path: root/common/config.go

// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package common

import (
    "flag"
    "fmt"
    "os"

    "github.com/rakyll/globalconf"
)

// Config struct
type ConfigManager struct {
    ExecPath string
    Debug    bool
    Diff     bool
    DiffType string
    Paranoia bool
    VmType   int

    conf *globalconf.GlobalConf
}

// Read config
//
// Initialize Config from Config File
func ReadConfig(ConfigFile string, Datadir string, EnvPrefix string) *ConfigManager {
    if !FileExist(ConfigFile) {
        // create ConfigFile if it does not exist, otherwise
        // globalconf will panic when trying to persist flags.
        fmt.Printf("config file '%s' doesn't exist, creating it\n", ConfigFile)
        os.Create(ConfigFile)
    }
    g, err := globalconf.NewWithOptions(&globalconf.Options{
        Filename:  ConfigFile,
        EnvPrefix: EnvPrefix,
    })
    if err != nil {
        fmt.Println(err)
    } else {
        g.ParseAll()
    }
    cfg := &ConfigManager{ExecPath: Datadir, Debug: true, conf: g, Paranoia: true}
    return cfg
}

// provides persistence for flags
func (c *ConfigManager) Save(key string, value interface{}) {
    f := &flag.Flag{Name: key, Value: newConfValue(value)}
    c.conf.Set("", f)
}

func (c *ConfigManager) Delete(key string) {
    c.conf.Delete("", key)
}

// private type implementing flag.Value
type confValue struct {
    value string
}

// generic constructor to allow persising non-string values directly
func newConfValue(value interface{}) *confValue {
    return &confValue{fmt.Sprintf("%v", value)}
}

func (self confValue) String() string     { return self.value }
func (self confValue) Set(s string) error { self.value = s; return nil }