go_study/fabric-main/common/ledger/blkstorage/blockfile_rw.go

91 lines
2.0 KiB
Go

/*
Copyright IBM Corp. All Rights Reserved.
SPDX-License-Identifier: Apache-2.0
*/
package blkstorage
import (
"os"
"github.com/hyperledger/fabric/internal/fileutil"
"github.com/pkg/errors"
)
// // WRITER ////
type blockfileWriter struct {
filePath string
file *os.File
}
func newBlockfileWriter(filePath string) (*blockfileWriter, error) {
writer := &blockfileWriter{filePath: filePath}
return writer, writer.open()
}
func (w *blockfileWriter) truncateFile(targetSize int) error {
fileStat, err := w.file.Stat()
if err != nil {
return errors.Wrapf(err, "error truncating the file [%s] to size [%d]", w.filePath, targetSize)
}
if fileStat.Size() > int64(targetSize) {
w.file.Truncate(int64(targetSize))
}
return nil
}
func (w *blockfileWriter) append(b []byte, sync bool) error {
_, err := w.file.Write(b)
if err != nil {
return err
}
if sync {
return w.file.Sync()
}
return nil
}
func (w *blockfileWriter) open() error {
file, err := os.OpenFile(w.filePath, os.O_RDWR|os.O_APPEND|os.O_CREATE, 0o660)
if err != nil {
return errors.Wrapf(err, "error opening block file writer for file %s", w.filePath)
}
if err := fileutil.SyncParentDir(w.filePath); err != nil {
return err
}
w.file = file
return nil
}
func (w *blockfileWriter) close() error {
return errors.WithStack(w.file.Close())
}
// // READER ////
type blockfileReader struct {
file *os.File
}
func newBlockfileReader(filePath string) (*blockfileReader, error) {
file, err := os.OpenFile(filePath, os.O_RDONLY, 0o600)
if err != nil {
return nil, errors.Wrapf(err, "error opening block file reader for file %s", filePath)
}
reader := &blockfileReader{file}
return reader, nil
}
func (r *blockfileReader) read(offset int, length int) ([]byte, error) {
b := make([]byte, length)
_, err := r.file.ReadAt(b, int64(offset))
if err != nil {
return nil, errors.Wrapf(err, "error reading block file for offset %d and length %d", offset, length)
}
return b, nil
}
func (r *blockfileReader) close() error {
return errors.WithStack(r.file.Close())
}