open-nomad/helper/raftutil/msgpack.go
2020-08-31 08:45:59 -04:00

93 lines
1.8 KiB
Go

package raftutil
import (
"bytes"
"fmt"
"time"
"unicode"
"github.com/hashicorp/go-msgpack/codec"
"github.com/hashicorp/nomad/nomad/structs"
)
// fixTime converts any suspected time.Time binary string representation to time.Time
func fixTime(v interface{}) {
switch v2 := v.(type) {
case map[string]interface{}:
for ek, ev := range v2 {
if s, ok := ev.(string); ok {
t, err := maybeDecodeTime(s)
if err == nil && isReasonableTime(t) {
v2[ek] = *t
}
} else {
fixTime(ev)
}
}
case []interface{}:
for _, e := range v2 {
fixTime(e)
}
default:
return
}
}
// maybeDecodeTime returns a time.Time representation if the string represents a msgpack
// representation of a date.
func maybeDecodeTime(v string) (*time.Time, error) {
if isASCII(v) {
return nil, fmt.Errorf("simple ascii string")
}
tt := &time.Time{}
var err error
err = tt.UnmarshalBinary([]byte(v))
if err == nil {
return tt, nil
}
switch len(v) {
case 4, 8, 12:
default:
return nil, fmt.Errorf("bad length: %d", len(v))
}
var nb bytes.Buffer
err = codec.NewEncoder(&nb, structs.MsgpackHandle).Encode(v)
if err != nil {
return nil, err
}
err = codec.NewDecoder(&nb, structs.MsgpackHandle).Decode(tt)
if err != nil {
return nil, err
}
return tt, nil
}
// isASCII returns true if all string characters are ASCII characters
func isASCII(s string) bool {
for i := 0; i < len(s); i++ {
if s[i] > unicode.MaxASCII {
return false
}
}
return true
}
// isReasonableTime returns true if the time is within some N years of current time
//
// It's can be used to rule out bad date interpretation (e.g. dates million years away).
func isReasonableTime(t *time.Time) bool {
if t.IsZero() {
return true
}
now := time.Now()
return t.Before(now.AddDate(20, 0, 0)) && t.After(now.AddDate(-20, 0, 0))
}