return stat, err
}
-// Get retrieves a block identified by the locator string "loc", and
-// returns its contents as a byte slice.
-//
-// Get returns a nil buffer IFF it returns a non-nil error.
-func (v *UnixVolume) Get(loc string) ([]byte, error) {
+// Get retrieves a block, copies it to the given slice, and returns
+// the number of bytes copied.
+func (v *UnixVolume) Get(loc string, buf []byte) (int, error) {
path := v.blockPath(loc)
stat, err := v.stat(path)
if err != nil {
- return nil, err
+ return 0, v.translateError(err)
+ }
+ if stat.Size() > int64(len(buf)) {
+ return 0, TooLongError
}
- buf := bufs.Get(int(stat.Size()))
+ var read int
+ size := int(stat.Size())
err = v.getFunc(path, func(rdr io.Reader) error {
- _, err = io.ReadFull(rdr, buf)
+ read, err = io.ReadFull(rdr, buf[:size])
return err
})
- if err != nil {
- bufs.Put(buf)
- return nil, err
- }
- return buf, nil
+ return read, err
}
// Compare returns nil if Get(loc) would return the same content as
func (v *UnixVolume) Compare(loc string, expect []byte) error {
path := v.blockPath(loc)
if _, err := v.stat(path); err != nil {
- return err
+ return v.translateError(err)
}
return v.getFunc(path, func(rdr io.Reader) error {
return compareReaderWithBuf(rdr, expect, loc[:32])
}
var blockDirRe = regexp.MustCompile(`^[0-9a-f]+$`)
+var blockFileRe = regexp.MustCompile(`^[0-9a-f]{32}$`)
// IndexTo writes (to the given Writer) a list of blocks found on this
// volume which begin with the specified prefix. If the prefix is an
if !strings.HasPrefix(name, prefix) {
continue
}
+ if !blockFileRe.MatchString(name) {
+ continue
+ }
_, err = fmt.Fprint(w,
name,
"+", fileInfo[0].Size(),
}
}
-// Delete deletes the block data from the unix storage
-func (v *UnixVolume) Delete(loc string) error {
+// Trash trashes the block data from the unix storage
+// If trashLifetime == 0, the block is deleted
+// Else, the block is renamed as path/{loc}.trash.{deadline},
+// where deadline = now + trashLifetime
+func (v *UnixVolume) Trash(loc string) error {
// Touch() must be called before calling Write() on a block. Touch()
// also uses lockfile(). This avoids a race condition between Write()
- // and Delete() because either (a) the file will be deleted and Touch()
+ // and Trash() because either (a) the file will be trashed and Touch()
// will signal to the caller that the file is not present (and needs to
// be re-written), or (b) Touch() will update the file's timestamp and
- // Delete() will read the correct up-to-date timestamp and choose not to
- // delete the file.
+ // Trash() will read the correct up-to-date timestamp and choose not to
+ // trash the file.
if v.readonly {
return MethodDisabledError
return nil
}
}
- return os.Remove(p)
+
+ if trashLifetime == 0 {
+ return os.Remove(p)
+ }
+ return os.Rename(p, fmt.Sprintf("%v.trash.%d", p, time.Now().Add(trashLifetime).Unix()))
+}
+
+// Untrash moves block from trash back into store
+// Look for path/{loc}.trash.{deadline} in storage,
+// and rename the first such file as path/{loc}
+func (v *UnixVolume) Untrash(loc string) (err error) {
+ if v.readonly {
+ return MethodDisabledError
+ }
+
+ files, err := ioutil.ReadDir(v.blockDir(loc))
+ if err != nil {
+ return err
+ }
+
+ if len(files) == 0 {
+ return os.ErrNotExist
+ }
+
+ foundTrash := false
+ prefix := fmt.Sprintf("%v.trash.", loc)
+ for _, f := range files {
+ if strings.HasPrefix(f.Name(), prefix) {
+ foundTrash = true
+ err = os.Rename(v.blockPath(f.Name()), v.blockPath(loc))
+ if err == nil {
+ break
+ }
+ }
+ }
+
+ if foundTrash == false {
+ return os.ErrNotExist
+ }
+
+ return
}
// blockDir returns the fully qualified directory name for the directory
func unlockfile(f *os.File) error {
return syscall.Flock(int(f.Fd()), syscall.LOCK_UN)
}
+
+// Where appropriate, translate a more specific filesystem error to an
+// error recognized by handlers, like os.ErrNotExist.
+func (v *UnixVolume) translateError(err error) error {
+ switch err.(type) {
+ case *os.PathError:
+ // stat() returns a PathError if the parent directory
+ // (not just the file itself) is missing
+ return os.ErrNotExist
+ default:
+ return err
+ }
+}
+
+var unixTrashLocRegexp = regexp.MustCompile(`/([0-9a-f]{32})\.trash\.(\d+)$`)
+
+// EmptyTrash walks hierarchy looking for {hash}.trash.*
+// and deletes those with deadline < now.
+func (v *UnixVolume) EmptyTrash() {
+ var bytesDeleted, bytesInTrash int64
+ var blocksDeleted, blocksInTrash int
+
+ err := filepath.Walk(v.root, func(path string, info os.FileInfo, err error) error {
+ if err != nil {
+ log.Printf("EmptyTrash: filepath.Walk: %v: %v", path, err)
+ return nil
+ }
+ if info.Mode().IsDir() {
+ return nil
+ }
+ matches := unixTrashLocRegexp.FindStringSubmatch(path)
+ if len(matches) != 3 {
+ return nil
+ }
+ deadline, err := strconv.ParseInt(matches[2], 10, 64)
+ if err != nil {
+ log.Printf("EmptyTrash: %v: ParseInt(%v): %v", path, matches[2], err)
+ return nil
+ }
+ bytesInTrash += info.Size()
+ blocksInTrash++
+ if deadline > time.Now().Unix() {
+ return nil
+ }
+ err = os.Remove(path)
+ if err != nil {
+ log.Printf("EmptyTrash: Remove %v: %v", path, err)
+ return nil
+ }
+ bytesDeleted += info.Size()
+ blocksDeleted++
+ return nil
+ })
+
+ if err != nil {
+ log.Printf("EmptyTrash error for %v: %v", v.String(), err)
+ }
+
+ log.Printf("EmptyTrash stats for %v: Deleted %v bytes in %v blocks. Remaining in trash: %v bytes in %v blocks.", v.String(), bytesDeleted, blocksDeleted, bytesInTrash-bytesDeleted, blocksInTrash-blocksDeleted)
+}
projects / arvados.git / blobdiff