diff --git a/redis/redis.go b/redis/redis.go new file mode 100644 index 0000000..3143d44 --- /dev/null +++ b/redis/redis.go @@ -0,0 +1,43 @@ +// Package redis provides a redis interface for http caching. +package redis + +import ( + "github.com/garyburd/redigo/redis" + "github.com/gregjones/httpcache" +) + +// cache is an implementation of httpcache.Cache that caches responses in a +// redis server. +type cache struct { + redis.Conn +} + +// cacheKey modifies an httpcache key for use in redis. Specifically, it +// prefixes keys to avoid collision with other data stored in redis. +func cacheKey(key string) string { + return "rediscache:" + key +} + +// Get returns the response corresponding to key if present. +func (c cache) Get(key string) (resp []byte, ok bool) { + item, err := redis.Bytes(c.Do("GET", cacheKey(key))) + if err != nil { + return nil, false + } + return item, true +} + +// Set saves a response to the cache as key. +func (c cache) Set(key string, resp []byte) { + c.Do("SET", cacheKey(key), resp) +} + +// Delete removes the response with key from the cache. +func (c cache) Delete(key string) { + c.Do("DEL", cacheKey(key)) +} + +// NewWithClient returns a new Cache with the given redis connection. +func NewWithClient(client redis.Conn) httpcache.Cache { + return cache{client} +} diff --git a/redis/redis_test.go b/redis/redis_test.go new file mode 100644 index 0000000..72f6f61 --- /dev/null +++ b/redis/redis_test.go @@ -0,0 +1,43 @@ +package redis + +import ( + "bytes" + "testing" + + "github.com/garyburd/redigo/redis" +) + +func TestRedisCache(t *testing.T) { + conn, err := redis.Dial("tcp", "localhost:6379") + if err != nil { + // TODO: rather than skip the test, fall back to a faked redis server + t.Skipf("skipping test; no server running at localhost:6379") + } + conn.Do("FLUSHALL") + + cache := NewWithClient(conn) + + key := "testKey" + _, ok := cache.Get(key) + if ok { + t.Fatal("retrieved key before adding it") + } + + val := []byte("some bytes") + cache.Set(key, val) + + retVal, ok := cache.Get(key) + if !ok { + t.Fatal("could not retrieve an element we just added") + } + if !bytes.Equal(retVal, val) { + t.Fatal("retrieved a different value than what we put in") + } + + cache.Delete(key) + + _, ok = cache.Get(key) + if ok { + t.Fatal("deleted key still present") + } +}