100 lines
2.0 KiB
Go
100 lines
2.0 KiB
Go
package handlers
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import (
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"github.com/hunterlong/statping/core"
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"net/http"
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"net/http/httptest"
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"sync"
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"time"
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)
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var CacheStorage Cacher
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type Cacher interface {
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Get(key string) []byte
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Delete(key string)
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Set(key string, content []byte, duration time.Duration)
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}
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// Item is a cached reference
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type Item struct {
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Content []byte
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Expiration int64
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}
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// Expired returns true if the item has expired.
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func (item Item) Expired() bool {
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if item.Expiration == 0 {
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return false
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}
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return time.Now().UnixNano() > item.Expiration
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}
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//Storage mecanism for caching strings in memory
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type Storage struct {
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items map[string]Item
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mu *sync.RWMutex
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}
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//NewStorage creates a new in memory CacheStorage
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func NewStorage() *Storage {
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return &Storage{
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items: make(map[string]Item),
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mu: &sync.RWMutex{},
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}
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}
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//Get a cached content by key
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func (s Storage) Get(key string) []byte {
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item := s.items[key]
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if item.Expired() {
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CacheStorage.Delete(key)
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return nil
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}
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return item.Content
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}
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func (s Storage) Delete(key string) {
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s.mu.Lock()
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defer s.mu.Unlock()
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delete(s.items, key)
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}
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//Set a cached content by key
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func (s Storage) Set(key string, content []byte, duration time.Duration) {
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s.mu.Lock()
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defer s.mu.Unlock()
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s.items[key] = Item{
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Content: content,
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Expiration: time.Now().Add(duration).UnixNano(),
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}
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}
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func cached(duration, contentType string, handler func(w http.ResponseWriter, r *http.Request)) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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content := CacheStorage.Get(r.RequestURI)
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w.Header().Set("Content-Type", contentType)
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if core.Configs == nil {
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handler(w, r)
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return
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}
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if content != nil {
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w.Write(content)
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} else {
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c := httptest.NewRecorder()
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handler(c, r)
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content := c.Body.Bytes()
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result := c.Result()
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if result.StatusCode != 200 {
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w.WriteHeader(result.StatusCode)
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w.Write(content)
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return
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}
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w.Write(content)
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if d, err := time.ParseDuration(duration); err == nil {
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go CacheStorage.Set(r.RequestURI, content, d)
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}
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}
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})
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}
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