Paprika.Cli provides more stats

src/Paprika.Cli/Program.cs

@@ -39,7 +39,7 @@ public override int Execute(CommandContext context, StatisticsSettings settings)
 
         var stats = new Layout("Stats");
 
-        AnsiConsole.Write("Gathering stats...");
+        AnsiConsole.WriteLine("Gathering stats...");
 
         StatisticsForPagedDb.Report(stats, read);
 

src/Paprika.Runner.Pareto/Program.cs

@@ -185,7 +185,9 @@ public static async Task Main(String[] args)
 
             var state = new StatisticsReporter(TrieType.State);
             var storage = new StatisticsReporter(TrieType.Storage);
-            read.Report(state, storage);
+            var counting = new PageCountingReporter();
+
+            read.Report(state, storage, counting, out _);
 
             spectre.Cancel();
             await reportingTask;

src/Paprika.Runner/StatisticsForPagedDb.cs

@@ -17,13 +17,22 @@ public static void Report(Layout reportTo, IReporting read)
         {
             var state = new StatisticsReporter(TrieType.State);
             var storage = new StatisticsReporter(TrieType.Storage);
+            var ids = new PageCountingReporter();
 
-            read.Report(state, storage);
+            read.Report(state, storage, ids, out var totalAbandoned);
 
             var report = new Layout()
-                .SplitColumns(
-                    BuildReport(state, "State"),
-                    BuildReport(storage, "Storage"));
+                .SplitRows(
+                    new Layout("top")
+                        .SplitColumns(
+                            BuildReport(state, "State"),
+                            BuildReport(storage, "Storage")),
+                    new Layout("bottom")
+                        .Update(new Panel(new Paragraph(
+                            $"- pages used for id mapping: {Page.FormatAsGb(ids.Count)}\n" +
+                                $"- total pages abandoned: {Page.FormatAsGb(totalAbandoned)}\n" +
+                            "")).Header("Other stats").Expand())
+                );
 
             reportTo.Update(new Panel(report).Header("Paprika tree statistics").Expand());
         }

src/Paprika.Tests/Store/PagedDbTests.cs

@@ -186,7 +186,22 @@ static void Assert(PagedDb db)
             var state = new StatisticsReporter(TrieType.State);
             var storage = new StatisticsReporter(TrieType.Storage);
 
-            read.Report(state, storage);
+            read.Report(state, storage, new JustLookingReporter(), out _);
+        }
+    }
+
+    private class JustLookingReporter : IReporter
+    {
+        public void ReportDataUsage(PageType type, int pageLevel, int trimmedNibbles, in SlottedArray array)
+        {
+        }
+
+        public void ReportPage(uint ageInBatches, PageType type)
+        {
+        }
+
+        public void ReportLeafOverflowCount(byte count)
+        {
         }
     }
 

src/Paprika/Store/AbandonedList.cs

@@ -1,5 +1,6 @@
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Diagnostics.Contracts;
 using System.Runtime.InteropServices;
 
 namespace Paprika.Store;
@@ -207,4 +208,25 @@ public void Accept(IPageVisitor visitor, IPageResolver resolver)
             }
         }
     }
-}
+
+    [Pure]
+    public long GatherTotalAbandoned(IPageResolver resolver)
+    {
+        resolver.Prefetch(Addresses);
+
+        long count = 0;
+
+        foreach (var addr in Addresses[..(int)EntriesCount])
+        {
+            var current = addr;
+            while (current.IsNull == false)
+            {
+                var abandoned = new AbandonedPage(resolver.GetAt(current));
+                count += abandoned.Count;
+                current = abandoned.Next;
+            }
+        }
+
+        return count;
+    }
+}

src/Paprika/Store/IReporter.cs

@@ -1,5 +1,3 @@
-using System.Diagnostics;
-using System.Runtime.InteropServices;
 using HdrHistogram;
 using Paprika.Crypto;
 using Paprika.Data;
@@ -26,7 +24,27 @@ public interface IReporter
 
 public interface IReporting
 {
-    void Report(IReporter state, IReporter storage);
+    void Report(IReporter state, IReporter storage, IReporter ids, out long totalAbandoned);
+}
+
+public class PageCountingReporter : IReporter
+{
+    public long Count { get; private set; }
+
+    public void ReportDataUsage(PageType type, int pageLevel, int trimmedNibbles, in SlottedArray array)
+    {
+        Count++;
+    }
+
+    public void ReportPage(uint ageInBatches, PageType type)
+    {
+        throw new NotImplementedException();
+    }
+
+    public void ReportLeafOverflowCount(byte count)
+    {
+        throw new NotImplementedException();
+    }
 }
 
 public class StatisticsReporter(TrieType trieType) : IReporter

src/Paprika/Store/Page.cs

@@ -116,4 +116,6 @@ public struct PageHeader
 
     public static Page DevOnlyNativeAlloc() =>
         new((byte*)NativeMemory.AlignedAlloc(PageSize, PageSize));
+
+    public static string FormatAsGb(long pageCount) => $"{(double)pageCount * PageSize / 1024 / 1024 / 1024:F2)}GB";
 }

src/Paprika/Store/PagedDb.cs

@@ -484,14 +484,20 @@ public bool TryGet(scoped in Key key, out ReadOnlySpan<byte> result)
             return root.TryGet(key, this, out result);
         }
 
-        public void Report(IReporter state, IReporter storage)
+        public void Report(IReporter state, IReporter storage, IReporter ids, out long totalAbandoned)
         {
-            if (root.Data.StateRoot.IsNull == false)
+            ref readonly var data = ref root.Data;
+
+            totalAbandoned = 0;
+            totalAbandoned = data.AbandonedList.GatherTotalAbandoned(this);
+
+            if (data.StateRoot.IsNull == false)
             {
                 new Merkle.StateRootPage(GetAt(root.Data.StateRoot)).Report(state, this, 0, 0);
             }
 
-            root.Data.Storage.Report(storage, this, 0, 0);
+            data.Storage.Report(storage, this, 0, 0);
+            data.Ids.Report(ids, this, 0, 0);
         }
 
         public uint BatchId => root.Header.BatchId;