1 files changed, 96 insertions, 0 deletions
diff --git a/deps/npm/node_modules/aws4/lru.js b/deps/npm/node_modules/aws4/lru.js
new file mode 100644
index 0000000000..333f66a443
--- /dev/null
+++ b/deps/npm/node_modules/aws4/lru.js
@@ -0,0 +1,96 @@
+module.exports = function(size) {
+  return new LruCache(size)
+}
+
+function LruCache(size) {
+  this.capacity = size | 0
+  this.map = Object.create(null)
+  this.list = new DoublyLinkedList()
+}
+
+LruCache.prototype.get = function(key) {
+  var node = this.map[key]
+  if (node == null) return undefined
+  this.used(node)
+  return node.val
+}
+
+LruCache.prototype.set = function(key, val) {
+  var node = this.map[key]
+  if (node != null) {
+    node.val = val
+  } else {
+    if (!this.capacity) this.prune()
+    if (!this.capacity) return false
+    node = new DoublyLinkedNode(key, val)
+    this.map[key] = node
+    this.capacity--
+  }
+  this.used(node)
+  return true
+}
+
+LruCache.prototype.used = function(node) {
+  this.list.moveToFront(node)
+}
+
+LruCache.prototype.prune = function() {
+  var node = this.list.pop()
+  if (node != null) {
+    delete this.map[node.key]
+    this.capacity++
+  }
+}
+
+
+function DoublyLinkedList() {
+  this.firstNode = null
+  this.lastNode = null
+}
+
+DoublyLinkedList.prototype.moveToFront = function(node) {
+  if (this.firstNode == node) return
+
+  this.remove(node)
+
+  if (this.firstNode == null) {
+    this.firstNode = node
+    this.lastNode = node
+    node.prev = null
+    node.next = null
+  } else {
+    node.prev = null
+    node.next = this.firstNode
+    node.next.prev = node
+    this.firstNode = node
+  }
+}
+
+DoublyLinkedList.prototype.pop = function() {
+  var lastNode = this.lastNode
+  if (lastNode != null) {
+    this.remove(lastNode)
+  }
+  return lastNode
+}
+
+DoublyLinkedList.prototype.remove = function(node) {
+  if (this.firstNode == node) {
+    this.firstNode = node.next
+  } else if (node.prev != null) {
+    node.prev.next = node.next
+  }
+  if (this.lastNode == node) {
+    this.lastNode = node.prev
+  } else if (node.next != null) {
+    node.next.prev = node.prev
+  }
+}
+
+
+function DoublyLinkedNode(key, val) {
+  this.key = key
+  this.val = val
+  this.prev = null
+  this.next = null
+}