You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: diff.go
    path of file: ./repos/gogs/internal/gitutil
    
    the code of the file until where you have to start completion: // 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 gitutil

import (
	"bytes"
	"fmt"
	"html"
	"html/template"
	"io"
	"sync"

	"github.com/sergi/go-diff/diffmatchpatch"
	"golang.org/x/net/html/charset"
	"golang.org/x/text/transform"

	"github.com/gogs/git-module"

	"gogs.io/gogs/internal/conf"
	"gogs.io/gogs/internal/template/highlight"
	"gogs.io/gogs/internal/tool"
)

// DiffSection is a wrapper to git.DiffSection with helper methods.
type DiffSection struct {
	*git.DiffSection

	initOnce sync.Once
	dmp      *diffmatchpatch.DiffMatchPatch
}

// ComputedInlineDiffFor computes i
    
func (s *DiffSection) ComputedInlineDiffFor(line *git.DiffLine) template.HTML {
	fallback := template.HTML(html.EscapeString(line.Content))
	if conf.Git.DisableDiffHighlight {
		return fallback
	}

	// Find equivalent diff line, ignore when not found.
	var diff1, diff2 string
	switch line.Type {
	case git.DiffLineAdd:
		compareLine := s.Line(git.DiffLineDelete, line.RightLine)
		if compareLine == nil {
			return fallback
		}

		diff1 = compareLine.Content
		diff2 = line.Content

	case git.DiffLineDelete:
		compareLine := s.Line(git.DiffLineAdd, line.LeftLine)
		if compareLine == nil {
			return fallback
		}

		diff1 = line.Content
		diff2 = compareLine.Content

	default:
		return fallback
	}

	s.initOnce.Do(func() {
		s.dmp = diffmatchpatch.New()
		s.dmp.DiffEditCost = 100
	})

	diffs := s.dmp.DiffMain(diff1[1:], diff2[1:], true)
	diffs = s.dmp.DiffCleanupEfficiency(diffs)

	return diffsToHTML(diffs, line.Type)
}