terraform: add a format byte to the diff file so we can iterate maybe

This commit is contained in:
Mitchell Hashimoto 2014-06-18 20:46:13 -07:00
parent e5b82931ff
commit 333ad153d0
1 changed files with 24 additions and 0 deletions

View File

@ -3,6 +3,7 @@ package terraform
import (
"bytes"
"encoding/gob"
"errors"
"fmt"
"io"
"sort"
@ -10,6 +11,8 @@ import (
"sync"
)
const diffFormatByte byte = 1
// Diff tracks the differences between resources to apply.
type Diff struct {
Resources map[string]*ResourceDiff
@ -21,6 +24,19 @@ type Diff struct {
func ReadDiff(src io.Reader) (*Diff, error) {
var result *Diff
var formatByte [1]byte
n, err := src.Read(formatByte[:])
if err != nil {
return nil, err
}
if n != len(formatByte) {
return nil, errors.New("failed to read diff version byte")
}
if formatByte[0] != diffFormatByte {
return nil, fmt.Errorf("unknown diff file version: %d", formatByte[0])
}
dec := gob.NewDecoder(src)
if err := dec.Decode(&result); err != nil {
return nil, err
@ -31,6 +47,14 @@ func ReadDiff(src io.Reader) (*Diff, error) {
// WriteDiff writes a diff somewhere in a binary format.
func WriteDiff(d *Diff, dst io.Writer) error {
n, err := dst.Write([]byte{diffFormatByte})
if err != nil {
return err
}
if n != 1 {
return errors.New("failed to write diff version byte")
}
return gob.NewEncoder(dst).Encode(d)
}