Specify buffer size

index.ts

@@ -11,7 +11,7 @@ export class File implements Writer {
     public constructor(options: WriterOptions & { path: string }) {
         const {path, ...rest} = options
         this._options = rest
-        this.sink = file(path).writer()
+        this.sink = file(path).writer({ highWaterMark: 128 * 1024 })
     }
 
     public log(_level: Level, ...data: any[]) : void {