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gitea/services/gitdiff/gitdiff.go

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20 KiB
Go

// Copyright 2014 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 gitdiff
import (
"bufio"
"bytes"
"context"
"fmt"
"html"
"html/template"
"io"
"io/ioutil"
"net/url"
"os"
"os/exec"
"sort"
"strconv"
"strings"
"code.gitea.io/gitea/models"
"code.gitea.io/gitea/modules/charset"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/highlight"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/process"
"code.gitea.io/gitea/modules/setting"
"github.com/sergi/go-diff/diffmatchpatch"
stdcharset "golang.org/x/net/html/charset"
"golang.org/x/text/transform"
)
// DiffLineType represents the type of a DiffLine.
type DiffLineType uint8
// DiffLineType possible values.
const (
DiffLinePlain DiffLineType = iota + 1
DiffLineAdd
DiffLineDel
DiffLineSection
)
// DiffFileType represents the type of a DiffFile.
type DiffFileType uint8
// DiffFileType possible values.
const (
DiffFileAdd DiffFileType = iota + 1
DiffFileChange
DiffFileDel
DiffFileRename
)
// DiffLineExpandDirection represents the DiffLineSection expand direction
type DiffLineExpandDirection uint8
// DiffLineExpandDirection possible values.
const (
DiffLineExpandNone DiffLineExpandDirection = iota + 1
DiffLineExpandSingle
DiffLineExpandUpDown
DiffLineExpandUp
DiffLineExpandDown
)
// DiffLine represents a line difference in a DiffSection.
type DiffLine struct {
LeftIdx int
RightIdx int
Type DiffLineType
Content string
Comments []*models.Comment
SectionInfo *DiffLineSectionInfo
}
// DiffLineSectionInfo represents diff line section meta data
type DiffLineSectionInfo struct {
Path string
LastLeftIdx int
LastRightIdx int
LeftIdx int
RightIdx int
LeftHunkSize int
RightHunkSize int
}
// BlobExceprtChunkSize represent max lines of excerpt
const BlobExceprtChunkSize = 20
// GetType returns the type of a DiffLine.
func (d *DiffLine) GetType() int {
return int(d.Type)
}
// CanComment returns whether or not a line can get commented
func (d *DiffLine) CanComment() bool {
return len(d.Comments) == 0 && d.Type != DiffLineSection
}
// GetCommentSide returns the comment side of the first comment, if not set returns empty string
func (d *DiffLine) GetCommentSide() string {
if len(d.Comments) == 0 {
return ""
}
return d.Comments[0].DiffSide()
}
// GetLineTypeMarker returns the line type marker
func (d *DiffLine) GetLineTypeMarker() string {
if strings.IndexByte(" +-", d.Content[0]) > -1 {
return d.Content[0:1]
}
return ""
}
// GetBlobExcerptQuery builds query string to get blob excerpt
func (d *DiffLine) GetBlobExcerptQuery() string {
query := fmt.Sprintf(
"last_left=%d&last_right=%d&"+
"left=%d&right=%d&"+
"left_hunk_size=%d&right_hunk_size=%d&"+
"path=%s",
d.SectionInfo.LastLeftIdx, d.SectionInfo.LastRightIdx,
d.SectionInfo.LeftIdx, d.SectionInfo.RightIdx,
d.SectionInfo.LeftHunkSize, d.SectionInfo.RightHunkSize,
url.QueryEscape(d.SectionInfo.Path))
return query
}
// GetExpandDirection gets DiffLineExpandDirection
func (d *DiffLine) GetExpandDirection() DiffLineExpandDirection {
if d.Type != DiffLineSection || d.SectionInfo == nil || d.SectionInfo.RightIdx-d.SectionInfo.LastRightIdx <= 1 {
return DiffLineExpandNone
}
if d.SectionInfo.LastLeftIdx <= 0 && d.SectionInfo.LastRightIdx <= 0 {
return DiffLineExpandUp
} else if d.SectionInfo.RightIdx-d.SectionInfo.LastRightIdx > BlobExceprtChunkSize && d.SectionInfo.RightHunkSize > 0 {
return DiffLineExpandUpDown
} else if d.SectionInfo.LeftHunkSize <= 0 && d.SectionInfo.RightHunkSize <= 0 {
return DiffLineExpandDown
}
return DiffLineExpandSingle
}
func getDiffLineSectionInfo(treePath, line string, lastLeftIdx, lastRightIdx int) *DiffLineSectionInfo {
leftLine, leftHunk, rightLine, righHunk := git.ParseDiffHunkString(line)
return &DiffLineSectionInfo{
Path: treePath,
LastLeftIdx: lastLeftIdx,
LastRightIdx: lastRightIdx,
LeftIdx: leftLine,
RightIdx: rightLine,
LeftHunkSize: leftHunk,
RightHunkSize: righHunk,
}
}
// escape a line's content or return <br> needed for copy/paste purposes
func getLineContent(content string) string {
if len(content) > 0 {
return html.EscapeString(content)
}
return "<br>"
}
// DiffSection represents a section of a DiffFile.
