151 lines
3.6 KiB
Go
151 lines
3.6 KiB
Go
// Copyright 2019 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package build
|
|
|
|
import (
|
|
"bufio"
|
|
"crypto/sha256"
|
|
"encoding/hex"
|
|
"fmt"
|
|
"io"
|
|
"log"
|
|
"net/http"
|
|
"os"
|
|
"path/filepath"
|
|
"strings"
|
|
)
|
|
|
|
// ChecksumDB keeps file checksums.
|
|
type ChecksumDB struct {
|
|
allChecksums []string
|
|
}
|
|
|
|
// MustLoadChecksums loads a file containing checksums.
|
|
func MustLoadChecksums(file string) *ChecksumDB {
|
|
content, err := os.ReadFile(file)
|
|
if err != nil {
|
|
log.Fatal("can't load checksum file: " + err.Error())
|
|
}
|
|
return &ChecksumDB{strings.Split(string(content), "\n")}
|
|
}
|
|
|
|
// Verify checks whether the given file is valid according to the checksum database.
|
|
func (db *ChecksumDB) Verify(path string) error {
|
|
fd, err := os.Open(path)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer fd.Close()
|
|
|
|
h := sha256.New()
|
|
if _, err := io.Copy(h, bufio.NewReader(fd)); err != nil {
|
|
return err
|
|
}
|
|
fileHash := hex.EncodeToString(h.Sum(nil))
|
|
if !db.findHash(filepath.Base(path), fileHash) {
|
|
return fmt.Errorf("invalid file hash %s for %s", fileHash, filepath.Base(path))
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (db *ChecksumDB) findHash(basename, hash string) bool {
|
|
want := hash + " " + basename
|
|
for _, line := range db.allChecksums {
|
|
if strings.TrimSpace(line) == want {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
// DownloadFile downloads a file and verifies its checksum.
|
|
func (db *ChecksumDB) DownloadFile(url, dstPath string) error {
|
|
if err := db.Verify(dstPath); err == nil {
|
|
fmt.Printf("%s is up-to-date\n", dstPath)
|
|
return nil
|
|
}
|
|
fmt.Printf("%s is stale\n", dstPath)
|
|
fmt.Printf("downloading from %s\n", url)
|
|
|
|
resp, err := http.Get(url)
|
|
if err != nil {
|
|
return fmt.Errorf("download error: %v", err)
|
|
} else if resp.StatusCode != http.StatusOK {
|
|
return fmt.Errorf("download error: status %d", resp.StatusCode)
|
|
}
|
|
defer resp.Body.Close()
|
|
if err := os.MkdirAll(filepath.Dir(dstPath), 0755); err != nil {
|
|
return err
|
|
}
|
|
fd, err := os.OpenFile(dstPath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
dst := newDownloadWriter(fd, resp.ContentLength)
|
|
_, err = io.Copy(dst, resp.Body)
|
|
dst.Close()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return db.Verify(dstPath)
|
|
}
|
|
|
|
type downloadWriter struct {
|
|
file *os.File
|
|
dstBuf *bufio.Writer
|
|
size int64
|
|
written int64
|
|
lastpct int64
|
|
}
|
|
|
|
func newDownloadWriter(dst *os.File, size int64) *downloadWriter {
|
|
return &downloadWriter{
|
|
file: dst,
|
|
dstBuf: bufio.NewWriter(dst),
|
|
size: size,
|
|
}
|
|
}
|
|
|
|
func (w *downloadWriter) Write(buf []byte) (int, error) {
|
|
n, err := w.dstBuf.Write(buf)
|
|
|
|
// Report progress.
|
|
w.written += int64(n)
|
|
pct := w.written * 10 / w.size * 10
|
|
if pct != w.lastpct {
|
|
if w.lastpct != 0 {
|
|
fmt.Print("...")
|
|
}
|
|
fmt.Print(pct, "%")
|
|
w.lastpct = pct
|
|
}
|
|
return n, err
|
|
}
|
|
|
|
func (w *downloadWriter) Close() error {
|
|
if w.lastpct > 0 {
|
|
fmt.Println() // Finish the progress line.
|
|
}
|
|
flushErr := w.dstBuf.Flush()
|
|
closeErr := w.file.Close()
|
|
if flushErr != nil {
|
|
return flushErr
|
|
}
|
|
return closeErr
|
|
}
|