functions: remove lru (#399)

api/server/internal/routecache/lru.go

@@ -1,77 +0,0 @@
-// Package routecache is meant to assist in resolving the most used routes at
-// an application. Implemented as a LRU, it returns always its full context for
-// iteration at the router handler.
-package routecache
-
-// based on groupcache's LRU
-
-import (
-	"container/list"
-
-	"github.com/iron-io/functions/api/models"
-)
-
-// Cache holds an internal linkedlist for hotness management. It is not safe
-// for concurrent use, must be guarded externally.
-type Cache struct {
-	MaxEntries int
-
-	ll    *list.List
-	cache map[string]*list.Element
-}
-
-// New returns a route cache.
-func New(maxentries int) *Cache {
-	return &Cache{
-		MaxEntries: maxentries,
-		ll:         list.New(),
-		cache:      make(map[string]*list.Element),
-	}
-}
-
-// Refresh updates internal linkedlist either adding a new route to the front,
-// or moving it to the front when used. It will discard seldom used routes.
-func (c *Cache) Refresh(route *models.Route) {
-	if c.cache == nil {
-		return
-	}
-
-	if ee, ok := c.cache[route.Path]; ok {
-		c.ll.MoveToFront(ee)
-		ee.Value = route
-		return
-	}
-
-	ele := c.ll.PushFront(route)
-	c.cache[route.Path] = ele
-	if c.MaxEntries != 0 && c.ll.Len() > c.MaxEntries {
-		c.removeOldest()
-	}
-}
-
-// Get looks up a path's route from the cache.
-func (c *Cache) Get(path string) (route *models.Route, ok bool) {
-	if c.cache == nil {
-		return
-	}
-	if ele, hit := c.cache[path]; hit {
-		c.ll.MoveToFront(ele)
-		return ele.Value.(*models.Route), true
-	}
-	return
-}
-
-func (c *Cache) removeOldest() {
-	if c.cache == nil {
-		return
-	}
-	if ele := c.ll.Back(); ele != nil {
-		c.removeElement(ele)
-	}
-}
-
-func (c *Cache) removeElement(e *list.Element) {
-	c.ll.Remove(e)
-	kv := e.Value.(*models.Route)
-	delete(c.cache, kv.Path)
-}