forked from gokrazy/rsync
/
generator.go
291 lines (253 loc) · 6.31 KB
/
generator.go
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package receivermaincmd
import (
"fmt"
"io"
"io/fs"
"os"
"path/filepath"
"time"
"github.com/superrxan/rsync"
"github.com/superrxan/rsync/internal/log"
"github.com/superrxan/rsync/internal/rsyncchecksum"
"github.com/superrxan/rsync/internal/rsynccommon"
)
// rsync/generator.c:generate_files()
func (rt *recvTransfer) generateFiles(fileList []*file) error {
phase := 0
for idx, f := range fileList {
// TODO: use a copy of f with .Mode |= S_IWUSR for directories, so
// that we can create files within all directories.
if err := rt.recvGenerator(idx, f); err != nil {
return err
}
}
phase++
log.Printf("generateFiles phase=%d", phase)
if err := rt.conn.WriteInt32(-1); err != nil {
return err
}
// TODO: re-do any files that failed
phase++
log.Printf("generateFiles phase=%d", phase)
if err := rt.conn.WriteInt32(-1); err != nil {
return err
}
log.Printf("generateFiles finished")
return nil
}
// rsync/generator.c:skip_file
func (rt *recvTransfer) skipFile(f *file, st os.FileInfo) (bool, error) {
if st.Size() != f.Length {
return false, nil
}
// TODO: always checksum flag
// TODO: size only
// TODO: ignore times
return modTimeEqual(st.ModTime(), f.ModTime), nil
}
func modTimeEqual(a, b time.Time) bool {
a = a.Truncate(time.Second)
b = b.Truncate(time.Second)
log.Printf("comparing mtime: %v vs. %v", a, b)
return a.Equal(b)
}
// rsync/rsync.c:set_perms
func (rt *recvTransfer) setPerms(f *file) error {
if rt.opts.DryRun {
return nil
}
local := filepath.Join(rt.dest, f.Name)
st, err := os.Lstat(local)
if err != nil {
return err
}
perm := fs.FileMode(f.Mode) & os.ModePerm
mode := f.Mode & rsync.S_IFMT
if rt.opts.PreserveTimes &&
mode != rsync.S_IFLNK &&
!modTimeEqual(st.ModTime(), f.ModTime) {
if err := os.Chtimes(local, f.ModTime, f.ModTime); err != nil {
return err
}
}
_, err = rt.setUid(f, local, st)
if err != nil {
return err
}
if mode != rsync.S_IFLNK {
if err := os.Chmod(local, perm); err != nil {
return err
}
}
return nil
}
// rsync/generator.c:recv_generator
func (rt *recvTransfer) recvGenerator(idx int, f *file) error {
if rt.listOnly() {
fmt.Fprintf(rt.env.stdout, "%s %11.0f %s %s\n",
f.FileMode().String(),
float64(f.Length), // TODO: rsync prints decimal separators
f.ModTime.Format("2006/01/02 15:04:05"),
f.Name)
return nil
}
log.Printf("recv_generator(f=%+v)", f)
local := filepath.Join(rt.dest, f.Name)
st, err := os.Lstat(local)
mode := f.Mode & rsync.S_IFMT
if mode == rsync.S_IFDIR {
if rt.opts.DryRun {
return nil
}
if err == nil && !st.IsDir() {
// A file (not a directory) with this name exists. Delete it so that
// we can create a directory instead.
if err := os.Remove(local); err != nil {
return fmt.Errorf("unlinking to make room for directory: %v", err)
}
err = fmt.Errorf("file removed")
}
if err != nil {
perm := fs.FileMode(f.Mode) & os.ModePerm
log.Printf("MkdirAll(%s, %v)", local, perm)
if err := os.MkdirAll(local, perm); err != nil {
// TODO: EEXIST is okay
return err
}
return nil
}
if err := rt.setPerms(f); err != nil {
return err
}
return nil
}
if rt.opts.PreserveLinks && mode == rsync.S_IFLNK {
// TODO: safe_symlinks option
if err == nil {
// local file exists, verify target matches
if target, err := os.Readlink(local); err == nil {
log.Printf("existing target: %q", target)
if target == f.LinkTarget {
if err := rt.setPerms(f); err != nil {
return err
}
return nil // skip
}
// fallthrough to create or replace the symlink
}
// fallthrough to create or replace the symlink
}
log.Printf("symlink %s -> %s", local, f.LinkTarget)
if err := symlink(f.LinkTarget, local); err != nil {
return err
}
if err := rt.setPerms(f); err != nil {
return err
}
return nil
}
if rt.opts.PreserveDevices && (mode == rsync.S_IFCHR ||
mode == rsync.S_IFBLK ||
mode == rsync.S_IFSOCK ||
mode == rsync.S_IFIFO) {
if err := rt.createDevice(f, st); err != nil {
return err
}
return nil
}
if rt.opts.PreserveHardlinks {
// TODO: hard link check
}
if !f.FileMode().IsRegular() {
// None of the Preserve* options is enabled, so just skip over
// non-regular files.
return nil
}
requestFullFile := func() error {
log.Printf("requesting: %s", f.Name)
if err := rt.conn.WriteInt32(int32(idx)); err != nil {
return err
}
if rt.opts.DryRun {
return nil
}
var sh rsync.SumHead
if err := sh.WriteTo(rt.conn); err != nil {
return err
}
return nil
}
if os.IsNotExist(err) {
return requestFullFile()
}
if err != nil {
return err
}
if !st.Mode().IsRegular() {
// A non-regular file with this name exists. Delete it so that we can
// create our file instead.
if err := os.Remove(local); err != nil {
return fmt.Errorf("unlinking to make room for regular file: %v", err)
}
return requestFullFile()
}
// TODO: update-only check
skip, err := rt.skipFile(f, st)
if err != nil {
return err
}
if skip {
log.Printf("skipping %s", local)
if err := rt.setPerms(f); err != nil {
return err
}
return nil
}
if rt.opts.DryRun {
if err := rt.conn.WriteInt32(int32(idx)); err != nil {
return err
}
return nil
}
// TODO: if deltas are disabled, request the file in full
in, err := os.Open(local)
if err != nil {
log.Printf("failed to open %s, continuing: %v", local, err)
return requestFullFile()
}
defer in.Close()
log.Printf("sending sums for: %s", f.Name)
if err := rt.conn.WriteInt32(int32(idx)); err != nil {
return err
}
return rt.generateAndSendSums(in, st.Size())
}
// rsync/generator.c:generate_and_send_sums
func (rt *recvTransfer) generateAndSendSums(in *os.File, fileLen int64) error {
sh := rsynccommon.SumSizesSqroot(fileLen)
if err := sh.WriteTo(rt.conn); err != nil {
return err
}
buf := make([]byte, int(sh.BlockLength))
remaining := fileLen
for i := int32(0); i < sh.ChecksumCount; i++ {
n1 := int64(sh.BlockLength)
if n1 > remaining {
n1 = remaining
}
b := buf[:n1]
if _, err := io.ReadFull(in, b); err != nil {
return err
}
sum1 := rsyncchecksum.Checksum1(b)
sum2 := rsyncchecksum.Checksum2(rt.seed, b)
if err := rt.conn.WriteInt32(int32(sum1)); err != nil {
return err
}
if _, err := rt.conn.Writer.Write(sum2); err != nil {
return err
}
remaining -= n1
}
return nil
}