2 goredo -- redo implementation on pure Go
3 Copyright (C) 2020 Sergey Matveev <stargrave@stargrave.org>
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, version 3 of the License.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>.
37 "go.cypherpunks.ru/recfile"
38 "golang.org/x/sys/unix"
42 EnvDepFd = "REDO_DEP_FD"
43 EnvDirPrefix = "REDO_DIRPREFIX"
44 EnvBuildUUID = "REDO_BUILD_UUID"
45 EnvStderrPrefix = "REDO_STDERR_PREFIX"
46 EnvTrace = "REDO_TRACE"
47 EnvStderrKeep = "REDO_LOGS"
48 EnvStderrSilent = "REDO_SILENT"
49 EnvNoSync = "REDO_NO_SYNC"
50 EnvStampPrev = "REDO_STAMP_PREV"
62 StderrKeep bool = false
63 StderrSilent bool = false
67 flagTrace = flag.Bool("x", false, "trace current target (sh -x) (set REDO_TRACE=1 for others too)")
68 flagStderrKeep = flag.Bool("logs", false, "keep job's stderr (REDO_LOGS=1)")
69 flagStderrSilent = flag.Bool("silent", false, "do not print job's stderr (REDO_SILENT=1)")
80 func (e RunErr) Unwrap() error { return e.Err }
82 func (e *RunErr) Name() string {
87 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
89 if e.Finished == nil {
92 return fmt.Sprintf("%s (%fsec)", name, e.Finished.Sub(*e.Started).Seconds())
95 func (e RunErr) Error() string {
96 return fmt.Sprintf("%s: %s", e.Name(), e.Err)
99 func mkdirs(pth string) error {
100 if _, err := os.Stat(pth); err == nil {
103 return os.MkdirAll(pth, os.FileMode(0777))
106 func tempsuffix() string {
107 return strconv.FormatInt((time.Now().UnixNano()+int64(os.Getpid()))&0xFFFFFFFF, 16)
110 func tempfile(dir, prefix string) (*os.File, error) {
111 // It respects umask, unlike ioutil.TempFile
112 name := path.Join(dir, TmpPrefix+prefix+"."+tempsuffix())
113 return os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, os.FileMode(0666))
116 func isModified(cwd, redoDir, tgt string) (bool, error) {
117 fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
119 if os.IsNotExist(err) {
125 r := recfile.NewReader(fdDep)
127 m, err := r.NextMap()
134 if m["Target"] != tgt {
137 fd, err := os.Open(path.Join(cwd, tgt))
139 if os.IsNotExist(err) {
145 ourTs, err := fileCtime(fd)
149 if ourTs != m["Ctime"] {
157 func syncDir(dir string) error {
158 fd, err := os.Open(dir)
167 func runScript(tgtOrig string, errs chan error, stampPrev string) error {
168 cwd, tgt := cwdAndTgt(tgtOrig)
169 redoDir := path.Join(cwd, RedoDir)
170 if err := mkdirs(redoDir); err != nil {
171 return TgtErr{tgtOrig, err}
175 fdLock, err := os.OpenFile(
176 path.Join(redoDir, tgt+LockSuffix),
177 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
181 return TgtErr{tgtOrig, err}
183 lockRelease := func() {
184 trace(CLock, "LOCK_UN: %s", fdLock.Name())
185 unix.Flock(int(fdLock.Fd()), unix.LOCK_UN)
188 trace(CLock, "LOCK_NB: %s", fdLock.Name())
190 // Waiting for job completion, already taken by someone else
191 if err = unix.Flock(int(fdLock.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
192 if uintptr(err.(syscall.Errno)) != uintptr(unix.EWOULDBLOCK) {
194 return TgtErr{tgtOrig, err}
196 trace(CDebug, "waiting: %s", tgtOrig)
200 trace(CLock, "LOCK_EX: %s", fdLock.Name())
201 unix.Flock(int(fdLock.Fd()), unix.LOCK_EX)
203 trace(CDebug, "waiting done: %s", tgtOrig)
205 fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
207 if os.IsNotExist(err) {
208 err = errors.New("was not built: no .dep")
213 depInfo, err = depRead(fdDep)
217 if depInfo.build != BuildUUID {
218 err = errors.New("was not built: build differs")
222 err = TgtErr{tgtOrig, err}
229 // Check if target is not modified externally
230 modified, err := isModified(cwd, redoDir, tgt)
233 return TgtErr{tgtOrig, err}
236 trace(CWarn, "%s externally modified: not redoing", tgtOrig)
239 return TgtErr{tgtOrig, err}
242 // Start preparing .dep
243 fdDep, err := tempfile(redoDir, tgt+DepSuffix)
246 return TgtErr{tgtOrig, err}
251 os.Remove(fdDep.Name())
253 if _, err = recfile.NewWriter(fdDep).WriteFields(
254 recfile.Field{Name: "Build", Value: BuildUUID},
257 return TgtErr{tgtOrig, err}
261 doFile, upLevels, err := findDo(fdDep, cwd, tgt)
264 return TgtErr{tgtOrig, err}
268 return TgtErr{tgtOrig, errors.New("no .do found")}
270 if err = writeDep(fdDep, cwd, doFile); err != nil {
272 return TgtErr{tgtOrig, err}
275 // Determine basename and DIRPREFIX
276 ents := strings.Split(cwd, "/")
277 ents = ents[len(ents)-upLevels:]
278 dirPrefix := path.Join(ents...)
