docker-compose-files/hyperledger_fabric/latest/examples/chaincode/go/utxo/util/util.go

105 lines
2.7 KiB
Go

/*
Copyright IBM Corp. 2016 All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package util
import (
"bytes"
"encoding/binary"
)
func decodeInt32(input []byte) (int32, []byte, error) {
var myint32 int32
buf1 := bytes.NewBuffer(input[0:4])
binary.Read(buf1, binary.LittleEndian, &myint32)
return myint32, input, nil
}
// ReadVarInt reads an int that is formatted in the Bitcoin style
// variable int format
func ReadVarInt(buffer *bytes.Buffer) uint64 {
var finalResult uint64
var variableLenInt uint8
binary.Read(buffer, binary.LittleEndian, &variableLenInt)
if variableLenInt < 253 {
finalResult = uint64(variableLenInt)
} else if variableLenInt == 253 {
var result uint16
binary.Read(buffer, binary.LittleEndian, &result)
finalResult = uint64(result)
} else if variableLenInt == 254 {
var result uint32
binary.Read(buffer, binary.LittleEndian, &result)
finalResult = uint64(result)
} else if variableLenInt == 255 {
var result uint64
binary.Read(buffer, binary.LittleEndian, &result)
finalResult = result
}
return finalResult
}
// ParseUTXOBytes parses a bitcoin style transaction
func ParseUTXOBytes(txAsUTXOBytes []byte) *TX {
buffer := bytes.NewBuffer(txAsUTXOBytes)
var version int32
binary.Read(buffer, binary.LittleEndian, &version)
inputCount := ReadVarInt(buffer)
newTX := &TX{}
for i := 0; i < int(inputCount); i++ {
newTXIN := &TX_TXIN{}
newTXIN.SourceHash = buffer.Next(32)
binary.Read(buffer, binary.LittleEndian, &newTXIN.Ix)
// Parse the script length and script bytes
scriptLength := ReadVarInt(buffer)
newTXIN.Script = buffer.Next(int(scriptLength))
// Appears to not be used currently
binary.Read(buffer, binary.LittleEndian, &newTXIN.Sequence)
newTX.Txin = append(newTX.Txin, newTXIN)
}
// Now the outputs
outputCount := ReadVarInt(buffer)
for i := 0; i < int(outputCount); i++ {
newTXOUT := &TX_TXOUT{}
binary.Read(buffer, binary.LittleEndian, &newTXOUT.Value)
// Parse the script length and script bytes
scriptLength := ReadVarInt(buffer)
newTXOUT.Script = buffer.Next(int(scriptLength))
newTX.Txout = append(newTX.Txout, newTXOUT)
}
binary.Read(buffer, binary.LittleEndian, &newTX.LockTime)
return newTX
}