// Copyright (c) 2014-2015 The btcsuite developers // Use of this source code is governed by an ISC // license that can be found in the LICENSE file. package wire import ( "fmt" "io" ) // BloomUpdateType specifies how the filter is updated when a match is found type BloomUpdateType uint8 const ( // BloomUpdateNone indicates the filter is not adjusted when a match is // found. BloomUpdateNone BloomUpdateType = 0 // BloomUpdateAll indicates if the filter matches any data element in a // public key script, the outpoint is serialized and inserted into the // filter. BloomUpdateAll BloomUpdateType = 1 ) const ( // MaxFilterLoadHashFuncs is the maximum number of hash functions to // load into the Bloom filter. MaxFilterLoadHashFuncs = 50 // MaxFilterLoadFilterSize is the maximum size in bytes a filter may be. MaxFilterLoadFilterSize = 36000 ) // MsgFilterLoad implements the Message interface and represents a kaspa // filterload message which is used to reset a Bloom filter. // // This message was not added until protocol version BIP0037Version. type MsgFilterLoad struct { Filter []byte HashFuncs uint32 Tweak uint32 Flags BloomUpdateType } // KaspaDecode decodes r using the kaspa protocol encoding into the receiver. // This is part of the Message interface implementation. func (msg *MsgFilterLoad) KaspaDecode(r io.Reader, pver uint32) error { var err error msg.Filter, err = ReadVarBytes(r, pver, MaxFilterLoadFilterSize, "filterload filter size") if err != nil { return err } err = readElements(r, &msg.HashFuncs, &msg.Tweak, &msg.Flags) if err != nil { return err } if msg.HashFuncs > MaxFilterLoadHashFuncs { str := fmt.Sprintf("too many filter hash functions for message "+ "[count %d, max %d]", msg.HashFuncs, MaxFilterLoadHashFuncs) return messageError("MsgFilterLoad.KaspaDecode", str) } return nil } // KaspaEncode encodes the receiver to w using the kaspa protocol encoding. // This is part of the Message interface implementation. func (msg *MsgFilterLoad) KaspaEncode(w io.Writer, pver uint32) error { size := len(msg.Filter) if size > MaxFilterLoadFilterSize { str := fmt.Sprintf("filterload filter size too large for message "+ "[size %d, max %d]", size, MaxFilterLoadFilterSize) return messageError("MsgFilterLoad.KaspaEncode", str) } if msg.HashFuncs > MaxFilterLoadHashFuncs { str := fmt.Sprintf("too many filter hash functions for message "+ "[count %d, max %d]", msg.HashFuncs, MaxFilterLoadHashFuncs) return messageError("MsgFilterLoad.KaspaEncode", str) } err := WriteVarBytes(w, pver, msg.Filter) if err != nil { return err } return writeElements(w, msg.HashFuncs, msg.Tweak, msg.Flags) } // Command returns the protocol command string for the message. This is part // of the Message interface implementation. func (msg *MsgFilterLoad) Command() string { return CmdFilterLoad } // MaxPayloadLength returns the maximum length the payload can be for the // receiver. This is part of the Message interface implementation. func (msg *MsgFilterLoad) MaxPayloadLength(pver uint32) uint32 { // Num filter bytes (varInt) + filter + 4 bytes hash funcs + // 4 bytes tweak + 1 byte flags. return uint32(VarIntSerializeSize(MaxFilterLoadFilterSize)) + MaxFilterLoadFilterSize + 9 } // NewMsgFilterLoad returns a new kaspa filterload message that conforms to // the Message interface. See MsgFilterLoad for details. func NewMsgFilterLoad(filter []byte, hashFuncs uint32, tweak uint32, flags BloomUpdateType) *MsgFilterLoad { return &MsgFilterLoad{ Filter: filter, HashFuncs: hashFuncs, Tweak: tweak, Flags: flags, } }