topic Re: Slow ResultBuffer in .NET Forum

Slow ResultBuffer

office — Wed, 14 Nov 2018 06:17:53 GMT

I want to save a lot of data in DWG via XRecord but when making the ResultBuffer for it, it is very slow.

Here is a sample code for the ResultBuffer:

        public static void SaveSurfaceDataToDictionary(string dictName)
        {
            ResultBuffer resultBuffer = new ResultBuffer();
            foreach (long objectHandle in Lisp.plineHandleList) //List length = 59260
            {
                resultBuffer.Add(new TypedValue((int)DxfCode.Handle, objectHandle));
            }
            SetXrecord(dictName, "ObjectHandleList", resultBuffer);

            resultBuffer = new ResultBuffer();
            foreach (TriangleNet.Geometry.Vertex v in Lisp.polygonList.Points) //List length = 22766
            {
                resultBuffer.Add(new TypedValue((int)DxfCode.UcsOrg, new Point3d(v.X, v.Y, v.Z)));
            }
            SetXrecord(dictName, "PolygonPointsList", resultBuffer);

            resultBuffer = new ResultBuffer();
            List<ISegment> segmentList = Lisp.polygonList.Segments;
            foreach (Segment segment in segmentList) //List length = 17022
            {
                TriangleNet.Geometry.Vertex v;
                v = segment.GetVertex(0);
                resultBuffer.Add(new TypedValue((int)DxfCode.UcsOrg, new Point3d(v.X, v.Y, v.Z)));
                v = segment.GetVertex(1);
                resultBuffer.Add(new TypedValue((int)DxfCode.UcsOrg, new Point3d(v.X, v.Y, v.Z)));
            }
            SetXrecord(dictName, "PolygonSegmentsList", resultBuffer);
        }

        public static void SetXrecord(string dictName, string key, ResultBuffer resbuf)
        {
            Document doc = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument;
            Database db = doc.Database;
            using (Transaction tr = db.TransactionManager.StartTransaction())
            {
                DBDictionary NOD =
                    (DBDictionary)tr.GetObject(db.NamedObjectsDictionaryId, OpenMode.ForRead);
                DBDictionary dict;
                if (NOD.Contains(dictName))
                {
                    dict = (DBDictionary)tr.GetObject(NOD.GetAt(dictName), OpenMode.ForWrite);
                }
                else
                {
                    dict = new DBDictionary();
                    NOD.UpgradeOpen();
                    NOD.SetAt(dictName, dict);
                    tr.AddNewlyCreatedDBObject(dict, true);
                }
                Xrecord xRec = new Xrecord();
                xRec.Data = resbuf;
                dict.SetAt(key, xRec);
                tr.AddNewlyCreatedDBObject(xRec, true);
                tr.Commit();
            }
        }

The ResultBuffer operation takes 12 seconds. Way to slow.

Any idea or alternative for this?

I want to keep my data in DWG database.

Re: Slow ResultBuffer

_gile — Wed, 14 Nov 2018 07:04:14 GMT

Hi,

Except the fact you could start the transaction and get or or create the dictionary only once in the SaveSurfaceDataToDictionary() method ans pass them to the SetXrecord() method I do not see anything unefficient in your code structure.

But we do not know anything about the custom objects you use (Lisp, TriangleNet.Geometry.Vertex, Segment). The implementation of these types may be the cause of the slow down.

Re: Slow ResultBuffer

office — Wed, 14 Nov 2018 07:19:38 GMT

The custom objects are alright.

The problem is the resultbuffer.

Here is a sample code which takes 21 seconds without any implementations:

        public static void SaveSurfaceDataToDictionary(string dictName)
        {
            ResultBuffer resultBuffer = new ResultBuffer();
            for (int i = 0; i < 50000; i++)
            {
                resultBuffer.Add(new TypedValue((int)DxfCode.Int32, i));
            }

            resultBuffer = new ResultBuffer();
            for (int i = 0; i < 50000; i++)
            {
                resultBuffer.Add(new TypedValue((int)DxfCode.Int32, i));
            }

            resultBuffer = new ResultBuffer();
            for (int i = 0; i < 50000; i++)
            {
                resultBuffer.Add(new TypedValue((int)DxfCode.Int32, i));
            }
        }

Re: Slow ResultBuffer

_gile — Wed, 14 Nov 2018 14:04:08 GMT

I made some tests and it looks like it is the Resultbuffer.Add() method which is very slow.

You should use the overload ResultBuffer(params TypedValue[]) constructor instead.

        [CommandMethod("BENCH")]
        public static void Bench()
        {
            var ed = Application.DocumentManager.MdiActiveDocument.Editor;
            BenchArray(ed);
            BenchAdd(ed);
        }

        public static void BenchArray(Editor ed)
        {
            var sw = new Stopwatch();
            sw.Start();
            var tvs = new TypedValue[50000];
            for (int i = 0; i < 50000; i++)
            {
                tvs[i] = new TypedValue((int)DxfCode.Int32, i);
            }
            ResultBuffer resbuf = new ResultBuffer(tvs);
            sw.Stop();
            ed.WriteMessage($"\nElapsed milliseconds to build from a TypedValues array: {sw.ElapsedMilliseconds}");
        }

        public static void BenchAdd(Editor ed)
        {
            var sw = new Stopwatch();
            sw.Start();
            var resbuf = new ResultBuffer();
            for (int i = 0; i < 50000; i++)
            {
                resbuf.Add(new TypedValue((int)DxfCode.Int32, i));
            }
            sw.Stop();
            ed.WriteMessage($"\nElapsed milliseconds to add 50000 TypedValues: {sw.ElapsedMilliseconds}");
        }

Gives:

Elapsed milliseconds to build from a TypedValues array: 18
Elapsed milliseconds to add 50000 TypedValues: 3734

Re: Slow ResultBuffer

office — Wed, 14 Nov 2018 15:28:25 GMT

Nice solution.

Now I can save my large data using the ResultBuffer in 0.2 seconds instead of 12 seconds.

Thank you very much for the solution 🙂