type DiffSection struct {
Name string
Lines []*DiffLine
}
var (
addedCodePrefix = []byte(`<span class="added-code">`)
removedCodePrefix = []byte(`<span class="removed-code">`)
codeTagSuffix = []byte(`</span>`)
)
func diffToHTML(diffs []diffmatchpatch.Diff, lineType DiffLineType) template.HTML {
buf := bytes.NewBuffer(nil)
for i := range diffs {
switch {
case diffs[i].Type == diffmatchpatch.DiffInsert && lineType == DiffLineAdd:
buf.Write(addedCodePrefix)
buf.WriteString(getLineContent(diffs[i].Text))
buf.Write(codeTagSuffix)
case diffs[i].Type == diffmatchpatch.DiffDelete && lineType == DiffLineDel:
buf.Write(removedCodePrefix)
buf.WriteString(getLineContent(diffs[i].Text))
buf.Write(codeTagSuffix)
case diffs[i].Type == diffmatchpatch.DiffEqual:
buf.WriteString(getLineContent(diffs[i].Text))
}
}
return template.HTML(buf.Bytes())
}
// GetLine gets a specific line by type (add or del) and file line number
func (diffSection *DiffSection) GetLine(lineType DiffLineType, idx int) *DiffLine {
var (
difference = 0
addCount = 0
delCount = 0
matchDiffLine *DiffLine
)
LOOP:
for _, diffLine := range diffSection.Lines {
switch diffLine.Type {
case DiffLineAdd:
addCount++
case DiffLineDel:
delCount++
default:
if matchDiffLine != nil {
break LOOP
}
difference = diffLine.RightIdx - diffLine.LeftIdx
addCount = 0
delCount = 0
}
switch lineType {
case DiffLineDel:
if diffLine.RightIdx == 0 && diffLine.LeftIdx == idx-difference {
matchDiffLine = diffLine
}
case DiffLineAdd:
if diffLine.LeftIdx == 0 && diffLine.RightIdx == idx+difference {
matchDiffLine = diffLine
}
}
}
if addCount == delCount {
return matchDiffLine
}
return nil
}
var diffMatchPatch = diffmatchpatch.New()
func init() {
diffMatchPatch.DiffEditCost = 100
}
// GetComputedInlineDiffFor computes inline diff for the given line.
func (diffSection *DiffSection) GetComputedInlineDiffFor(diffLine *DiffLine) template.HTML {
if setting.Git.DisableDiffHighlight {
return template.HTML(getLineContent(diffLine.Content[1:]))
}
var (
compareDiffLine *DiffLine
diff1 string
diff2 string
)
// try to find equivalent diff line. ignore, otherwise
switch diffLine.Type {
case DiffLineAdd:
compareDiffLine = diffSection.GetLine(DiffLineDel, diffLine.RightIdx)
if compareDiffLine == nil {
return template.HTML(getLineContent(diffLine.Content[1:]))
}
diff1 = compareDiffLine.Content
diff2 = diffLine.Content
case DiffLineDel:
compareDiffLine = diffSection.GetLine(DiffLineAdd, diffLine.LeftIdx)
if compareDiffLine == nil {
return template.HTML(getLineContent(diffLine.Content[1:]))
}
diff1 = diffLine.Content
diff2 = compareDiffLine.Content
default:
if strings.IndexByte(" +-", diffLine.Content[0]) > -1 {
return template.HTML(getLineContent(diffLine.Content[1:]))
}
return template.HTML(getLineContent(diffLine.Content))
}
diffRecord := diffMatchPatch.DiffMain(diff1[1:], diff2[1:], true)
diffRecord = diffMatchPatch.DiffCleanupEfficiency(diffRecord)
return diffToHTML(diffRecord, diffLine.Type)
}
// DiffFile represents a file diff.
type DiffFile struct {
Name string
OldName string
Index int
Addition, Deletion int
Type DiffFileType
IsCreated bool
IsDeleted bool
IsBin bool
IsLFSFile bool
IsRenamed bool
IsSubmodule bool
Sections []*DiffSection
IsIncomplete bool
}
// GetType returns type of diff file.
