vitess-gh/go/jscfg/jscfg.go

47 строки
1.2 KiB
Go

// Copyright 2012, Google Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package jscfg
// A few simple macros for keeping JSON config files human readable
// and consistent.
import (
"encoding/json"
"fmt"
"io/ioutil"
"code.google.com/p/vitess/go/ioutil2"
)
func ToJson(val interface{}) string {
data, err := json.MarshalIndent(val, "", " ")
// This is not strictly the spirit of panic. This is meant to be used
// where it would be a programming error to have json encoding fail.
if err != nil {
panic(err)
}
return string(data)
}
// Atomically write a marshaled structure to disk.
func WriteJson(filename string, val interface{}) error {
data, err := json.MarshalIndent(val, " ", " ")
if err != nil {
return fmt.Errorf("WriteJson failed: %v %v", filename, err)
}
return ioutil2.WriteFileAtomic(filename, data, 0660)
}
func ReadJson(filename string, val interface{}) error {
data, err := ioutil.ReadFile(filename)
if err != nil {
return fmt.Errorf("ReadJson failed: %T %v", val, err)
}
if err = json.Unmarshal(data, val); err != nil {
return fmt.Errorf("ReadJson failed: %T %v %v", val, filename, err)
}
return nil
}