oauth2/cache.go

60 lines
1.3 KiB
Go

// Copyright 2014 The oauth2 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 oauth2
import (
"encoding/json"
"io/ioutil"
"os"
)
// Cache represents a token cacher.
type Cache interface {
// Reads a cached token.
// It may return a nil value if no token is cached.
Read() (token *Token, err error)
// Write writes a token to the specified file.
Write(token *Token)
}
// NewFileCache creates a new file cache.
func NewFileCache(filename string) (cache *FileCache) {
return &FileCache{filename: filename}
}
// FileCache represents a file based token cacher.
type FileCache struct {
// Handler to be invoked if an error occurs during writing.
ErrorHandler func(error)
filename string
}
func (f *FileCache) Read() (token *Token, err error) {
data, err := ioutil.ReadFile(f.filename)
if os.IsNotExist(err) {
// no token has cached before, skip reading
return nil, nil
}
if err != nil {
return
}
if err = json.Unmarshal(data, &token); err != nil {
return
}
return
}
// Write writes a token to the specified file.
func (f *FileCache) Write(token *Token) {
data, err := json.Marshal(token)
if err == nil {
err = ioutil.WriteFile(f.filename, data, 0644)
}
if f.ErrorHandler != nil {
f.ErrorHandler(err)
}
}