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- // Copyright 2013 Martini Authors
- // Copyright 2014 The Macaron Authors
- //
- // Licensed under the Apache 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://www.apache.org/licenses/LICENSE-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 macaron
- import (
- "encoding/base64"
- "log"
- "net/http"
- "path"
- "path/filepath"
- "strings"
- "sync"
- )
- // StaticOptions is a struct for specifying configuration options for the macaron.Static middleware.
- type StaticOptions struct {
- // Prefix is the optional prefix used to serve the static directory content
- Prefix string
- // SkipLogging will disable [Static] log messages when a static file is served.
- SkipLogging bool
- // IndexFile defines which file to serve as index if it exists.
- IndexFile string
- // Expires defines which user-defined function to use for producing a HTTP Expires Header
- // https://developers.google.com/speed/docs/insights/LeverageBrowserCaching
- Expires func() string
- // ETag defines if we should add an ETag header
- // https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching#validating-cached-responses-with-etags
- ETag bool
- // FileSystem is the interface for supporting any implmentation of file system.
- FileSystem http.FileSystem
- }
- // FIXME: to be deleted.
- type staticMap struct {
- lock sync.RWMutex
- data map[string]*http.Dir
- }
- func (sm *staticMap) Set(dir *http.Dir) {
- sm.lock.Lock()
- defer sm.lock.Unlock()
- sm.data[string(*dir)] = dir
- }
- func (sm *staticMap) Get(name string) *http.Dir {
- sm.lock.RLock()
- defer sm.lock.RUnlock()
- return sm.data[name]
- }
- func (sm *staticMap) Delete(name string) {
- sm.lock.Lock()
- defer sm.lock.Unlock()
- delete(sm.data, name)
- }
- var statics = staticMap{sync.RWMutex{}, map[string]*http.Dir{}}
- // staticFileSystem implements http.FileSystem interface.
- type staticFileSystem struct {
- dir *http.Dir
- }
- func newStaticFileSystem(directory string) staticFileSystem {
- if !filepath.IsAbs(directory) {
- directory = filepath.Join(Root, directory)
- }
- dir := http.Dir(directory)
- statics.Set(&dir)
- return staticFileSystem{&dir}
- }
- func (fs staticFileSystem) Open(name string) (http.File, error) {
- return fs.dir.Open(name)
- }
- func prepareStaticOption(dir string, opt StaticOptions) StaticOptions {
- // Defaults
- if len(opt.IndexFile) == 0 {
- opt.IndexFile = "index.html"
- }
- // Normalize the prefix if provided
- if opt.Prefix != "" {
- // Ensure we have a leading '/'
- if opt.Prefix[0] != '/' {
- opt.Prefix = "/" + opt.Prefix
- }
- // Remove any trailing '/'
- opt.Prefix = strings.TrimRight(opt.Prefix, "/")
- }
- if opt.FileSystem == nil {
- opt.FileSystem = newStaticFileSystem(dir)
- }
- return opt
- }
- func prepareStaticOptions(dir string, options []StaticOptions) StaticOptions {
- var opt StaticOptions
- if len(options) > 0 {
- opt = options[0]
- }
- return prepareStaticOption(dir, opt)
- }
- func staticHandler(ctx *Context, log *log.Logger, opt StaticOptions) bool {
- if ctx.Req.Method != "GET" && ctx.Req.Method != "HEAD" {
- return false
- }
- file := ctx.Req.URL.Path
- // if we have a prefix, filter requests by stripping the prefix
- if opt.Prefix != "" {
- if !strings.HasPrefix(file, opt.Prefix) {
- return false
- }
- file = file[len(opt.Prefix):]
- if file != "" && file[0] != '/' {
- return false
- }
- }
- f, err := opt.FileSystem.Open(file)
- if err != nil {
- return false
- }
- defer f.Close()
- fi, err := f.Stat()
- if err != nil {
- return true // File exists but fail to open.
- }
- // Try to serve index file
- if fi.IsDir() {
- // Redirect if missing trailing slash.
- if !strings.HasSuffix(ctx.Req.URL.Path, "/") {
- http.Redirect(ctx.Resp, ctx.Req.Request, ctx.Req.URL.Path+"/", http.StatusFound)
- return true
- }
- file = path.Join(file, opt.IndexFile)
- f, err = opt.FileSystem.Open(file)
- if err != nil {
- return false // Discard error.
- }
- defer f.Close()
- fi, err = f.Stat()
- if err != nil || fi.IsDir() {
- return true
- }
- }
- if !opt.SkipLogging {
- log.Println("[Static] Serving " + file)
- }
- // Add an Expires header to the static content
- if opt.Expires != nil {
- ctx.Resp.Header().Set("Expires", opt.Expires())
- }
- if opt.ETag {
- tag := GenerateETag(string(fi.Size()), fi.Name(), fi.ModTime().UTC().Format(http.TimeFormat))
- ctx.Resp.Header().Set("ETag", tag)
- }
- http.ServeContent(ctx.Resp, ctx.Req.Request, file, fi.ModTime(), f)
- return true
- }
- // GenerateETag generates an ETag based on size, filename and file modification time
- func GenerateETag(fileSize, fileName, modTime string) string {
- etag := fileSize + fileName + modTime
- return base64.StdEncoding.EncodeToString([]byte(etag))
- }
- // Static returns a middleware handler that serves static files in the given directory.
- func Static(directory string, staticOpt ...StaticOptions) Handler {
- opt := prepareStaticOptions(directory, staticOpt)
- return func(ctx *Context, log *log.Logger) {
- staticHandler(ctx, log, opt)
- }
- }
- // Statics registers multiple static middleware handlers all at once.
- func Statics(opt StaticOptions, dirs ...string) Handler {
- if len(dirs) == 0 {
- panic("no static directory is given")
- }
- opts := make([]StaticOptions, len(dirs))
- for i := range dirs {
- opts[i] = prepareStaticOption(dirs[i], opt)
- }
- return func(ctx *Context, log *log.Logger) {
- for i := range opts {
- if staticHandler(ctx, log, opts[i]) {
- return
- }
- }
- }
- }
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