Add LRU cache

Author: thedae

go.mod

@@ -1,3 +1,5 @@
 module github.com/krakendio/httpcache
 
 go 1.19
+
+require github.com/hashicorp/golang-lru v1.0.2

go.sum

@@ -0,0 +1,2 @@
+github.com/hashicorp/golang-lru v1.0.2 h1:dV3g9Z/unq5DpblPpw+Oqcv4dU/1omnb4Ok8iPY6p1c=
+github.com/hashicorp/golang-lru v1.0.2/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=

httpcache.go

@@ -13,7 +13,6 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"strings"
-	"sync"
 	"time"
 )
 
@@ -57,40 +56,6 @@ func CachedResponse(c Cache, req *http.Request) (resp *http.Response, err error)
 	return http.ReadResponse(bufio.NewReader(b), req)
 }
 
-// MemoryCache is an implemtation of Cache that stores responses in an in-memory map.
-type MemoryCache struct {
-	mu    sync.RWMutex
-	items map[string][]byte
-}
-
-// Get returns the []byte representation of the response and true if present, false if not
-func (c *MemoryCache) Get(key string) (resp []byte, ok bool) {
-	c.mu.RLock()
-	resp, ok = c.items[key]
-	c.mu.RUnlock()
-	return resp, ok
-}
-
-// Set saves response resp to the cache with key
-func (c *MemoryCache) Set(key string, resp []byte) {
-	c.mu.Lock()
-	c.items[key] = resp
-	c.mu.Unlock()
-}
-
-// Delete removes key from the cache
-func (c *MemoryCache) Delete(key string) {
-	c.mu.Lock()
-	delete(c.items, key)
-	c.mu.Unlock()
-}
-
-// NewMemoryCache returns a new Cache that will store items in an in-memory map
-func NewMemoryCache() *MemoryCache {
-	c := &MemoryCache{items: map[string][]byte{}}
-	return c
-}
-
 // Transport is an implementation of http.RoundTripper that will return values from a cache
 // where possible (avoiding a network request) and will additionally add validators (etag/if-modified-since)
 // to repeated requests allowing servers to return 304 / Not Modified
@@ -552,3 +517,9 @@ func NewMemoryCacheTransport() *Transport {
 	t := NewTransport(c)
 	return t
 }
+
+func NewLruCacheTransport(size int) *Transport {
+	c := NewLruCache(size)
+	t := NewTransport(c)
+	return t
+}

lru.go

@@ -0,0 +1,30 @@
+package httpcache
+
+import (
+	lru "github.com/hashicorp/golang-lru"
+)
+
+type LruCache struct {
+	cache *lru.Cache
+}
+
+func NewLruCache(size int) *LruCache {
+	c, _ := lru.New(size)
+	return &LruCache{cache: c}
+}
+
+func (c *LruCache) Get(key string) ([]byte, bool) {
+	v, ok := c.cache.Get(key)
+	if !ok {
+		return nil, false
+	}
+	return v.([]byte), true
+}
+
+func (c *LruCache) Set(key string, resp []byte) {
+	c.cache.Add(key, resp)
+}
+
+func (c *LruCache) Delete(key string) {
+	c.cache.Remove(key)
+}

memory.go

@@ -0,0 +1,37 @@
+package httpcache
+
+import "sync"
+
+// MemoryCache is an implemtation of Cache that stores responses in an in-memory map.
+type MemoryCache struct {
+	mu    sync.RWMutex
+	items map[string][]byte
+}
+
+// Get returns the []byte representation of the response and true if present, false if not
+func (c *MemoryCache) Get(key string) (resp []byte, ok bool) {
+	c.mu.RLock()
+	resp, ok = c.items[key]
+	c.mu.RUnlock()
+	return resp, ok
+}
+
+// Set saves response resp to the cache with key
+func (c *MemoryCache) Set(key string, resp []byte) {
+	c.mu.Lock()
+	c.items[key] = resp
+	c.mu.Unlock()
+}
+
+// Delete removes key from the cache
+func (c *MemoryCache) Delete(key string) {
+	c.mu.Lock()
+	delete(c.items, key)
+	c.mu.Unlock()
+}
+
+// NewMemoryCache returns a new Cache that will store items in an in-memory map
+func NewMemoryCache() *MemoryCache {
+	c := &MemoryCache{items: map[string][]byte{}}
+	return c
+}

test/test_test.go

@@ -10,3 +10,7 @@ import (
 func TestMemoryCache(t *testing.T) {
 	test.Cache(t, httpcache.NewMemoryCache())
 }
+
+func TestLruCache(t *testing.T) {
+	test.Cache(t, httpcache.NewLruCache(10))
+}