Subversion Repositories openrisc

// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package mime implements parts of the MIME spec.
package mime

import (
        "fmt"
        "strings"
        "sync"
)

var mimeTypes = map[string]string{
        ".css":  "text/css; charset=utf-8",
        ".gif":  "image/gif",
        ".htm":  "text/html; charset=utf-8",
        ".html": "text/html; charset=utf-8",
        ".jpg":  "image/jpeg",
        ".js":   "application/x-javascript",
        ".pdf":  "application/pdf",
        ".png":  "image/png",
        ".xml":  "text/xml; charset=utf-8",
}

var mimeLock sync.RWMutex

var once sync.Once

// TypeByExtension returns the MIME type associated with the file extension ext.
// The extension ext should begin with a leading dot, as in ".html".
// When ext has no associated type, TypeByExtension returns "".
//
// The built-in table is small but on unix it is augmented by the local
// system's mime.types file(s) if available under one or more of these
// names:
//
//   /etc/mime.types
//   /etc/apache2/mime.types
//   /etc/apache/mime.types
//
// Windows system mime types are extracted from registry.
//
// Text types have the charset parameter set to "utf-8" by default.
func TypeByExtension(ext string) string {
        once.Do(initMime)
        mimeLock.RLock()
        typename := mimeTypes[ext]
        mimeLock.RUnlock()
        return typename
}

// AddExtensionType sets the MIME type associated with
// the extension ext to typ.  The extension should begin with
// a leading dot, as in ".html".
func AddExtensionType(ext, typ string) error {
        if ext == "" || ext[0] != '.' {
                return fmt.Errorf(`mime: extension "%s" misses dot`, ext)
        }
        once.Do(initMime)
        return setExtensionType(ext, typ)
}

func setExtensionType(extension, mimeType string) error {
        _, param, err := ParseMediaType(mimeType)
        if err != nil {
                return err
        }
        if strings.HasPrefix(mimeType, "text/") && param["charset"] == "" {
                param["charset"] = "utf-8"
                mimeType = FormatMediaType(mimeType, param)
        }
        mimeLock.Lock()
        mimeTypes[extension] = mimeType
        mimeLock.Unlock()
        return nil
}