diff --git a/blob.go b/blob.go index 10b8ea4..dd30849 100644 --- a/blob.go +++ b/blob.go @@ -6,7 +6,11 @@ package git import ( "bytes" + "fmt" "io" + "io/ioutil" + "os" + "os/exec" ) // Blob represents a Git object. @@ -29,3 +33,36 @@ func (b *Blob) Data() (io.Reader, error) { func (b *Blob) DataPipeline(stdout, stderr io.Writer) error { return NewCommand("show", b.ID.String()).RunInDirPipeline(b.repo.Path, stdout, stderr) } + +type cmdReadCloser struct { + cmd *exec.Cmd + stdout io.Reader +} + +func (c cmdReadCloser) Read(p []byte) (int, error) { + return c.stdout.Read(p) +} + +func (c cmdReadCloser) Close() error { + io.Copy(ioutil.Discard, c.stdout) + return c.cmd.Wait() +} + +// DataAsync gets a ReadCloser for the contents of a blob without reading it all. +// Calling the Close function on the result will discard all unread output. +func (b *Blob) DataAsync() (io.ReadCloser, error) { + cmd := exec.Command("git", "show", b.ID.String()) + cmd.Dir = b.repo.Path + cmd.Stderr = os.Stderr + + stdout, err := cmd.StdoutPipe() + if err != nil { + return nil, fmt.Errorf("StdoutPipe: %v", err) + } + + if err = cmd.Start(); err != nil { + return nil, fmt.Errorf("Start: %v", err) + } + + return cmdReadCloser{stdout: stdout, cmd: cmd}, nil +}