forgejo/modules/git/diff.go
zeripath 5cb0c9aa0d
Propagate context and ensure git commands run in request context ()
This PR continues the work in  by progressively ensuring that git
commands run within the request context.

This now means that the if there is a git repo already open in the context it will be used instead of reopening it.

Signed-off-by: Andrew Thornton <art27@cantab.net>
2022-01-19 23:26:57 +00:00

319 lines
9.7 KiB
Go

// Copyright 2020 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 (
"bufio"
"bytes"
"context"
"fmt"
"io"
"os"
"os/exec"
"regexp"
"strconv"
"strings"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/process"
)
// RawDiffType type of a raw diff.
type RawDiffType string
// RawDiffType possible values.
const (
RawDiffNormal RawDiffType = "diff"
RawDiffPatch RawDiffType = "patch"
)
// GetRawDiff dumps diff results of repository in given commit ID to io.Writer.
func GetRawDiff(ctx context.Context, repoPath, commitID string, diffType RawDiffType, writer io.Writer) error {
return GetRawDiffForFile(ctx, repoPath, "", commitID, diffType, "", writer)
}
// GetRawDiffForFile dumps diff results of file in given commit ID to io.Writer.
func GetRawDiffForFile(ctx context.Context, repoPath, startCommit, endCommit string, diffType RawDiffType, file string, writer io.Writer) error {
repo, closer, err := RepositoryFromContextOrOpen(ctx, repoPath)
if err != nil {
return fmt.Errorf("OpenRepository: %v", err)
}
defer closer.Close()
return GetRepoRawDiffForFile(repo, startCommit, endCommit, diffType, file, writer)
}
// GetRepoRawDiffForFile dumps diff results of file in given commit ID to io.Writer according given repository
func GetRepoRawDiffForFile(repo *Repository, startCommit, endCommit string, diffType RawDiffType, file string, writer io.Writer) error {
commit, err := repo.GetCommit(endCommit)
if err != nil {
return err
}
fileArgs := make([]string, 0)
if len(file) > 0 {
fileArgs = append(fileArgs, "--", file)
}
// FIXME: graceful: These commands should have a timeout
ctx, _, finished := process.GetManager().AddContext(repo.Ctx, fmt.Sprintf("GetRawDiffForFile: [repo_path: %s]", repo.Path))
defer finished()
var cmd *exec.Cmd
switch diffType {
case RawDiffNormal:
if len(startCommit) != 0 {
cmd = exec.CommandContext(ctx, GitExecutable, append([]string{"diff", "-M", startCommit, endCommit}, fileArgs...)...)
} else if commit.ParentCount() == 0 {
cmd = exec.CommandContext(ctx, GitExecutable, append([]string{"show", endCommit}, fileArgs...)...)
} else {
c, _ := commit.Parent(0)
cmd = exec.CommandContext(ctx, GitExecutable, append([]string{"diff", "-M", c.ID.String(), endCommit}, fileArgs...)...)
}
case RawDiffPatch:
if len(startCommit) != 0 {
query := fmt.Sprintf("%s...%s", endCommit, startCommit)
cmd = exec.CommandContext(ctx, GitExecutable, append([]string{"format-patch", "--no-signature", "--stdout", "--root", query}, fileArgs...)...)
} else if commit.ParentCount() == 0 {
cmd = exec.CommandContext(ctx, GitExecutable, append([]string{"format-patch", "--no-signature", "--stdout", "--root", endCommit}, fileArgs...)...)
} else {
c, _ := commit.Parent(0)
query := fmt.Sprintf("%s...%s", endCommit, c.ID.String())
cmd = exec.CommandContext(ctx, GitExecutable, append([]string{"format-patch", "--no-signature", "--stdout", query}, fileArgs...)...)
}
default:
return fmt.Errorf("invalid diffType: %s", diffType)
}
stderr := new(bytes.Buffer)
cmd.Dir = repo.Path
cmd.Stdout = writer
cmd.Stderr = stderr
if err = cmd.Run(); err != nil {
return fmt.Errorf("Run: %v - %s", err, stderr)
}
return nil
}
// ParseDiffHunkString parse the diffhunk content and return
func ParseDiffHunkString(diffhunk string) (leftLine, leftHunk, rightLine, righHunk int) {
ss := strings.Split(diffhunk, "@@")
ranges := strings.Split(ss[1][1:], " ")
leftRange := strings.Split(ranges[0], ",")
leftLine, _ = strconv.Atoi(leftRange[0][1:])
if len(leftRange) > 1 {
leftHunk, _ = strconv.Atoi(leftRange[1])
}
if len(ranges) > 1 {
rightRange := strings.Split(ranges[1], ",")
rightLine, _ = strconv.Atoi(rightRange[0])
if len(rightRange) > 1 {
righHunk, _ = strconv.Atoi(rightRange[1])
}
} else {
log.Debug("Parse line number failed: %v", diffhunk)
rightLine = leftLine
righHunk = leftHunk
}
return
}
// Example: @@ -1,8 +1,9 @@ => [..., 1, 8, 1, 9]
var hunkRegex = regexp.MustCompile(`^@@ -(?P<beginOld>[0-9]+)(,(?P<endOld>[0-9]+))? \+(?P<beginNew>[0-9]+)(,(?P<endNew>[0-9]+))? @@`)
const cmdDiffHead = "diff --git "
func isHeader(lof string, inHunk bool) bool {
return strings.HasPrefix(lof, cmdDiffHead) || (!inHunk && (strings.HasPrefix(lof, "---") || strings.HasPrefix(lof, "+++")))
}
// CutDiffAroundLine cuts a diff of a file in way that only the given line + numberOfLine above it will be shown
// it also recalculates hunks and adds the appropriate headers to the new diff.
