How to use CacheFile method of lang Package

1// Copyright © 2013-14 Steve Francia <spf@spf13.com>.2//3// Licensed under the Simple Public License, Version 2.0 (the "License");4// you may not use this file except in compliance with the License.5// You may obtain a copy of the License at6// http://opensource.org/licenses/Simple-2.07//8// Unless required by applicable law or agreed to in writing, software9// distributed under the License is distributed on an "AS IS" BASIS,10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.11// See the License for the specific language governing permissions and12// limitations under the License.13package helpers14import (15	"bytes"16	"crypto/sha1"17	"fmt"18	"github.com/spf13/hugo/hugofs"19	jww "github.com/spf13/jwalterweatherman"20	"github.com/spf13/viper"21	"io"22	"io/ioutil"23	"os/exec"24	"path/filepath"25	"sort"26	"strings"27)28const pygmentsBin = "pygmentize"29// HasPygments checks to see if Pygments is installed and available30// on the system.31func HasPygments() bool {32	if _, err := exec.LookPath(pygmentsBin); err != nil {33		return false34	}35	return true36}37// Highlight takes some code and returns highlighted code.38func Highlight(code, lang, optsStr string) string {39	if !HasPygments() {40		jww.WARN.Println("Highlighting requires Pygments to be installed and in the path")41		return code42	}43	options, err := parsePygmentsOpts(optsStr)44	if err != nil {45		jww.ERROR.Print(err.Error())46		return code47	}48	// Try to read from cache first49	hash := sha1.New()50	io.WriteString(hash, code)51	io.WriteString(hash, lang)52	io.WriteString(hash, options)53	fs := hugofs.OsFs54	cacheDir := viper.GetString("CacheDir")55	var cachefile string56	if cacheDir != "" {57		cachefile = filepath.Join(cacheDir, fmt.Sprintf("pygments-%x", hash.Sum(nil)))58		exists, err := Exists(cachefile, fs)59		if err != nil {60			jww.ERROR.Print(err.Error())61			return code62		}63		if exists {64			f, err := fs.Open(cachefile)65			if err != nil {66				jww.ERROR.Print(err.Error())67				return code68			}69			s, err := ioutil.ReadAll(f)70			if err != nil {71				jww.ERROR.Print(err.Error())72				return code73			}74			return string(s)75		}76	}77	// No cache file, render and cache it78	var out bytes.Buffer79	var stderr bytes.Buffer80	var langOpt string81	if lang == "" {82		langOpt = "-g" // Try guessing the language83	} else {84		langOpt = "-l" + lang85	}86	cmd := exec.Command(pygmentsBin, langOpt, "-fhtml", "-O", options)87	cmd.Stdin = strings.NewReader(code)88	cmd.Stdout = &out89	cmd.Stderr = &stderr90	if err := cmd.Run(); err != nil {91		jww.ERROR.Print(stderr.String())92		return code93	}94	str := out.String()95	// inject code tag into Pygments output96	if lang != "" && strings.Contains(str, "<pre>") {97		codeTag := fmt.Sprintf(`<pre><code class="language-%s" data-lang="%s">`, lang, lang)98		str = strings.Replace(str, "<pre>", codeTag, 1)99		str = strings.Replace(str, "</pre>", "</code></pre>", 1)100	}101	if cachefile != "" {102		// Write cache file103		if err := WriteToDisk(cachefile, strings.NewReader(str), fs); err != nil {104			jww.ERROR.Print(stderr.String())105		}106	}107	return str108}109var pygmentsKeywords = make(map[string]bool)110func init() {111	pygmentsKeywords["style"] = true112	pygmentsKeywords["encoding"] = true113	pygmentsKeywords["noclasses"] = true114	pygmentsKeywords["hl_lines"] = true115	pygmentsKeywords["linenos"] = true116	pygmentsKeywords["classprefix"] = true117}118func parsePygmentsOpts(in string) (string, error) {119	in = strings.Trim(in, " ")120	style := viper.GetString("PygmentsStyle")121	noclasses := "true"122	if viper.GetBool("PygmentsUseClasses") {123		noclasses = "false"124	}125	if len(in) == 0 {126		return fmt.Sprintf("style=%s,noclasses=%s,encoding=utf8", style, noclasses), nil127	}128	options := make(map[string]string)129	o := strings.Split(in, ",")130	for _, v := range o {131		keyVal := strings.Split(v, "=")132		key := strings.ToLower(strings.Trim(keyVal[0], " "))133		if len(keyVal) != 2 || !pygmentsKeywords[key] {134			return "", fmt.Errorf("invalid Pygments option: %s", key)135		}136		options[key] = keyVal[1]137	}138	if _, ok := options["style"]; !ok {139		options["style"] = style140	}141	if _, ok := options["noclasses"]; !ok {142		options["noclasses"] = noclasses143	}144	if _, ok := options["encoding"]; !ok {145		options["encoding"] = "utf8"146	}147	var keys []string148	for k := range options {149		keys = append(keys, k)150	}151	sort.Strings(keys)152	var optionsStr string153	for i, k := range keys {154		optionsStr += fmt.Sprintf("%s=%s", k, options[k])155		if i < len(options)-1 {156			optionsStr += ","157		}158	}159	return optionsStr, nil160}...

