Table: optimized rendering performance

2021-12-27 18:24:37 +01:00
parent 01a80032b0
commit 940616cd3e
4 changed files with 59 additions and 74 deletions
@@ -103,7 +103,7 @@ namespace QuestPDF.Examples
                .ProducePdf()
                .PageSize(PageSizes.A4)
                .ShowResults()
-                .Render(container => GeneratePerformanceStructure(container, 100));
+                .Render(container => GeneratePerformanceStructure(container, 2));
        }
        
        [Test]
@@ -117,7 +117,7 @@ namespace QuestPDF.Examples
                .EnableCaching()
                .EnableDebugging(false)
                .ShowResults()
-                .Render(container => GeneratePerformanceStructure(container, 1000));
+                .Render(container => GeneratePerformanceStructure(container, 100));
        }
        
        public static void GeneratePerformanceStructure(IContainer container, int repeats)
@@ -136,16 +136,16 @@ namespace QuestPDF.Examples
                        columns.RelativeColumn();
                    });

-                    foreach (var _ in Enumerable.Range(0, repeats))
+                    foreach (var i in Enumerable.Range(0, repeats))
                    {
                        table.Cell().RowSpan(3).LabelCell("Project");
                        table.Cell().RowSpan(3).ValueCell(Placeholders.Sentence());
                
+                        table.Cell().LabelCell("Report number");
+                        table.Cell().ValueCell(i.ToString());
+                        
                        table.Cell().LabelCell("Date");
                        table.Cell().ValueCell(Placeholders.ShortDate());
-                
-                        table.Cell().LabelCell("Report number");
-                        table.Cell().ValueCell(Placeholders.Integer());

                        table.Cell().LabelCell("Inspector");
                        table.Cell().ValueCell("Marcin Ziąbek");
@@ -179,8 +179,6 @@ namespace QuestPDF.Examples
                
                        table.Cell().LabelCell("Remarks");
                        table.Cell().ColumnSpan(3).ValueCell(Placeholders.Paragraph());
-
-                        table.Cell().ColumnSpan(4).BorderBottom(2);
                    }
                });
        }
@@ -1,25 +0,0 @@
-using System;
-using System.Collections.Generic;
-
-namespace QuestPDF.Elements.Table
-{
-    internal static class EnumerableExtensions
-    {
-        public static IEnumerable<T> Scan<T>(this IEnumerable<T> input, Func<T, T, T> accumulate)
-        {
-            using var enumerator = input.GetEnumerator();
-            
-            if (!enumerator.MoveNext())
-                yield break;
-            
-            var state = enumerator.Current;
-            yield return state;
-            
-            while (enumerator.MoveNext())
-            {
-                state = accumulate(state, enumerator.Current);
-                yield return state;
-            }
-        }
-    }
-}
@@ -2,11 +2,38 @@
 using System.Collections.Generic;
 using System.Linq;
 using QuestPDF.Drawing;
-using QuestPDF.Fluent;
 using QuestPDF.Infrastructure;

 namespace QuestPDF.Elements.Table
 {
+    /// <summary>
+    /// This dictionary allows to access key that does not exist.
+    /// Instead of throwing an exception, it returns a default value.
+    /// </summary>
+    internal class DynamicDictionary<TKey, TValue>
+    {
+        private TValue Default { get; }
+        private IDictionary<TKey, TValue> Dictionary { get; } = new Dictionary<TKey, TValue>();
+
+        public DynamicDictionary()
+        {
+            
+        }
+        
+        public DynamicDictionary(TValue defaultValue)
+        {
+            Default = defaultValue;
+        }
+        
+        public TValue this[TKey key]
+        {
+            get => Dictionary.TryGetValue(key, out var value) ? value : Default;
+            set => Dictionary[key] = value;
+        }
+
+        public List<KeyValuePair<TKey, TValue>> Items => Dictionary.ToList();
+    }
+    
    internal class Table : Element, IStateResettable
    {
        public List<TableColumnDefinition> Columns { get; } = new List<TableColumnDefinition>();
@@ -26,7 +53,7 @@ namespace QuestPDF.Elements.Table
        public void ResetState()
        {
            if (RowsCount == default)
-                RowsCount = Children.Max(x => x.Row + x.RowSpan);
+                RowsCount = Children.Max(x => x.Row + x.RowSpan - 1);

            if (OrderedChildren == default)
            {
@@ -35,7 +62,7 @@ namespace QuestPDF.Elements.Table
                    .ToDictionary(x => x.Key, x => x.OrderBy(y => y.Column).ToArray());
            
                OrderedChildren = Enumerable
-                    .Range(0, RowsCount)
+                    .Range(0, RowsCount + 1)
                    .Select(x => groups.TryGetValue(x, out var output) ? output : Array.Empty<TableCell>())
                    .ToArray();   
            }
@@ -93,12 +120,9 @@ namespace QuestPDF.Elements.Table
                .ToList()
                .ForEach(x => cellOffsets[x] = Columns[x - 1].Width + cellOffsets[x - 1]);
            
-            
-            
            // update row heights
-            var rowsCount = RowsCount;
-            var rowBottomOffsets = new float[rowsCount];
-            var childrenToTry = Enumerable.Range(CurrentRow - 1, RowsCount - CurrentRow).SelectMany(x => OrderedChildren[x]);
+            var rowBottomOffsets = new DynamicDictionary<int, float>();
+            var childrenToTry = Enumerable.Range(CurrentRow, RowsCount - CurrentRow + 1).SelectMany(x => OrderedChildren[x]);

            var currentRow = CurrentRow;
            
