run.go

   1 /*
   2 goredo -- redo implementation on pure Go
   3 Copyright (C) 2020-2021 Sergey Matveev <stargrave@stargrave.org>
   4
   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.
   8
   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.
  13
  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/>.
  16 */
  17
  18 // Targets runner
  19
  20 package main
  21
  22 import (
  23         "bufio"
  24         "errors"
  25         "flag"
  26         "fmt"
  27         "io"
  28         "os"
  29         "os/exec"
  30         "path"
  31         "path/filepath"
  32         "strings"
  33         "sync"
  34         "syscall"
  35         "time"
  36
  37         "go.cypherpunks.ru/recfile"
  38         "go.cypherpunks.ru/tai64n"
  39         "golang.org/x/sys/unix"
  40 )
  41
  42 const (
  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"
  51
  52         RedoDir    = ".redo"
  53         LockSuffix = ".lock"
  54         DepSuffix  = ".dep"
  55         TmpPrefix  = ".redo."
  56         LogSuffix  = ".log"
  57 )
  58
  59 var (
  60         NoSync       bool = false
  61         StderrKeep   bool = false
  62         StderrSilent bool = false
  63         StderrPrefix string
  64         Jobs         sync.WaitGroup
  65
  66         flagTrace        = flag.Bool("x", false, "trace (sh -x) current targets")
  67         flagTraceAll     = flag.Bool("xx", false, fmt.Sprintf("trace (sh -x) all targets (%s=1)", EnvTrace))
  68         flagStderrKeep   = flag.Bool("logs", false, fmt.Sprintf("keep job's stderr (%s=1)", EnvStderrKeep))
  69         flagStderrSilent = flag.Bool("silent", false, fmt.Sprintf("do not print job's stderr (%s=1)", EnvStderrSilent))
  70 )
  71
  72 type RunErr struct {
  73         Tgt      string
  74         DoFile   string
  75         Started  *time.Time
  76         Finished *time.Time
  77         Err      error
  78 }
  79
  80 func (e *RunErr) Name() string {
  81         var name string
  82         if e.DoFile == "" {
  83                 name = e.Tgt
  84         } else {
  85                 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
  86         }
  87         if e.Finished == nil {
  88                 return name
  89         }
  90         return fmt.Sprintf("%s (%fsec)", name, e.Finished.Sub(*e.Started).Seconds())
  91 }
  92
  93 func (e RunErr) Error() string {
  94         return fmt.Sprintf("%s: %s", e.Name(), e.Err)
  95 }
  96
  97 func mkdirs(pth string) error {
  98         if _, err := os.Stat(pth); err == nil {
  99                 return nil
 100         }
 101         return os.MkdirAll(pth, os.FileMode(0777))
 102 }
 103
 104 func isModified(cwd, redoDir, tgt string) (bool, string, error) {
 105         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 106         if err != nil {
 107                 if os.IsNotExist(err) {
 108                         return false, "", nil
 109                 }
 110                 return false, "", err
 111         }
 112         defer fdDep.Close()
 113         r := recfile.NewReader(fdDep)
 114         var ourTs string
 115         for {
 116                 m, err := r.NextMap()
 117                 if err != nil {
 118                         if err == io.EOF {
 119                                 break
 120                         }
 121                         return false, "", err
 122                 }
 123                 if m["Target"] != tgt {
 124                         continue
 125                 }
 126                 fd, err := os.Open(path.Join(cwd, tgt))
 127                 if err != nil {
 128                         if os.IsNotExist(err) {
 129                                 return false, "", nil
 130                         }
 131                         return false, "", err
 132                 }
 133                 defer fd.Close()
 134                 ourTs, err = fileCtime(fd)
 135                 if err != nil {
 136                         return false, "", err
 137                 }
 138                 if ourTs != m["Ctime"] {
 139                         return true, ourTs, nil
 140                 }
 141                 break
 142         }
 143         return false, ourTs, nil
 144 }
 145
 146 func syncDir(dir string) error {
 147         fd, err := os.Open(dir)
 148         if err != nil {
 149                 return err
 150         }
 151         err = fd.Sync()
 152         fd.Close()
 153         return err
 154 }
 155
 156 func runScript(tgtOrig string, errs chan error, traced bool) error {
 157         cwd, tgt := cwdAndTgt(tgtOrig)
 158         redoDir := path.Join(cwd, RedoDir)
 159         if err := mkdirs(redoDir); err != nil {
 160                 return TgtErr{tgtOrig, err}
 161         }
 162
