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forgejo/models/git_diff.go
2016-01-09 15:04:28 +08:00

418 lines
10 KiB
Go

// Copyright 2014 The Gogs 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 models
import (
"bufio"
"bytes"
"fmt"
"html"
"html/template"
"io"
"io/ioutil"
"os"
"os/exec"
"strings"
"github.com/Unknwon/com"
"github.com/sergi/go-diff/diffmatchpatch"
"golang.org/x/net/html/charset"
"golang.org/x/text/transform"
"github.com/gogits/git-module"
"github.com/gogits/gogs/modules/base"
"github.com/gogits/gogs/modules/log"
"github.com/gogits/gogs/modules/process"
)
type DiffLineType uint8
const (
DIFF_LINE_PLAIN DiffLineType = iota + 1
DIFF_LINE_ADD
DIFF_LINE_DEL
DIFF_LINE_SECTION
)
type DiffFileType uint8
const (
DIFF_FILE_ADD DiffFileType = iota + 1
DIFF_FILE_CHANGE
DIFF_FILE_DEL
DIFF_FILE_RENAME
)
type DiffLine struct {
LeftIdx int
RightIdx int
Type DiffLineType
Content string
ParsedContent template.HTML
}
func (d *DiffLine) GetType() int {
return int(d.Type)
}
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 {
var buf bytes.Buffer
for i := range diffs {
if diffs[i].Type == diffmatchpatch.DiffInsert && lineType == DIFF_LINE_ADD {
buf.Write(addedCodePrefix)
buf.WriteString(html.EscapeString(diffs[i].Text))
buf.Write(codeTagSuffix)
} else if diffs[i].Type == diffmatchpatch.DiffDelete && lineType == DIFF_LINE_DEL {
buf.Write(removedCodePrefix)
buf.WriteString(html.EscapeString(diffs[i].Text))
buf.Write(codeTagSuffix)
} else if diffs[i].Type == diffmatchpatch.DiffEqual {
buf.WriteString(html.EscapeString(diffs[i].Text))
}
}
return template.HTML(buf.Bytes())
}
// get an specific line by type (add or del) and file line number
func (diffSection *DiffSection) GetLine(lineType DiffLineType, idx int) *DiffLine {
difference := 0
for _, diffLine := range diffSection.Lines {
if diffLine.Type == DIFF_LINE_PLAIN {
// get the difference of line numbers between ADD and DEL versions
difference = diffLine.RightIdx - diffLine.LeftIdx
continue
}
if lineType == DIFF_LINE_DEL {
if diffLine.RightIdx == 0 && diffLine.LeftIdx == idx-difference {
return diffLine
}
} else if lineType == DIFF_LINE_ADD {
if diffLine.LeftIdx == 0 && diffLine.RightIdx == idx+difference {
return diffLine
}
}
}
return nil
}
// computes diff of each diff line and set the HTML on diffLine.ParsedContent
func (diffSection *DiffSection) ComputeLinesDiff() {
for _, diffLine := range diffSection.Lines {
var compareDiffLine *DiffLine
var diff1, diff2 string
diffLine.ParsedContent = template.HTML(html.EscapeString(diffLine.Content[1:]))
// just compute diff for adds and removes
if diffLine.Type != DIFF_LINE_ADD && diffLine.Type != DIFF_LINE_DEL {
continue
}
// try to find equivalent diff line. ignore, otherwise
if diffLine.Type == DIFF_LINE_ADD {
compareDiffLine = diffSection.GetLine(DIFF_LINE_DEL, diffLine.RightIdx)
if compareDiffLine == nil {
continue
}
diff1 = compareDiffLine.Content
diff2 = diffLine.Content
} else {
compareDiffLine = diffSection.GetLine(DIFF_LINE_ADD, diffLine.LeftIdx)
if compareDiffLine == nil {
continue
}
diff1 = diffLine.Content
diff2 = compareDiffLine.Content
}
dmp := diffmatchpatch.New()
diffRecord := dmp.DiffMain(diff1[1:], diff2[1:], true)
diffRecord = dmp.DiffCleanupSemantic(diffRecord)
diffLine.ParsedContent = diffToHTML(diffRecord, diffLine.Type)
}
}
type DiffFile struct {
Name string
OldName string
Index int
Addition, Deletion int
Type DiffFileType
IsCreated bool
IsDeleted bool
IsBin bool
IsRenamed bool
Sections []*DiffSection
}
func (diffFile *DiffFile) GetType() int {
return int(diffFile.Type)
}
type Diff struct {
TotalAddition, TotalDeletion int
Files []*DiffFile
}
func (diff *Diff) NumFiles() int {
return len(diff.Files)
}
const DIFF_HEAD = "diff --git "
func ParsePatch(maxlines 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
)
input := bufio.NewReader(reader)
isEOF := false
for {
if isEOF {
break
}
line, err := input.ReadString('\n')
if err != nil {
if err == io.EOF {
isEOF = true
} else {
return nil, fmt.Errorf("ReadString: %v", err)
}
}
if len(line) > 0 && line[len(line)-1] == '\n' {
// Remove line break.