@@ -106,59 +130,47 @@ namespace QuestPDF.Elements.Table
            {
                if (child.Row > currentRow)
                {
+                    rowBottomOffsets[currentRow] = Math.Max(rowBottomOffsets[currentRow], rowBottomOffsets[currentRow - 1]);
+                        
                    if (rowBottomOffsets[currentRow - 1] > availableSpace.Height + Single.Epsilon)
                        break;
                    
                    currentRow = child.Row;
                }

-                var rowIndex = child.Row - 1;
-                
-                if (rowIndex > 1)
-                    rowBottomOffsets[rowIndex] = Math.Max(rowBottomOffsets[rowIndex], rowBottomOffsets[rowIndex-1]);
-                
-                var topOffset = 0f;
-
-                if (rowIndex > 0)
-                    topOffset = rowBottomOffsets[rowIndex - 1]; // look at previous row
+                var topOffset = rowBottomOffsets[child.Row - 1];
                
                var height = GetCellSize(child).Height;
                var cellBottomOffset = height + topOffset;
                
-                var targetRowId = child.Row + child.RowSpan - 2; // -1 because indexing starts at 0, -1 because rowSpan starts at 1
+                var targetRowId = child.Row + child.RowSpan - 1; // -1 because rowSpan starts at 1
                rowBottomOffsets[targetRowId] = Math.Max(rowBottomOffsets[targetRowId], cellBottomOffset);
            }
+
+            var rowHeights = new DynamicDictionary<int, float>();
            
            Enumerable
-                .Range(1, rowsCount - 1)
-                .ToList()
-                .ForEach(x => rowBottomOffsets[x] = Math.Max(rowBottomOffsets[x], rowBottomOffsets[x-1]));
-            
-            var rowHeights = new float[rowsCount];
-            rowHeights[0] = rowBottomOffsets[0];
-            
-            Enumerable
-                .Range(1, rowsCount - 1)
+                .Range(CurrentRow, rowBottomOffsets.Items.Count)
                .ToList()
                .ForEach(x => rowHeights[x] = rowBottomOffsets[x] - rowBottomOffsets[x-1]);
            
            // find rows count to render in this pass
-            var rowsToDisplay = rowHeights.Scan((x, y) => x + y).Count(x => x <= availableSpace.Height + Size.Epsilon);
-            rowHeights = rowHeights.Take(rowsToDisplay).ToArray();
-            
-            var totalHeight = rowHeights.Sum();
-            var totalWidth = Columns.Sum(x => x.Width);
-            
-            foreach (var cell in Children)
-            {
-                if (cell.Row >= CurrentRow && cell.Row > rowsToDisplay)
-                    continue;
+            var maxRowToDisplay = rowBottomOffsets.Items.Where(x => x.Value <= availableSpace.Height + Size.Epsilon).Max(x => x.Key);

+            var totalHeight = rowHeights.Items.Where(x => x.Key <= maxRowToDisplay).Sum(x => x.Value);
+            var totalWidth = Columns.Sum(x => x.Width);
+
+            var childrenToDraw = Enumerable
+                .Range(CurrentRow, maxRowToDisplay - CurrentRow + 1)
+                .SelectMany(x => OrderedChildren[x]);
+            
+            foreach (var cell in childrenToDraw)
+            {
                var leftOffset = cellOffsets[cell.Column - 1];
-                var topOffset = cell.Row == 1 ? 0 : rowBottomOffsets[cell.Row - 2];
+                var topOffset = cell.Row == 1 ? 0 : rowBottomOffsets[cell.Row - 1];

                var width = GetCellWidth(cell);
-                var height = Enumerable.Range(cell.Row - 1, cell.RowSpan).TakeWhile(x => x < rowHeights.Length).Select(x => rowHeights[x]).Sum();
+                var height = Enumerable.Range(cell.Row, cell.RowSpan).Select(x => rowHeights[x]).Sum();

                cellRenderingCommands.Add(new TableCellRenderingCommand()
                {
@@ -172,7 +184,7 @@ namespace QuestPDF.Elements.Table
            {
                Size = new Size(totalWidth, totalHeight),
                CellRenderingCommands = cellRenderingCommands,
-                MaxRowRendered = rowsToDisplay
+                MaxRowRendered = maxRowToDisplay
            };
            
            float GetCellWidth(TableCell cell)
@@ -7,7 +7,7 @@
        <Version>2021.12.0</Version>
        <PackageDescription>QuestPDF is an open-source, modern and battle-tested library that can help you with generating PDF documents by offering friendly, discoverable and predictable C# fluent API.</PackageDescription>
        <PackageReleaseNotes>$([System.IO.File]::ReadAllText("$(MSBuildProjectDirectory)/Resources/ReleaseNotes.txt"))</PackageReleaseNotes>
-        <LangVersion>10</LangVersion>
+        <LangVersion>9</LangVersion>
        <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
        <PackageIcon>Logo.png</PackageIcon>
        <PackageIconUrl>https://www.questpdf.com/images/package-logo.png</PackageIconUrl>