gitea/modules/git/repo_compare.go
zeripath 920608e592
Support direct comparison (git diff a..b) as well merge comparison (a...b) (#16635)
This PR changes the compare page to make the "..." in the between branches a clickable
link. This changes the comparison type from "..." to "..". Similarly it makes the
initial compare icon clickable to switch the head and base branches.

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
2021-09-27 13:19:34 +01:00

254 lines
8.3 KiB
Go

// Copyright 2015 The Gogs Authors. All rights reserved.
// Copyright 2019 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package git
import (
"bytes"
"fmt"
"io"
"regexp"
"strconv"
"strings"
"time"
logger "code.gitea.io/gitea/modules/log"
)
// CompareInfo represents needed information for comparing references.
type CompareInfo struct {
MergeBase string
BaseCommitID string
HeadCommitID string
Commits []*Commit
NumFiles int
}
// GetMergeBase checks and returns merge base of two branches and the reference used as base.
func (repo *Repository) GetMergeBase(tmpRemote string, base, head string) (string, string, error) {
if tmpRemote == "" {
tmpRemote = "origin"
}
if tmpRemote != "origin" {
tmpBaseName := "refs/remotes/" + tmpRemote + "/tmp_" + base
// Fetch commit into a temporary branch in order to be able to handle commits and tags
_, err := NewCommand("fetch", tmpRemote, base+":"+tmpBaseName).RunInDir(repo.Path)
if err == nil {
base = tmpBaseName
}
}
stdout, err := NewCommand("merge-base", "--", base, head).RunInDir(repo.Path)
return strings.TrimSpace(stdout), base, err
}
// GetCompareInfo generates and returns compare information between base and head branches of repositories.
func (repo *Repository) GetCompareInfo(basePath, baseBranch, headBranch string, directComparison bool) (_ *CompareInfo, err error) {
var (
remoteBranch string
tmpRemote string
)
// We don't need a temporary remote for same repository.
if repo.Path != basePath {
// Add a temporary remote
tmpRemote = strconv.FormatInt(time.Now().UnixNano(), 10)
if err = repo.AddRemote(tmpRemote, basePath, false); err != nil {
return nil, fmt.Errorf("AddRemote: %v", err)
}
defer func() {
if err := repo.RemoveRemote(tmpRemote); err != nil {
logger.Error("GetPullRequestInfo: RemoveRemote: %v", err)
}
}()
}
compareInfo := new(CompareInfo)
compareInfo.HeadCommitID, err = GetFullCommitID(repo.Path, headBranch)
if err != nil {
compareInfo.HeadCommitID = headBranch
}
compareInfo.MergeBase, remoteBranch, err = repo.GetMergeBase(tmpRemote, baseBranch, headBranch)
if err == nil {
compareInfo.BaseCommitID, err = GetFullCommitID(repo.Path, remoteBranch)
if err != nil {
compareInfo.BaseCommitID = remoteBranch
}
separator := "..."
baseCommitID := compareInfo.MergeBase
if directComparison {
separator = ".."
baseCommitID = compareInfo.BaseCommitID
}
// We have a common base - therefore we know that ... should work
logs, err := NewCommand("log", baseCommitID+separator+headBranch, prettyLogFormat).RunInDirBytes(repo.Path)
if err != nil {
return nil, err
}
compareInfo.Commits, err = repo.parsePrettyFormatLogToList(logs)
if err != nil {
return nil, fmt.Errorf("parsePrettyFormatLogToList: %v", err)
}
} else {
compareInfo.Commits = []*Commit{}
compareInfo.MergeBase, err = GetFullCommitID(repo.Path, remoteBranch)
if err != nil {
compareInfo.MergeBase = remoteBranch
}
compareInfo.BaseCommitID = compareInfo.MergeBase
}
// Count number of changed files.
// This probably should be removed as we need to use shortstat elsewhere
// Now there is git diff --shortstat but this appears to be slower than simply iterating with --nameonly
compareInfo.NumFiles, err = repo.GetDiffNumChangedFiles(remoteBranch, headBranch, directComparison)
if err != nil {
return nil, err
}
return compareInfo, nil
}
type lineCountWriter struct {
numLines int
}
// Write counts the number of newlines in the provided bytestream
func (l *lineCountWriter) Write(p []byte) (n int, err error) {
n = len(p)
l.numLines += bytes.Count(p, []byte{'\000'})
return
}
// GetDiffNumChangedFiles counts the number of changed files
// This is substantially quicker than shortstat but...
func (repo *Repository) GetDiffNumChangedFiles(base, head string, directComparison bool) (int, error) {
