// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package core
import (
"errors"
"io"
"os"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/rlp"
)
// errNoActiveJournal is returned if a transaction is attempted to be inserted
// into the journal, but no such file is currently open.
var errNoActiveJournal = errors.New("no active journal")
// devNull is a WriteCloser that just discards anything written into it. Its
// goal is to allow the transaction journal to write into a fake journal when
// loading transactions on startup without printing warnings due to no file
// being readt for write.
type devNull struct{}
func (*devNull) Write(p []byte) (n int, err error) { return len(p), nil }
func (*devNull) Close() error { return nil }
// txJournal is a rotating log of transactions with the aim of storing locally
// created transactions to allow non-executed ones to survive node restarts.
type txJournal struct {
path string // Filesystem path to store the transactions at
writer io.WriteCloser // Output stream to write new transactions into
}
// newTxJournal creates a new transaction journal to
func newTxJournal(path string) *txJournal {
return &txJournal{
path: path,
}
}
// load parses a transaction journal dump from disk, loading its contents into
// the specified pool.
func (journal *txJournal) load(add func([]*types.Transaction) []error) error {
// Skip the parsing if the journal file doens't exist at all
if _, err := os.Stat(journal.path); os.IsNotExist(err) {
return nil
}
// Open the journal for loading any past transactions
input, err := os.Open(journal.path)
if err != nil {
return err
}
defer input.Close()
// Temporarily discard any journal additions (don't double add on load)
journal.writer = new(devNull)
defer func() { journal.writer = nil }()
// Inject all transactions from the journal into the pool
stream := rlp.NewStream(input, 0)
total, dropped := 0, 0
// Create a method to load a limited batch of transactions and bump the
// appropriate progress counters. Then use this method to load all the
// journalled transactions in small-ish batches.
loadBatch := func(txs types.Transactions) {
for _, err := range add(txs) {
if err != nil {
log.Debug("Failed to add journaled transaction", "err", err)
dropped++
}
}
}
var (
failure error
batch types.Transactions
)
for {
// Parse the next transaction and terminate on error
tx := new(types.Transaction)
if err = stream.Decode(tx); err != nil {
if err != io.EOF {
failure = err
}
if batch.Len() > 0 {
loadBatch(batch)
}
break
}
// New transaction parsed, queue up for later, import if threnshold is reached
total++
if batch = append(batch, tx); batch.Len() > 1024 {
loadBatch(batch)
batch = batch[:0]
}
}
log.Info("Loaded local transaction journal", "transactions", total, "dropped", dropped)
return failure
}
// insert adds the specified transaction to the local disk journal.
func (journal *txJournal) insert(tx *types.Transaction) error {
if journal.writer == nil {
return errNoActiveJournal
}
if err := rlp.Encode(journal.writer, tx); err != nil {
return err
}
return nil
}
// rotate regenerates the transaction journal based on the current contents of
// the transaction pool.
func (journal *txJournal) rotate(all map[common.Address]types.Transactions) error {
// Close the current journal (if any is open)
if journal.writer != nil {
if err := journal.writer.Close(); err != nil {
return err
}
journal.writer = nil
}
// Generate a new journal with the contents of the current pool
replacement, err := os.OpenFile(journal.path+".new", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0755)
if err != nil {
return err
}
journaled := 0
for _, txs := range all {
for _, tx := range txs {
if err = rlp.Encode(replacement, tx); err != nil {
replacement.Close()
return err
}
}
journaled += len(txs)
}
replacement.Close()
// Replace the live journal with the newly generated one
if err = os.Rename(journal.path+".new", journal.path); err != nil {
return err
}
sink, err := os.OpenFile(journal.path, os.O_WRONLY|os.O_APPEND, 0755)
if err != nil {
return err
}
journal.writer = sink
log.Info("Regenerated local transaction journal", "transactions", journaled, "accounts", len(all))
return nil
}
// close flushes the transaction journal contents to disk and closes the file.
func (journal *txJournal) close() error {
var err error
if journal.writer != nil {
err = journal.writer.Close()
journal.writer = nil
}
return err
}
