run.go

   1 /*
   2 goredo -- djb's 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  = ".rec"
  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, *Inode, error) {
 105         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 106         if err != nil {
 107                 if os.IsNotExist(err) {
 108                         return false, nil, nil
 109                 }
 110                 return false, nil, err
 111         }
 112         defer fdDep.Close()
 113         r := recfile.NewReader(fdDep)
 114         var ourInode *Inode
 115         for {
 116                 m, err := r.NextMap()
 117                 if err != nil {
 118                         if err == io.EOF {
 119                                 break
 120                         }
 121                         return false, nil, 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, nil
 130                         }
 131                         return false, nil, err
 132                 }
 133                 ourInode, err = inodeFromFile(fd)
 134                 fd.Close()
 135                 if err != nil {
 136                         return false, nil, err
 137                 }
 138                 theirInode, err := inodeFromRec(m)
 139                 if err != nil {
 140                         return false, nil, err
 141                 }
 142                 if !ourInode.Equals(theirInode) {
 143                         return true, ourInode, nil
 144                 }
 145                 break
 146         }
 147         return false, ourInode, nil
 148 }
 149
 150 func syncDir(dir string) error {
 151         fd, err := os.Open(dir)
 152         if err != nil {
 153                 return err
 154         }
 155         err = fd.Sync()
 156         fd.Close()
 157         return err
 158 }
 159
 160 func runScript(tgtOrig string, errs chan error, traced bool) error {
 161         cwd, tgt := cwdAndTgt(tgtOrig)
 162         redoDir := path.Join(cwd, RedoDir)
 163         if err := mkdirs(redoDir); err != nil {
 164                 return TgtErr{tgtOrig, err}
 165         }
 166
 167         // Acquire lock
 168         fdLock, err := os.OpenFile(
 169                 path.Join(redoDir, tgt+LockSuffix),
 170                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 171                 os.FileMode(0666),
 172         )
 173         if err != nil {
 174                 return TgtErr{tgtOrig, err}
 175         }
 176         lockRelease := func() {
 177                 trace(CLock, "LOCK_UN: %s", fdLock.Name())
 178                 unix.Flock(int(fdLock.Fd()), unix.LOCK_UN)
 179                 fdLock.Close()
 180         }
 181         trace(CLock, "LOCK_NB: %s", fdLock.Name())
 182
 183         // Waiting for job completion, already taken by someone else
 184         if err = unix.Flock(int(fdLock.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
 185                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EWOULDBLOCK) {
 186                         fdLock.Close()
 187                         return TgtErr{tgtOrig, err}
 188                 }
 189                 Jobs.Add(1)
 190                 trace(CDebug, "waiting: %s", tgtOrig)
 191                 if FdStatus != nil {
 192                         FdStatus.Write([]byte{StatusWait})
 193                 }
 194                 go func() {
 195                         defer Jobs.Done()
 196                         trace(CLock, "LOCK_EX: %s", fdLock.Name())
 197                         unix.Flock(int(fdLock.Fd()), unix.LOCK_EX)
 198                         lockRelease()
 199                         trace(CDebug, "waiting done: %s", tgtOrig)
 200                         if FdStatus != nil {
 201                                 FdStatus.Write([]byte{StatusWaited})
 202                         }
 203                         var depInfo *DepInfo
 204                         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 205                         if err != nil {
 206                                 if os.IsNotExist(err) {
 207                                         err = errors.New("was not built: no .rec")
 208                                 }
 209                                 goto Finish
 210                         }
 211                         defer fdDep.Close()
 212                         depInfo, err = depRead(fdDep)
 213                         if err != nil {
 214                                 goto Finish
 215                         }
 216                         if depInfo.build != BuildUUID {
 217                                 err = errors.New("was not built: build differs")
 218                         }
 219                 Finish:
 220                         if err != nil {
 221                                 err = TgtErr{tgtOrig, err}
 222                         }
 223                         errs <- err
 224                 }()
 225                 return nil
 226         }
 227
 228         // Check if target is not modified externally
 229         modified, inodePrev, err := isModified(cwd, redoDir, tgt)
 230         if err != nil {
 231                 lockRelease()
 232                 return TgtErr{tgtOrig, err}
 233         }
 234         if modified {
 235                 trace(CWarn, "%s externally modified: not redoing", tgtOrig)
 236                 lockRelease()
 237                 go func() {
 238                         errs <- nil
 239                 }()
 240                 return nil
 241         }
 242
 243         // Start preparing .rec
 244         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 245         if err != nil {
 246                 lockRelease()
 247                 return TgtErr{tgtOrig, err}
 248         }
 249         fdDepPath := fdDep.Name()
 250         cleanup := func() {
 251                 lockRelease()
 252                 fdDep.Close()
 253                 os.Remove(fdDep.Name())
 254         }
 255         if _, err = recfile.NewWriter(fdDep).WriteFields(
 256                 recfile.Field{Name: "Build", Value: BuildUUID},
 257         ); err != nil {
 258                 cleanup()
 259                 return TgtErr{tgtOrig, err}
 260         }
 261
 262         // Find .do
 263         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 264         if err != nil {
 265                 cleanup()
 266                 return TgtErr{tgtOrig, err}
 267         }
 268         if doFile == "" {
 269                 cleanup()
 270                 return TgtErr{tgtOrig, errors.New("no .do found")}
 271         }
 272
 273         // Determine basename and DIRPREFIX
 274         doFileRelPath := doFile
 275         ents := strings.Split(cwd, "/")
 276         ents = ents[len(ents)-upLevels:]
 277         dirPrefix := path.Join(ents...)
