config add dump support

config/config.go

@@ -1,7 +1,10 @@
 package config
 
 import (
+	"bytes"
 	"github.com/BurntSushi/toml"
+	"github.com/siddontang/go/ioutil2"
+	"io"
 	"io/ioutil"
 )
 
@@ -123,3 +126,19 @@ func (cfg *LevelDBConfig) Adjust() {
 		cfg.MaxOpenFiles = 1024
 	}
 }
+
+func (cfg *Config) Dump(w io.Writer) error {
+	e := toml.NewEncoder(w)
+	e.Indent = ""
+	return e.Encode(cfg)
+}
+
+func (cfg *Config) DumpFile(fileName string) error {
+	var b bytes.Buffer
+
+	if err := cfg.Dump(&b); err != nil {
+		return err
+	}
+
+	return ioutil2.WriteFileAtomic(fileName, b.Bytes(), 0644)
+}

config/config_test.go

@@ -1,13 +1,25 @@
 package config
 
 import (
+	"os"
+	"reflect"
 	"testing"
 )
 
 func TestConfig(t *testing.T) {
-	_, err := NewConfigWithFile("./ledis.toml")
+	cfg, err := NewConfigWithFile("./config.toml")
 	if err != nil {
 		t.Fatal(err)
 	}
 
+	defer os.Remove("./config.toml.bak")
+	if err := cfg.DumpFile("./config.toml.bak"); err != nil {
+		t.Fatal(err)
+	}
+
+	if c, err := NewConfigWithFile("./config.toml.bak"); err != nil {
+		t.Fatal(err)
+	} else if !reflect.DeepEqual(cfg, c) {
+		t.Fatal("must equal")
+	}
 }