func (diffFile *DiffFile) GetType() int {
return int(diffFile.Type)
}
// GetHighlightClass returns highlight class for a filename.
func (diffFile *DiffFile) GetHighlightClass() string {
return highlight.FileNameToHighlightClass(diffFile.Name)
}
// GetTailSection creates a fake DiffLineSection if the last section is not the end of the file
func (diffFile *DiffFile) GetTailSection(gitRepo *git.Repository, leftCommitID, rightCommitID string) *DiffSection {
if len(diffFile.Sections) == 0 || diffFile.Type != DiffFileChange || diffFile.IsBin || diffFile.IsLFSFile {
return nil
}
leftCommit, err := gitRepo.GetCommit(leftCommitID)
if err != nil {
return nil
}
rightCommit, err := gitRepo.GetCommit(rightCommitID)
if err != nil {
return nil
}
lastSection := diffFile.Sections[len(diffFile.Sections)-1]
lastLine := lastSection.Lines[len(lastSection.Lines)-1]
leftLineCount := getCommitFileLineCount(leftCommit, diffFile.Name)
rightLineCount := getCommitFileLineCount(rightCommit, diffFile.Name)
if leftLineCount <= lastLine.LeftIdx || rightLineCount <= lastLine.RightIdx {
return nil
}
tailDiffLine := &DiffLine{
Type: DiffLineSection,
Content: " ",
SectionInfo: &DiffLineSectionInfo{
Path: diffFile.Name,
LastLeftIdx: lastLine.LeftIdx,
LastRightIdx: lastLine.RightIdx,
LeftIdx: leftLineCount,
RightIdx: rightLineCount,
}}
tailSection := &DiffSection{Lines: []*DiffLine{tailDiffLine}}
return tailSection
}
func getCommitFileLineCount(commit *git.Commit, filePath string) int {
blob, err := commit.GetBlobByPath(filePath)
if err != nil {
return 0
}
lineCount, err := blob.GetBlobLineCount()
if err != nil {
return 0
}
return lineCount
}
// Diff represents a difference between two git trees.
type Diff struct {
TotalAddition, TotalDeletion int
Files []*DiffFile
IsIncomplete bool
}
// LoadComments loads comments into each line
func (diff *Diff) LoadComments(issue *models.Issue, currentUser *models.User) error {
allComments, err := models.FetchCodeComments(issue, currentUser)
if err != nil {
return err
}
for _, file := range diff.Files {
if lineCommits, ok := allComments[file.Name]; ok {
for _, section := range file.Sections {
for _, line := range section.Lines {
if comments, ok := lineCommits[int64(line.LeftIdx*-1)]; ok {
line.Comments = append(line.Comments, comments...)
}
if comments, ok := lineCommits[int64(line.RightIdx)]; ok {
line.Comments = append(line.Comments, comments...)
}
sort.SliceStable(line.Comments, func(i, j int) bool {
return line.Comments[i].CreatedUnix < line.Comments[j].CreatedUnix
})
}
}
}
}
return nil
}
// NumFiles returns number of files changes in a diff.
func (diff *Diff) NumFiles() int {
return len(diff.Files)
}
const cmdDiffHead = "diff --git "
// ParsePatch builds a Diff object from a io.Reader and some
// parameters.
// TODO: move this function to gogits/git-module
func ParsePatch(maxLines, maxLineCharacters, maxFiles int, reader io.Reader) (*Diff, error) {
var (
diff = &Diff{Files: make([]*DiffFile, 0)}
curFile = &DiffFile{}
curSection = &DiffSection{
Lines: make([]*DiffLine, 0, 10),
}
leftLine, rightLine int
lineCount int
curFileLinesCount int
curFileLFSPrefix bool
)
input := bufio.NewReader(reader)
isEOF := false
for !isEOF {
var linebuf bytes.Buffer
for {
b, err := input.ReadByte()
if err != nil {
if err == io.EOF {
isEOF = true
break
} else {
return nil, fmt.Errorf("ReadByte: %v", err)
}
}
if b == '\n' {
break
}
if linebuf.Len() < maxLineCharacters {
linebuf.WriteByte(b)
} else if linebuf.Len() == maxLineCharacters {
curFile.IsIncomplete = true
}
}
line := linebuf.String()
if strings.HasPrefix(line, "+++ ") || strings.HasPrefix(line, "--- ") || len(line) == 0 {
continue
}
trimLine := strings.Trim(line, "+- ")
if trimLine == models.LFSMetaFileIdentifier {
curFileLFSPrefix = true
}
if curFileLFSPrefix && strings.HasPrefix(trimLine, models.LFSMetaFileOidPrefix) {
oid := strings.TrimPrefix(trimLine, models.LFSMetaFileOidPrefix)
if len(oid) == 64 {
m := &models.LFSMetaObject{Oid: oid}
count, err := models.Count(m)
if err == nil && count > 0 {
curFile.IsBin = true
curFile.IsLFSFile = true
curSection.Lines = nil
}
}
}
curFileLinesCount++
lineCount++
// Diff data too large, we only show the first about maxLines lines
if curFileLinesCount >= maxLines {
curFile.IsIncomplete = true
}
switch {
case line[0] == ' ':
diffLine := &DiffLine{Type: DiffLinePlain, Content: line, LeftIdx: leftLine, RightIdx: rightLine}
leftLine++
rightLine++
curSection.Lines = append(curSection.Lines, diffLine)
continue
case line[0] == '@':
curSection = &DiffSection{}
curFile.Sections = append(curFile.Sections, curSection)
lineSectionInfo := getDiffLineSectionInfo(curFile.Name, line, leftLine-1, rightLine-1)
diffLine := &DiffLine{
Type: DiffLineSection,
Content: line,
SectionInfo: lineSectionInfo,
}
curSection.Lines = append(curSection.Lines, diffLine)
// update line number.
