X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=run.go;h=366240557fff22680d401ae11b3d7de2ddb3ed01;hb=3c87984511180d7bf865574123195588ea8c044c;hp=ea14641a9304bd85adbee7c988cebdcc3059242c;hpb=d8abe40c66df8d79a025524c0d230959cacf9465;p=goredo.git

diff --git a/run.go b/run.go
index ea14641..3662405 100644
--- a/run.go
+++ b/run.go
@@ -1,6 +1,6 @@
 /*
 goredo -- djb's redo implementation on pure Go
-Copyright (C) 2020-2021 Sergey Matveev <stargrave@stargrave.org>
+Copyright (C) 2020-2022 Sergey Matveev <stargrave@stargrave.org>
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -51,6 +51,7 @@ const (
 	EnvStderrKeep   = "REDO_LOGS"
 	EnvStderrSilent = "REDO_SILENT"
 	EnvNoSync       = "REDO_NO_SYNC"
+	EnvStopIfMod    = "REDO_STOP_IF_MODIFIED"
 
 	RedoDir      = ".redo"
 	LockSuffix   = ".lock"
@@ -65,6 +66,7 @@ var (
 	StderrKeep   = false
 	StderrSilent = false
 	StderrPrefix string
+	StopIfMod    = false
 	Jobs         sync.WaitGroup
 
 	flagTrace        *bool
@@ -126,24 +128,26 @@ func mkdirs(pth string) error {
 	return os.MkdirAll(pth, os.FileMode(0777))
 }
 
-func isModified(cwd, redoDir, tgt string) (bool, *Inode, error) {
+func isModified(cwd, redoDir, tgt string) (bool, *Inode, string, error) {
 	fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 	if err != nil {
 		if os.IsNotExist(err) {
-			return false, nil, nil
+			return false, nil, "", nil
 		}
-		return false, nil, err
+		return false, nil, "", err
 	}
 	defer fdDep.Close()
 	r := recfile.NewReader(fdDep)
+	var modified bool
 	var ourInode *Inode
+	var hshPrev string
 	for {
 		m, err := r.NextMap()
 		if err != nil {
 			if errors.Is(err, io.EOF) {
 				break
 			}
-			return false, nil, err
+			return false, nil, "", err
 		}
 		if m["Type"] != DepTypeIfchange || m["Target"] != tgt {
 			continue
@@ -151,25 +155,24 @@ func isModified(cwd, redoDir, tgt string) (bool, *Inode, error) {
 		fd, err := os.Open(path.Join(cwd, tgt))
 		if err != nil {
 			if os.IsNotExist(err) {
-				return false, nil, nil
+				return false, nil, "", nil
 			}
-			return false, nil, err
+			return false, nil, "", err
 		}
 		ourInode, err = inodeFromFile(fd)
 		fd.Close()
 		if err != nil {
-			return false, nil, err
+			return false, nil, "", err
 		}
 		theirInode, err := inodeFromRec(m)
 		if err != nil {
-			return false, nil, err
-		}
-		if !ourInode.Equals(theirInode) {
-			return true, ourInode, nil
+			return false, nil, "", err
 		}
+		hshPrev = m["Hash"]
+		modified = !ourInode.Equals(theirInode)
 		break
 	}
-	return false, ourInode, nil
+	return modified, ourInode, hshPrev, nil
 }
 
 func syncDir(dir string) error {
@@ -198,9 +201,14 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 	if err != nil {
 		return TgtError{tgtOrig, err}
 	}
+	flock := unix.Flock_t{
+		Type:   unix.F_WRLCK,
+		Whence: io.SeekStart,
+	}
 	lockRelease := func() {
 		tracef(CLock, "LOCK_UN: %s", fdLock.Name())
-		if err := unix.Flock(int(fdLock.Fd()), unix.LOCK_UN); err != nil {
+		flock.Type = unix.F_UNLCK
+		if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 			log.Fatalln(err)
 		}
 		fdLock.Close()
@@ -208,13 +216,16 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 	tracef(CLock, "LOCK_NB: %s", fdLock.Name())
 
 	// Waiting for job completion, already taken by someone else
-	if err = unix.Flock(int(fdLock.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
-		if uintptr(err.(syscall.Errno)) != uintptr(unix.EWOULDBLOCK) {
+	if err = unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
+		if uintptr(err.(syscall.Errno)) != uintptr(unix.EAGAIN) {
 			fdLock.Close()
 			return TgtError{tgtOrig, err}
 		}
 		Jobs.Add(1)
-		tracef(CDebug, "waiting: %s", tgtOrig)
+		if err = unix.FcntlFlock(fdLock.Fd(), unix.F_GETLK, &flock); err != nil {
+			log.Fatalln(err)
+		}
+		tracef(CDebug, "waiting: %s (pid=%d)", tgtOrig, flock.Pid)
 		if FdStatus != nil {
 			if _, err = FdStatus.Write([]byte{StatusWait}); err != nil {
 				log.Fatalln(err)
@@ -223,7 +234,7 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 		go func() {
 			defer Jobs.Done()
 			tracef(CLock, "LOCK_EX: %s", fdLock.Name())
-			if err := unix.Flock(int(fdLock.Fd()), unix.LOCK_EX); err != nil {
+			if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLKW, &flock); err != nil {
 				log.Fatalln(err)
 			}
 			lockRelease()
@@ -259,14 +270,17 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 	}
 
