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/>.
38 "go.cypherpunks.ru/recfile"
39 "golang.org/x/sys/unix"
43 EnvDepFd = "REDO_DEP_FD"
44 EnvDirPrefix = "REDO_DIRPREFIX"
45 EnvBuildUUID = "REDO_BUILD_UUID"
46 EnvStderrPrefix = "REDO_STDERR_PREFIX"
47 EnvTrace = "REDO_TRACE"
48 EnvStderrKeep = "REDO_LOGS"
49 EnvStderrSilent = "REDO_SILENT"
50 EnvNoSync = "REDO_NO_SYNC"
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, string, error) {
117 fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
119 if os.IsNotExist(err) {
120 return false, "", nil
122 return false, "", err
125 r := recfile.NewReader(fdDep)
128 m, err := r.NextMap()
133 return false, "", err
135 if m["Target"] != tgt {
138 fd, err := os.Open(path.Join(cwd, tgt))
140 if os.IsNotExist(err) {
141 return false, "", nil
143 return false, "", err
146 ourTs, err = fileCtime(fd)
148 return false, "", err
150 if ourTs != m["Ctime"] {
151 return true, ourTs, nil
155 return false, ourTs, nil
158 func syncDir(dir string) error {
159 fd, err := os.Open(dir)
168 func runScript(tgtOrig string, errs chan error) error {
169 cwd, tgt := cwdAndTgt(tgtOrig)
170 redoDir := path.Join(cwd, RedoDir)
171 if err := mkdirs(redoDir); err != nil {
172 return TgtErr{tgtOrig, err}
176 fdLock, err := os.OpenFile(
177 path.Join(redoDir, tgt+LockSuffix),
178 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
182 return TgtErr{tgtOrig, err}
184 lockRelease := func() {
185 trace(CLock, "LOCK_UN: %s", fdLock.Name())
186 unix.Flock(int(fdLock.Fd()), unix.LOCK_UN)
189 trace(CLock, "LOCK_NB: %s", fdLock.Name())
191 // Waiting for job completion, already taken by someone else
192 if err = unix.Flock(int(fdLock.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
193 if uintptr(err.(syscall.Errno)) != uintptr(unix.EWOULDBLOCK) {
195 return TgtErr{tgtOrig, err}
197 trace(CDebug, "waiting: %s", tgtOrig)
201 trace(CLock, "LOCK_EX: %s", fdLock.Name())
202 unix.Flock(int(fdLock.Fd()), unix.LOCK_EX)
204 trace(CDebug, "waiting done: %s", tgtOrig)
206 fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
208 if os.IsNotExist(err) {
209 err = errors.New("was not built: no .dep")
214 depInfo, err = depRead(fdDep)
218 if depInfo.build != BuildUUID {
219 err = errors.New("was not built: build differs")
223 err = TgtErr{tgtOrig, err}
230 // Check if target is not modified externally
231 modified, tsPrev, err := isModified(cwd, redoDir, tgt)
234 return TgtErr{tgtOrig, err}
237 trace(CWarn, "%s externally modified: not redoing", tgtOrig)
245 // Start preparing .dep
246 fdDep, err := tempfile(redoDir, tgt+DepSuffix)
249 return TgtErr{tgtOrig, err}
254 os.Remove(fdDep.Name())
256 if _, err = recfile.NewWriter(fdDep).WriteFields(
257 recfile.Field{Name: "Build", Value: BuildUUID},
260 return TgtErr{tgtOrig, err}
264 doFile, upLevels, err := findDo(fdDep, cwd, tgt)
267 return TgtErr{tgtOrig, err}
271 return TgtErr{tgtOrig, errors.New("no .do found")}
273 if err = writeDep(fdDep, cwd, doFile); err != nil {
275 return TgtErr{tgtOrig, err}
278 // Determine basename and DIRPREFIX
279 ents := strings.Split(cwd, "/")
280 ents = ents[len(ents)-upLevels:]
281 dirPrefix := path.Join(ents...)
283 for i := 0; i < upLevels; i++ {
284 cwd = path.Join(cwd, "..")