// Warning: Only one-file diffs are allowed.
func CutDiffAroundLine(originalDiff io.Reader, line int64, old bool, numbersOfLine int) (string, error) {
if line == 0 || numbersOfLine == 0 {
// no line or num of lines => no diff
return "", nil
}
scanner := bufio.NewScanner(originalDiff)
hunk := make([]string, 0)
// begin is the start of the hunk containing searched line
// end is the end of the hunk ...
// currentLine is the line number on the side of the searched line (differentiated by old)
// otherLine is the line number on the opposite side of the searched line (differentiated by old)
var begin, end, currentLine, otherLine int64
var headerLines int
inHunk := false
for scanner.Scan() {
lof := scanner.Text()
// Add header to enable parsing
if isHeader(lof, inHunk) {
if strings.HasPrefix(lof, cmdDiffHead) {
inHunk = false
}
hunk = append(hunk, lof)
headerLines++
}
if currentLine > line {
break
}
// Detect "hunk" with contains commented lof
if strings.HasPrefix(lof, "@@") {
inHunk = true
// Already got our hunk. End of hunk detected!
if len(hunk) > headerLines {
break
}
// A map with named groups of our regex to recognize them later more easily
submatches := hunkRegex.FindStringSubmatch(lof)
groups := make(map[string]string)
for i, name := range hunkRegex.SubexpNames() {
if i != 0 && name != "" {
groups[name] = submatches[i]
}
}
if old {
begin, _ = strconv.ParseInt(groups["beginOld"], 10, 64)
end, _ = strconv.ParseInt(groups["endOld"], 10, 64)
// init otherLine with begin of opposite side
otherLine, _ = strconv.ParseInt(groups["beginNew"], 10, 64)
} else {
begin, _ = strconv.ParseInt(groups["beginNew"], 10, 64)
if groups["endNew"] != "" {
end, _ = strconv.ParseInt(groups["endNew"], 10, 64)
} else {
end = 0
}
// init otherLine with begin of opposite side
otherLine, _ = strconv.ParseInt(groups["beginOld"], 10, 64)
}
end += begin // end is for real only the number of lines in hunk
// lof is between begin and end
if begin <= line && end >= line {
hunk = append(hunk, lof)
currentLine = begin
continue
}
} else if len(hunk) > headerLines {
hunk = append(hunk, lof)
// Count lines in context
switch lof[0] {
case '+':
if !old {
currentLine++
} else {
otherLine++
}
case '-':
if old {
currentLine++
} else {
otherLine++
}
case '\\':
// FIXME: handle `\ No newline at end of file`
default:
currentLine++
otherLine++
}
}
}
err := scanner.Err()
if err != nil {
return "", err
}
// No hunk found
if currentLine == 0 {
return "", nil
}
// headerLines + hunkLine (1) = totalNonCodeLines
if len(hunk)-headerLines-1 <= numbersOfLine {
// No need to cut the hunk => return existing hunk
return strings.Join(hunk, "\n"), nil
}
var oldBegin, oldNumOfLines, newBegin, newNumOfLines int64
if old {
oldBegin = currentLine
newBegin = otherLine
} else {
oldBegin = otherLine
newBegin = currentLine
}
// headers + hunk header
newHunk := make([]string, headerLines)
// transfer existing headers
copy(newHunk, hunk[:headerLines])
// transfer last n lines
newHunk = append(newHunk, hunk[len(hunk)-numbersOfLine-1:]...)
// calculate newBegin, ... by counting lines
for i := len(hunk) - 1; i >= len(hunk)-numbersOfLine; i-- {
switch hunk[i][0] {
case '+':
newBegin--
newNumOfLines++
case '-':
oldBegin--
oldNumOfLines++
default:
oldBegin--
newBegin--
newNumOfLines++
oldNumOfLines++
}
}
// construct the new hunk header
newHunk[headerLines] = fmt.Sprintf("@@ -%d,%d +%d,%d @@",
oldBegin, oldNumOfLines, newBegin, newNumOfLines)
return strings.Join(newHunk, "\n"), nil
}
// GetAffectedFiles returns the affected files between two commits
func GetAffectedFiles(repo *Repository, oldCommitID, newCommitID string, env []string) ([]string, error) {
stdoutReader, stdoutWriter, err := os.Pipe()
if err != nil {
log.Error("Unable to create os.Pipe for %s", repo.Path)
return nil, err
}
defer func() {
_ = stdoutReader.Close()
_ = stdoutWriter.Close()
}()
affectedFiles := make([]string, 0, 32)
// Run `git diff --name-only` to get the names of the changed files
err = NewCommandContext(repo.Ctx, "diff", "--name-only", oldCommitID, newCommitID).
RunInDirTimeoutEnvFullPipelineFunc(env, -1, repo.Path,
stdoutWriter, nil, nil,
func(ctx context.Context, cancel context.CancelFunc) error {
// Close the writer end of the pipe to begin processing
_ = stdoutWriter.Close()
defer func() {
// Close the reader on return to terminate the git command if necessary
_ = stdoutReader.Close()
}()
// Now scan the output from the command
scanner := bufio.NewScanner(stdoutReader)
for scanner.Scan() {
path := strings.TrimSpace(scanner.Text())
if len(path) == 0 {
continue
}
affectedFiles = append(affectedFiles, path)
}
return scanner.Err()
})
if err != nil {
log.Error("Unable to get affected files for commits from %s to %s in %s: %v", oldCommitID, newCommitID, repo.Path, err)
}
return affectedFiles, err
}