status-go/mailserver/db_key.go

66 lines
1.4 KiB
Go

package mailserver
import (
"encoding/binary"
"errors"
"github.com/ethereum/go-ethereum/common"
)
const (
// DBKeyLength is a size of the envelope key.
DBKeyLength = common.HashLength + timestampLength
)
var (
// ErrInvalidByteSize is returned when DBKey can't be created
// from a byte slice because it has invalid length.
ErrInvalidByteSize = errors.New("byte slice has invalid length")
)
// DBKey key to be stored in a db.
type DBKey struct {
timestamp uint32
hash common.Hash
raw []byte
}
// Bytes returns a bytes representation of the DBKey.
func (k *DBKey) Bytes() []byte {
return k.raw
}
// NewDBKey creates a new DBKey with the given values.
func NewDBKey(timestamp uint32, h common.Hash) *DBKey {
var k DBKey
k.timestamp = timestamp
k.hash = h
k.raw = make([]byte, DBKeyLength)
binary.BigEndian.PutUint32(k.raw, k.timestamp)
copy(k.raw[4:], k.hash[:])
return &k
}
// NewDBKeyFromBytes creates a DBKey from a byte slice.
func NewDBKeyFromBytes(b []byte) (*DBKey, error) {
if len(b) != DBKeyLength {
return nil, ErrInvalidByteSize
}
return &DBKey{
raw: b,
timestamp: binary.BigEndian.Uint32(b),
hash: common.BytesToHash(b[4:]),
}, nil
}
// mustNewDBKeyFromBytes panics if creating a key from a byte slice fails.
// Check if a byte slice has DBKeyLength length before using it.
func mustNewDBKeyFromBytes(b []byte) *DBKey {
k, err := NewDBKeyFromBytes(b)
if err != nil {
panic(err)
}
return k
}