Avoid empty mmap files by using .tmp files to write headers

Signed-off-by: 's avatarGanesh Vernekar <cs15btech11018@iith.ac.in>
parent 9a75b5f8
......@@ -220,19 +220,20 @@ func (w *Writer) cut() error {
func cutSegmentFile(dirFile *os.File, magicNumber uint32, chunksFormat byte, allocSize int64) (headerSize int, newFile *os.File, seq int, err error) {
p, seq, err := nextSequenceFile(dirFile.Name())
if err != nil {
return 0, nil, 0, err
return 0, nil, 0, errors.Wrap(err, "next sequence file")
}
f, err := os.OpenFile(p, os.O_WRONLY|os.O_CREATE, 0666)
ptmp := p + ".tmp"
f, err := os.OpenFile(ptmp, os.O_WRONLY|os.O_CREATE, 0666)
if err != nil {
return 0, nil, 0, err
return 0, nil, 0, errors.Wrap(err, "open temp file")
}
if allocSize > 0 {
if err = fileutil.Preallocate(f, allocSize, true); err != nil {
return 0, nil, 0, err
return 0, nil, 0, errors.Wrap(err, "preallocate")
}
}
if err = dirFile.Sync(); err != nil {
return 0, nil, 0, err
return 0, nil, 0, errors.Wrap(err, "sync directory")
}
// Write header metadata for new file.
......@@ -242,7 +243,23 @@ func cutSegmentFile(dirFile *os.File, magicNumber uint32, chunksFormat byte, all
n, err := f.Write(metab)
if err != nil {
return 0, nil, 0, err
return 0, nil, 0, errors.Wrap(err, "write header")
}
if err := f.Close(); err != nil {
return 0, nil, 0, errors.Wrap(err, "close temp file")
}
if err := fileutil.Rename(ptmp, p); err != nil {
return 0, nil, 0, errors.Wrap(err, "replace file")
}
f, err = os.OpenFile(p, os.O_WRONLY, 0666)
if err != nil {
return 0, nil, 0, errors.Wrap(err, "open final file")
}
// Skip the header for the further writes.
if _, err := f.Seek(int64(n), 0); err != nil {
return 0, nil, 0, errors.Wrap(err, "seek in final file")
}
return n, f, seq, nil
}
......
......@@ -125,19 +125,5 @@ func Replace(from, to string) error {
}
}
if err := os.Rename(from, to); err != nil {
return err
}
// Directory was renamed; sync parent dir to persist rename.
pdir, err := OpenDir(filepath.Dir(to))
if err != nil {
return err
}
if err = pdir.Sync(); err != nil {
pdir.Close()
return err
}
return pdir.Close()
return Rename(from, to)
}
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