From 2d200e5f0d61af283127c82986f541bc149587a8 Mon Sep 17 00:00:00 2001
From: velvettear <daniel.sommer@velvettear.de>
Date: Tue, 28 May 2024 16:16:08 +0200
Subject: [PATCH] implement multithreading and handle timeouts

---
 .gitignore                |  2 +-
 .vscode/launch.json       |  4 ++-
 internal/config/config.go |  9 ++++++
 main.go                   | 61 ++++++++++++++++++++++++++++++++-------
 4 files changed, 64 insertions(+), 12 deletions(-)

diff --git a/.gitignore b/.gitignore
index 04ace28..d970015 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1 @@
-tagcleaner
\ No newline at end of file
+id3tool
\ No newline at end of file
diff --git a/.vscode/launch.json b/.vscode/launch.json
index 65fe4ee..2887162 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -9,7 +9,9 @@
       "program": "${workspaceFolder}/main.go",
       "args": [
         "--debug",
-        "/home/velvettear/downloads/test"
+        "--timeout",
+        "5",
+        "/tmp/share/music"
       ]
     }
   ]
diff --git a/internal/config/config.go b/internal/config/config.go
index 046f683..abfbccd 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -2,6 +2,7 @@ package config
 
 import (
 	"os"
+	"strconv"
 	"strings"
 
 	"git.velvettear.de/velvettear/loggo"
@@ -9,6 +10,7 @@ import (
 
 var Directory string
 var FramesToKeep []string
+var Timeout int
 
 // check program arguments and set variables accordingly
 func CheckArguments() {
@@ -24,6 +26,10 @@ func CheckArguments() {
 			fallthrough
 		case "--frames":
 			framesToKeep = strings.Split(os.Args[index+1], ",")
+		case "-t":
+			fallthrough
+		case "--timeout":
+			Timeout, _ = strconv.Atoi(os.Args[index+1])
 		case "-h":
 			fallthrough
 		case "--help":
@@ -38,6 +44,9 @@ func CheckArguments() {
 			FramesToKeep = append(FramesToKeep, strings.ToUpper(strings.TrimSpace(frame)))
 		}
 	}
+	if Timeout <= 0 {
+		Timeout = 30
+	}
 }
 
 // print the help
diff --git a/main.go b/main.go
index 399cf51..60d5cc6 100644
--- a/main.go
+++ b/main.go
@@ -5,8 +5,10 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
+	"runtime"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"git.velvettear.de/velvettear/id3tool/internal/config"
@@ -14,6 +16,12 @@ import (
 	"github.com/bogem/id3v2/v2"
 )
 
+var taskLimiter = make(chan struct{}, runtime.NumCPU())
+var taskCommunication = make(chan task)
+var waitGroup = sync.WaitGroup{}
+var counter int
+var taskState = make(map[int]task)
+
 func main() {
 	loggo.SetLogFormat("[$LOGLEVEL$] > $MESSAGE$ ($EXTRAS$) [$TIMEDIFF$]")
 
@@ -31,33 +39,60 @@ func main() {
 	}
 
 	filepath.WalkDir(config.Directory, filterValidFiles)
+	waitGroup.Wait()
 }
 
 func filterValidFiles(path string, dir fs.DirEntry, err error) error {
 	if err != nil {
 		return err
 	}
-	tmp := filepath.Clean(path)
-	loggo.Debug(tmp)
+
 	extension := filepath.Ext(path)
 	if dir.IsDir() || (extension != ".flac" && extension != ".mp3") {
 		return nil
 	}
-	cleanFrames(path)
+
+	counter++
+	waitGroup.Add(1)
+	taskLimiter <- struct{}{}
+	tmp := task{counter, path, false}
+	go func(tmp task) {
+		go func(tmp task) {
+			time.Sleep(time.Duration(config.Timeout) * time.Second)
+			tmp.timeout = true
+			taskCommunication <- tmp
+			<-taskLimiter
+		}(tmp)
+		cleanFrames(tmp.id, tmp.file)
+		tmp.timeout = false
+		taskCommunication <- tmp
+		<-taskLimiter
+	}(tmp)
+
+	result := <-taskCommunication
+	check := taskState[result.id]
+	if check.id == 0 {
+		taskState[result.id] = result
+		if result.timeout {
+			loggo.Warning("(" + strconv.Itoa(result.id) + ") cleaning of file's '" + result.file + "' id3 tags timed out")
+		}
+	}
+
+	waitGroup.Done()
 	return nil
 }
 
-func cleanFrames(file string) {
+func cleanFrames(id int, file string) {
 	if len(file) == 0 {
 		return
 	}
 
 	timestamp := time.Now()
-	loggo.Info("cleaning file's '" + file + "' id3 tags...")
+	loggo.Info("(" + strconv.Itoa(id) + ") cleaning file's '" + file + "' id3 tags...")
 
 	tag, err := id3v2.Open(file, id3v2.Options{Parse: true})
 	if err != nil {
-		loggo.Error("encountered an error opening the file '"+file+"' for reading the id3 tags", err.Error())
+		loggo.Error("("+strconv.Itoa(id)+") encountered an error opening the file '"+file+"' for reading the id3 tags", err.Error())
 		return
 	}
 	defer tag.Close()
@@ -73,16 +108,16 @@ func cleanFrames(file string) {
 
 	}
 	if deleted > 0 {
-		loggo.Debug("saving modified id3 tags (" + strconv.Itoa(deleted) + " deleted) to file '" + file + "'...")
+		loggo.Debug("(" + strconv.Itoa(id) + ") saving modified id3 tags (" + strconv.Itoa(deleted) + " deleted) to file '" + file + "'...")
 		err := tag.Save()
 		if err != nil {
-			loggo.Error("encountered an error saving the modified id3 tags to file '"+file+"'", err.Error())
+			loggo.Error("("+strconv.Itoa(id)+") encountered an error saving the modified id3 tags to file '"+file+"'", err.Error())
 			return
 		}
-		loggo.DebugTimed("deleted "+strconv.Itoa(deleted)+" tags", timestamp.UnixMilli())
+		loggo.DebugTimed("("+strconv.Itoa(id)+") deleted "+strconv.Itoa(deleted)+" tag(s) from file '"+file+"'", timestamp.UnixMilli())
 	}
 
-	loggo.DebugTimed("finished cleaning file", timestamp.UnixMilli())
+	loggo.DebugTimed("("+strconv.Itoa(id)+") finished cleaning file's '"+file+"' id3 tags", timestamp.UnixMilli())
 }
 
 func frameFilter(frame string) bool {
@@ -93,3 +128,9 @@ func frameFilter(frame string) bool {
 	}
 	return true
 }
+
+type task struct {
+	id      int
+	file    string
+	timeout bool
+}