 163         // Acquire lock
 164         fdLock, err := os.OpenFile(
 165                 path.Join(redoDir, tgt+LockSuffix),
 166                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 167                 os.FileMode(0666),
 168         )
 169         if err != nil {
 170                 return TgtErr{tgtOrig, err}
 171         }
 172         lockRelease := func() {
 173                 trace(CLock, "LOCK_UN: %s", fdLock.Name())
 174                 unix.Flock(int(fdLock.Fd()), unix.LOCK_UN)
 175                 fdLock.Close()
 176         }
 177         trace(CLock, "LOCK_NB: %s", fdLock.Name())
 178
 179         // Waiting for job completion, already taken by someone else
 180         if err = unix.Flock(int(fdLock.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
 181                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EWOULDBLOCK) {
 182                         fdLock.Close()
 183                         return TgtErr{tgtOrig, err}
 184                 }
 185                 Jobs.Add(1)
 186                 trace(CDebug, "waiting: %s", tgtOrig)
 187                 if FdStatus != nil {
 188                         FdStatus.Write([]byte{StatusWait})
 189                 }
 190                 go func() {
 191                         defer Jobs.Done()
 192                         trace(CLock, "LOCK_EX: %s", fdLock.Name())
 193                         unix.Flock(int(fdLock.Fd()), unix.LOCK_EX)
 194                         lockRelease()
 195                         trace(CDebug, "waiting done: %s", tgtOrig)
 196                         if FdStatus != nil {
 197                                 FdStatus.Write([]byte{StatusWaited})
 198                         }
 199                         var depInfo *DepInfo
 200                         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 201                         if err != nil {
 202                                 if os.IsNotExist(err) {
 203                                         err = errors.New("was not built: no .dep")
 204                                 }
 205                                 goto Finish
 206                         }
 207                         defer fdDep.Close()
 208                         depInfo, err = depRead(fdDep)
 209                         if err != nil {
 210                                 goto Finish
 211                         }
 212                         if depInfo.build != BuildUUID {
 213                                 err = errors.New("was not built: build differs")
 214                         }
 215                 Finish:
 216                         if err != nil {
 217                                 err = TgtErr{tgtOrig, err}
 218                         }
 219                         errs <- err
 220                 }()
 221                 return nil
 222         }
 223
 224         // Check if target is not modified externally
 225         modified, tsPrev, err := isModified(cwd, redoDir, tgt)
 226         if err != nil {
 227                 lockRelease()
 228                 return TgtErr{tgtOrig, err}
 229         }
 230         if modified {
 231                 trace(CWarn, "%s externally modified: not redoing", tgtOrig)
 232                 lockRelease()
 233                 go func() {
 234                         errs <- nil
 235                 }()
 236                 return nil
 237         }
 238
 239         // Start preparing .dep
 240         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 241         if err != nil {
 242                 lockRelease()
 243                 return TgtErr{tgtOrig, err}
 244         }
 245         cleanup := func() {
 246                 lockRelease()
 247                 fdDep.Close()
 248                 os.Remove(fdDep.Name())
 249         }
 250         if _, err = recfile.NewWriter(fdDep).WriteFields(
 251                 recfile.Field{Name: "Build", Value: BuildUUID},
 252         ); err != nil {
 253                 cleanup()
 254                 return TgtErr{tgtOrig, err}
 255         }
 256
 257         // Find .do
 258         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 259         if err != nil {
 260                 cleanup()
 261                 return TgtErr{tgtOrig, err}
 262         }
 263         if doFile == "" {
 264                 cleanup()
 265                 return TgtErr{tgtOrig, errors.New("no .do found")}
 266         }
 267
 268         // Determine basename and DIRPREFIX
 269         doFileRelPath := doFile
 270         ents := strings.Split(cwd, "/")
 271         ents = ents[len(ents)-upLevels:]
 272         dirPrefix := path.Join(ents...)
 273         cwdOrig := cwd
 274         for i := 0; i < upLevels; i++ {
 275                 cwd = path.Join(cwd, "..")
