feat(cache-control): add cache control handler (#13)

* add cache control

* feat(cache-control): add cache control handler

* chore(cache-control): remove unused function

* fix(expiry): add condition for expired response

* chore(example): add example how to use

Author: bxcodec

README.md

@@ -79,8 +79,13 @@ for i:=0; i< 10; i++ {
 //TODO(bxcodec)
 
 
-## Contribution
 
+## Inspirations and Thanks
+- [pquerna/cachecontrol](github.com/pquerna/cachecontrol) for the Cache-Header Extraction
+
+
+## Contribution
 ---
 
-To contrib to this project, you can open a PR or an issue.
+To contrib to this project, you can open a PR or an issue.
+

cache/cache.go

@@ -16,19 +16,17 @@ var (
 
 // Interactor ...
 type Interactor interface {
-	Set(key string, value CachedResponse) error
+	Set(key string, value CachedResponse, duration time.Duration) error
 	Get(key string) (CachedResponse, error)
 	Delete(key string) error
 }
 
 // CachedResponse represent the cacher struct item
 type CachedResponse struct {
-	// StatusCode     int       `json:"statusCode"`
-	DumpedResponse []byte `json:"response"`
-	// DumpedBody     []byte    `json:"body"`
-	RequestURI    string    `json:"requestUri"`
-	RequestMethod string    `json:"requestMethod"`
-	CachedTime    time.Time `json:"cachedTime"`
+	DumpedResponse []byte    `json:"response"`      // The dumped response body
+	RequestURI     string    `json:"requestUri"`    // The requestURI of the response
+	RequestMethod  string    `json:"requestMethod"` // The HTTP Method that call the request for this response
+	CachedTime     time.Time `json:"cachedTime"`    // The timestamp when this response is Cached
 }
 
 // Validate will validate the cached response
@@ -48,6 +46,5 @@ func (c *CachedResponse) Validate() (err error) {
 	if c.CachedTime.IsZero() {
 		return ErrInvalidCachedResponse
 	}
-
 	return
 }

cache/inmem/inmem.go

@@ -1,6 +1,8 @@
 package inmem
 
 import (
+	"time"
+
 	memcache "github.com/bxcodec/gotcha/cache"
 	"github.com/bxcodec/hache/cache"
 )
@@ -16,7 +18,8 @@ func NewCache(c memcache.Cache) cache.Interactor {
 	}
 }
 
-func (i *inmemCache) Set(key string, value cache.CachedResponse) (err error) {
+func (i *inmemCache) Set(key string, value cache.CachedResponse, duration time.Duration) (err error) {
+	// TODO(bxcodec): add custom duration here based on user response result on the fly
 	return i.cache.Set(key, value)
 }
 

control/cache-control.go

@@ -0,0 +1,31 @@
+package control
+
+import (
+	// "github.com/pquerna/cachecontrol/cacheobject"
+	cacheobject "github.com/bxcodec/hache/control/cacheheader"
+	"net/http"
+	"time"
+)
+
+type Options struct {
+	// Set to True for a prviate cache, which is not shared amoung users (eg, in a browser)
+	// Set to False for a "shared" cache, which is more common in a server context.
+	PrivateCache bool
+}
+
+// Given an HTTP Request, the future Status Code, and an ResponseWriter,
+// determine the possible reasons a response SHOULD NOT be cached.
+func CachableResponseWriter(req *http.Request,
+	statusCode int,
+	resp http.ResponseWriter,
+	opts Options) ([]cacheobject.Reason, time.Time, error) {
+	return cacheobject.UsingRequestResponse(req, statusCode, resp.Header(), opts.PrivateCache)
+}
+
+// Given an HTTP Request and Response, determine the possible reasons a response SHOULD NOT
+// be cached.
+func CachableResponse(req *http.Request,
+	resp *http.Response,
+	opts Options) ([]cacheobject.Reason, time.Time, error) {
+	return cacheobject.UsingRequestResponse(req, resp.StatusCode, resp.Header, opts.PrivateCache)
+}