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author | Florian Dold <florian.dold@gmail.com> | 2016-10-10 03:43:44 +0200 |
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committer | Florian Dold <florian.dold@gmail.com> | 2016-10-10 03:43:44 +0200 |
commit | abd94a7f5a50f43c797a11b53549ae48fff667c3 (patch) | |
tree | ab8ed457f65cdd72e13e0571d2975729428f1551 /node_modules/lru-cache/lib | |
parent | a0247c6a3fd6a09a41a7e35a3441324c4dcb58be (diff) | |
download | wallet-core-abd94a7f5a50f43c797a11b53549ae48fff667c3.tar.xz |
add node_modules to address #4364
Diffstat (limited to 'node_modules/lru-cache/lib')
-rw-r--r-- | node_modules/lru-cache/lib/lru-cache.js | 334 |
1 files changed, 334 insertions, 0 deletions
diff --git a/node_modules/lru-cache/lib/lru-cache.js b/node_modules/lru-cache/lib/lru-cache.js new file mode 100644 index 000000000..2bbe653be --- /dev/null +++ b/node_modules/lru-cache/lib/lru-cache.js @@ -0,0 +1,334 @@ +;(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 +} + +})() |