github.com/btcsuite/btcd@v0.24.0/wire/msggetcfilters.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  // MaxGetCFiltersReqRange the maximum number of filters that may be requested in
    14  // a getcfheaders message.
    15  const MaxGetCFiltersReqRange = 1000
    16  
    17  // MsgGetCFilters implements the Message interface and represents a bitcoin
    18  // getcfilters message. It is used to request committed filters for a range of
    19  // blocks.
    20  type MsgGetCFilters struct {
    21  	FilterType  FilterType
    22  	StartHeight uint32
    23  	StopHash    chainhash.Hash
    24  }
    25  
    26  // BtcDecode decodes r using the bitcoin protocol encoding into the receiver.
    27  // This is part of the Message interface implementation.
    28  func (msg *MsgGetCFilters) BtcDecode(r io.Reader, pver uint32, _ MessageEncoding) error {
    29  	buf := binarySerializer.Borrow()
    30  	defer binarySerializer.Return(buf)
    31  
    32  	if _, err := io.ReadFull(r, buf[:1]); err != nil {
    33  		return err
    34  	}
    35  	msg.FilterType = FilterType(buf[0])
    36  
    37  	if _, err := io.ReadFull(r, buf[:4]); err != nil {
    38  		return err
    39  	}
    40  	msg.StartHeight = littleEndian.Uint32(buf[:4])
    41  
    42  	_, err := io.ReadFull(r, msg.StopHash[:])
    43  	return err
    44  }
    45  
    46  // BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
    47  // This is part of the Message interface implementation.
    48  func (msg *MsgGetCFilters) BtcEncode(w io.Writer, pver uint32, _ MessageEncoding) error {
    49  	buf := binarySerializer.Borrow()
    50  	defer binarySerializer.Return(buf)
    51  
    52  	buf[0] = byte(msg.FilterType)
    53  	if _, err := w.Write(buf[:1]); err != nil {
    54  		return err
    55  	}
    56  
    57  	littleEndian.PutUint32(buf[:4], msg.StartHeight)
    58  	if _, err := w.Write(buf[:4]); err != nil {
    59  		return err
    60  	}
    61  
    62  	_, err := w.Write(msg.StopHash[:])
    63  	return err
    64  }
    65  
    66  // Command returns the protocol command string for the message.  This is part
    67  // of the Message interface implementation.
    68  func (msg *MsgGetCFilters) Command() string {
    69  	return CmdGetCFilters
    70  }
    71  
    72  // MaxPayloadLength returns the maximum length the payload can be for the
    73  // receiver.  This is part of the Message interface implementation.
    74  func (msg *MsgGetCFilters) MaxPayloadLength(pver uint32) uint32 {
    75  	// Filter type + uint32 + block hash
    76  	return 1 + 4 + chainhash.HashSize
    77  }
    78  
    79  // NewMsgGetCFilters returns a new bitcoin getcfilters message that conforms to
    80  // the Message interface using the passed parameters and defaults for the
    81  // remaining fields.
    82  func NewMsgGetCFilters(filterType FilterType, startHeight uint32,
    83  	stopHash *chainhash.Hash) *MsgGetCFilters {
    84  	return &MsgGetCFilters{
    85  		FilterType:  filterType,
    86  		StartHeight: startHeight,
    87  		StopHash:    *stopHash,
    88  	}
    89  }