leftLine = lineSectionInfo.LeftIdx
rightLine = lineSectionInfo.RightIdx
continue
case line[0] == '+':
curFile.Addition++
diff.TotalAddition++
diffLine := &DiffLine{Type: DiffLineAdd, Content: line, RightIdx: rightLine}
rightLine++
curSection.Lines = append(curSection.Lines, diffLine)
continue
case line[0] == '-':
curFile.Deletion++
diff.TotalDeletion++
diffLine := &DiffLine{Type: DiffLineDel, Content: line, LeftIdx: leftLine}
if leftLine > 0 {
leftLine++
}
curSection.Lines = append(curSection.Lines, diffLine)
case strings.HasPrefix(line, "Binary"):
curFile.IsBin = true
continue
}
// Get new file.
if strings.HasPrefix(line, cmdDiffHead) {
if len(diff.Files) >= maxFiles {
diff.IsIncomplete = true
_, err := io.Copy(ioutil.Discard, reader)
if err != nil {
return nil, fmt.Errorf("Copy: %v", err)
}
break
}
var middle int
// Note: In case file name is surrounded by double quotes (it happens only in git-shell).
// e.g. diff --git "a/xxx" "b/xxx"
hasQuote := line[len(cmdDiffHead)] == '"'
if hasQuote {
middle = strings.Index(line, ` "b/`)
} else {
middle = strings.Index(line, " b/")
}
beg := len(cmdDiffHead)
a := line[beg+2 : middle]
b := line[middle+3:]
if hasQuote {
// Keep the entire string in double quotes for now
a = line[beg:middle]
b = line[middle+1:]
var err error
a, err = strconv.Unquote(a)
if err != nil {
return nil, fmt.Errorf("Unquote: %v", err)
}
b, err = strconv.Unquote(b)
if err != nil {
return nil, fmt.Errorf("Unquote: %v", err)
}
// Now remove the /a /b
a = a[2:]
b = b[2:]
}
curFile = &DiffFile{
Name: b,
OldName: a,
Index: len(diff.Files) + 1,
Type: DiffFileChange,
Sections: make([]*DiffSection, 0, 10),
IsRenamed: a != b,
}
diff.Files = append(diff.Files, curFile)
curFileLinesCount = 0
leftLine = 1
rightLine = 1
curFileLFSPrefix = false
// Check file diff type and is submodule.
for {
line, err := input.ReadString('\n')
if err != nil {
if err == io.EOF {
isEOF = true
} else {
return nil, fmt.Errorf("ReadString: %v", err)
}
}
switch {
case strings.HasPrefix(line, "new file"):
curFile.Type = DiffFileAdd
curFile.IsCreated = true
case strings.HasPrefix(line, "deleted"):
curFile.Type = DiffFileDel
curFile.IsDeleted = true
case strings.HasPrefix(line, "index"):
curFile.Type = DiffFileChange
case strings.HasPrefix(line, "similarity index 100%"):
curFile.Type = DiffFileRename
}
if curFile.Type > 0 {
if strings.HasSuffix(line, " 160000\n") {
curFile.IsSubmodule = true
}
break
}
}
}
}
// FIXME: detect encoding while parsing.
var buf bytes.Buffer
for _, f := range diff.Files {
buf.Reset()
for _, sec := range f.Sections {
for _, l := range sec.Lines {
buf.WriteString(l.Content)
buf.WriteString("\n")
}
}
charsetLabel, err := charset.DetectEncoding(buf.Bytes())
if charsetLabel != "UTF-8" && err == nil {
encoding, _ := stdcharset.Lookup(charsetLabel)
if encoding != nil {
d := encoding.NewDecoder()
for _, sec := range f.Sections {
for _, l := range sec.Lines {
if c, _, err := transform.String(d, l.Content); err == nil {
l.Content = c
}
}
}
}
}
}
return diff, nil
}
// GetDiffRange builds a Diff between two commits of a repository.
