >= 0 && i < this._itemCount; k--) if (this._lruList[k]) {
var hit = this._lruList[k]
if (!isStale(this, hit)) {
//Do not store staled hits
++i
arr.push({
k: hit.key,
v: hit.value,
e: hit.now + (hit.maxAge || 0)
});
}
}
//arr has the most read first
return arr
}
LRUCache.prototype.dumpLru = function () {
return this._lruList
}
LRUCache.prototype.set = function (key, value, maxAge) {
maxAge = maxAge || this._maxAge
typeCheckKey(key)
var now = maxAge ? Date.now() : 0
var len = this._lengthCalculator(value)
if (hOP(this._cache, key)) {
if (len > this._max) {
del(this, this._cache[key])
return false
}
// dispose of the old one before overwriting
if (this._dispose)
this._dispose(key, this._cache[key].value)
this._cache[key].now = now
this._cache[key].maxAge = maxAge
this._cache[key].value = value
this._length += (len - this._cache[key].length)
this._cache[key].length = len
this.get(key)
if (this._length > this._max)
trim(this)
return true
}
var hit = new Entry(key, value, this._mru++, 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._lruList[hit.lu] = this._cache[key] = hit
this._itemCount ++
if (this._length > this._max)
trim(this)
return true
}
LRUCache.prototype.has = function (key) {
typeCheckKey(key)
if (!hOP(this._cache, key)) return false
var hit = this._cache[key]
if (isStale(this, hit)) {
return false
}
return true
}
LRUCache.prototype.get = function (key) {
typeCheckKey(key)
return get(this, key, true)
}
LRUCache.prototype.peek = function (key) {
typeCheckKey(key)
return get(this, key, false)
}
LRUCache.prototype.pop = function () {
var hit = this._lruList[this._lru]
del(this, hit)
return hit || null
}
LRUCache.prototype.del = function (key) {
typeCheckKey(key)
del(this, this._cache[key])
}
LRUCache.prototype.load = function (arr) {
//reset the cache
this.reset();
var now = Date.now()
//A previous serialized cache has the most recent items first
for (var l = arr.length - 1; l >= 0; l-- ) {
var hit = arr[l]
typeCheckKey(hit.k)
var 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 {
var maxAge = expiresAt - now
//dont add already expired items
if (maxAge > 0) this.set(hit.k, hit.v, maxAge)
}
}
}
function get (self, key, doUse) {
typeCheckKey(key)
var hit = self._cache[key]
if (hit) {
if (isStale(self, hit)) {
del(self, hit)
if (!self._allowStale) hit = undefined
} else {
if (doUse) use(self, hit)
}
if (hit) hit = hit.value
}
return hit
}
function isStale(self, hit) {
if (!hit || (!hit.maxAge && !self._maxAge)) return false
var stale = false;
var diff = Date.now() - hit.now
if (hit.maxAge) {
stale = diff > hit.maxAge
} else {
stale = self._maxAge && (diff > self._maxAge)
}
return stale;
}
function use (self, hit) {
shiftLU(self, hit)
hit.lu = self._mru ++
self._lruList[hit.lu] = hit
}
function trim (self) {
while (self._lru < self._mru && self._length > self._max)
del(self, self._lruList[self._lru])
}
function shiftLU (self, hit) {
delete self._lruList[ hit.lu ]
while (self._lru < self._mru && !self._lruList[self._lru]) self._lru ++
}
function del (self, hit) {
if (hit) {
if (self._dispose) self._dispose(hit.key, hit.value)
self._length -= hit.length
self._itemCount --
delete self._cache[ hit.key ]
shiftLU(self, hit)
}
}
// classy, since V8 prefers predictable objects.
function Entry (key, value, lu, length, now, maxAge) {
this.key = key
this.value = value
this.lu = lu
this.length = length
this.now = now
if (maxAge) this.maxAge = maxAge
}
})()
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