assets: use statik to compile static files into binary files

vendor/github.com/rakyll/statik/fs/fs.go

@@ -0,0 +1,146 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// 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 contains an HTTP file system that works with zip contents.
+package fs
+
+import (
+	"archive/zip"
+	"bytes"
+	"errors"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"strings"
+	"sync"
+)
+
+var zipData string
+
+type statikFS struct {
+	files map[string]*zip.File
+}
+
+// Registers zip contents data, later used to initialize
+// the statik file system.
+func Register(data string) {
+	zipData = data
+}
+
+// Creates a new file system with the registered zip contents data.
+func New() (http.FileSystem, error) {
+	if zipData == "" {
+		return nil, errors.New("statik/fs: No zip data registered.")
+	}
+	zipReader, err := zip.NewReader(strings.NewReader(zipData), int64(len(zipData)))
+	if err != nil {
+		return nil, err
+	}
+	files := make(map[string]*zip.File)
+	for _, file := range zipReader.File {
+		files["/"+file.Name] = file
+	}
+	return &statikFS{files: files}, nil
+}
+
+// Opens a file, unzip the contents and initializes
+// readers. Returns os.ErrNotExists if file is not
+// found in the archive.
+func (fs *statikFS) Open(name string) (http.File, error) {
+	name = strings.Replace(name, "//", "/", -1)
+	f, ok := fs.files[name]
+
+	// The file doesn't match, but maybe it's a directory,
+	// thus we should look for index.html
+	if !ok {
+		indexName := strings.Replace(name+"/index.html", "//", "/", -1)
+		f, ok = fs.files[indexName]
+
+		if !ok {
+			return nil, os.ErrNotExist
+		}
+
+		return newFile(f, true)
+	}
+	return newFile(f, false)
+}
+
+var nopCloser = ioutil.NopCloser(nil)
+
+func newFile(zf *zip.File, isDir bool) (*file, error) {
+	rc, err := zf.Open()
+	if err != nil {
+		return nil, err
+	}
+	defer rc.Close()
+	all, err := ioutil.ReadAll(rc)
+	if err != nil {
+		return nil, err
+	}
+	return &file{
+		FileInfo: zf.FileInfo(),
+		data:     all,
+		readerAt: bytes.NewReader(all),
+		Closer:   nopCloser,
+		isDir:    isDir,
+	}, nil
+}
+
+// Represents an HTTP file, acts as a bridge between
+// zip.File and http.File.
+type file struct {
+	os.FileInfo
+	io.Closer
+
+	data     []byte // non-nil if regular file
+	reader   *io.SectionReader
+	readerAt io.ReaderAt // over data
+	isDir    bool
+
+	once sync.Once
+}
+
+func (f *file) newReader() {
+	f.reader = io.NewSectionReader(f.readerAt, 0, f.FileInfo.Size())
+}
+
+// Reads bytes into p, returns the number of read bytes.
+func (f *file) Read(p []byte) (n int, err error) {
+	f.once.Do(f.newReader)
+	return f.reader.Read(p)
+}
+
+// Seeks to the offset.
+func (f *file) Seek(offset int64, whence int) (ret int64, err error) {
+	f.once.Do(f.newReader)
+	return f.reader.Seek(offset, whence)
+}
+
+// Stats the file.
+func (f *file) Stat() (os.FileInfo, error) {
+	return f, nil
+}
+
+// IsDir returns true if the file location represents a directory.
+func (f *file) IsDir() bool {
+	return f.isDir
+}
+
+// Returns an empty slice of files, directory
+// listing is disabled.
+func (f *file) Readdir(count int) ([]os.FileInfo, error) {
+	// directory listing is disabled.
+	return make([]os.FileInfo, 0), nil
+}