146 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			146 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Go
		
	
	
	
| // Copyright 2013 com 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 com
 | |
| 
 | |
| import (
 | |
| 	"fmt"
 | |
| 	"io"
 | |
| 	"io/ioutil"
 | |
| 	"math"
 | |
| 	"os"
 | |
| 	"path"
 | |
| )
 | |
| 
 | |
| // Storage unit constants.
 | |
| const (
 | |
| 	Byte  = 1
 | |
| 	KByte = Byte * 1024
 | |
| 	MByte = KByte * 1024
 | |
| 	GByte = MByte * 1024
 | |
| 	TByte = GByte * 1024
 | |
| 	PByte = TByte * 1024
 | |
| 	EByte = PByte * 1024
 | |
| )
 | |
| 
 | |
| func logn(n, b float64) float64 {
 | |
| 	return math.Log(n) / math.Log(b)
 | |
| }
 | |
| 
 | |
| func humanateBytes(s uint64, base float64, sizes []string) string {
 | |
| 	if s < 10 {
 | |
| 		return fmt.Sprintf("%dB", s)
 | |
| 	}
 | |
| 	e := math.Floor(logn(float64(s), base))
 | |
| 	suffix := sizes[int(e)]
 | |
| 	val := float64(s) / math.Pow(base, math.Floor(e))
 | |
| 	f := "%.0f"
 | |
| 	if val < 10 {
 | |
| 		f = "%.1f"
 | |
| 	}
 | |
| 
 | |
| 	return fmt.Sprintf(f+"%s", val, suffix)
 | |
| }
 | |
| 
 | |
| // HumaneFileSize calculates the file size and generate user-friendly string.
 | |
| func HumaneFileSize(s uint64) string {
 | |
| 	sizes := []string{"B", "KB", "MB", "GB", "TB", "PB", "EB"}
 | |
| 	return humanateBytes(s, 1024, sizes)
 | |
| }
 | |
| 
 | |
| // FileMTime returns file modified time and possible error.
 | |
| func FileMTime(file string) (int64, error) {
 | |
| 	f, err := os.Stat(file)
 | |
| 	if err != nil {
 | |
| 		return 0, err
 | |
| 	}
 | |
| 	return f.ModTime().Unix(), nil
 | |
| }
 | |
| 
 | |
| // FileSize returns file size in bytes and possible error.
 | |
| func FileSize(file string) (int64, error) {
 | |
| 	f, err := os.Stat(file)
 | |
| 	if err != nil {
 | |
| 		return 0, err
 | |
| 	}
 | |
| 	return f.Size(), nil
 | |
| }
 | |
| 
 | |
| // Copy copies file from source to target path.
 | |
| func Copy(src, dest string) error {
 | |
| 	// Gather file information to set back later.
 | |
| 	si, err := os.Lstat(src)
 | |
| 	if err != nil {
 | |
| 		return err
 | |
| 	}
 | |
| 
 | |
| 	// Handle symbolic link.
 | |
| 	if si.Mode()&os.ModeSymlink != 0 {
 | |
| 		target, err := os.Readlink(src)
 | |
| 		if err != nil {
 | |
| 			return err
 | |
| 		}
 | |
| 		// NOTE: os.Chmod and os.Chtimes don't recoganize symbolic link,
 | |
| 		// which will lead "no such file or directory" error.
 | |
| 		return os.Symlink(target, dest)
 | |
| 	}
 | |
| 
 | |
| 	sr, err := os.Open(src)
 | |
| 	if err != nil {
 | |
| 		return err
 | |
| 	}
 | |
| 	defer sr.Close()
 | |
| 
 | |
| 	dw, err := os.Create(dest)
 | |
| 	if err != nil {
 | |
| 		return err
 | |
| 	}
 | |
| 	defer dw.Close()
 | |
| 
 | |
| 	if _, err = io.Copy(dw, sr); err != nil {
 | |
| 		return err
 | |
| 	}
 | |
| 
 | |
| 	// Set back file information.
 | |
| 	if err = os.Chtimes(dest, si.ModTime(), si.ModTime()); err != nil {
 | |
| 		return err
 | |
| 	}
 | |
| 	return os.Chmod(dest, si.Mode())
 | |
| }
 | |
| 
 | |
| // WriteFile writes data to a file named by filename.
 | |
| // If the file does not exist, WriteFile creates it
 | |
| // and its upper level paths.
 | |
| func WriteFile(filename string, data []byte) error {
 | |
| 	os.MkdirAll(path.Dir(filename), os.ModePerm)
 | |
| 	return ioutil.WriteFile(filename, data, 0655)
 | |
| }
 | |
| 
 | |
| // IsFile returns true if given path is a file,
 | |
| // or returns false when it's a directory or does not exist.
 | |
| func IsFile(filePath string) bool {
 | |
| 	f, e := os.Stat(filePath)
 | |
| 	if e != nil {
 | |
| 		return false
 | |
| 	}
 | |
| 	return !f.IsDir()
 | |
| }
 | |
| 
 | |
| // IsExist checks whether a file or directory exists.
 | |
| // It returns false when the file or directory does not exist.
 | |
| func IsExist(path string) bool {
 | |
| 	_, err := os.Stat(path)
 | |
| 	return err == nil || os.IsExist(err)
 | |
| }
 |