 278         cwdOrig := cwd
 279         for i := 0; i < upLevels; i++ {
 280                 cwd = path.Join(cwd, "..")
 281                 doFileRelPath = path.Join("..", doFileRelPath)
 282         }
 283         cwd = path.Clean(cwd)
 284         doFilePath := path.Join(cwd, doFile)
 285         basename := tgt
 286         runErr := RunErr{Tgt: tgtOrig}
 287         if strings.HasPrefix(doFile, "default.") {
 288                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 289                 runErr.DoFile = doFileRelPath
 290         }
 291
 292         if err = writeDep(fdDep, cwdOrig, doFileRelPath); err != nil {
 293                 cleanup()
 294                 return TgtErr{tgtOrig, err}
 295         }
 296         fdDep.Close()
 297         trace(CWait, "%s", runErr.Name())
 298
 299         // Prepare command line
 300         var cmdName string
 301         var args []string
 302         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 303                 cmdName = doFilePath
 304                 args = make([]string, 0, 3)
 305         } else {
 306                 cmdName = "/bin/sh"
 307                 if traced {
 308                         args = append(args, "-ex")
 309                 } else {
 310                         args = append(args, "-e")
 311                 }
 312                 args = append(args, doFile)
 313         }
 314
 315         // Temporary file for stdout
 316         fdStdout, err := tempfile(cwdOrig, tgt)
 317         if err != nil {
 318                 cleanup()
 319                 return TgtErr{tgtOrig, err}
 320         }
 321         stdoutPath := fdStdout.Name()
 322         fdStdout.Close()
 323         tmpPath := stdoutPath + ".3" // and for $3
 324         tmpPathRel, err := filepath.Rel(cwd, tmpPath)
 325         if err != nil {
 326                 panic(err)
 327         }
 328         args = append(
 329                 args,
 330                 path.Join(dirPrefix, tgt),
 331                 path.Join(dirPrefix, basename),
 332                 tmpPathRel,
 333         )
 334
 335         cmd := exec.Command(cmdName, args...)
 336         cmd.Dir = cwd
 337         // cmd.Stdin reads from /dev/null by default
 338         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 339         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 340         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 341
 342         childStderrPrefix := tempsuffix()
 343         cmd.Env = append(cmd.Env, fmt.Sprintf(
 344                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 345         ))
 346
 347         fdNum := 0
 348         if FdStatus == nil {
 349                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 350         } else {
 351                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 352                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 353                 fdNum++
 354         }
 355
 356         if JSR == nil {
 357                 // infinite jobs
 358                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJSFd))
 359         } else {
 360                 cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 361                 cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 362                 cmd.Env = append(cmd.Env, fmt.Sprintf(
 363                         "%s=%d,%d", EnvJSFd, 3+fdNum+0, 3+fdNum+1,
 364                 ))
 365                 fdNum += 2
 366         }
 367
 368         // Preparing stderr
 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
 395                 started := time.Now()
 396                 runErr.Started = &started
 397                 fdStdout, err = os.OpenFile(stdoutPath, os.O_RDWR, os.FileMode(0666))
 398                 if err != nil {
 399                         runErr.Err = err
 400                         errs <- runErr
 401                         return
 402                 }
 403                 cmd.Stdout = fdStdout
 404                 fdDep, err = os.OpenFile(fdDepPath, os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 405                 if err != nil {
 406                         runErr.Err = err
 407                         errs <- runErr
 408                         return
 409                 }
 410                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 411                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 412                 fdNum++
 413
 414                 defer func() {
 415                         jsRelease(shCtx)
 416                         lockRelease()
 417                         fdDep.Close()
 418                         fdStdout.Close()
 419                         if fdStderr != nil {
 420                                 fdStderr.Close()
 421                         }
 422                         os.Remove(fdDep.Name())
 423                         os.Remove(fdStdout.Name())
 424                         os.Remove(tmpPath)
 425                         os.Remove(fdLock.Name())
 426                         if FdStatus != nil {
 427                                 FdStatus.Write([]byte{StatusDone})
 428                         }
 429                         Jobs.Done()
 430                 }()
 431                 stderr, err := cmd.StderrPipe()
 432                 if err != nil {
 433                         runErr.Err = err
 434                         errs <- runErr
 435                         return
 436                 }
 437                 started = time.Now()
 438                 err = cmd.Start()
 439                 if err != nil {
 440                         runErr.Err = err
 441                         errs <- runErr
 442                         return
 443                 }
 444                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 445                 trace(CDebug, "%s runs %s", tgtOrig, pid)
 446
 447                 stderrTerm := make(chan struct{}, 0)
 448                 go func() {
 449                         scanner := bufio.NewScanner(stderr)
 450                         var line string
 451                         ts := new(tai64n.TAI64N)
 452                         for scanner.Scan() {
 453                                 line = scanner.Text()
 454                                 if strings.HasPrefix(line, childStderrPrefix) {
