github.com/btcsuite/btcd@v0.24.0/wire/msggetcfheaders.go (about)

     1  // Copyright (c) 2017 The btcsuite developers
     2  // Use of this source code is governed by an ISC
     3  // license that can be found in the LICENSE file.
     4  
     5  package wire
     6  
     7  import (
     8  	"io"
     9  
    10  	"github.com/btcsuite/btcd/chaincfg/chainhash"
    11  )
    12  
    13  // MsgGetCFHeaders is a message similar to MsgGetHeaders, but for committed
    14  // filter headers. It allows to set the FilterType field to get headers in the
    15  // chain of basic (0x00) or extended (0x01) headers.
    16  type MsgGetCFHeaders struct {
    17  	FilterType  FilterType
    18  	StartHeight uint32
    19  	StopHash    chainhash.Hash
    20  }
    21  
    22  // BtcDecode decodes r using the bitcoin protocol encoding into the receiver.
    23  // This is part of the Message interface implementation.
    24  func (msg *MsgGetCFHeaders) BtcDecode(r io.Reader, pver uint32, _ MessageEncoding) error {
    25  	buf := binarySerializer.Borrow()
    26  	defer binarySerializer.Return(buf)
    27  
    28  	if _, err := io.ReadFull(r, buf[:1]); err != nil {
    29  		return err
    30  	}
    31  	msg.FilterType = FilterType(buf[0])
    32  
    33  	if _, err := io.ReadFull(r, buf[:4]); err != nil {
    34  		return err
    35  	}
    36  	msg.StartHeight = littleEndian.Uint32(buf[:4])
    37  
    38  	_, err := io.ReadFull(r, msg.StopHash[:])
    39  	return err
    40  }
    41  
    42  // BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
    43  // This is part of the Message interface implementation.
    44  func (msg *MsgGetCFHeaders) BtcEncode(w io.Writer, pver uint32, _ MessageEncoding) error {
    45  	buf := binarySerializer.Borrow()
    46  	defer binarySerializer.Return(buf)
    47  
    48  	buf[0] = byte(msg.FilterType)
    49  	if _, err := w.Write(buf[:1]); err != nil {
    50  		return err
    51  	}
    52  
    53  	littleEndian.PutUint32(buf[:4], msg.StartHeight)
    54  	if _, err := w.Write(buf[:4]); err != nil {
    55  		return err
    56  	}
    57  
    58  	_, err := w.Write(msg.StopHash[:])
    59  	return err
    60  }
    61  
    62  // Command returns the protocol command string for the message.  This is part
    63  // of the Message interface implementation.
    64  func (msg *MsgGetCFHeaders) Command() string {
    65  	return CmdGetCFHeaders
    66  }
    67  
    68  // MaxPayloadLength returns the maximum length the payload can be for the
    69  // receiver.  This is part of the Message interface implementation.
    70  func (msg *MsgGetCFHeaders) MaxPayloadLength(pver uint32) uint32 {
    71  	// Filter type + uint32 + block hash
    72  	return 1 + 4 + chainhash.HashSize
    73  }
    74  
    75  // NewMsgGetCFHeaders returns a new bitcoin getcfheader message that conforms to
    76  // the Message interface using the passed parameters and defaults for the
    77  // remaining fields.
    78  func NewMsgGetCFHeaders(filterType FilterType, startHeight uint32,
    79  	stopHash *chainhash.Hash) *MsgGetCFHeaders {
    80  	return &MsgGetCFHeaders{
    81  		FilterType:  filterType,
    82  		StartHeight: startHeight,
    83  		StopHash:    *stopHash,
    84  	}
    85  }