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Find file Copy path
5756895 Jun 15, 2018
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// Copyright 2018 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 dirhash defines hashes over directory trees.
package dirhash
import (
"archive/zip"
"crypto/sha256"
"encoding/base64"
"errors"
"fmt"
"io"
"os"
"path/filepath"
"sort"
"strings"
)
var DefaultHash = Hash1
type Hash func(files []string, open func(string) (io.ReadCloser, error)) (string, error)
func Hash1(files []string, open func(string) (io.ReadCloser, error)) (string, error) {
h := sha256.New()
files = append([]string(nil), files...)
sort.Strings(files)
for _, file := range files {
if strings.Contains(file, "\n") {
return "", errors.New("filenames with newlines are not supported")
}
r, err := open(file)
if err != nil {
return "", err
}
hf := sha256.New()
_, err = io.Copy(hf, r)
r.Close()
if err != nil {
return "", err
}
fmt.Fprintf(h, "%x %s\n", hf.Sum(nil), file)
}
return "h1:" + base64.StdEncoding.EncodeToString(h.Sum(nil)), nil
}
func HashDir(dir, prefix string, hash Hash) (string, error) {
files, err := DirFiles(dir, prefix)
if err != nil {
return "", err
}
osOpen := func(name string) (io.ReadCloser, error) {
return os.Open(filepath.Join(dir, strings.TrimPrefix(name, prefix)))
}
return hash(files, osOpen)
}
func DirFiles(dir, prefix string) ([]string, error) {
var files []string
dir = filepath.Clean(dir)
err := filepath.Walk(dir, func(file string, info os.FileInfo, err error) error {
if err != nil {
return err
}
if info.IsDir() {
return nil
}
rel := file
if dir != "." {
rel = file[len(dir)+1:]
}
f := filepath.Join(prefix, rel)
files = append(files, filepath.ToSlash(f))
return nil
})
if err != nil {
return nil, err
}
return files, nil
}
func HashZip(zipfile string, hash Hash) (string, error) {
z, err := zip.OpenReader(zipfile)
if err != nil {
return "", err
}
defer z.Close()
var files []string
zfiles := make(map[string]*zip.File)
for _, file := range z.File {
files = append(files, file.Name)
zfiles[file.Name] = file
}
zipOpen := func(name string) (io.ReadCloser, error) {
f := zfiles[name]
if f == nil {
return nil, fmt.Errorf("file %q not found in zip", name) // should never happen
}
return f.Open()
}
return hash(files, zipOpen)
}