core: refactor api for trie journal

cmd/utils/flags.go

@@ -367,7 +367,7 @@ var (
 	}
 	JournalFileFlag = &cli.BoolFlag{
 		Name:     "journalfile",
-		Usage:    "Enable the in-memory trie node layers to store to wal file when shutdown in pbss (default = false)",
+		Usage:    "Enable journal file to store the TrieJournal when shutdown in pbss (default = false)",
 		Value:    false,
 		Category: flags.StateCategory,
 	}

triedb/pathdb/journal.go

@@ -74,18 +74,18 @@ type journalStorage struct {
 	Slots      [][]byte
 }
 
-// journalDB is a journal implementation that stores the journal in db.
-type journalDB struct {
+// journalKV is a journal implementation that stores the journal in db as a single kv.
+type journalKV struct {
 	Journal
 	journalBuf bytes.Buffer   // Used for temporary storage in memory, and finally uniformly written to the database during sync.
 	diskdb     ethdb.Database // Persistent storage for matured trie nodes
 }
 
-// journalWAL is a journal implementation that stores the journal in a file.
-type journalWAL struct {
+// journalFile is a journal implementation that stores the journal in a file.
+type journalFile struct {
 	Journal
-	journalFile string
-	journalFd   *os.File
+	file string   // the file used to store the TrieJournal
+	fd   *os.File // the file's fd
 }
 
 // loadJournal tries to parse the layer journal from the disk.
@@ -512,76 +512,76 @@ type Journal interface {
 	Size() uint64
 }
 
-func newJournal(journalFile string, db ethdb.Database) Journal {
-	if len(journalFile) == 0 {
-		return &journalDB{
+func newJournal(file string, db ethdb.Database) Journal {
+	if len(file) == 0 {
+		return &journalKV{
 			diskdb: db,
 		}
 	} else {
-		return &journalWAL{
-			journalFile: journalFile,
+		return &journalFile{
+			file: file,
 		}
 	}
 }
 
-func (db *journalDB) newJournalWriter() io.Writer {
+func (db *journalKV) newJournalWriter() io.Writer {
 	return &db.journalBuf
 }
 
-func (db *journalDB) newJournalReader() (*rlp.Stream, error) {
+func (db *journalKV) newJournalReader() (*rlp.Stream, error) {
 	journal := rawdb.ReadTrieJournal(db.diskdb)
 	if len(journal) == 0 {
 		return nil, errMissJournal
 	}
 	return rlp.NewStream(bytes.NewReader(journal), 0), nil
 }
 
-func (db *journalDB) Sync() {
+func (db *journalKV) Sync() {
 	rawdb.WriteTrieJournal(db.diskdb, db.journalBuf.Bytes())
 	db.journalBuf.Reset()
 }
 
-func (db *journalDB) Delete() {
+func (db *journalKV) Delete() {
 	rawdb.DeleteTrieJournal(db.diskdb)
 }
 
-func (db *journalDB) Close() {
+func (db *journalKV) Close() {
 }
 
-func (db *journalDB) Size() uint64 {
+func (db *journalKV) Size() uint64 {
 	return uint64(db.journalBuf.Len())
 }
 
 // newJournalWriter creates a new journal writer.
-func (wal *journalWAL) newJournalWriter() io.Writer {
+func (wal *journalFile) newJournalWriter() io.Writer {
 	var err error
-	wal.journalFd, err = os.OpenFile(wal.journalFile, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
+	wal.fd, err = os.OpenFile(wal.file, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
 	if err != nil {
 		return nil
 	}
-	return wal.journalFd
+	return wal.fd
 }
 
 // newJournalReader creates a new journal reader.
-func (wal *journalWAL) newJournalReader() (*rlp.Stream, error) {
+func (wal *journalFile) newJournalReader() (*rlp.Stream, error) {
 	var err error
-	wal.journalFd, err = os.Open(wal.journalFile)
+	wal.fd, err = os.Open(wal.file)
 	if errors.Is(err, fs.ErrNotExist) {
 		return nil, errMissJournal
 	}
 	if err != nil {
 		return nil, err
 	}
-	return rlp.NewStream(wal.journalFd, 0), nil
+	return rlp.NewStream(wal.fd, 0), nil
 }
 
 // Sync flushes the journal writer.
-func (wal *journalWAL) Sync() {
+func (wal *journalFile) Sync() {
 }
 
 // Delete deletes the journal.
-func (wal *journalWAL) Delete() {
-	file := wal.journalFile
+func (wal *journalFile) Delete() {
+	file := wal.file
 	_, err := os.Stat(file)
 	if os.IsNotExist(err) {
 		return
@@ -593,14 +593,14 @@ func (wal *journalWAL) Delete() {
 }
 
 // Close closes the journal.
-func (wal *journalWAL) Close() {
-	wal.journalFd.Close()
+func (wal *journalFile) Close() {
+	wal.fd.Close()
 }
 
 // Size returns the size of the journal.
-func (wal *journalWAL) Size() uint64 {
-	if wal.journalFd != nil {
-		fileInfo, err := wal.journalFd.Stat()
+func (wal *journalFile) Size() uint64 {
+	if wal.fd != nil {
+		fileInfo, err := wal.fd.Stat()
 		if err != nil {
 			log.Crit("Failed to stat journal", "err", err)
 		}