lotus/blockstore/splitstore/coldset.go
2022-06-14 17:00:51 +02:00

102 lines
1.6 KiB
Go

package splitstore
import (
"bufio"
"io"
"os"
cid "github.com/ipfs/go-cid"
"golang.org/x/xerrors"
)
type ColdSetWriter struct {
file *os.File
buf *bufio.Writer
}
type ColdSetReader struct {
file *os.File
buf *bufio.Reader
}
func NewColdSetWriter(path string) (*ColdSetWriter, error) {
file, err := os.OpenFile(path, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
if err != nil {
return nil, xerrors.Errorf("error creating coldset: %w", err)
}
buf := bufio.NewWriter(file)
return &ColdSetWriter{
file: file,
buf: buf,
}, nil
}
func NewColdSetReader(path string) (*ColdSetReader, error) {
file, err := os.Open(path)
if err != nil {
return nil, xerrors.Errorf("error opening coldset: %w", err)
}
buf := bufio.NewReader(file)
return &ColdSetReader{
file: file,
buf: buf,
}, nil
}
func (s *ColdSetWriter) Write(c cid.Cid) error {
return writeRawCid(s.buf, c, false)
}
func (s *ColdSetWriter) Close() error {
if s.file == nil {
return nil
}
err1 := s.buf.Flush()
err2 := s.file.Close()
s.buf = nil
s.file = nil
if err1 != nil {
return err1
}
return err2
}
func (s *ColdSetReader) ForEach(f func(cid.Cid) error) error {
hbuf := make([]byte, 256)
for {
next, err := readRawCid(s.buf, hbuf)
if err != nil {
if err == io.EOF {
return nil
}
return xerrors.Errorf("error reading coldset: %w", err)
}
if err := f(next); err != nil {
return err
}
}
}
func (s *ColdSetReader) Reset() error {
_, err := s.file.Seek(0, io.SeekStart)
return err
}
func (s *ColdSetReader) Close() error {
if s.file == nil {
return nil
}
err := s.file.Close()
s.file = nil
s.buf = nil
return err
}