123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225 |
- // Copyright 2015 The Gogs Authors. All rights reserved.
- // Copyright 2020 The Gitea Authors. All rights reserved.
- // SPDX-License-Identifier: MIT
-
- package highlight
-
- import (
- "bufio"
- "bytes"
- "fmt"
- gohtml "html"
- "io"
- "path/filepath"
- "strings"
- "sync"
-
- "code.gitea.io/gitea/modules/analyze"
- "code.gitea.io/gitea/modules/log"
- "code.gitea.io/gitea/modules/setting"
- "code.gitea.io/gitea/modules/util"
-
- "github.com/alecthomas/chroma/v2"
- "github.com/alecthomas/chroma/v2/formatters/html"
- "github.com/alecthomas/chroma/v2/lexers"
- "github.com/alecthomas/chroma/v2/styles"
- lru "github.com/hashicorp/golang-lru"
- )
-
- // don't index files larger than this many bytes for performance purposes
- const sizeLimit = 1024 * 1024
-
- var (
- // For custom user mapping
- highlightMapping = map[string]string{}
-
- once sync.Once
-
- cache *lru.TwoQueueCache
-
- githubStyles = styles.Get("github")
- )
-
- // NewContext loads custom highlight map from local config
- func NewContext() {
- once.Do(func() {
- highlightMapping = setting.GetHighlightMapping()
-
- // The size 512 is simply a conservative rule of thumb
- c, err := lru.New2Q(512)
- if err != nil {
- panic(fmt.Sprintf("failed to initialize LRU cache for highlighter: %s", err))
- }
- cache = c
- })
- }
-
- // Code returns a HTML version of code string with chroma syntax highlighting classes and the matched lexer name
- func Code(fileName, language, code string) (string, string) {
- NewContext()
-
- // diff view newline will be passed as empty, change to literal '\n' so it can be copied
- // preserve literal newline in blame view
- if code == "" || code == "\n" {
- return "\n", ""
- }
-
- if len(code) > sizeLimit {
- return code, ""
- }
-
- var lexer chroma.Lexer
-
- if len(language) > 0 {
- lexer = lexers.Get(language)
-
- if lexer == nil {
- // Attempt stripping off the '?'
- if idx := strings.IndexByte(language, '?'); idx > 0 {
- lexer = lexers.Get(language[:idx])
- }
- }
- }
-
- if lexer == nil {
- if val, ok := highlightMapping[filepath.Ext(fileName)]; ok {
- // use mapped value to find lexer
- lexer = lexers.Get(val)
- }
- }
-
- if lexer == nil {
- if l, ok := cache.Get(fileName); ok {
- lexer = l.(chroma.Lexer)
- }
- }
-
- if lexer == nil {
- lexer = lexers.Match(fileName)
- if lexer == nil {
- lexer = lexers.Fallback
- }
- cache.Add(fileName, lexer)
- }
-
- lexerName := formatLexerName(lexer.Config().Name)
-
- return CodeFromLexer(lexer, code), lexerName
- }
-
- // CodeFromLexer returns a HTML version of code string with chroma syntax highlighting classes
- func CodeFromLexer(lexer chroma.Lexer, code string) string {
- formatter := html.New(html.WithClasses(true),
- html.WithLineNumbers(false),
- html.PreventSurroundingPre(true),
- )
-
- htmlbuf := bytes.Buffer{}
- htmlw := bufio.NewWriter(&htmlbuf)
-
- iterator, err := lexer.Tokenise(nil, code)
- if err != nil {
- log.Error("Can't tokenize code: %v", err)
- return code
- }
- // style not used for live site but need to pass something
- err = formatter.Format(htmlw, githubStyles, iterator)
- if err != nil {
- log.Error("Can't format code: %v", err)
- return code
- }
-
- _ = htmlw.Flush()
- // Chroma will add newlines for certain lexers in order to highlight them properly
- // Once highlighted, strip them here, so they don't cause copy/paste trouble in HTML output
- return strings.TrimSuffix(htmlbuf.String(), "\n")
- }
-
- // File returns a slice of chroma syntax highlighted HTML lines of code and the matched lexer name
- func File(fileName, language string, code []byte) ([]string, string, error) {
- NewContext()
-
- if len(code) > sizeLimit {
- return PlainText(code), "", nil
- }
-
- formatter := html.New(html.WithClasses(true),
- html.WithLineNumbers(false),
- html.PreventSurroundingPre(true),
- )
-
- var lexer chroma.Lexer
-
- // provided language overrides everything
- if language != "" {
- lexer = lexers.Get(language)
- }
-
- if lexer == nil {
- if val, ok := highlightMapping[filepath.Ext(fileName)]; ok {
- lexer = lexers.Get(val)
- }
- }
-
- if lexer == nil {
- guessLanguage := analyze.GetCodeLanguage(fileName, code)
-
- lexer = lexers.Get(guessLanguage)
- if lexer == nil {
- lexer = lexers.Match(fileName)
- if lexer == nil {
- lexer = lexers.Fallback
- }
- }
- }
-
- lexerName := formatLexerName(lexer.Config().Name)
-
- iterator, err := lexer.Tokenise(nil, string(code))
- if err != nil {
- return nil, "", fmt.Errorf("can't tokenize code: %w", err)
- }
-
- tokensLines := chroma.SplitTokensIntoLines(iterator.Tokens())
- htmlBuf := &bytes.Buffer{}
-
- lines := make([]string, 0, len(tokensLines))
- for _, tokens := range tokensLines {
- iterator = chroma.Literator(tokens...)
- err = formatter.Format(htmlBuf, githubStyles, iterator)
- if err != nil {
- return nil, "", fmt.Errorf("can't format code: %w", err)
- }
- lines = append(lines, htmlBuf.String())
- htmlBuf.Reset()
- }
-
- return lines, lexerName, nil
- }
-
- // PlainText returns non-highlighted HTML for code
- func PlainText(code []byte) []string {
- r := bufio.NewReader(bytes.NewReader(code))
- m := make([]string, 0, bytes.Count(code, []byte{'\n'})+1)
- for {
- content, err := r.ReadString('\n')
- if err != nil && err != io.EOF {
- log.Error("failed to read string from buffer: %v", err)
- break
- }
- if content == "" && err == io.EOF {
- break
- }
- s := gohtml.EscapeString(content)
- m = append(m, s)
- }
- return m
- }
-
- func formatLexerName(name string) string {
- if name == "fallback" {
- return "Plaintext"
- }
-
- return util.ToTitleCaseNoLower(name)
- }
|