add a new config option

Signed-off-by: a1012112796 <[email protected]>

Author: a1012112796

custom/conf/app.example.ini

@@ -691,6 +691,12 @@ ROUTER = console
 ;; Disables highlight of added and removed changes
 ;DISABLE_DIFF_HIGHLIGHT = false
 ;;
+;; max size of one file that can be full highlight on git diff ui.
+;; if the file is too big, it will be renderd line by line, 
+;; sometimes it will lead a not good highlight result.
+;;
+;MAX_DIFF_HIGHLIGHT_FILE_SIZE = 5 * 1024
+;;
 ;; Max number of lines allowed in a single file in diff view
 ;MAX_GIT_DIFF_LINES = 1000
 ;;

docs/content/doc/administration/config-cheat-sheet.en-us.md

@@ -1081,6 +1081,7 @@ Default templates for project boards:
 - `HOME_PATH`: **%(APP_DATA_PATH)s/home**: The HOME directory for Git.
    This directory will be used to contain the `.gitconfig` and possible `.gnupg` directories that Gitea's git calls will use. If you can confirm Gitea is the only application running in this environment, you can set it to the normal home directory for Gitea user.
 - `DISABLE_DIFF_HIGHLIGHT`: **false**: Disables highlight of added and removed changes.
+- `MAX_DIFF_HIGHLIGHT_FILE_SIZE`: **5120** max size of one file that can be full highlight on git diff ui.
 - `MAX_GIT_DIFF_LINES`: **1000**: Max number of lines allowed of a single file in diff view.
 - `MAX_GIT_DIFF_LINE_CHARACTERS`: **5000**: Max character count per line highlighted in diff view.
 - `MAX_GIT_DIFF_FILES`: **100**: Max number of files shown in diff view.

modules/setting/git.go

@@ -40,6 +40,7 @@ var Git = struct {
 		Pull    int
 		GC      int `ini:"GC"`
 	} `ini:"git.timeout"`
+	MaxDiffHighlightFileSize int64
 }{
 	Reflog: struct {
 		Enabled    bool
@@ -76,6 +77,7 @@ var Git = struct {
 		Pull:    300,
 		GC:      60,
 	},
+	MaxDiffHighlightFileSize: 5 * 1024,
 }
 
 func loadGitFrom(rootCfg ConfigProvider) {

routers/web/repo/compare.go

@@ -932,20 +932,31 @@ func getExcerptLines(commit *git.Commit, filePath string, idxLeft, idxRight, chu
 		return nil, err
 	}
 
-	content, err := io.ReadAll(reader)
-	_ = reader.Close()
-	if err != nil {
-		log.Error("io.ReadAll: %v", err)
-		return nil, err
-	}
+	var (
+		scanner             *bufio.Scanner
+		highlightedContent []string
+	)
 
-	highlightedContent, _, err := highlight.File(filePath, "", content)
-	if err != nil {
-		log.Error("highlight.File: %v", err)
-		return nil, err
+	if blob.Size() >= setting.Git.MaxDiffHighlightFileSize {
+		defer reader.Close()
+		scanner = bufio.NewScanner(reader)
+	} else {
+		content, err := io.ReadAll(reader)
+		_ = reader.Close()
+		if err != nil {
+			log.Error("io.ReadAll: %v", err)
+			return nil, err
+		}
+
+		highlightedContent, _, err = highlight.File(filePath, "", content)
+		if err != nil {
+			log.Error("highlight.File: %v", err)
+			return nil, err
+		}
+
+		scanner = bufio.NewScanner(bytes.NewBuffer(content))
 	}
 
-	scanner := bufio.NewScanner(bytes.NewBuffer(content))
 	var diffLines []*gitdiff.DiffLine
 	for line := 0; line < idxRight+chunkSize; line++ {
 		if ok := scanner.Scan(); !ok {
@@ -960,9 +971,13 @@ func getExcerptLines(commit *git.Commit, filePath string, idxLeft, idxRight, chu
 			RightIdx:            line + 1,
 			Type:                gitdiff.DiffLinePlain,
 			Content:             " " + lineText,
-			HighlightContent:    highlightedContent[line],
-			HasHighlightContent: true,
 		}
+
+		if highlightedContent != nil {
+			diffLine.HighlightContent = highlightedContent[line]
+			diffLine.HasHighlightContent = true
+		}
+
 		diffLines = append(diffLines, diffLine)
 	}
 	return diffLines, nil

services/gitdiff/gitdiff.go

@@ -1116,7 +1116,7 @@ func GetDiff(gitRepo *git.Repository, opts *DiffOptions, files ...string) (*Diff
 			return nil, ""
 		}
 
-		if entry.Blob().Size() >= setting.UI.MaxDisplayFileSize/2 {
+		if entry.Blob().Size() >= setting.Git.MaxDiffHighlightFileSize {
 			return nil, ""
 		}