cachehandler

README

cachehandler

Package cachehandler provides net/http middleware that caches HTTP responses.

Inspired by go-chi/stampede. https://github.com/go-chi/stampede

The HTTP response is stored in the cache and calls to handlers with the same key are merged.

Example

package cachehandler_test

import (
	"fmt"
	"net/http"
	"net/http/httptest"
	"time"

	"github.com/johejo/cachehandler"
)

func Example() {
	mux := http.NewServeMux()
	m := cachehandler.NewMiddleware(1000, 1*time.Hour, cachehandler.BasicKeyFunc())
	var called int
	mux.Handle("/", m.Wrap(http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
		called++
	})))

	ts := httptest.NewServer(mux)
	defer ts.Close()

	resp1, err := http.Get(ts.URL + "/foo")
	if err != nil {
		panic(err)
	}
	defer resp1.Body.Close()

	resp2, err := http.Get(ts.URL + "/foo")
	if err != nil {
		panic(err)
	}
	defer resp2.Body.Close()

	fmt.Printf("called %d", called)

	// Output:
	// called 1
}

License

MIT

Author

Mitsuo Heijo

Documentation

Overview

Package cachehandler provides net/http middleware that caches HTTP responses. Inspired by go-chi/stampede. https://github.com/go-chi/stampede The HTTP response is stored in the cache and calls to handlers with the same key are merged.

Example

package main

import (
	"fmt"
	"net/http"
	"net/http/httptest"
	"time"

	"github.com/johejo/cachehandler"
)

func main() {
	mux := http.NewServeMux()
	m := cachehandler.NewMiddleware(1000, 1*time.Hour, cachehandler.BasicKeyFunc())
	var called int
	mux.Handle("/", m.Wrap(http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
		called++
	})))

	ts := httptest.NewServer(mux)
	defer ts.Close()

	resp1, err := http.Get(ts.URL + "/foo")
	if err != nil {
		panic(err)
	}
	defer resp1.Body.Close()

	resp2, err := http.Get(ts.URL + "/foo")
	if err != nil {
		panic(err)
	}
	defer resp2.Body.Close()

	fmt.Printf("called %d", called)

}

Output:

called 1

Index

• type CacheStats
• type KeyFunc
  • func BasicKeyFunc() KeyFunc
• type Middleware
  • func NewMiddleware(max int, ttl time.Duration, keyFn KeyFunc) *Middleware
  • func (m *Middleware) Stats() CacheStats
  • func (m *Middleware) Wrap(next http.Handler) http.Handler

Examples

• Package

Types

type CacheStats

type CacheStats struct {
	Hits, Misses   int // cache effectiveness
	Added, Evicted int // number of added and evicted records
}

CacheStats describes cache statistics.

type KeyFunc

type KeyFunc func(w http.ResponseWriter, r *http.Request) (string, bool)

KeyFunc is type that returns key for cache. If the key func returns false, the Middleware does not call next handler chains.

func BasicKeyFunc

func BasicKeyFunc() KeyFunc

BasicKeyFunc returns a KeyFunc that uses http method and url as key.

type Middleware

type Middleware struct {
	// contains filtered or unexported fields
}

Middleware describes cachehandler

func NewMiddleware

func NewMiddleware(max int, ttl time.Duration, keyFn KeyFunc) *Middleware

NewMiddleware returns net/http middleware that caches http responses.

func (*Middleware) Stats

func (m *Middleware) Stats() CacheStats

func (*Middleware) Wrap

func (m *Middleware) Wrap(next http.Handler) http.Handler