func execSend(path string, parent string, diff io.Writer) (retErr error) {
defer func() {
protolog.Debug(&Send{path, parent, errorToString(retErr)})
}()
if parent == "" {
return executil.RunStdout(diff, "btrfs", "send", path)
}
return executil.RunStdout(diff, "btrfs", "send", "-p", parent, path)
}
func execSubvolumeFindNew(commit string, fromCommit string, out io.Writer) (retErr error) {
defer func() {
protolog.Debug(&SubvolumeFindNew{commit, fromCommit, errorToString(retErr)})
}()
if fromCommit == "" {
return executil.RunStdout(out, "btrfs", "subvolume", "find-new", commit, "0")
}
transid, err := execTransID(fromCommit)
if err != nil {
return err
}
return executil.RunStdout(out, "btrfs", "subvolume", "find-new", commit, transid)
}
func execTransID(path string) (result string, retErr error) {
defer func() {
protolog.Debug(&TransID{path, result, errorToString(retErr)})
}()
// "9223372036854775810" == 2 ** 63 we use a very big number there so that
// we get the transid of the from path. According to the internet this is
// the nicest way to get it from btrfs.
var buffer bytes.Buffer
if err := executil.RunStdout(&buffer, "btrfs", "subvolume", "find-new", path, "9223372036854775808"); err != nil {
return "", err
}
scanner := bufio.NewScanner(&buffer)
for scanner.Scan() {
// scanner.Text() looks like this:
// transid marker was 907
// 0 1 2 3
tokens := strings.Split(scanner.Text(), " ")
if len(tokens) != 4 {
return "", fmt.Errorf("pachyderm: failed to parse find-new output")
}
return tokens[3], nil
}
if scanner.Err() != nil {
return "", scanner.Err()
}
return "", fmt.Errorf("pachyderm: empty output from find-new")
}
func execSubvolumeList(path string, fromCommit string, ascending bool, out io.Writer) (retErr error) {
defer func() {
protolog.Debug(&SubvolumeList{path, fromCommit, ascending, errorToString(retErr)})
}()
var sort string
if ascending {
sort = "+ogen"
} else {
sort = "-ogen"
}
if fromCommit == "" {
return executil.RunStdout(out, "btrfs", "subvolume", "list", "-a", "--sort", sort, path)
}
transid, err := execTransID(fromCommit)
if err != nil {
return err
}
return executil.RunStdout(out, "btrfs", "subvolume", "list", "-aC", "+"+transid, "--sort", sort, path)
}