286 cwd = path.Clean(cwd)
288 runErr := RunErr{Tgt: tgtOrig}
289 if strings.HasPrefix(doFile, "default.") {
290 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
291 runErr.DoFile = doFile
293 trace(CWait, "%s", runErr.Name())
294 doFile = path.Base(doFile)
296 // Prepare command line
299 if err = unix.Access(path.Join(cwd, doFile), unix.X_OK); err == nil {
300 // Ordinary executable file
302 args = make([]string, 0, 3)
304 fd, err := os.Open(path.Join(cwd, doFile))
307 return TgtErr{tgtOrig, err}
309 buf := make([]byte, 512)
310 n, err := fd.Read(buf)
313 return TgtErr{tgtOrig, err}
315 if n > 3 && string(buf[:3]) == "#!/" {
317 t := string(buf[2:n])
318 nlIdx := strings.Index(t, "\n")
321 return TgtErr{tgtOrig, errors.New("not fully read shebang")}
323 args = strings.Split(t[:nlIdx], " ")
324 cmdName, args = args[0], args[1:]
329 args = append(args, "-ex")
331 args = append(args, "-e")
334 args = append(args, doFile)
337 // Temporary file for stdout
338 fdStdout, err := tempfile(cwd, tgt)
341 return TgtErr{tgtOrig, err}
343 tmpPath := fdStdout.Name() + ".3" // and for $3
344 args = append(args, tgt, basename, path.Base(tmpPath))
346 cmd := exec.Command(cmdName, args...)
348 cmd.Stdout = fdStdout
349 cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
350 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
351 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
353 childStderrPrefix := tempsuffix()
354 cmd.Env = append(cmd.Env, fmt.Sprintf(
355 "%s=%s", EnvStderrPrefix, childStderrPrefix,
358 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
360 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
364 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJSFd))
366 cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
367 cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
368 cmd.Env = append(cmd.Env, fmt.Sprintf(
369 "%s=%d,%d", EnvJSFd, 3+fdNum+0, 3+fdNum+1,
375 stderr, err := cmd.StderrPipe()
379 var fdStderr *os.File
381 fdStderr, err = os.OpenFile(
382 path.Join(redoDir, tgt+LogSuffix),
383 os.O_WRONLY|os.O_CREATE,
388 return TgtErr{tgtOrig, err}
392 shCtx := fmt.Sprintf("sh: %s: %s %s [%s]", tgtOrig, cmdName, args, cwd)
393 trace(CDebug, "%s", shCtx)
406 os.Remove(fdDep.Name())
407 os.Remove(fdStdout.Name())
409 os.Remove(fdLock.Name())
412 started := time.Now()
413 runErr.Started = &started
420 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
421 trace(CDebug, "%s runs %s", tgtOrig, pid)
423 stderrTerm := make(chan struct{}, 0)
425 scanner := bufio.NewScanner(stderr)
429 line = scanner.Text()
430 if strings.HasPrefix(line, childStderrPrefix) {
431 line = line[len(childStderrPrefix):]
432 os.Stderr.WriteString(StderrPrefix + line + "\n")
437 fmt.Fprintf(fdStderr, "@%s %s\n", hex.EncodeToString(ts[:]), line)
443 trace(CNone, "%s", line)
445 trace(CNone, "%s %s", pid, line)
451 // Wait for job completion
454 finished := time.Now()
455 runErr.Finished = &finished
463 if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
464 ts, err := fileCtime(fd)
466 if err == nil && ts != tsPrev {
467 runErr.Err = errors.New("$1 was explicitly touched")
474 // Does it produce both stdout and tmp?
475 fiStdout, err := os.Stat(fdStdout.Name())
482 _, err = os.Stat(tmpPath)
484 if fiStdout.Size() > 0 {
485 runErr.Err = errors.New("created both tmp and stdout")
490 } else if !os.IsNotExist(err) {
496 // Determine what file we must process at last
499 fd, err = os.Open(tmpPath)
504 } else if fiStdout.Size() > 0 {
508 // Do we need to ifcreate it, of ifchange with renaming?
510 err = ifcreate(fdDep, tgt)
521 err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
526 err = syncDir(cwdOrig)
531 err = writeDep(fdDep, cwdOrig, tgt)
544 err = os.Rename(fdDep.Name(), path.Join(redoDir, tgt+DepSuffix))
549 err = syncDir(redoDir)
561 func isOkRun(err error) bool {
565 if err, ok := err.(RunErr); ok && err.Err == nil {
566 trace(CRedo, "%s", err.Name())
569 trace(CErr, "%s", err)