 276                 doFileRelPath = path.Join("..", doFileRelPath)
 277         }
 278         cwd = path.Clean(cwd)
 279         doFilePath := path.Join(cwd, doFile)
 280         basename := tgt
 281         runErr := RunErr{Tgt: tgtOrig}
 282         if strings.HasPrefix(doFile, "default.") {
 283                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 284                 runErr.DoFile = doFileRelPath
 285         }
 286
 287         if err = writeDep(fdDep, cwdOrig, doFileRelPath); err != nil {
 288                 cleanup()
 289                 return TgtErr{tgtOrig, err}
 290         }
 291         trace(CWait, "%s", runErr.Name())
 292
 293         // Prepare command line
 294         var cmdName string
 295         var args []string
 296         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 297                 cmdName = doFilePath
 298                 args = make([]string, 0, 3)
 299         } else {
 300                 cmdName = "/bin/sh"
 301                 if traced {
 302                         args = append(args, "-ex")
 303                 } else {
 304                         args = append(args, "-e")
 305                 }
 306                 args = append(args, doFile)
 307         }
 308
 309         // Temporary file for stdout
 310         fdStdout, err := tempfile(cwdOrig, tgt)
 311         if err != nil {
 312                 cleanup()
 313                 return TgtErr{tgtOrig, err}
 314         }
 315         tmpPath := fdStdout.Name() + ".3" // and for $3
 316         tmpPathRel, err := filepath.Rel(cwd, tmpPath)
 317         if err != nil {
 318                 panic(err)
 319         }
 320         args = append(
 321                 args,
 322                 path.Join(dirPrefix, tgt),
 323                 path.Join(dirPrefix, basename),
 324                 tmpPathRel,
 325         )
 326
 327         cmd := exec.Command(cmdName, args...)
 328         cmd.Dir = cwd
 329         cmd.Stdout = fdStdout
 330         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 331         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 332         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 333
 334         childStderrPrefix := tempsuffix()
 335         cmd.Env = append(cmd.Env, fmt.Sprintf(
 336                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 337         ))
 338
 339         fdNum := 0
 340         cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 341         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 342         fdNum++
 343
 344         if FdStatus == nil {
 345                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 346         } else {
 347                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 348                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 349                 fdNum++
 350         }
 351
 352         if JSR == nil {
 353                 // infinite jobs
 354                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJSFd))
 355         } else {
 356                 cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 357                 cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 358                 cmd.Env = append(cmd.Env, fmt.Sprintf(
 359                         "%s=%d,%d", EnvJSFd, 3+fdNum+0, 3+fdNum+1,
 360                 ))
 361                 fdNum += 2
 362         }
 363
 364         // Preparing stderr
 365         stderr, err := cmd.StderrPipe()
 366         if err != nil {
 367                 panic(err)
 368         }
 369         var fdStderr *os.File
 370         if StderrKeep {
 371                 fdStderr, err = os.OpenFile(
 372                         path.Join(redoDir, tgt+LogSuffix),
 373                         os.O_WRONLY|os.O_CREATE,
 374                         os.FileMode(0666),
 375                 )
 376                 if err != nil {
 377                         cleanup()
 378                         return TgtErr{tgtOrig, err}
 379                 }
 380                 fdStderr.Truncate(0)
 381         }
 382         shCtx := fmt.Sprintf(
 383                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 384                 tgtOrig, cmdName, args, cwd, dirPrefix,
 385         )
 386         trace(CDebug, "%s", shCtx)
 387
 388         Jobs.Add(1)
 389         go func() {
 390                 jsAcquire(shCtx)
 391                 if FdStatus != nil {
 392                         FdStatus.Write([]byte{StatusRun})
 393                 }
 394                 defer func() {
 395                         jsRelease(shCtx)
 396                         lockRelease()
 397                         fdDep.Close()
 398                         fdStdout.Close()
 399                         if fdStderr != nil {
 400                                 fdStderr.Close()
 401                         }
 402                         os.Remove(fdDep.Name())
 403                         os.Remove(fdStdout.Name())
 404                         os.Remove(tmpPath)
 405                         os.Remove(fdLock.Name())
 406                         if FdStatus != nil {
 407                                 FdStatus.Write([]byte{StatusDone})
 408                         }
 409                         Jobs.Done()
 410                 }()
 411                 started := time.Now()
 412                 runErr.Started = &started
 413                 err := cmd.Start()
 414                 if err != nil {
 415                         runErr.Err = err
 416                         errs <- runErr
 417                         return
 418                 }
 419                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 420                 trace(CDebug, "%s runs %s", tgtOrig, pid)
 421
 422                 stderrTerm := make(chan struct{}, 0)
 423                 go func() {
 424                         scanner := bufio.NewScanner(stderr)
 425                         var line string
 426                         ts := new(tai64n.TAI64N)
 427                         for scanner.Scan() {
 428                                 line = scanner.Text()
 429                                 if strings.HasPrefix(line, childStderrPrefix) {
 430                                         line = line[len(childStderrPrefix):]
 431                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 432                                         continue
 433                                 }
 434                                 if fdStderr != nil {
 435                                         tai64n.FromTime(time.Now(), ts)
 436                                         LogMutex.Lock()
 437                                         fmt.Fprintf(fdStderr, "%s %s\n", ts.Encode(), line)
 438                                         LogMutex.Unlock()
 439                                 }
 440                                 if StderrSilent {
 441                                         continue
 442                                 }
 443                                 if MyPid == 0 {
 444                                         trace(CNone, "%s", line)
 445                                 } else {
 446                                         trace(CNone, "%s %s", pid, line)
 447                                 }
 448                         }
 449                         close(stderrTerm)
 450                 }()
 451
 452                 // Wait for job completion
 453                 <-stderrTerm
 454                 err = cmd.Wait()
 455                 finished := time.Now()
 456                 runErr.Finished = &finished
 457                 if err != nil {
 458                         runErr.Err = err
 459                         errs <- runErr
 460                         return
 461                 }
 462
 463                 // Was $1 touched?