line = line[:len(line)-1]
}
if strings.HasPrefix(line, "+++ ") || strings.HasPrefix(line, "--- ") {
continue
} else if len(line) == 0 {
continue
}
lineCount++
// Diff data too large, we only show the first about maxlines lines
if lineCount >= maxlines {
log.Warn("Diff data too large")
io.Copy(ioutil.Discard, reader)
diff.Files = nil
return diff, nil
}
switch {
case line[0] == ' ':
diffLine := &DiffLine{Type: DIFF_LINE_PLAIN, 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)
ss := strings.Split(line, "@@")
diffLine := &DiffLine{Type: DIFF_LINE_SECTION, Content: line}
curSection.Lines = append(curSection.Lines, diffLine)
// Parse line number.
ranges := strings.Split(ss[1][1:], " ")
leftLine, _ = com.StrTo(strings.Split(ranges[0], ",")[0][1:]).Int()
if len(ranges) > 1 {
rightLine, _ = com.StrTo(strings.Split(ranges[1], ",")[0]).Int()
} else {
log.Warn("Parse line number failed: %v", line)
rightLine = leftLine
}
continue
case line[0] == '+':
curFile.Addition++
diff.TotalAddition++
diffLine := &DiffLine{Type: DIFF_LINE_ADD, Content: line, RightIdx: rightLine}
rightLine++
curSection.Lines = append(curSection.Lines, diffLine)
continue
case line[0] == '-':
curFile.Deletion++
diff.TotalDeletion++
diffLine := &DiffLine{Type: DIFF_LINE_DEL, 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, DIFF_HEAD) {
middle := -1
// 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(DIFF_HEAD)] == '"'
if hasQuote {
middle = strings.Index(line, ` "b/`)
} else {
middle = strings.Index(line, " b/")
}
beg := len(DIFF_HEAD)
a := line[beg+2 : middle]
b := line[middle+3:]
if hasQuote {
a = string(git.UnescapeChars([]byte(a[1 : len(a)-1])))
b = string(git.UnescapeChars([]byte(b[1 : len(b)-1])))
}
curFile = &DiffFile{
Name: a,
Index: len(diff.Files) + 1,
Type: DIFF_FILE_CHANGE,
Sections: make([]*DiffSection, 0, 10),
}
diff.Files = append(diff.Files, curFile)
// Check file diff type.
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 = DIFF_FILE_ADD
curFile.IsCreated = true
case strings.HasPrefix(line, "deleted"):
curFile.Type = DIFF_FILE_DEL
curFile.IsDeleted = true
case strings.HasPrefix(line, "index"):
curFile.Type = DIFF_FILE_CHANGE
case strings.HasPrefix(line, "similarity index 100%"):
curFile.Type = DIFF_FILE_RENAME
curFile.IsRenamed = true
curFile.OldName = curFile.Name
curFile.Name = b
}
if curFile.Type > 0 {
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 := base.DetectEncoding(buf.Bytes())
if charsetLabel != "UTF-8" && err == nil {
encoding, _ := charset.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
}
func GetDiffRange(repoPath, beforeCommitID string, afterCommitID string, maxlines int) (*Diff, error) {
repo, err := git.OpenRepository(repoPath)
if err != nil {
return nil, err
}
commit, err := repo.GetCommit(afterCommitID)
if err != nil {
return nil, err
}
var cmd *exec.Cmd
// if "after" commit given
if len(beforeCommitID) == 0 {
// First commit of repository.
if commit.ParentCount() == 0 {
cmd = exec.Command("git", "show", afterCommitID)
} else {
c, _ := commit.Parent(0)
cmd = exec.Command("git", "diff", "-M", c.ID.String(), afterCommitID)
}
} else {
cmd = exec.Command("git", "diff", "-M", beforeCommitID, afterCommitID)
}
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.Add(fmt.Sprintf("GetDiffRange (%s)", repoPath), cmd)
defer process.Remove(pid)
diff, err := ParsePatch(maxlines, stdout)
if err != nil {
return nil, fmt.Errorf("ParsePatch: %v", err)
}
if err = cmd.Wait(); err != nil {
return nil, fmt.Errorf("Wait: %v", err)
}
return diff, nil
}
func GetDiffCommit(repoPath, commitId string, maxlines int) (*Diff, error) {
return GetDiffRange(repoPath, "", commitId, maxlines)
}