1package controllers2import (3	"io/ioutil"4	"net/http"5	"os"6	"path"7	"strings"8	"github.com/astaxie/beego"9	"github.com/beego/website/models"10)11type BaseController struct {12	beego.Controller13	Lang string14	// static file cache support15	cacheFile   string16	cacheEnable bool17	cacheBody   []byte18}19func (bc *BaseController) Prepare() {20	if bc.Lang = bc.Ctx.GetCookie("lang"); bc.Lang == "" {21		bc.Lang = "en-US"22	}23	bc.Data["Lang"] = bc.Lang24	bc.Data["I18n"] = models.I18ns[strings.ToLower(bc.Lang)]25	bc.cacheFile = path.Join(beego.AppConfig.DefaultString("cache_dir", "_cache"), bc.Lang, bc.Ctx.Input.URL())26	if !strings.HasSuffix(bc.cacheFile, ".html") {27		bc.cacheFile += ".html"28	}29	if fi, _ := os.Stat(bc.cacheFile); fi != nil && !fi.IsDir() {30		http.ServeFile(bc.Ctx.ResponseWriter, bc.Ctx.Request, bc.cacheFile)31		bc.StopRun()32	}33	bc.Layout = "layout.html"34	bc.setProperTemplateFile()35	bc.Data["Title"] = "Beego Website"36	bc.Data["HomeNav"] = models.HomeNav37	bc.Data["DocNav"] = models.DocNav38	bc.Data["Type"] = "page"39}40func (bc *BaseController) setProperTemplateFile() {41	p := bc.Ctx.Request.URL.Path42	paths := strings.Split(p, "/")43	if len(paths) >= 2 {44		bc.TplName = paths[1]45	}46	if bc.TplName == "" {47		bc.TplName = "index.html"48	}49	if !strings.HasSuffix(bc.TplName, ".html") {50		bc.TplName += ".html"51	}52}53func (bc *BaseController) Render() error {54	if renderBytes, _ := bc.RenderBytes(); len(renderBytes) > 0 {55		bc.cacheBody = renderBytes56		bc.cacheEnable = beego.AppConfig.DefaultBool("cache_flag", false)57	}58	return bc.Controller.Render()59}60func (bc *BaseController) Finish() {61	if bc.cacheEnable {62		os.MkdirAll(path.Dir(bc.cacheFile), os.ModePerm)63		ioutil.WriteFile(bc.cacheFile, bc.cacheBody, os.ModePerm) // todo : error handle64	}65}...

1import (2func main() {3	gol.CacheFile("testfile", "test data")4	fmt.Println(gol.ReadFile("testfile"))5}6import (7func main() {8	gol.CacheFile("testfile", "t

1import (2func main() {3	f, err := os.Open("1.go")4	if err != nil {5		fmt.Println("Error opening file")6	}7	src, err := scanner.ScanFile(fset, "1.go", f, 0)8	if err != nil {9		fmt.Println("Error scanning file")10	}11	f, err = parser.ParseFile(fset, "1.go", src, 0)12	if err != nil {13		fmt.Println("Error parsing file")14	}15	lang.CacheFile(fset, f)16}17import (18func main() {19	f, err := os.Open("2.go")20	if err != nil {21		fmt.Println("Error opening file")22	}23	src, err := scanner.ScanFile(fset, "2.go", f, 0)24	if err != nil {25		fmt.Println("Error scanning file")26	}27	f, err = parser.ParseFile(fset, "2.go", src, 0)28	if err != nil {29		fmt.Println("Error parsing file")30	}