gitea/modules/git/blame.go
Giteabot e15fe85335
Read previous info from git blame (#28306) (#28310)
Backport #28306 by @KN4CK3R

Fixes #28280

Reads the `previous` info from the `git blame` output instead of
calculating it afterwards.

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
2023-12-01 08:27:35 +01:00

207 lines
4.7 KiB
Go

// Copyright 2019 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package git
import (
"bufio"
"bytes"
"context"
"fmt"
"io"
"os"
"regexp"
"strings"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/util"
)
// BlamePart represents block of blame - continuous lines with one sha
type BlamePart struct {
Sha string
Lines []string
PreviousSha string
PreviousPath string
}
// BlameReader returns part of file blame one by one
type BlameReader struct {
output io.WriteCloser
reader io.ReadCloser
bufferedReader *bufio.Reader
done chan error
lastSha *string
ignoreRevsFile *string
}
func (r *BlameReader) UsesIgnoreRevs() bool {
return r.ignoreRevsFile != nil
}
var shaLineRegex = regexp.MustCompile("^([a-z0-9]{40})")
// NextPart returns next part of blame (sequential code lines with the same commit)
func (r *BlameReader) NextPart() (*BlamePart, error) {
var blamePart *BlamePart
if r.lastSha != nil {
blamePart = &BlamePart{
Sha: *r.lastSha,
Lines: make([]string, 0),
}
}
var lineBytes []byte
var isPrefix bool
var err error
for err != io.EOF {
lineBytes, isPrefix, err = r.bufferedReader.ReadLine()
if err != nil && err != io.EOF {
return blamePart, err
}
if len(lineBytes) == 0 {
// isPrefix will be false
continue
}
line := string(lineBytes)
lines := shaLineRegex.FindStringSubmatch(line)
if lines != nil {
sha1 := lines[1]
if blamePart == nil {
blamePart = &BlamePart{
Sha: sha1,
Lines: make([]string, 0),
}
}
if blamePart.Sha != sha1 {
r.lastSha = &sha1
// need to munch to end of line...
for isPrefix {
_, isPrefix, err = r.bufferedReader.ReadLine()
if err != nil && err != io.EOF {
return blamePart, err
}
}
return blamePart, nil
}
} else if line[0] == '\t' {
blamePart.Lines = append(blamePart.Lines, line[1:])
} else if strings.HasPrefix(line, "previous ") {
parts := strings.SplitN(line[len("previous "):], " ", 2)
blamePart.PreviousSha = parts[0]
blamePart.PreviousPath = parts[1]
}
// need to munch to end of line...
for isPrefix {
_, isPrefix, err = r.bufferedReader.ReadLine()
if err != nil && err != io.EOF {
return blamePart, err
}
}
}
r.lastSha = nil
return blamePart, nil
}
// Close BlameReader - don't run NextPart after invoking that
func (r *BlameReader) Close() error {
err := <-r.done
r.bufferedReader = nil
_ = r.reader.Close()
_ = r.output.Close()
if r.ignoreRevsFile != nil {
_ = util.Remove(*r.ignoreRevsFile)
}
return err
}
// CreateBlameReader creates reader for given repository, commit and file
func CreateBlameReader(ctx context.Context, repoPath string, commit *Commit, file string, bypassBlameIgnore bool) (*BlameReader, error) {
var ignoreRevsFile *string
if CheckGitVersionAtLeast("2.23") == nil && !bypassBlameIgnore {
ignoreRevsFile = tryCreateBlameIgnoreRevsFile(commit)
}
cmd := NewCommandContextNoGlobals(ctx, "blame", "--porcelain")
if ignoreRevsFile != nil {
// Possible improvement: use --ignore-revs-file /dev/stdin on unix
// There is no equivalent on Windows. May be implemented if Gitea uses an external git backend.
cmd.AddOptionValues("--ignore-revs-file", *ignoreRevsFile)
}
cmd.AddDynamicArguments(commit.ID.String()).
AddDashesAndList(file).
SetDescription(fmt.Sprintf("GetBlame [repo_path: %s]", repoPath))
reader, stdout, err := os.Pipe()
if err != nil {
if ignoreRevsFile != nil {
_ = util.Remove(*ignoreRevsFile)
}
return nil, err
}
done := make(chan error, 1)
go func() {
stderr := bytes.Buffer{}
// TODO: it doesn't work for directories (the directories shouldn't be "blamed"), and the "err" should be returned by "Read" but not by "Close"
err := cmd.Run(&RunOpts{
UseContextTimeout: true,
Dir: repoPath,
Stdout: stdout,
Stderr: &stderr,
})
done <- err
_ = stdout.Close()
if err != nil {
log.Error("Error running git blame (dir: %v): %v, stderr: %v", repoPath, err, stderr.String())
}
}()
bufferedReader := bufio.NewReader(reader)
return &BlameReader{
output: stdout,
reader: reader,
bufferedReader: bufferedReader,
done: done,
ignoreRevsFile: ignoreRevsFile,
}, nil
}
func tryCreateBlameIgnoreRevsFile(commit *Commit) *string {
entry, err := commit.GetTreeEntryByPath(".git-blame-ignore-revs")
if err != nil {
return nil
}
r, err := entry.Blob().DataAsync()
if err != nil {
return nil
}
defer r.Close()
f, err := os.CreateTemp("", "gitea_git-blame-ignore-revs")
if err != nil {
return nil
}
_, err = io.Copy(f, r)
_ = f.Close()
if err != nil {
_ = util.Remove(f.Name())
return nil
}
return util.ToPointer(f.Name())
}