goldsmith/file.go

133 lines
2.8 KiB
Go

/*
* Copyright (c) 2015 Alex Yatskov <alex@foosoft.net>
* Author: Alex Yatskov <alex@foosoft.net>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package goldsmith
import (
"bytes"
"io"
"io/ioutil"
"os"
"path"
)
type file struct {
path string
meta map[string]interface{}
reader *bytes.Reader
asset string
}
func (f *file) export(dstPath string) error {
if err := os.MkdirAll(path.Dir(dstPath), 0755); err != nil {
return err
}
fw, err := os.Create(dstPath)
if err != nil {
return err
}
defer fw.Close()
if f.reader == nil {
fr, err := os.Open(f.asset)
if err != nil {
return err
}
defer fr.Close()
if _, err := io.Copy(fw, fr); err != nil {
return err
}
} else {
if _, err := f.Seek(0, os.SEEK_SET); err != nil {
return err
}
if _, err := f.WriteTo(fw); err != nil {
return err
}
}
return nil
}
func (f *file) cache() error {
if f.reader != nil {
return nil
}
data, err := ioutil.ReadFile(f.asset)
if err != nil {
return err
}
f.reader = bytes.NewReader(data)
return nil
}
//
// File Implementation
//
func (f *file) Path() string {
return f.path
}
func (f *file) Meta() map[string]interface{} {
return f.meta
}
func (f *file) Apply(m map[string]interface{}) {
for key, value := range m {
f.meta[key] = value
}
}
func (f *file) Read(p []byte) (int, error) {
if err := f.cache(); err != nil {
return 0, err
}
return f.reader.Read(p)
}
func (f *file) WriteTo(w io.Writer) (int64, error) {
if err := f.cache(); err != nil {
return 0, err
}
return f.reader.WriteTo(w)
}
func (f *file) Seek(offset int64, whence int) (int64, error) {
if f.reader == nil && offset == 0 && (whence == os.SEEK_SET || whence == os.SEEK_CUR) {
return 0, nil
}
if err := f.cache(); err != nil {
return 0, err
}
return f.reader.Seek(offset, whence)
}