Refactor git command context & pipeline (#36406)

Less and simpler code, fewer bugs

services/repository/contributors_graph.go

@@ -8,7 +8,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"os"
+	"io"
 	"strconv"
 	"strings"
 	"sync"
@@ -117,24 +117,16 @@ func getExtendedCommitStats(repo *git.Repository, revision string /*, limit int
 	if err != nil {
 		return nil, err
 	}
-	stdoutReader, stdoutWriter, err := os.Pipe()
-	if err != nil {
-		return nil, err
-	}
-	defer func() {
-		_ = stdoutReader.Close()
-		_ = stdoutWriter.Close()
-	}()
 
 	gitCmd := gitcmd.NewCommand("log", "--shortstat", "--no-merges", "--pretty=format:---%n%aN%n%aE%n%as", "--reverse")
 	// AddOptionFormat("--max-count=%d", limit)
 	gitCmd.AddDynamicArguments(baseCommit.ID.String())
 
+	var stdoutReader io.ReadCloser
 	var extendedCommitStats []*ExtendedCommitStats
 	err = gitCmd.WithDir(repo.Path).
-		WithStdout(stdoutWriter).
-		WithPipelineFunc(func(ctx context.Context, cancel context.CancelFunc) error {
-			_ = stdoutWriter.Close()
+		WithStdoutReader(&stdoutReader).
+		WithPipelineFunc(func(ctx gitcmd.Context) error {
 			scanner := bufio.NewScanner(stdoutReader)
 
 			for scanner.Scan() {
@@ -186,7 +178,6 @@ func getExtendedCommitStats(repo *git.Repository, revision string /*, limit int
 				}
 				extendedCommitStats = append(extendedCommitStats, res)
 			}
-			_ = stdoutReader.Close()
 			return nil
 		}).
 		RunWithStderr(repo.Ctx)

services/repository/files/temp_repo.go

@@ -362,25 +362,15 @@ func (t *TemporaryUploadRepository) Push(ctx context.Context, doer *user_model.U
 
 // DiffIndex returns a Diff of the current index to the head
 func (t *TemporaryUploadRepository) DiffIndex(ctx context.Context) (*gitdiff.Diff, error) {
-	stdoutReader, stdoutWriter, err := os.Pipe()
-	if err != nil {
-		return nil, fmt.Errorf("unable to open stdout pipe: %w", err)
-	}
-	defer func() {
-		_ = stdoutReader.Close()
-		_ = stdoutWriter.Close()
-	}()
 	var diff *gitdiff.Diff
-	err = gitcmd.NewCommand("diff-index", "--src-prefix=\\a/", "--dst-prefix=\\b/", "--cached", "-p", "HEAD").
+	var stdoutReader io.ReadCloser
+	err := gitcmd.NewCommand("diff-index", "--src-prefix=\\a/", "--dst-prefix=\\b/", "--cached", "-p", "HEAD").
 		WithTimeout(30 * time.Second).
 		WithDir(t.basePath).
-		WithStdout(stdoutWriter).
-		WithPipelineFunc(func(ctx context.Context, cancel context.CancelFunc) error {
-			_ = stdoutWriter.Close()
-			defer cancel()
+		WithStdoutReader(&stdoutReader).
+		WithPipelineFunc(func(ctx gitcmd.Context) error {
 			var diffErr error
 			diff, diffErr = gitdiff.ParsePatch(ctx, setting.Git.MaxGitDiffLines, setting.Git.MaxGitDiffLineCharacters, setting.Git.MaxGitDiffFiles, stdoutReader, "")
-			_ = stdoutReader.Close()
 			if diffErr != nil {
 				// if the diffErr is not nil, it will be returned as the error of "Run()"
 				return fmt.Errorf("ParsePatch: %w", diffErr)
@@ -388,7 +378,7 @@ func (t *TemporaryUploadRepository) DiffIndex(ctx context.Context) (*gitdiff.Dif
 			return nil
 		}).
 		RunWithStderr(ctx)
-	if err != nil && !git.IsErrCanceledOrKilled(err) {
+	if err != nil && !gitcmd.IsErrorCanceledOrKilled(err) {
 		return nil, fmt.Errorf("unable to run diff-index pipeline in temporary repo: %w", err)
 	}
 

services/repository/gitgraph/graph.go

@@ -6,8 +6,7 @@ package gitgraph
 import (
 	"bufio"
 	"bytes"
-	"context"
-	"os"
+	"io"
 
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/git/gitcmd"
@@ -44,20 +43,14 @@ func GetCommitGraph(r *git.Repository, page, maxAllowedColors int, hidePRRefs bo
 	}
 	graph := NewGraph()
 
-	stdoutReader, stdoutWriter, err := os.Pipe()
-	if err != nil {
-		return nil, err
-	}
 	commitsToSkip := setting.UI.GraphMaxCommitNum * (page - 1)
 
-	scanner := bufio.NewScanner(stdoutReader)
-
+	var stdoutReader io.ReadCloser
 	if err := graphCmd.
 		WithDir(r.Path).
-		WithStdout(stdoutWriter).
-		WithPipelineFunc(func(ctx context.Context, cancel context.CancelFunc) error {
-			_ = stdoutWriter.Close()
-			defer stdoutReader.Close()
+		WithStdoutReader(&stdoutReader).
+		WithPipelineFunc(func(ctx gitcmd.Context) error {
+			scanner := bufio.NewScanner(stdoutReader)
 			parser := &Parser{}
 			parser.firstInUse = -1
 			parser.maxAllowedColors = maxAllowedColors
@@ -89,8 +82,7 @@ func GetCommitGraph(r *git.Repository, page, maxAllowedColors int, hidePRRefs bo
 				line := scanner.Bytes()
 				if bytes.IndexByte(line, '*') >= 0 {
 					if err := parser.AddLineToGraph(graph, row, line); err != nil {
-						cancel()
-						return err
+						return ctx.CancelWithCause(err)
 					}
 					break
 				}
@@ -101,8 +93,7 @@ func GetCommitGraph(r *git.Repository, page, maxAllowedColors int, hidePRRefs bo
 				row++
 				line := scanner.Bytes()
 				if err := parser.AddLineToGraph(graph, row, line); err != nil {
-					cancel()
-					return err
+					return ctx.CancelWithCause(err)
 				}
 			}
 			return scanner.Err()