algebrite

Version:

Computer Algebra System in Coffeescript

github.com/davidedc/Algebrite

davidedc/Algebrite

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text/coffeescript

class DoubleLinkedList constructor: -> @headNode = @tailNode = null # removes the last element. Since # we move used elements to head, the last # element is *probably* a relatively # unused one. remove: (node) -> if node.pre node.pre.next = node.next else @headNode = node.next if node.next node.next.pre = node.pre else @tailNode = node.pre insertBeginning: (node) -> if @headNode node.next = @headNode @headNode.pre = node @headNode = node else @headNode = @tailNode = node moveToHead: (node) -> @remove node @insertBeginning node clear: -> @headNode = @tailNode = null class LRUCache constructor: (@capacity = 10, @maxAge = 60000) -> @_linkList = new DoubleLinkedList() @reset() @hitCount = @missCount = 0 resetHitMissCount: -> @hitCount = @missCount = 0 keys: -> return Object.keys @_hash values: -> values = @keys().map (key) => @get key return values.filter (v) -> v isnt undefined remove: (key) -> if @_hash[key]? node = @_hash[key] @_linkList.remove node delete @_hash[key] if node.data.onDispose then node.data.onDispose.call this, node.data.key, node.data.value @size-- reset: -> @_hash = {} @size = 0 @resetHitMissCount() @_linkList.clear() set: (key, value, onDispose) -> node = @_hash[key] if node node.data.value = value node.data.onDispose = onDispose @_refreshNode node else if @size is @capacity then @remove @_linkList.tailNode.data.key createNode = (data, pre, next) -> {data, pre, next} node = createNode {key, value, onDispose} node.data.lastVisitTime = Date.now() @_linkList.insertBeginning node @_hash[key] = node @size++ return get: (key) -> node = @_hash[key] if !node @missCount++ return undefined if @_isExpiredNode node @remove key @missCount++ return undefined @_refreshNode node @hitCount++ return node.data.value _refreshNode: (node) -> node.data.lastVisitTime = Date.now() @_linkList.moveToHead node _isExpiredNode: (node) -> return Date.now() - node.data.lastVisitTime > @maxAge has: (key) -> return @_hash[key]?