79 lines
1.4 KiB
Go
79 lines
1.4 KiB
Go
package blockchain
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import (
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"bytes"
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"crypto/sha256"
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"encoding/gob"
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"encoding/hex"
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"fmt"
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"log"
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)
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type Transaction struct {
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ID []byte
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Inputs []TxInput
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Outputs []TxOutput
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}
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func (tx *Transaction) SetID() {
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var encoded bytes.Buffer
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var hash [32]byte
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encode := gob.NewEncoder(&encoded)
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err := encode.Encode(tx)
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Handle(err)
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hash = sha256.Sum256(encoded.Bytes())
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tx.ID = hash[:]
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}
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func CoinbaseTx(to, data string) *Transaction {
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if data == "" {
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data = fmt.Sprintf("COints to %s", to)
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}
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txin := TxInput{[]byte{}, -1, data}
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txout := TxOutput{100, to}
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tx := Transaction{nil, []TxInput{txin}, []TxOutput{txout}}
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tx.SetID()
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return &tx
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}
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func NewTransaction(from, to string, amount int, chain *BlockChain) *Transaction {
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var inputs []TxInput
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var outputs []TxOutput
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acc, validOutputs := chain.FindSpendableOutputs(from, amount)
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if acc < amount {
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log.Panic("Error: not enough funds")
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}
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for txid, outs := range validOutputs {
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txID, err := hex.DecodeString(txid)
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Handle(err)
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for _, out := range outs {
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input := TxInput{txID, out, from}
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inputs = append(inputs, input)
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}
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}
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outputs = append(outputs, TxOutput{amount, to})
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if acc > amount {
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outputs = append(outputs, TxOutput{acc - amount, from})
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}
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tx := Transaction{nil, inputs, outputs}
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tx.SetID()
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return &tx
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}
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func (tx *Transaction) IsCoinbase() bool {
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return len(tx.Inputs) == 1 && len(tx.Inputs[0].ID) == 0 && tx.Inputs[0].Out == -1
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}
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