 455                                         line = line[len(childStderrPrefix):]
 456                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 457                                         continue
 458                                 }
 459                                 if fdStderr != nil {
 460                                         tai64n.FromTime(time.Now(), ts)
 461                                         LogMutex.Lock()
 462                                         fmt.Fprintf(fdStderr, "%s %s\n", ts.Encode(), line)
 463                                         LogMutex.Unlock()
 464                                 }
 465                                 if StderrSilent {
 466                                         continue
 467                                 }
 468                                 if MyPid == 0 {
 469                                         trace(CNone, "%s", line)
 470                                 } else {
 471                                         trace(CNone, "%s %s", pid, line)
 472                                 }
 473                         }
 474                         close(stderrTerm)
 475                 }()
 476
 477                 // Wait for job completion
 478                 <-stderrTerm
 479                 err = cmd.Wait()
 480                 finished := time.Now()
 481                 runErr.Finished = &finished
 482                 if err != nil {
 483                         runErr.Err = err
 484                         errs <- runErr
 485                         return
 486                 }
 487
 488                 // Was $1 touched?
 489                 if inodePrev != nil {
 490                         if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 491                                 inode, err := inodeFromFile(fd)
 492                                 fd.Close()
 493                                 if err == nil && !inode.Equals(inodePrev) {
 494                                         runErr.Err = errors.New("$1 was explicitly touched")
 495                                         errs <- runErr
 496                                         return
 497                                 }
 498                         }
 499                 }
 500
 501                 // Does it produce both stdout and tmp?
 502                 fiStdout, err := os.Stat(fdStdout.Name())
 503                 if err != nil {
 504                         runErr.Err = err
 505                         errs <- runErr
 506                         return
 507                 }
 508                 tmpExists := false
 509                 _, err = os.Stat(tmpPath)
 510                 if err == nil {
 511                         if fiStdout.Size() > 0 {
 512                                 runErr.Err = errors.New("created both tmp and stdout")
 513                                 errs <- runErr
 514                                 return
 515                         }
 516                         tmpExists = true
 517                 } else if !os.IsNotExist(err) {
 518                         runErr.Err = err
 519                         errs <- runErr
 520                         return
 521                 }
 522
 523                 // Determine what file we must process at last
 524                 var fd *os.File
 525                 if tmpExists {
 526                         fd, err = os.Open(tmpPath)
 527                         if err != nil {
 528                                 goto Finish
 529                         }
 530                         defer fd.Close()
 531                 } else if fiStdout.Size() > 0 {
 532                         fd = fdStdout
 533                 }
 534
 535                 // Do we need to ifcreate it, of ifchange with renaming?
 536                 if fd == nil {
 537                         os.Remove(path.Join(cwdOrig, tgt))
 538                         err = ifcreate(fdDep, tgt)
 539                         if err != nil {
 540                                 goto Finish
 541                         }
 542                 } else {
 543                         if !NoSync {
 544                                 err = fd.Sync()
 545                                 if err != nil {
 546                                         goto Finish
 547                                 }
 548                         }
 549                         err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
 550                         if err != nil {
 551                                 goto Finish
 552                         }
 553                         if !NoSync {
 554                                 err = syncDir(cwdOrig)
 555                                 if err != nil {
 556                                         goto Finish
 557                                 }
 558                         }
 559                         err = writeDep(fdDep, cwdOrig, tgt)
 560                         if err != nil {
 561                                 goto Finish
 562                         }
 563                 }
 564
 565                 // Commit .rec
 566                 if !NoSync {
 567                         err = fdDep.Sync()
 568                         if err != nil {
 569                                 goto Finish
 570                         }
 571                 }
 572                 err = os.Rename(fdDep.Name(), path.Join(redoDir, tgt+DepSuffix))
 573                 if err != nil {
 574                         goto Finish
 575                 }
 576                 if !NoSync {
 577                         err = syncDir(redoDir)
 578                         if err != nil {
 579                                 goto Finish
 580                         }
 581                 }
 582         Finish:
 583                 runErr.Err = err
 584                 errs <- runErr
 585         }()
 586         return nil
 587 }
 588
 589 func isOkRun(err error) bool {
 590         if err == nil {
 591                 return true
 592         }
 593         if err, ok := err.(RunErr); ok && err.Err == nil {
 594                 trace(CRedo, "%s", err.Name())
 595                 return true
 596         }
 597         trace(CErr, "%s", err)
 598         return false
 599 }