// passing the empty string as beforeCommitID returns a diff from the
// parent commit.
func GetDiffRange(repoPath, beforeCommitID, afterCommitID string, maxLines, maxLineCharacters, maxFiles int) (*Diff, error) {
return GetDiffRangeWithWhitespaceBehavior(repoPath, beforeCommitID, afterCommitID, maxLines, maxLineCharacters, maxFiles, "")
}
// GetDiffRangeWithWhitespaceBehavior builds a Diff between two commits of a repository.
// Passing the empty string as beforeCommitID returns a diff from the parent commit.
// The whitespaceBehavior is either an empty string or a git flag
func GetDiffRangeWithWhitespaceBehavior(repoPath, beforeCommitID, afterCommitID string, maxLines, maxLineCharacters, maxFiles int, whitespaceBehavior string) (*Diff, error) {
gitRepo, err := git.OpenRepository(repoPath)
if err != nil {
return nil, err
}
defer gitRepo.Close()
commit, err := gitRepo.GetCommit(afterCommitID)
if err != nil {
return nil, err
}
// FIXME: graceful: These commands should likely have a timeout
ctx, cancel := context.WithCancel(git.DefaultContext)
defer cancel()
var cmd *exec.Cmd
if len(beforeCommitID) == 0 && commit.ParentCount() == 0 {
cmd = exec.CommandContext(ctx, git.GitExecutable, "show", afterCommitID)
} else {
actualBeforeCommitID := beforeCommitID
if len(actualBeforeCommitID) == 0 {
parentCommit, _ := commit.Parent(0)
actualBeforeCommitID = parentCommit.ID.String()
}
diffArgs := []string{"diff", "-M"}
if len(whitespaceBehavior) != 0 {
diffArgs = append(diffArgs, whitespaceBehavior)
}
diffArgs = append(diffArgs, actualBeforeCommitID)
diffArgs = append(diffArgs, afterCommitID)
cmd = exec.CommandContext(ctx, git.GitExecutable, diffArgs...)
beforeCommitID = actualBeforeCommitID
}
cmd.Dir = repoPath
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)
}
pid := process.GetManager().Add(fmt.Sprintf("GetDiffRange [repo_path: %s]", repoPath), cancel)
defer process.GetManager().Remove(pid)
diff, err := ParsePatch(maxLines, maxLineCharacters, maxFiles, stdout)
if err != nil {
return nil, fmt.Errorf("ParsePatch: %v", err)
}
for _, diffFile := range diff.Files {
tailSection := diffFile.GetTailSection(gitRepo, beforeCommitID, afterCommitID)
if tailSection != nil {
diffFile.Sections = append(diffFile.Sections, tailSection)
}
}
if err = cmd.Wait(); err != nil {
return nil, fmt.Errorf("Wait: %v", err)
}
return diff, nil
}
// GetDiffCommit builds a Diff representing the given commitID.
func GetDiffCommit(repoPath, commitID string, maxLines, maxLineCharacters, maxFiles int) (*Diff, error) {
return GetDiffRange(repoPath, "", commitID, maxLines, maxLineCharacters, maxFiles)
}
// CommentAsDiff returns c.Patch as *Diff
func CommentAsDiff(c *models.Comment) (*Diff, error) {
diff, err := ParsePatch(setting.Git.MaxGitDiffLines,
setting.Git.MaxGitDiffLineCharacters, setting.Git.MaxGitDiffFiles, strings.NewReader(c.Patch))
if err != nil {
return nil, err
}
if len(diff.Files) == 0 {
return nil, fmt.Errorf("no file found for comment ID: %d", c.ID)
}
secs := diff.Files[0].Sections
if len(secs) == 0 {
return nil, fmt.Errorf("no sections found for comment ID: %d", c.ID)
}
return diff, nil
}
// CommentMustAsDiff executes AsDiff and logs the error instead of returning
func CommentMustAsDiff(c *models.Comment) *Diff {
diff, err := CommentAsDiff(c)
if err != nil {
log.Warn("CommentMustAsDiff: %v", err)
}
return diff
}