Fix SQLite queue

Signed-off-by: Hadi <112569860+anotherhadi@users.noreply.github.com>

internal/db/db.go

@@ -18,6 +18,10 @@ func Open(path string) (*DB, error) {
 	if err != nil {
 		return nil, err
 	}
+	// SQLite only supports one concurrent writer; a pool of connections would
+	// cause SQLITE_BUSY errors when multiple proxy goroutines try to insert
+	// history entries at the same time.
+	conn.SetMaxOpenConns(1)
 	d := &DB{conn: conn, path: path}
 	if err := d.migrate(); err != nil {
 		conn.Close()

internal/intercept/broker.go

@@ -195,17 +195,19 @@ func (b *Broker) SaveEntry(f *proxy.Flow) {
 	if config.Global.History.SkipDuplicates {
 		var dup bool
 		entry, dup, err = d.InsertIfNotDuplicate(pending, body)
-		if dup || err != nil {
+		if dup {
 			return
 		}
 	} else {
 		entry, err = d.InsertEntry(pending, body)
 	}
-	if err == nil {
+	if err != nil {
+		log.Printf("intercept: failed to save history entry: %v", err)
+		return
+	}
 	if cb := b.onNewEntry; cb != nil {
 		go cb(entry)
 	}
-	}
 }
 
 func (b *Broker) Decide(p *PendingRequest, d Decision) {