From: Sergey Matveev <stargrave@stargrave.org>
Date: Sat, 11 Mar 2023 19:44:33 +0000 (+0300)
Subject: fsnotify optimisation
X-Git-Url: http://www.git.stargrave.org/?p=mmc.git;a=commitdiff_plain;h=e011d6f52f2e39006d8a4398ff846f4951b8290c

fsnotify optimisation
---

diff --git a/cmd/mmc/main.go b/cmd/mmc/main.go
index 85cb759..99e9f3a 100644
--- a/cmd/mmc/main.go
+++ b/cmd/mmc/main.go
@@ -197,7 +197,6 @@ func main() {
 		go func(u *model.User) {
 			var dc *model.Channel
 			for {
-				time.Sleep(mmc.SleepTime)
 				fd, err := os.OpenFile(pth, os.O_RDONLY, os.FileMode(0666))
 				if err != nil {
 					continue
@@ -310,7 +309,6 @@ func main() {
 		}
 		go func(ch *model.Channel) {
 			for {
-				time.Sleep(mmc.SleepTime)
 				fd, err := os.OpenFile(pth, os.O_RDONLY, os.FileMode(0666))
 				if err != nil {
 					continue
diff --git a/cmd/rd/main.go b/cmd/rd/main.go
index 4bb8b24..0d7e70b 100644
--- a/cmd/rd/main.go
+++ b/cmd/rd/main.go
@@ -23,8 +23,8 @@ import (
 	"log"
 	"os"
 	"path"
-	"time"
 
+	"github.com/fsnotify/fsnotify"
 	"github.com/mattermost/mattermost-server/v6/model"
 	"go.cypherpunks.ru/recfile"
 	"go.stargrave.org/mmc"
@@ -84,16 +84,22 @@ func main() {
 	for _, m := range ms {
 		printPost(m)
 	}
-	fi, err := fd.Stat()
+
+	watcher, err := fsnotify.NewWatcher()
 	if err != nil {
 		log.Fatalln(err)
 	}
-	size := fi.Size()
+	if err = watcher.Add(pth); err != nil {
+		log.Fatalln(err)
+	}
 	for {
-		time.Sleep(mmc.SleepTime)
-		fi, err = os.Stat(pth)
-		if fi.Size() == size {
-			continue
+		select {
+		case err = <-watcher.Errors:
+			log.Fatalln(err)
+		case event := <-watcher.Events:
+			if !event.Has(fsnotify.Write) {
+				continue
+			}
 		}
 		unlock, err = mmc.Lock(lockPth)
 		if err != nil {
@@ -110,7 +116,6 @@ func main() {
 			}
 			printPost(m)
 		}
-		size = fi.Size()
 		unlock()
 	}
 }
diff --git a/go.mod b/go.mod
index 0814771..59f35f0 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.20
 
 require (
 	github.com/davecgh/go-spew v1.1.1
+	github.com/fsnotify/fsnotify v1.6.0
 	github.com/mattermost/mattermost-server/v6 v6.7.2
 	go.cypherpunks.ru/recfile v0.5.1
 	golang.org/x/sys v0.6.0
diff --git a/go.sum b/go.sum
index 2fd506e..092d7ff 100644
--- a/go.sum
+++ b/go.sum
@@ -435,6 +435,8 @@ github.com/frankban/quicktest v1.11.3/go.mod h1:wRf/ReqHper53s+kmmSZizM8NamnL3IM
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
 github.com/fsnotify/fsnotify v1.5.1/go.mod h1:T3375wBYaZdLLcVNkcVbzGHY7f1l/uK5T5Ai1i3InKU=
+github.com/fsnotify/fsnotify v1.6.0 h1:n+5WquG0fcWoWp6xPWfHdbskMCQaFnG6PfBrh1Ky4HY=
+github.com/fsnotify/fsnotify v1.6.0/go.mod h1:sl3t1tCWJFWoRz9R8WJCbQihKKwmorjAbSClcnxKAGw=
 github.com/fsouza/fake-gcs-server v1.17.0/go.mod h1:D1rTE4YCyHFNa99oyJJ5HyclvN/0uQR+pM/VdlL83bw=
 github.com/fullsailor/pkcs7 v0.0.0-20190404230743-d7302db945fa/go.mod h1:KnogPXtdwXqoenmZCw6S+25EAm2MkxbG0deNDu4cbSA=
 github.com/gabriel-vasile/mimetype v1.3.1/go.mod h1:fA8fi6KUiG7MgQQ+mEWotXoEOvmxRtOJlERCzSmRvr8=
@@ -1697,6 +1699,7 @@ golang.org/x/sys v0.0.0-20211019181941-9d821ace8654/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220114195835-da31bd327af9/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220403205710-6acee93ad0eb/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220908164124-27713097b956/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0 h1:MVltZSvRTcU2ljQOhs94SXPftV6DCNnZViHeQps87pQ=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
diff --git a/lock.go b/lock.go
index e1a4b40..271b39c 100644
--- a/lock.go
+++ b/lock.go
@@ -37,7 +37,7 @@ func Lock(what string) (func(), error) {
 		Type:   unix.F_WRLCK,
 		Whence: io.SeekStart,
 	}
-	if err = unix.FcntlFlock(fd.Fd(), unix.F_SETLK, &flock); err != nil {
+	if err = unix.FcntlFlock(fd.Fd(), unix.F_SETLKW, &flock); err != nil {
 		fd.Close()
 		return dummy, err
 	}