// Now there is git diff --shortstat but this appears to be slower than simply iterating with --nameonly
w := &lineCountWriter{}
stderr := new(bytes.Buffer)
separator := "..."
if directComparison {
separator = ".."
}
if err := NewCommand("diff", "-z", "--name-only", base+separator+head).
RunInDirPipeline(repo.Path, w, stderr); err != nil {
if strings.Contains(stderr.String(), "no merge base") {
// git >= 2.28 now returns an error if base and head have become unrelated.
// previously it would return the results of git diff -z --name-only base head so let's try that...
w = &lineCountWriter{}
stderr.Reset()
if err = NewCommand("diff", "-z", "--name-only", base, head).RunInDirPipeline(repo.Path, w, stderr); err == nil {
return w.numLines, nil
}
}
return 0, fmt.Errorf("%v: Stderr: %s", err, stderr)
}
return w.numLines, nil
}
// GetDiffShortStat counts number of changed files, number of additions and deletions
func (repo *Repository) GetDiffShortStat(base, head string) (numFiles, totalAdditions, totalDeletions int, err error) {
numFiles, totalAdditions, totalDeletions, err = GetDiffShortStat(repo.Path, base+"..."+head)
if err != nil && strings.Contains(err.Error(), "no merge base") {
return GetDiffShortStat(repo.Path, base, head)
}
return
}
// GetDiffShortStat counts number of changed files, number of additions and deletions
func GetDiffShortStat(repoPath string, args ...string) (numFiles, totalAdditions, totalDeletions int, err error) {
// Now if we call:
// $ git diff --shortstat 1ebb35b98889ff77299f24d82da426b434b0cca0...788b8b1440462d477f45b0088875
// we get:
// " 9902 files changed, 2034198 insertions(+), 298800 deletions(-)\n"
args = append([]string{
"diff",
"--shortstat",
}, args...)
stdout, err := NewCommand(args...).RunInDir(repoPath)
if err != nil {
return 0, 0, 0, err
}
return parseDiffStat(stdout)
}
var shortStatFormat = regexp.MustCompile(
`\s*(\d+) files? changed(?:, (\d+) insertions?\(\+\))?(?:, (\d+) deletions?\(-\))?`)
func parseDiffStat(stdout string) (numFiles, totalAdditions, totalDeletions int, err error) {
if len(stdout) == 0 || stdout == "\n" {
return 0, 0, 0, nil
}
groups := shortStatFormat.FindStringSubmatch(stdout)
if len(groups) != 4 {
return 0, 0, 0, fmt.Errorf("unable to parse shortstat: %s groups: %s", stdout, groups)
}
numFiles, err = strconv.Atoi(groups[1])
if err != nil {
return 0, 0, 0, fmt.Errorf("unable to parse shortstat: %s. Error parsing NumFiles %v", stdout, err)
}
if len(groups[2]) != 0 {
totalAdditions, err = strconv.Atoi(groups[2])
if err != nil {
return 0, 0, 0, fmt.Errorf("unable to parse shortstat: %s. Error parsing NumAdditions %v", stdout, err)
}
}
if len(groups[3]) != 0 {
totalDeletions, err = strconv.Atoi(groups[3])
if err != nil {
return 0, 0, 0, fmt.Errorf("unable to parse shortstat: %s. Error parsing NumDeletions %v", stdout, err)
}
}
return
}
// GetDiffOrPatch generates either diff or formatted patch data between given revisions
func (repo *Repository) GetDiffOrPatch(base, head string, w io.Writer, formatted bool) error {
if formatted {
return repo.GetPatch(base, head, w)
}
return repo.GetDiff(base, head, w)
}
// GetDiff generates and returns patch data between given revisions.
func (repo *Repository) GetDiff(base, head string, w io.Writer) error {
return NewCommand("diff", "-p", "--binary", base, head).
RunInDirPipeline(repo.Path, w, nil)
}
// GetPatch generates and returns format-patch data between given revisions.
func (repo *Repository) GetPatch(base, head string, w io.Writer) error {
stderr := new(bytes.Buffer)
err := NewCommand("format-patch", "--binary", "--stdout", base+"..."+head).
RunInDirPipeline(repo.Path, w, stderr)
if err != nil && bytes.Contains(stderr.Bytes(), []byte("no merge base")) {
return NewCommand("format-patch", "--binary", "--stdout", base, head).
RunInDirPipeline(repo.Path, w, nil)
}
return err
}
// GetDiffFromMergeBase generates and return patch data from merge base to head
func (repo *Repository) GetDiffFromMergeBase(base, head string, w io.Writer) error {
stderr := new(bytes.Buffer)
err := NewCommand("diff", "-p", "--binary", base+"..."+head).
RunInDirPipeline(repo.Path, w, stderr)
if err != nil && bytes.Contains(stderr.Bytes(), []byte("no merge base")) {
return NewCommand("diff", "-p", "--binary", base, head).
RunInDirPipeline(repo.Path, w, nil)
}
return err
}