blob: 462f0e5419eb59e6cff27a73d9e33fb4fa0d449f [file] [log] [blame]
// +build !appengine
// Package memcache provides an implementation of httpcache.Cache that uses
// gomemcache to store cached responses.
// When built for Google App Engine, this package will provide an
// implementation that uses App Engine's memcache service. See the
// appengine.go file in this package for details.
package memcache
import (
// Cache is an implementation of httpcache.Cache that caches responses in a
// memcache server.
type Cache struct {
// cacheKey modifies an httpcache key for use in memcache. Specifically, it
// prefixes keys to avoid collision with other data stored in memcache.
func cacheKey(key string) string {
return "httpcache:" + key
// Get returns the response corresponding to key if present.
func (c *Cache) Get(key string) (resp []byte, ok bool) {
item, err := c.Client.Get(cacheKey(key))
if err != nil {
return nil, false
return item.Value, true
// Set saves a response to the cache as key.
func (c *Cache) Set(key string, resp []byte) {
item := &memcache.Item{
Key: cacheKey(key),
Value: resp,
// Delete removes the response with key from the cache.
func (c *Cache) Delete(key string) {
// New returns a new Cache using the provided memcache server(s) with equal
// weight. If a server is listed multiple times, it gets a proportional amount
// of weight.
func New(server ...string) *Cache {
return NewWithClient(memcache.New(server...))
// NewWithClient returns a new Cache with the given memcache client.
func NewWithClient(client *memcache.Client) *Cache {
return &Cache{client}