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package main
import (
"bufio"
"fmt"
"io"
"os"
"os/exec"
"path/filepath"
"runtime"
"strconv"
"strings"
)
//#include <unistd.h>
import "C"
var arg_max = int(C.sysconf(C._SC_ARG_MAX))
func errhandle(err error) {
if err != nil {
panic(err)
}
}
func findLikelyDups(paths []string) map[string][]string {
ret := map[string][]string{}
var err error
for i := range paths {
paths[i], err = filepath.Abs(paths[i])
errhandle(err)
}
cmd := exec.Command("find", append(paths, "-type", "f", "-printf", "%s %p\\0")...)
stdout, err := cmd.StdoutPipe()
errhandle(err)
cmd.Stderr = os.Stderr
errhandle(cmd.Start())
rd := bufio.NewReader(stdout)
for {
line, err := rd.ReadString('\x00')
if line == "" && err == io.EOF {
break
}
errhandle(err)
parts := strings.SplitN(strings.TrimSuffix(line, "\x00"), " ", 2)
if len(parts) != 2 {
panic("wut")
}
size := parts[0]
filename := parts[1]
basename := filepath.Base(filename)
key := size + " " + basename
ret[key] = append(ret[key], filename)
}
errhandle(cmd.Wait())
for key := range ret {
if len(ret[key]) < 2 {
delete(ret, key)
}
}
return ret
}
func getFiemaps(paths []string) map[string][]string {
ret := map[string][]string{}
fmt.Fprintf(os.Stderr, "Getting fiemaps for %d files...\n", len(paths))
for len(paths) > 0 {
_paths := paths
arg_len := 0
for i := range _paths {
arg_len += len(_paths[i])+1
if arg_len > arg_max/2 {
_paths = _paths[:i-1]
break
}
}
paths = paths[len(_paths):]
fmt.Fprintf(os.Stderr, " -> %d\n", len(_paths))
cmd := exec.Command("./cow-extent-map", append([]string{"-m", "--"}, _paths...)...)
stdout, err := cmd.StdoutPipe()
errhandle(err)
cmd.Stderr = os.Stderr
errhandle(cmd.Start())
rd := bufio.NewReader(stdout)
for {
filename, err := rd.ReadString('\x00')
if filename == "" && err == io.EOF {
break
}
filename = strings.TrimSuffix(filename, "\x00")
if !strings.HasPrefix(filename, "/") {
panic("ugly filename")
}
errhandle(err)
fiemap, err := rd.ReadString('\x00')
fiemap = strings.TrimSuffix(fiemap, "\x00")
if !(strings.HasPrefix(fiemap, "logical=") || fiemap == "") {
panic("ugly fiemap")
}
errhandle(err)
ret[fiemap] = append(ret[fiemap], filename)
}
errhandle(cmd.Wait())
}
fmt.Fprintf(os.Stderr, "...done\n")
return ret
}
func getChecksums(paths []string) map[string][]string {
ret := map[string][]string{}
fmt.Fprintf(os.Stderr, "Generating checksums for %d files...\n", len(paths))
for len(paths) > 0 {
_paths := paths
arg_len := 0
for i := range _paths {
arg_len += len(_paths[i])+1
if arg_len > arg_max/2 {
_paths = _paths[:i-1]
break
}
}
paths = paths[len(_paths):]
fmt.Fprintf(os.Stderr, " -> %d\n", len(_paths))
cmd := exec.Command("sha256sum", append([]string{"--"}, _paths...)...)
stdout, err := cmd.StdoutPipe()
errhandle(err)
cmd.Stderr = os.Stderr
errhandle(cmd.Start())
rd := bufio.NewReader(stdout)
for {
line, err := rd.ReadString('\n')
if line == "" && err == io.EOF {
break
}
errhandle(err)
parts := strings.SplitN(strings.TrimSuffix(line, "\n"), " ", 2)
if len(parts) != 2 {
panic("wut")
}
checksum := parts[0]
filename := strings.TrimPrefix(parts[1], " ")
ret[checksum] = append(ret[checksum], filename)
}
errhandle(cmd.Wait())
}
fmt.Fprintf(os.Stderr, "...done\n")
return ret
}
func main() {
// we have no parallelism, don't let syscalls fan-out weird on
// many-core systems
runtime.GOMAXPROCS(1)
likely := findLikelyDups(os.Args[1:])
var flatLikely []string
for _, filenames := range likely {
flatLikely = append(flatLikely, filenames...)
}
fiemap2filenames := getFiemaps(flatLikely)
filename2fiemap := map[string]string{}
for fiemap, filenames := range fiemap2filenames {
for _, filename := range filenames {
if _, ok := filename2fiemap[filename]; ok {
panic("not ok")
}
filename2fiemap[filename] = fiemap
}
}
spanningFiles := make([]string, len(fiemap2filenames))
i := 0
for _, filenames := range fiemap2filenames {
spanningFiles[i] = filenames[0]
i++
}
checksum2filenames := getChecksums(spanningFiles)
checksum2fiemaps := map[string][]string{}
for checksum, filenames := range checksum2filenames {
for _, filename := range filenames {
checksum2fiemaps[checksum] = append(checksum2fiemaps[checksum], filename2fiemap[filename])
}
}
for checksum, fiemaps := range checksum2fiemaps {
if len(fiemaps) < 2 {
delete(checksum2fiemaps, checksum)
}
}
fmt.Fprintf(os.Stderr, "Deduplicating %d sets of files...\n", len(checksum2fiemaps))
for checksum, fiemaps := range checksum2fiemaps {
// choose the fiemap with the fewest extents
minFiemap := fiemaps[0]
minFiemapLen := strings.Count(minFiemap, "\n")
for _, fiemap := range fiemaps {
fiemapLen := strings.Count(fiemap, "\n")
if fiemapLen < minFiemapLen {
minFiemap = fiemap
minFiemapLen = fiemapLen
}
}
srcFile := fiemap2filenames[minFiemap][0]
var dupFiles []string
for _, fiemap := range fiemaps {
if fiemap == minFiemap {
continue
}
dupFiles = append(dupFiles, fiemap2filenames[fiemap]...)
}
stat, err := os.Stat(srcFile)
errhandle(err)
args := []string{
"-r", "--", strconv.FormatInt(stat.Size(), 10),
srcFile, "0",
}
for _, dupFile := range dupFiles {
args = append(args, dupFile, "0")
}
cmd := exec.Command("./cow-dedupe-range", args...)
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
fmt.Println("#", checksum)
fmt.Println(cmd.Args)
errhandle(cmd.Run())
}
}
|
