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

     1  // Copyright (c) 2018 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  // MsgGetCFCheckpt is a request for filter headers at evenly spaced intervals
    14  // throughout the blockchain history. It allows to set the FilterType field to
    15  // get headers in the chain of basic (0x00) or extended (0x01) headers.
    16  type MsgGetCFCheckpt struct {
    17  	FilterType FilterType
    18  	StopHash   chainhash.Hash
    19  }
    20  
    21  // BtcDecode decodes r using the bitcoin protocol encoding into the receiver.
    22  // This is part of the Message interface implementation.
    23  func (msg *MsgGetCFCheckpt) BtcDecode(r io.Reader, pver uint32, _ MessageEncoding) error {
    24  	buf := binarySerializer.Borrow()
    25  	defer binarySerializer.Return(buf)
    26  
    27  	if _, err := io.ReadFull(r, buf[:1]); err != nil {
    28  		return err
    29  	}
    30  	msg.FilterType = FilterType(buf[0])
    31  
    32  	_, err := io.ReadFull(r, msg.StopHash[:])
    33  	return err
    34  }
    35  
    36  // BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
    37  // This is part of the Message interface implementation.
    38  func (msg *MsgGetCFCheckpt) BtcEncode(w io.Writer, pver uint32, _ MessageEncoding) error {
    39  	buf := binarySerializer.Borrow()
    40  	defer binarySerializer.Return(buf)
    41  
    42  	buf[0] = byte(msg.FilterType)
    43  	if _, err := w.Write(buf[:1]); err != nil {
    44  		return err
    45  	}
    46  
    47  	_, err := w.Write(msg.StopHash[:])
    48  	return err
    49  }
    50  
    51  // Command returns the protocol command string for the message.  This is part
    52  // of the Message interface implementation.
    53  func (msg *MsgGetCFCheckpt) Command() string {
    54  	return CmdGetCFCheckpt
    55  }
    56  
    57  // MaxPayloadLength returns the maximum length the payload can be for the
    58  // receiver.  This is part of the Message interface implementation.
    59  func (msg *MsgGetCFCheckpt) MaxPayloadLength(pver uint32) uint32 {
    60  	// Filter type + uint32 + block hash
    61  	return 1 + chainhash.HashSize
    62  }
    63  
    64  // NewMsgGetCFCheckpt returns a new bitcoin getcfcheckpt message that conforms
    65  // to the Message interface using the passed parameters and defaults for the
    66  // remaining fields.
    67  func NewMsgGetCFCheckpt(filterType FilterType, stopHash *chainhash.Hash) *MsgGetCFCheckpt {
    68  	return &MsgGetCFCheckpt{
    69  		FilterType: filterType,
    70  		StopHash:   *stopHash,
    71  	}
    72  }