 464                 if tsPrev != "" {
 465                         if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 466                                 ts, err := fileCtime(fd)
 467                                 fd.Close()
 468                                 if err == nil && ts != tsPrev {
 469                                         runErr.Err = errors.New("$1 was explicitly touched")
 470                                         errs <- runErr
 471                                         fd.Close()
 472                                         return
 473                                 }
 474                         }
 475                 }
 476
 477                 // Does it produce both stdout and tmp?
 478                 fiStdout, err := os.Stat(fdStdout.Name())
 479                 if err != nil {
 480                         runErr.Err = err
 481                         errs <- runErr
 482                         return
 483                 }
 484                 tmpExists := false
 485                 _, err = os.Stat(tmpPath)
 486                 if err == nil {
 487                         if fiStdout.Size() > 0 {
 488                                 runErr.Err = errors.New("created both tmp and stdout")
 489                                 errs <- runErr
 490                                 return
 491                         }
 492                         tmpExists = true
 493                 } else if !os.IsNotExist(err) {
 494                         runErr.Err = err
 495                         errs <- runErr
 496                         return
 497                 }
 498
 499                 // Determine what file we must process at last
 500                 var fd *os.File
 501                 if tmpExists {
 502                         fd, err = os.Open(tmpPath)
 503                         if err != nil {
 504                                 goto Finish
 505                         }
 506                         defer fd.Close()
 507                 } else if fiStdout.Size() > 0 {
 508                         fd = fdStdout
 509                 }
 510
 511                 // Do we need to ifcreate it, of ifchange with renaming?
 512                 if fd == nil {
 513                         os.Remove(path.Join(cwdOrig, tgt))
 514                         err = ifcreate(fdDep, tgt)
 515                         if err != nil {
 516                                 goto Finish
 517                         }
 518                 } else {
 519                         if !NoSync {
 520                                 err = fd.Sync()
 521                                 if err != nil {
 522                                         goto Finish
 523                                 }
 524                         }
 525                         err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
 526                         if err != nil {
 527                                 goto Finish
 528                         }
 529                         if !NoSync {
 530                                 err = syncDir(cwdOrig)
 531                                 if err != nil {
 532                                         goto Finish
 533                                 }
 534                         }
 535                         err = writeDep(fdDep, cwdOrig, tgt)
 536                         if err != nil {
 537                                 goto Finish
 538                         }
 539                 }
 540
 541                 // Commit .dep
 542                 if !NoSync {
 543                         err = fdDep.Sync()
 544                         if err != nil {
 545                                 goto Finish
 546                         }
 547                 }
 548                 err = os.Rename(fdDep.Name(), path.Join(redoDir, tgt+DepSuffix))
 549                 if err != nil {
 550                         goto Finish
 551                 }
 552                 if !NoSync {
 553                         err = syncDir(redoDir)
 554                         if err != nil {
 555                                 goto Finish
 556                         }
 557                 }
 558         Finish:
 559                 runErr.Err = err
 560                 errs <- runErr
 561         }()
 562         return nil
 563 }
 564
 565 func isOkRun(err error) bool {
 566         if err == nil {
 567                 return true
 568         }
 569         if err, ok := err.(RunErr); ok && err.Err == nil {
 570                 trace(CRedo, "%s", err.Name())
 571                 return true
 572         }
 573         trace(CErr, "%s", err)
 574         return false
 575 }