dnscrypt-proxy/vendor/github.com/sourcegraph/go-diff/diff/print.go

142 lines
3.1 KiB
Go

package diff
import (
"bytes"
"fmt"
"io"
"path/filepath"
"time"
)
// PrintMultiFileDiff prints a multi-file diff in unified diff format.
func PrintMultiFileDiff(ds []*FileDiff) ([]byte, error) {
var buf bytes.Buffer
for _, d := range ds {
diff, err := PrintFileDiff(d)
if err != nil {
return nil, err
}
if _, err := buf.Write(diff); err != nil {
return nil, err
}
}
return buf.Bytes(), nil
}
// PrintFileDiff prints a FileDiff in unified diff format.
//
// TODO(sqs): handle escaping whitespace/etc. chars in filenames
func PrintFileDiff(d *FileDiff) ([]byte, error) {
var buf bytes.Buffer
for _, xheader := range d.Extended {
if _, err := fmt.Fprintln(&buf, xheader); err != nil {
return nil, err
}
}
// FileDiff is added/deleted file
// No further hunks printing needed
if d.NewName == "" {
_, err := fmt.Fprintf(&buf, onlyInMessage, filepath.Dir(d.OrigName), filepath.Base(d.OrigName))
if err != nil {
return nil, err
}
return buf.Bytes(), nil
}
if d.Hunks == nil {
return buf.Bytes(), nil
}
if err := printFileHeader(&buf, "--- ", d.OrigName, d.OrigTime); err != nil {
return nil, err
}
if err := printFileHeader(&buf, "+++ ", d.NewName, d.NewTime); err != nil {
return nil, err
}
ph, err := PrintHunks(d.Hunks)
if err != nil {
return nil, err
}
if _, err := buf.Write(ph); err != nil {
return nil, err
}
return buf.Bytes(), nil
}
func printFileHeader(w io.Writer, prefix string, filename string, timestamp *time.Time) error {
if _, err := fmt.Fprint(w, prefix, filename); err != nil {
return err
}
if timestamp != nil {
if _, err := fmt.Fprint(w, "\t", timestamp.Format(diffTimeFormatLayout)); err != nil {
return err
}
}
if _, err := fmt.Fprintln(w); err != nil {
return err
}
return nil
}
// PrintHunks prints diff hunks in unified diff format.
func PrintHunks(hunks []*Hunk) ([]byte, error) {
var buf bytes.Buffer
for _, hunk := range hunks {
_, err := fmt.Fprintf(&buf,
"@@ -%d,%d +%d,%d @@", hunk.OrigStartLine, hunk.OrigLines, hunk.NewStartLine, hunk.NewLines,
)
if err != nil {
return nil, err
}
if hunk.Section != "" {
_, err := fmt.Fprint(&buf, " ", hunk.Section)
if err != nil {
return nil, err
}
}
if _, err := fmt.Fprintln(&buf); err != nil {
return nil, err
}
if hunk.OrigNoNewlineAt == 0 {
if _, err := buf.Write(hunk.Body); err != nil {
return nil, err
}
} else {
if _, err := buf.Write(hunk.Body[:hunk.OrigNoNewlineAt]); err != nil {
return nil, err
}
if err := printNoNewlineMessage(&buf); err != nil {
return nil, err
}
if _, err := buf.Write(hunk.Body[hunk.OrigNoNewlineAt:]); err != nil {
return nil, err
}
}
if !bytes.HasSuffix(hunk.Body, []byte{'\n'}) {
if _, err := fmt.Fprintln(&buf); err != nil {
return nil, err
}
if err := printNoNewlineMessage(&buf); err != nil {
return nil, err
}
}
}
return buf.Bytes(), nil
}
func printNoNewlineMessage(w io.Writer) error {
if _, err := w.Write([]byte(noNewlineMessage)); err != nil {
return err
}
if _, err := fmt.Fprintln(w); err != nil {
return err
}
return nil
}