Improved performance of Select (Value) node by using arrays directly …

…and removing output slice count by using new DynamicOutputWriter class.
vvvv · Feb 10, 2014 · 54744cc · 54744cc
1 parent 3018178
commit 54744cc
Showing 1 changed file with 52 additions and 54 deletions.
diff --git a/vvvv45/src/nodes/plugins/_SpreadOperations/SelectNode.cs b/vvvv45/src/nodes/plugins/_SpreadOperations/SelectNode.cs
@@ -25,79 +25,77 @@ public void Evaluate(int spreadMax)
             if (!StreamUtils.AnyChanged(FDataIn, FSelectIn)) return;
             spreadMax = StreamUtils.GetSpreadMax(FDataIn, FSelectIn);
 
-            // Compute the output length
-            var outputLength = 0;
-            var selectLength = FSelectIn.Length;
-            if (selectLength > 0)
+            // Early exit
+            if (spreadMax == 0)
             {
-                var selectSum = FSelectIn.Sum();
-                var remainder = 0;
-                var numSlicesPerSelect = Math.DivRem(spreadMax, selectLength, out remainder);
-                outputLength = selectSum * numSlicesPerSelect;
-                if (remainder > 0)
-                    outputLength += FSelectIn.Take(remainder).Sum();
+                FDataOut.Length = 0;
+                FFormerSliceOut.Length = 0;
+                return;
             }
 
-            // Set the length of the outputs
-            FDataOut.Length = outputLength;
-            FFormerSliceOut.Length = outputLength;
-
-            // Early exit
-            if (outputLength == 0) return;
-
             // Fetch readers and writers
             using (var dataReader = FDataIn.GetCyclicReader())
             using (var selectReader = FSelectIn.GetCyclicReader())
-            using (var dataWriter = FDataOut.GetWriter())
-            using (var formerSliceWriter = FFormerSliceOut.GetWriter())
-            // Grab buffers from pool
-            using (var dataInBuffer = MemoryPool<T>.GetBuffer())
-            using (var dataOutBuffer = MemoryPool<T>.GetBuffer())
-            using (var selectBuffer = MemoryPool<int>.GetBuffer())
-            using (var sliceBuffer = MemoryPool<int>.GetBuffer())
+            using (var dataWriter = FDataOut.GetDynamicWriter())
+            using (var formerSliceWriter = FFormerSliceOut.GetDynamicWriter())
             {
-                var numSlicesToRead = spreadMax;
-                var offset = 0;
-                var formerSlice = 0;
-                while (numSlicesToRead > 0)
+                // Grab buffers from pool
+                var dataInBuffer = MemoryPool<T>.GetArray();
+                var dataOutBuffer = MemoryPool<T>.GetArray();
+                var selectBuffer = MemoryPool<int>.GetArray();
+                var sliceBuffer = MemoryPool<int>.GetArray();
+                try
                 {
-                    var blockSize = Math.Min(StreamUtils.BUFFER_SIZE, numSlicesToRead);
-                    dataReader.Read(dataInBuffer.Array, 0, blockSize);
-                    selectReader.Read(selectBuffer.Array, 0, blockSize);
-
-                    // This loop iterates through the input data
-                    for (int i = 0; i < blockSize; i++)
+                    var numSlicesToRead = spreadMax;
+                    var offset = 0;
+                    var formerSlice = 0;
+                    while (numSlicesToRead > 0)
                     {
-                        var data = dataInBuffer.Array[i];
-                        var select = selectBuffer.Array[i];
+                        var blockSize = Math.Min(StreamUtils.BUFFER_SIZE, numSlicesToRead);
+                        dataReader.Read(dataInBuffer, 0, blockSize);
+                        selectReader.Read(selectBuffer, 0, blockSize);
 
-                        // This loop replicates the input data on the output select times
-                        for (int j = 0; j < select; j++)
+                        // This loop iterates through the input data
+                        for (int i = 0; i < blockSize; i++)
                         {
-                            // Buffer result data
-                            dataOutBuffer.Array[offset] = data;
-                            sliceBuffer.Array[offset] = formerSlice;
-                            offset++;
+                            var data = dataInBuffer[i];
+                            var select = selectBuffer[i];
 
-                            // Write data out if buffer is full
-                            if (offset == StreamUtils.BUFFER_SIZE)
+                            // This loop replicates the input data on the output select times
+                            for (int j = 0; j < select; j++)
                             {
-                                dataWriter.Write(dataOutBuffer.Array, 0, StreamUtils.BUFFER_SIZE);
-                                formerSliceWriter.Write(sliceBuffer.Array, 0, StreamUtils.BUFFER_SIZE);
-                                offset = 0;
+                                // Buffer result data
+                                dataOutBuffer[offset] = data;
+                                sliceBuffer[offset] = formerSlice;
+                                offset++;
+
+                                // Write data out if buffer is full
+                                if (offset == StreamUtils.BUFFER_SIZE)
+                                {
+                                    dataWriter.Write(dataOutBuffer, 0, StreamUtils.BUFFER_SIZE);
+                                    formerSliceWriter.Write(sliceBuffer, 0, StreamUtils.BUFFER_SIZE);
+                                    offset = 0;
+                                }
                             }
+
+                            formerSlice++;
                         }
 
-                        formerSlice++;
+                        numSlicesToRead -= blockSize;
+                    }
+                    // Write any buffered output data left
+                    if (offset > 0)
+                    {
+                        dataWriter.Write(dataOutBuffer, 0, offset);
+                        formerSliceWriter.Write(sliceBuffer, 0, offset);
                     }
-
-                    numSlicesToRead -= blockSize;
                 }
-                // Write any buffered output data left
-                if (offset > 0)
+                finally
                 {
-                    dataWriter.Write(dataOutBuffer.Array, 0, offset);
-                    formerSliceWriter.Write(sliceBuffer.Array, 0, offset);
+                    MemoryPool<T>.PutArray(dataInBuffer);
+                    MemoryPool<T>.PutArray(dataOutBuffer);
+                    MemoryPool<int>.PutArray(selectBuffer);
+                    MemoryPool<int>.PutArray(sliceBuffer);
                 }
             }
         }