 	// Check if target is not modified externally
-	modified, inodePrev, err := isModified(cwd, redoDir, tgt)
+	modified, inodePrev, hshPrev, err := isModified(cwd, redoDir, tgt)
 	if err != nil {
 		lockRelease()
 		return TgtError{tgtOrig, err}
 	}
 	if modified {
-		tracef(CWarn, "%s externally modified: not redoing", tgtOrig)
 		lockRelease()
+		if StopIfMod {
+			return fmt.Errorf("%s externally modified", tgtOrig)
+		}
+		tracef(CWarn, "%s externally modified: not redoing", tgtOrig)
 		go func() {
 			errs <- nil
 		}()
@@ -322,7 +336,7 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 		runErr.DoFile = doFileRelPath
 	}
 
-	if err = writeDep(fdDep, cwdOrig, doFileRelPath); err != nil {
+	if err = depWrite(fdDep, cwdOrig, doFileRelPath, ""); err != nil {
 		cleanup()
 		return TgtError{tgtOrig, err}
 	}
@@ -616,10 +630,9 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 
 		// Was $1 touched?
 		if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
-			errTouched := Err1WasTouched
 			if inodePrev == nil {
 				fd.Close()
-				runErr.Err = errTouched
+				runErr.Err = Err1WasTouched
 				errs <- runErr
 				return
 			}
@@ -631,7 +644,7 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 				return
 			}
 			if !inode.Equals(inodePrev) {
-				runErr.Err = errTouched
+				runErr.Err = Err1WasTouched
 				errs <- runErr
 				return
 			}
@@ -683,7 +696,7 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 			fd = fdStdout
 		}
 
-		// Do we need to ifcreate it, of ifchange with renaming?
+		// Do we need to ifcreate it, or ifchange with renaming?
 		if fd == nil {
 			os.Remove(path.Join(cwdOrig, tgt))
 			err = ifcreate(fdDep, tgt)
@@ -691,6 +704,39 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 				goto Finish
 			}
 		} else {
+			var hsh string
+			if hshPrev != "" {
+				_, err = fd.Seek(0, io.SeekStart)
+				if err != nil {
+					goto Finish
+				}
+				hsh, err = fileHash(fd)
+				if err != nil {
+					goto Finish
+				}
+				if hsh == hshPrev {
+					tracef(CDebug, "%s has same hash, not renaming", tgtOrig)
+					err = os.Remove(fd.Name())
+					if err != nil {
+						goto Finish
+					}
+					err = os.Chtimes(path.Join(cwdOrig, tgt), finished, finished)
+					if err != nil {
+						goto Finish
+					}
+					if !NoSync {
+						err = syncDir(cwdOrig)
+						if err != nil {
+							goto Finish
+						}
+					}
+					err = depWrite(fdDep, cwdOrig, tgt, hshPrev)
+					if err != nil {
+						goto Finish
+					}
+					goto RecCommit
+				}
+			}
 			if !NoSync {
 				err = fd.Sync()
 				if err != nil {
@@ -707,12 +753,13 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 					goto Finish
 				}
 			}
-			err = writeDep(fdDep, cwdOrig, tgt)
+			err = depWrite(fdDep, cwdOrig, tgt, hsh)
 			if err != nil {
 				goto Finish
 			}
 		}
 
+	RecCommit:
 		// Commit .rec
 		if !NoSync {
 			err = fdDep.Sync()
@@ -731,6 +778,26 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
 				goto Finish
 			}
 		}
+
+		// Post-commit .rec sanitizing
+		fdDep.Close()
+		if fdDepR, err := os.Open(fdDepPath); err == nil {
+			depInfo, err := depRead(fdDepR)
+			fdDepR.Close()
+			if err != nil {
+				goto Finish
+			}
+			ifchangeSeen := make(map[string]struct{}, len(depInfo.ifchanges))
+			for _, dep := range depInfo.ifchanges {
+				ifchangeSeen[dep["Target"]] = struct{}{}
+			}
+			for _, dep := range depInfo.ifcreates {
+				if _, exists := ifchangeSeen[dep]; exists {
+					tracef(CWarn, "simultaneous ifcreate and ifchange records: %s", tgt)
+				}
+			}
+		}
+
 	Finish:
 		runErr.Err = err
 		errs <- runErr