Remove follow from commits by file (go-gitea#20765)

The use of `--follow` makes getting these commits very slow on large repositories
as it results in searching the whole commit tree for a blob.

Now as nice as the results of `--follow` are, I am uncertain whether it is really
of sufficient importance to keep around.

Fix go-gitea#20764

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

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

modules/git/repo_commit.go

@@ -7,6 +7,8 @@ package git
 
 import (
 	"bytes"
+	"encoding/hex"
+	"fmt"
 	"io"
 	"strconv"
 	"strings"
@@ -209,9 +211,9 @@ func (repo *Repository) CommitsByFileAndRange(revision, file string, page int) (
 	}()
 	go func() {
 		stderr := strings.Builder{}
-		err := NewCommand(repo.Ctx, "log", revision, "--follow",
+		err := NewCommand(repo.Ctx, "rev-list", revision,
 			"--max-count="+strconv.Itoa(setting.Git.CommitsRangeSize*page),
-			prettyLogFormat, "--", file).
+			"--skip="+strconv.Itoa(skip), "--", file).
 			Run(&RunOpts{
 				Dir:    repo.Path,
 				Stdout: stdoutWriter,
@@ -224,32 +226,30 @@ func (repo *Repository) CommitsByFileAndRange(revision, file string, page int) (
 		}
 	}()
 
-	if skip > 0 {
-		_, err := io.CopyN(io.Discard, stdoutReader, int64(skip*41))
-		if err != nil {
+	commits := []*Commit{}
+	shaline := [41]byte{}
+	var sha1 SHA1
+	for {
+		n, err := io.ReadFull(stdoutReader, shaline[:])
+		if err != nil || n < 40 {
 			if err == io.EOF {
-				return []*Commit{}, nil
+				err = nil
 			}
-			_ = stdoutReader.CloseWithError(err)
+			return commits, err
+		}
+		n, err = hex.Decode(sha1[:], shaline[0:40])
+		if n != 20 {
+			err = fmt.Errorf("invalid sha %q", string(shaline[:40]))
+		}
+		if err != nil {
 			return nil, err
 		}
+		commit, err := repo.getCommit(sha1)
+		if err != nil {
+			return nil, err
+		}
+		commits = append(commits, commit)
 	}
-
-	stdout, err := io.ReadAll(stdoutReader)
-	if err != nil {
-		return nil, err
-	}
-	return repo.parsePrettyFormatLogToList(stdout)
-}
-
-// CommitsByFileAndRangeNoFollow return the commits according revision file and the page
-func (repo *Repository) CommitsByFileAndRangeNoFollow(revision, file string, page int) ([]*Commit, error) {
-	stdout, _, err := NewCommand(repo.Ctx, "log", revision, "--skip="+strconv.Itoa((page-1)*50),
-		"--max-count="+strconv.Itoa(setting.Git.CommitsRangeSize), prettyLogFormat, "--", file).RunStdBytes(&RunOpts{Dir: repo.Path})
-	if err != nil {
-		return nil, err
-	}
-	return repo.parsePrettyFormatLogToList(stdout)
 }
 
 // FilesCountBetween return the number of files changed between two commits

routers/api/v1/repo/wiki.go

@@ -427,9 +427,9 @@ func ListPageRevisions(ctx *context.APIContext) {
 	}
 
 	// get Commit Count
-	commitsHistory, err := wikiRepo.CommitsByFileAndRangeNoFollow("master", pageFilename, page)
+	commitsHistory, err := wikiRepo.CommitsByFileAndRange("master", pageFilename, page)
 	if err != nil {
-		ctx.Error(http.StatusInternalServerError, "CommitsByFileAndRangeNoFollow", err)
+		ctx.Error(http.StatusInternalServerError, "CommitsByFileAndRange", err)
 		return
 	}
 

routers/web/repo/wiki.go

@@ -360,12 +360,12 @@ func renderRevisionPage(ctx *context.Context) (*git.Repository, *git.TreeEntry)
 	}
 
 	// get Commit Count
-	commitsHistory, err := wikiRepo.CommitsByFileAndRangeNoFollow("master", pageFilename, page)
+	commitsHistory, err := wikiRepo.CommitsByFileAndRange("master", pageFilename, page)
 	if err != nil {
 		if wikiRepo != nil {
 			wikiRepo.Close()
 		}
-		ctx.ServerError("CommitsByFileAndRangeNoFollow", err)
+		ctx.ServerError("CommitsByFileAndRange", err)
 		return nil, nil
 	}
 	ctx.Data["Commits"] = git_model.ConvertFromGitCommit(commitsHistory, ctx.Repo.Repository)