hugo/helpers/pygments.go
2015-05-07 03:45:51 +02:00

181 lines
4 KiB
Go

// Copyright © 2013-14 Steve Francia <spf@spf13.com>.
//
// Licensed under the Simple Public License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://opensource.org/licenses/Simple-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package helpers
import (
"bytes"
"crypto/sha1"
"fmt"
"github.com/spf13/hugo/hugofs"
jww "github.com/spf13/jwalterweatherman"
"github.com/spf13/viper"
"io"
"io/ioutil"
"os/exec"
"path/filepath"
"sort"
"strings"
)
const pygmentsBin = "pygmentize"
// HasPygments checks to see if Pygments is installed and available
// on the system.
func HasPygments() bool {
if _, err := exec.LookPath(pygmentsBin); err != nil {
return false
}
return true
}
// Highlight takes some code and returns highlighted code.
func Highlight(code, lang, optsStr string) string {
if !HasPygments() {
jww.WARN.Println("Highlighting requires Pygments to be installed and in the path")
return code
}
options, err := parsePygmentsOpts(optsStr)
if err != nil {
jww.ERROR.Print(err.Error())
return code
}
// Try to read from cache first
hash := sha1.New()
io.WriteString(hash, code)
io.WriteString(hash, lang)
io.WriteString(hash, options)
fs := hugofs.OsFs
cacheDir := viper.GetString("CacheDir")
var cachefile string
if cacheDir != "" {
cachefile = filepath.Join(cacheDir, fmt.Sprintf("pygments-%x", hash.Sum(nil)))
exists, err := Exists(cachefile, fs)
if err != nil {
jww.ERROR.Print(err.Error())
return code
}
if exists {
f, err := fs.Open(cachefile)
if err != nil {
jww.ERROR.Print(err.Error())
return code
}
s, err := ioutil.ReadAll(f)
if err != nil {
jww.ERROR.Print(err.Error())
return code
}
return string(s)
}
}
// No cache file, render and cache it
var out bytes.Buffer
var stderr bytes.Buffer
cmd := exec.Command(pygmentsBin, "-l"+lang, "-fhtml", "-O", options)
cmd.Stdin = strings.NewReader(code)
cmd.Stdout = &out
cmd.Stderr = &stderr
if err := cmd.Run(); err != nil {
jww.ERROR.Print(stderr.String())
return code
}
if cachefile != "" {
// Write cache file
if err := WriteToDisk(cachefile, bytes.NewReader(out.Bytes()), fs); err != nil {
jww.ERROR.Print(stderr.String())
}
}
return out.String()
}
var pygmentsKeywords = make(map[string]bool)
func init() {
pygmentsKeywords["style"] = true
pygmentsKeywords["encoding"] = true
pygmentsKeywords["noclasses"] = true
pygmentsKeywords["hl_lines"] = true
pygmentsKeywords["linenos"] = true
pygmentsKeywords["classprefix"] = true
}
func parsePygmentsOpts(in string) (string, error) {
in = strings.Trim(in, " ")
style := viper.GetString("PygmentsStyle")
noclasses := "true"
if viper.GetBool("PygmentsUseClasses") {
noclasses = "false"
}
if len(in) == 0 {
return fmt.Sprintf("style=%s,noclasses=%s,encoding=utf8", style, noclasses), nil
}
options := make(map[string]string)
o := strings.Split(in, ",")
for _, v := range o {
keyVal := strings.Split(v, "=")
key := strings.ToLower(strings.Trim(keyVal[0], " "))
if len(keyVal) != 2 || !pygmentsKeywords[key] {
return "", fmt.Errorf("invalid Pygments option: %s", key)
}
options[key] = keyVal[1]
}
if _, ok := options["style"]; !ok {
options["style"] = style
}
if _, ok := options["noclasses"]; !ok {
options["noclasses"] = noclasses
}
if _, ok := options["encoding"]; !ok {
options["encoding"] = "utf8"
}
var keys []string
for k := range options {
keys = append(keys, k)
}
sort.Strings(keys)
var optionsStr string
for i, k := range keys {
optionsStr += fmt.Sprintf("%s=%s", k, options[k])
if i < len(options)-1 {
optionsStr += ","
}
}
return optionsStr, nil
}