280 for i := 0; i < upLevels; i++ {
281 cwd = path.Join(cwd, "..")
283 cwd = path.Clean(cwd)
285 runErr := RunErr{Tgt: tgtOrig}
286 if strings.HasPrefix(doFile, "default.") {
287 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
288 runErr.DoFile = doFile
290 trace(CWait, "%s", runErr.Name())
291 doFile = path.Base(doFile)
293 // Prepare command line
296 if err = unix.Access(path.Join(cwd, doFile), unix.X_OK); err == nil {
297 // Ordinary executable file
299 args = make([]string, 0, 3)
301 fd, err := os.Open(path.Join(cwd, doFile))
304 return TgtErr{tgtOrig, err}
306 buf := make([]byte, 512)
307 n, err := fd.Read(buf)
310 return TgtErr{tgtOrig, err}
312 if n > 3 && string(buf[:3]) == "#!/" {
314 t := string(buf[2:n])
315 nlIdx := strings.Index(t, "\n")
318 return TgtErr{tgtOrig, errors.New("not fully read shebang")}
320 args = strings.Split(t[:nlIdx], " ")
321 cmdName, args = args[0], args[1:]
326 args = append(args, "-ex")
328 args = append(args, "-e")
331 args = append(args, doFile)
334 // Temporary file for stdout
335 fdStdout, err := tempfile(cwd, tgt)
338 return TgtErr{tgtOrig, err}
340 tmpPath := fdStdout.Name() + ".3" // and for $3
341 args = append(args, tgt, basename, path.Base(tmpPath))
343 cmd := exec.Command(cmdName, args...)
345 cmd.Stdout = fdStdout
346 cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
347 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
348 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
351 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvStampPrev, stampPrev))
354 childStderrPrefix := tempsuffix()
355 cmd.Env = append(cmd.Env, fmt.Sprintf(
356 "%s=%s", EnvStderrPrefix, childStderrPrefix,
359 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
361 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
365 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJSFd))
367 cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
368 cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
369 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d,%d", EnvJSFd, 3+fdNum+0, 3+fdNum+1))
374 stderr, err := cmd.StderrPipe()
378 var fdStderr *os.File
380 fdStderr, err = os.OpenFile(
381 path.Join(redoDir, tgt+LogSuffix),
382 os.O_WRONLY|os.O_CREATE,
387 return TgtErr{tgtOrig, err}
391 shCtx := fmt.Sprintf("sh: %s: %s %s [%s]", tgtOrig, cmdName, args, cwd)
392 trace(CDebug, "%s", shCtx)
405 os.Remove(fdDep.Name())
406 os.Remove(fdStdout.Name())
408 os.Remove(fdLock.Name())
411 started := time.Now()
412 runErr.Started = &started
419 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
420 trace(CDebug, "%s runs %s", tgtOrig, pid)
422 stderrTerm := make(chan struct{}, 0)
424 scanner := bufio.NewScanner(stderr)
428 line = scanner.Text()
429 if strings.HasPrefix(line, childStderrPrefix) {
430 line = line[len(childStderrPrefix):]
431 os.Stderr.WriteString(StderrPrefix + line + "\n")
436 fmt.Fprintf(fdStderr, "@%s %s\n", hex.EncodeToString(ts[:]), line)
442 trace(CNone, "%s", line)
444 trace(CNone, "%s %s", pid, line)
450 // Wait for job completion
453 finished := time.Now()
454 runErr.Finished = &finished
461 // Does it produce both stdout and tmp?
462 fiStdout, err := os.Stat(fdStdout.Name())
469 _, err = os.Stat(tmpPath)
471 if fiStdout.Size() > 0 {
472 runErr.Err = errors.New("created both tmp and stdout")
477 } else if !os.IsNotExist(err) {
483 // Determine what file we must process at last
486 fd, err = os.Open(tmpPath)
491 } else if fiStdout.Size() > 0 {
495 // Do we need to ifcreate it, of ifchange with renaming?
497 err = ifcreate(fdDep, tgt)
508 err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
513 err = syncDir(cwdOrig)
518 err = writeDep(fdDep, cwdOrig, tgt)
531 err = os.Rename(fdDep.Name(), path.Join(redoDir, tgt+DepSuffix))
536 err = syncDir(redoDir)