Exemplo n.º 1
0
// acceptTransactionSet verifies that a transaction set is allowed to be in the
// transaction pool, and then adds it to the transaction pool.
func (tp *TransactionPool) acceptTransactionSet(ts []types.Transaction) error {
	if len(ts) == 0 {
		return errEmptySet
	}

	// Remove all transactions that have been confirmed in the transaction set.
	err := tp.db.Update(func(tx *bolt.Tx) error {
		oldTS := ts
		ts = []types.Transaction{}
		for _, txn := range oldTS {
			if !tp.transactionConfirmed(tx, txn.ID()) {
				ts = append(ts, txn)
			}
		}
		return nil
	})
	if err != nil {
		return err
	}
	// If no transactions remain, return a dublicate error.
	if len(ts) == 0 {
		return modules.ErrDuplicateTransactionSet
	}

	// Check the composition of the transaction set, including fees and
	// IsStandard rules.
	err = tp.checkTransactionSetComposition(ts)
	if err != nil {
		return err
	}

	// Check for conflicts with other transactions, which would indicate a
	// double-spend. Legal children of a transaction set will also trigger the
	// conflict-detector.
	oids := relatedObjectIDs(ts)
	var conflicts []TransactionSetID
	for _, oid := range oids {
		conflict, exists := tp.knownObjects[oid]
		if exists {
			conflicts = append(conflicts, conflict)
		}
	}
	if len(conflicts) > 0 {
		return tp.handleConflicts(ts, conflicts)
	}
	cc, err := tp.consensusSet.TryTransactionSet(ts)
	if err != nil {
		return modules.NewConsensusConflict(err.Error())
	}

	// Add the transaction set to the pool.
	setID := TransactionSetID(crypto.HashObject(ts))
	tp.transactionSets[setID] = ts
	for _, oid := range oids {
		tp.knownObjects[oid] = setID
	}
	tp.transactionSetDiffs[setID] = cc
	tp.transactionListSize += len(encoding.Marshal(ts))
	return nil
}
Exemplo n.º 2
0
// acceptTransactionSet verifies that a transaction set is allowed to be in the
// transaction pool, and then adds it to the transaction pool.
func (tp *TransactionPool) acceptTransactionSet(ts []types.Transaction) error {
	if len(ts) == 0 {
		return errEmptySet
	}

	// Check the composition of the transaction set, including fees and
	// IsStandard rules.
	err := tp.checkTransactionSetComposition(ts)
	if err != nil {
		return err
	}

	// Check for conflicts with other transactions, which would indicate a
	// double-spend. Legal children of a transaction set will also trigger the
	// conflict-detector.
	oids := relatedObjectIDs(ts)
	var conflicts []TransactionSetID
	for _, oid := range oids {
		conflict, exists := tp.knownObjects[oid]
		if exists {
			conflicts = append(conflicts, conflict)
		}
	}
	if len(conflicts) > 0 {
		return tp.handleConflicts(ts, conflicts)
	}
	cc, err := tp.consensusSet.TryTransactionSet(ts)
	if err != nil {
		return modules.NewConsensusConflict(err.Error())
	}

	// Add the transaction set to the pool.
	setID := TransactionSetID(crypto.HashObject(ts))
	tp.transactionSets[setID] = ts
	for _, oid := range oids {
		tp.knownObjects[oid] = setID
	}
	tp.transactionSetDiffs[setID] = cc
	tp.transactionListSize += len(encoding.Marshal(ts))
	return nil
}
Exemplo n.º 3
0
// handleConflicts detects whether the conflicts in the transaction pool are
// legal children of the new transaction pool set or not.
func (tp *TransactionPool) handleConflicts(ts []types.Transaction, conflicts []TransactionSetID) error {
	// Create a list of all the transaction ids that compose the set of
	// conflicts.
	conflictMap := make(map[types.TransactionID]TransactionSetID)
	for _, conflict := range conflicts {
		conflictSet := tp.transactionSets[conflict]
		for _, conflictTxn := range conflictSet {
			conflictMap[conflictTxn.ID()] = conflict
		}
	}

	// Discard all duplicate transactions from the input transaction set.
	var dedupSet []types.Transaction
	for _, t := range ts {
		_, exists := conflictMap[t.ID()]
		if exists {
			continue
		}
		dedupSet = append(dedupSet, t)
	}
	if len(dedupSet) == 0 {
		return modules.ErrDuplicateTransactionSet
	}
	// If transactions were pruned, it's possible that the set of
	// dependencies/conflicts has also reduced. To minimize computational load
	// on the consensus set, we want to prune out all of the conflicts that are
	// no longer relevant. As an example, consider the transaction set {A}, the
	// set {B}, and the new set {A, C}, where C is dependent on B. {A} and {B}
	// are both conflicts, but after deduplication {A} is no longer a conflict.
	// This is recursive, but it is guaranteed to run only once as the first
	// deduplication is guaranteed to be complete.
	if len(dedupSet) < len(ts) {
		oids := relatedObjectIDs(dedupSet)
		var conflicts []TransactionSetID
		for _, oid := range oids {
			conflict, exists := tp.knownObjects[oid]
			if exists {
				conflicts = append(conflicts, conflict)
			}
		}
		return tp.handleConflicts(dedupSet, conflicts)
	}

	// Merge all of the conflict sets with the input set (input set goes last
	// to preserve dependency ordering), and see if the set as a whole is both
	// small enough to be legal and valid as a set. If no, return an error. If
	// yes, add the new set to the pool, and eliminate the old set. The output
	// diff objects can be repeated, (no need to remove those). Just need to
	// remove the conflicts from tp.transactionSets.
	var superset []types.Transaction
	supersetMap := make(map[TransactionSetID]struct{})
	for _, conflict := range conflictMap {
		supersetMap[conflict] = struct{}{}
	}
	for conflict := range supersetMap {
		superset = append(superset, tp.transactionSets[conflict]...)
	}
	superset = append(superset, dedupSet...)

	// Check the composition of the transaction set, including fees and
	// IsStandard rules (this is a new set, the rules must be rechecked).
	err := tp.checkTransactionSetComposition(superset)
	if err != nil {
		return err
	}

	// Check that the transaction set is valid.
	cc, err := tp.consensusSet.TryTransactionSet(superset)
	if err != nil {
		return modules.NewConsensusConflict(err.Error())
	}

	// Remove the conflicts from the transaction pool. The diffs do not need to
	// be removed, they will be overwritten later in the function.
	for _, conflict := range conflictMap {
		conflictSet := tp.transactionSets[conflict]
		tp.transactionListSize -= len(encoding.Marshal(conflictSet))
		delete(tp.transactionSets, conflict)
		delete(tp.transactionSetDiffs, conflict)
	}

	// Add the transaction set to the pool.
	setID := TransactionSetID(crypto.HashObject(superset))
	tp.transactionSets[setID] = superset
	for _, diff := range cc.SiacoinOutputDiffs {
		tp.knownObjects[ObjectID(diff.ID)] = setID
	}
	for _, diff := range cc.FileContractDiffs {
		tp.knownObjects[ObjectID(diff.ID)] = setID
	}
	for _, diff := range cc.SiafundOutputDiffs {
		tp.knownObjects[ObjectID(diff.ID)] = setID
	}
	tp.transactionSetDiffs[setID] = cc
	tp.transactionListSize += len(encoding.Marshal(superset))
	return nil
}