MemStat.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using ByteSizeLib;
using CommandLine;
using Microsoft.Diagnostics.Runtime;

namespace MemStat
{
    internal class Program
    {
        static void Main(string[] args)
        {
            var result = Parser.Default.ParseArguments<Options>(args);
            result.WithNotParsed(errors =>
            {
                foreach (var error in errors)
                    Console.WriteLine(error);
            });
            result.WithParsed(options =>
            {
                using (var target = DataTarget.AttachToProcess(options.Pid, 5000, AttachFlag.NonInvasive))
                {
                    var runtimeInfo = target.ClrVersions.First();
                    var runtime = runtimeInfo.CreateRuntime();
                    if (!runtime.Heap.CanWalkHeap)
                    {
                        Console.WriteLine("Cannot walk the heap!");
                        return;
                    }
                    var typeInfo = new Dictionary<ClrType, InstancesInfo>();
                    var totalSize = 0ul;
                    foreach (var obj in runtime.Heap.EnumerateObjects())
                    {
                        totalSize += obj.Size;
                        if (typeInfo.TryGetValue(obj.Type, out var info))
                        {
                            info.Count++;
                            info.Size += obj.Size;
                        }
                        else
                        {
                            typeInfo.Add(obj.Type, new InstancesInfo
                            {
                                Count = 1,
                                Size = obj.Size
                            });
                        }
                    }
                    PrintToConsole(options, typeInfo, totalSize);
                    if(!string.IsNullOrEmpty(options.File))
                        PrintToFile(options, typeInfo, totalSize);
                }

            });
            Console.WriteLine("Enter to exit...");
            Console.ReadLine();
        }

        static void PrintToFile(Options options, Dictionary<ClrType, InstancesInfo> typeInfo, ulong totalSize)
        {
            using (var writer = new StreamWriter(options.File))
            {
                writer.WriteLine($"Total: {ByteSize.FromBytes(totalSize)}");
                foreach (var kv in typeInfo.OrderByDescending(kv => kv.Value.Size))
                {
                    writer.WriteLine($"{kv.Key.Name,-60}\t{kv.Value.Count}\t{ByteSize.FromBytes(kv.Value.Size)}");
                }
            }
        }

        static void PrintToConsole(Options options, Dictionary<ClrType, InstancesInfo> typeInfo, ulong totalSize)
        {
            Console.WriteLine("...");
            foreach (var kv in typeInfo.OrderByDescending(kv => kv.Value.Size).Take(options.Number).Reverse())
            {
                Console.WriteLine($"{kv.Key.Name,-60}\t{kv.Value.Count}\t{ByteSize.FromBytes(kv.Value.Size)}");
            }
            Console.WriteLine($"Total: {ByteSize.FromBytes(totalSize)}");
        }
    }
}