gitea/modules/markup/renderer.go
Lunny Xiao 9d99f6ab19
Refactor renders (#15175)
* Refactor renders

* Some performance optimization

* Fix comment

* Transform reader

* Fix csv test

* Fix test

* Fix tests

* Improve optimaziation

* Fix test

* Fix test

* Detect file encoding with reader

* Improve optimaziation

* reduce memory usage

* improve code

* fix build

* Fix test

* Fix for go1.15

* Fix render

* Fix comment

* Fix lint

* Fix test

* Don't use NormalEOF when unnecessary

* revert change on util.go

* Apply suggestions from code review

Co-authored-by: zeripath <art27@cantab.net>

* rename function

* Take NormalEOF back

Co-authored-by: zeripath <art27@cantab.net>
2021-04-19 18:25:08 -04:00

202 lines
5.0 KiB
Go

// Copyright 2017 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 markup
import (
"context"
"errors"
"fmt"
"io"
"path/filepath"
"strings"
"sync"
"code.gitea.io/gitea/modules/setting"
)
// Init initialize regexps for markdown parsing
func Init() {
getIssueFullPattern()
NewSanitizer()
if len(setting.Markdown.CustomURLSchemes) > 0 {
CustomLinkURLSchemes(setting.Markdown.CustomURLSchemes)
}
// since setting maybe changed extensions, this will reload all renderer extensions mapping
extRenderers = make(map[string]Renderer)
for _, renderer := range renderers {
for _, ext := range renderer.Extensions() {
extRenderers[strings.ToLower(ext)] = renderer
}
}
}
// RenderContext represents a render context
type RenderContext struct {
Ctx context.Context
Filename string
Type string
IsWiki bool
URLPrefix string
Metas map[string]string
DefaultLink string
}
// Renderer defines an interface for rendering markup file to HTML
type Renderer interface {
Name() string // markup format name
Extensions() []string
Render(ctx *RenderContext, input io.Reader, output io.Writer) error
}
var (
extRenderers = make(map[string]Renderer)
renderers = make(map[string]Renderer)
)
// RegisterRenderer registers a new markup file renderer
func RegisterRenderer(renderer Renderer) {
renderers[renderer.Name()] = renderer
for _, ext := range renderer.Extensions() {
extRenderers[strings.ToLower(ext)] = renderer
}
}
// GetRendererByFileName get renderer by filename
func GetRendererByFileName(filename string) Renderer {
extension := strings.ToLower(filepath.Ext(filename))
return extRenderers[extension]
}
// GetRendererByType returns a renderer according type
func GetRendererByType(tp string) Renderer {
return renderers[tp]
}
// Render renders markup file to HTML with all specific handling stuff.
func Render(ctx *RenderContext, input io.Reader, output io.Writer) error {
if ctx.Type != "" {
return renderByType(ctx, input, output)
} else if ctx.Filename != "" {
return renderFile(ctx, input, output)
}
return errors.New("Render options both filename and type missing")
}
// RenderString renders Markup string to HTML with all specific handling stuff and return string
func RenderString(ctx *RenderContext, content string) (string, error) {
var buf strings.Builder
if err := Render(ctx, strings.NewReader(content), &buf); err != nil {
return "", err
}
return buf.String(), nil
}
func render(ctx *RenderContext, parser Renderer, input io.Reader, output io.Writer) error {
var wg sync.WaitGroup
var err error
pr, pw := io.Pipe()
defer func() {
_ = pr.Close()
_ = pw.Close()
}()
pr2, pw2 := io.Pipe()
defer func() {
_ = pr2.Close()
_ = pw2.Close()
}()
wg.Add(1)
go func() {
buf := SanitizeReader(pr2)
_, err = io.Copy(output, buf)
_ = pr2.Close()
wg.Done()
}()
wg.Add(1)
go func() {
err = PostProcess(ctx, pr, pw2)
_ = pr.Close()
_ = pw2.Close()
wg.Done()
}()
if err1 := parser.Render(ctx, input, pw); err1 != nil {
return err1
}
_ = pw.Close()
wg.Wait()
return err
}
// ErrUnsupportedRenderType represents
type ErrUnsupportedRenderType struct {
Type string
}
func (err ErrUnsupportedRenderType) Error() string {
return fmt.Sprintf("Unsupported render type: %s", err.Type)
}
func renderByType(ctx *RenderContext, input io.Reader, output io.Writer) error {
if renderer, ok := renderers[ctx.Type]; ok {
return render(ctx, renderer, input, output)
}
return ErrUnsupportedRenderType{ctx.Type}
}
// ErrUnsupportedRenderExtension represents the error when extension doesn't supported to render
type ErrUnsupportedRenderExtension struct {
Extension string
}
func (err ErrUnsupportedRenderExtension) Error() string {
return fmt.Sprintf("Unsupported render extension: %s", err.Extension)
}
func renderFile(ctx *RenderContext, input io.Reader, output io.Writer) error {
extension := strings.ToLower(filepath.Ext(ctx.Filename))
if renderer, ok := extRenderers[extension]; ok {
return render(ctx, renderer, input, output)
}
return ErrUnsupportedRenderExtension{extension}
}
// Type returns if markup format via the filename
func Type(filename string) string {
if parser := GetRendererByFileName(filename); parser != nil {
return parser.Name()
}
return ""
}
// IsMarkupFile reports whether file is a markup type file
func IsMarkupFile(name, markup string) bool {
if parser := GetRendererByFileName(name); parser != nil {
return parser.Name() == markup
}
return false
}
// IsReadmeFile reports whether name looks like a README file
// based on its name. If an extension is provided, it will strictly
// match that extension.
// Note that the '.' should be provided in ext, e.g ".md"
func IsReadmeFile(name string, ext ...string) bool {
name = strings.ToLower(name)
if len(ext) > 0 {
return name == "readme"+ext[0]
}
if len(name) < 6 {
return false
} else if len(name) == 6 {
return name == "readme"
}
return name[:7] == "readme."
}