neo-go/pkg/network/payload/headers.go
2020-03-03 17:21:42 +03:00

49 lines
1.1 KiB
Go

package payload
import (
"github.com/nspcc-dev/neo-go/pkg/core/block"
"github.com/nspcc-dev/neo-go/pkg/io"
"github.com/pkg/errors"
)
// Headers payload.
type Headers struct {
Hdrs []*block.Header
}
// Users can at most request 2k header.
const (
MaxHeadersAllowed = 2000
)
// ErrTooManyHeaders is an error returned when too many headers were received.
var ErrTooManyHeaders = errors.Errorf("too many headers were received (max: %d)", MaxHeadersAllowed)
// DecodeBinary implements Serializable interface.
func (p *Headers) DecodeBinary(br *io.BinReader) {
lenHeaders := br.ReadVarUint()
var limitExceeded bool
// C# node does it silently
if limitExceeded = lenHeaders > MaxHeadersAllowed; limitExceeded {
lenHeaders = MaxHeadersAllowed
}
p.Hdrs = make([]*block.Header, lenHeaders)
for i := 0; i < int(lenHeaders); i++ {
header := &block.Header{}
header.DecodeBinary(br)
p.Hdrs[i] = header
}
if br.Err == nil && limitExceeded {
br.Err = ErrTooManyHeaders
}
}
// EncodeBinary implements Serializable interface.
func (p *Headers) EncodeBinary(bw *io.BinWriter) {
bw.WriteArray(p.Hdrs)
}