seaweedfs/weed/util/config.go
2013-02-10 03:25:35 -08:00

129 lines
2.5 KiB
Go

// Copyright 2011 Numerotron Inc.
// Use of this source code is governed by an MIT-style license
// that can be found in the LICENSE file.
//
// Developed at www.stathat.com by Patrick Crosby
// Contact us on twitter with any questions: twitter.com/stat_hat
// The jconfig package provides a simple, basic configuration file parser using JSON.
package util
import (
"bytes"
"encoding/json"
"log"
"os"
)
type Config struct {
data map[string]interface{}
filename string
}
func newConfig() *Config {
result := new(Config)
result.data = make(map[string]interface{})
return result
}
// Loads config information from a JSON file
func LoadConfig(filename string) *Config {
result := newConfig()
result.filename = filename
err := result.parse()
if err != nil {
log.Fatalf("error loading config file %s: %s", filename, err)
}
return result
}
// Loads config information from a JSON string
func LoadConfigString(s string) *Config {
result := newConfig()
err := json.Unmarshal([]byte(s), &result.data)
if err != nil {
log.Fatalf("error parsing config string %s: %s", s, err)
}
return result
}
func (c *Config) StringMerge(s string) {
next := LoadConfigString(s)
c.merge(next.data)
}
func (c *Config) LoadMerge(filename string) {
next := LoadConfig(filename)
c.merge(next.data)
}
func (c *Config) merge(ndata map[string]interface{}) {
for k, v := range ndata {
c.data[k] = v
}
}
func (c *Config) parse() error {
f, err := os.Open(c.filename)
if err != nil {
return err
}
defer f.Close()
b := new(bytes.Buffer)
_, err = b.ReadFrom(f)
if err != nil {
return err
}
err = json.Unmarshal(b.Bytes(), &c.data)
if err != nil {
return err
}
return nil
}
// Returns a string for the config variable key
func (c *Config) GetString(key string) string {
result, present := c.data[key]
if !present {
return ""
}
return result.(string)
}
// Returns an int for the config variable key
func (c *Config) GetInt(key string) int {
x, ok := c.data[key]
if !ok {
return -1
}
return int(x.(float64))
}
// Returns a float for the config variable key
func (c *Config) GetFloat(key string) float64 {
x, ok := c.data[key]
if !ok {
return -1
}
return x.(float64)
}
// Returns a bool for the config variable key
func (c *Config) GetBool(key string) bool {
x, ok := c.data[key]
if !ok {
return false
}
return x.(bool)
}
// Returns an array for the config variable key
func (c *Config) GetArray(key string) []interface{} {
result, present := c.data[key]
if !present {
return []interface{}(nil)
}
return result.([]interface{})
}