code refactoring, enabled memory db persist to fs.

server/memory_db.go

@@ -108,4 +108,14 @@ func (m *MemoryDB) Restore() {
 	feed, _ := os.ReadFile("session.dat")
 	session := Session{}
 	json.Unmarshal(feed, &session)
+
+	for _, proc := range session.Processes {
+		db.table.Store(proc.Id, &Process{
+			id:       proc.Id,
+			url:      proc.Info.URL,
+			Info:     proc.Info,
+			Progress: proc.Progress,
+			mem:      m,
+		})
+	}
 }

server/process.go

@@ -171,14 +171,17 @@ func (p *Process) Kill() error {
 	// has been spawned with setPgid = true. To properly kill
 	// all subprocesses a SIGTERM need to be sent to the correct
 	// process group
-	pgid, err := syscall.Getpgid(p.proc.Pid)
-	if err != nil {
+	if p.proc != nil {
+		pgid, err := syscall.Getpgid(p.proc.Pid)
+		if err != nil {
+			return err
+		}
+		err = syscall.Kill(-pgid, syscall.SIGTERM)
+
+		log.Println("Killed process", p.id)
 		return err
 	}
-	err = syscall.Kill(-pgid, syscall.SIGTERM)
-
-	log.Println("Killed process", p.id)
-	return err
+	return nil
 }
 
 // Returns the available format for this URL

server/rest/handlers.go

@@ -21,6 +21,13 @@ type DirectoryEntry struct {
 	SHASum string `json:"shaSum"`
 }
 
+func isValidEntry(d fs.DirEntry) bool {
+	return !d.IsDir() &&
+		!strings.HasPrefix(d.Name(), ".") &&
+		!strings.HasSuffix(d.Name(), ".part") &&
+		!strings.HasSuffix(d.Name(), ".ytdl")
+}
+
 func walkDir(root string) (*[]DirectoryEntry, error) {
 	files := []DirectoryEntry{}
 
@@ -28,7 +35,7 @@ func walkDir(root string) (*[]DirectoryEntry, error) {
 		if err != nil {
 			return err
 		}
-		if !d.IsDir() && !strings.HasPrefix(d.Name(), ".") {
+		if isValidEntry(d) {
 			h := sha256.New()
 			h.Write([]byte(path))
 

server/server.go

@@ -1,12 +1,17 @@
 package server
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"io/fs"
 	"log"
 	"net/http"
 	"net/rpc"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
 
 	"github.com/gofiber/fiber/v2"
 	"github.com/gofiber/fiber/v2/middleware/cors"
@@ -18,6 +23,8 @@ import (
 var db MemoryDB
 
 func RunBlocking(port int, frontend fs.FS) {
+	db.Restore()
+
 	service := new(Service)
 	rpc.Register(service)
 
@@ -73,5 +80,34 @@ func RunBlocking(port int, frontend fs.FS) {
 
 	app.Server().StreamRequestBody = true
 
+	go periodicallyPersist()
+	go gracefulShutdown(app)
+
 	log.Fatal(app.Listen(fmt.Sprintf(":%d", port)))
 }
+
+func gracefulShutdown(app *fiber.App) {
+	ctx, stop := signal.NotifyContext(context.Background(),
+		os.Interrupt,
+		syscall.SIGTERM,
+		syscall.SIGQUIT,
+	)
+
+	go func() {
+		<-ctx.Done()
+		log.Println("shutdown signal received")
+
+		defer func() {
+			db.Persist()
+			stop()
+			app.ShutdownWithTimeout(time.Second * 5)
+		}()
+	}()
+}
+
+func periodicallyPersist() {
+	for {
+		db.Persist()
+		time.Sleep(time.Minute * 5)
+	}
+}

server/service.go

@@ -72,12 +72,15 @@ func (t *Service) Running(args NoArgs, running *Running) error {
 func (t *Service) Kill(args string, killed *string) error {
 	log.Println("Trying killing process with id", args)
 	proc, err := db.Get(args)
+
 	if err != nil {
 		return err
 	}
 	if proc != nil {
 		err = proc.Kill()
 	}
+
+	db.Delete(proc.id)
 	return err
 }