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// Copyright 2012 The Gorilla Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package context
import (
"net/http"
"sync"
"time"
)
var (
mutex sync.RWMutex
data = make(map[*http.Request]map[interface{}]interface{})
datat = make(map[*http.Request]int64)
)
// Set stores a value for a given key in a given request.
func Set(r *http.Request, key, val interface{}) {
mutex.Lock()
if data[r] == nil {
data[r] = make(map[interface{}]interface{})
datat[r] = time.Now().Unix()
}
data[r][key] = val
mutex.Unlock()
}
// Get returns a value stored for a given key in a given request.
func Get(r *http.Request, key interface{}) interface{} {
mutex.RLock()
if ctx := data[r]; ctx != nil {
value := ctx[key]
mutex.RUnlock()
return value
}
mutex.RUnlock()
return nil
}
// GetOk returns stored value and presence state like multi-value return of map access.
func GetOk(r *http.Request, key interface{}) (interface{}, bool) {
mutex.RLock()
if _, ok := data[r]; ok {
value, ok := data[r][key]
mutex.RUnlock()
return value, ok
}
mutex.RUnlock()
return nil, false
}
// GetAll returns all stored values for the request as a map. Nil is returned for invalid requests.
func GetAll(r *http.Request) map[interface{}]interface{} {
mutex.RLock()
if context, ok := data[r]; ok {
result := make(map[interface{}]interface{}, len(context))
for k, v := range context {
result[k] = v
}
mutex.RUnlock()
return result
}
mutex.RUnlock()
return nil
}
// GetAllOk returns all stored values for the request as a map and a boolean value that indicates if
// the request was registered.
func GetAllOk(r *http.Request) (map[interface{}]interface{}, bool) {
mutex.RLock()
context, ok := data[r]
result := make(map[interface{}]interface{}, len(context))
for k, v := range context {
result[k] = v
}
mutex.RUnlock()
return result, ok
}
// Delete removes a value stored for a given key in a given request.
func Delete(r *http.Request, key interface{}) {
mutex.Lock()
if data[r] != nil {
delete(data[r], key)
}
mutex.Unlock()
}
// Clear removes all values stored for a given request.
//
// This is usually called by a handler wrapper to clean up request
// variables at the end of a request lifetime. See ClearHandler().
func Clear(r *http.Request) {
mutex.Lock()
clear(r)
mutex.Unlock()
}
// clear is Clear without the lock.
func clear(r *http.Request) {
delete(data, r)
delete(datat, r)
}
// Purge removes request data stored for longer than maxAge, in seconds.
// It returns the amount of requests removed.
//
// If maxAge <= 0, all request data is removed.
//
// This is only used for sanity check: in case context cleaning was not
// properly set some request data can be kept forever, consuming an increasing
// amount of memory. In case this is detected, Purge() must be called
// periodically until the problem is fixed.
func Purge(maxAge int) int {
mutex.Lock()
count := 0
if maxAge <= 0 {
count = len(data)
data = make(map[*http.Request]map[interface{}]interface{})
datat = make(map[*http.Request]int64)
} else {
min := time.Now().Unix() - int64(maxAge)
for r := range data {
if datat[r] < min {
clear(r)
count++
}
}
}
mutex.Unlock()
return count
}
// ClearHandler wraps an http.Handler and clears request values at the end
// of a request lifetime.
func ClearHandler(h http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
defer Clear(r)
h.ServeHTTP(w, r)
})
}
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