refactor: consolidate ForkReader-like implementations to IOCommand

zfs/fork_reader.go

@@ -1,62 +0,0 @@
-package zfs
-
-import (
-	"bytes"
-	"fmt"
-	"io"
-	"os/exec"
-)
-
-// A ForkReader is an io.Reader for a forked process's stdout.
-// It Wait()s for the process to exit and - if it exits with error - returns this exit error
-// on subsequent Read()s.
-type ForkExecReader struct {
-	Cmd       *exec.Cmd
-	InStream  io.Reader
-	StderrBuf *bytes.Buffer
-}
-
-func NewForkExecReader(command string, args ...string) (r *ForkExecReader, err error) {
-
-	r = &ForkExecReader{}
-
-	r.Cmd = exec.Command(command, args...)
-
-	r.InStream, err = r.Cmd.StdoutPipe()
-	if err != nil {
-		return
-	}
-
-	r.StderrBuf = bytes.NewBuffer(make([]byte, 0, 1024))
-	r.Cmd.Stderr = r.StderrBuf
-
-	if err = r.Cmd.Start(); err != nil {
-		return
-	}
-
-	return
-
-}
-
-type ForkExecReaderError struct {
-	WaitErr error
-	Stderr  []byte
-}
-
-func (e ForkExecReaderError) Error() string {
-	return fmt.Sprintf("underlying process exited with error: %s\nstderr: %s\n", e.WaitErr, e.Stderr)
-}
-
-func (t *ForkExecReader) Read(buf []byte) (n int, err error) {
-	n, err = t.InStream.Read(buf)
-	if err == io.EOF {
-		waitErr := t.Cmd.Wait()
-		if waitErr != nil {
-			err = ForkExecReaderError{
-				WaitErr: waitErr,
-				Stderr:  t.StderrBuf.Bytes(),
-			}
-		}
-	}
-	return
-}

zfs/zfs.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"github.com/zrepl/zrepl/util"
 	"io"
 	"os/exec"
 	"strings"
@@ -114,7 +115,7 @@ func ZFSSend(fs DatasetPath, from, to *FilesystemVersion) (stream io.Reader, err
 		args = append(args, "-i", from.ToAbsPath(fs), to.ToAbsPath(fs))
 	}
 
-	stream, err = NewForkExecReader(ZFS_BINARY, args...)
+	stream, err = util.RunIOCommand(ZFS_BINARY, args...)
 
 	return
 }