Trim Libplanet's last block. Download executables from <https://drive.google.com/drive/folders/1H599214BzuI4GImvfo6AKUydHV1tB-v8?usp=sharing>.

.gitignore

bin/
obj/

build.ps1

#!/usr/local/bin/pwsh
$target = "netcoreapp2.2"
$platforms = @("osx-x64","win-x64")
$results = @()
foreach ($rid in $platforms) {
  dotnet publish -c Release -r $rid --self-contained true
  $dest = "bin/Release/LibplanetBlockTrimmer.$rid.zip"
  if (Test-Path $dest) {
    Remove-Item $dest
  }
  Compress-Archive `
    -Path bin/Release/$target/$rid/publish/* `
    -DestinationPath $dest
  $results += $dest
}
foreach ($dest in $results) {
  echo $dest
}

LibplanetBlockTrimmer.csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.2</TargetFramework>
    <RootNamespace>LibplanetBlockTrimmer</RootNamespace>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Ben.Demystifier" Version="0.1.4" />
    <PackageReference Include="Libplanet" Version="0.2.1" />
  </ItemGroup>
</Project>

Program.cs

using Libplanet;
using Libplanet.Store;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Security.Cryptography;

namespace LibplanetBlockTrimmer
{
    class Program
    {
        static int Main(string[] args)
        {
            try
            {
                return ProgramMain(args);
            }
            catch (Exception e)
            {
                Console.Error.WriteLine(e.Demystify());
                return 1;
            }
        }

        static int ProgramMain(string[] args)
        {
            TextWriter stderr = Console.Error;
            string path = args.Length < 1 ? "." : args[0];
            IStore store;
            try
            {
                store = new FileStore(path);
            }
            catch (ArgumentException e)
            {
                stderr.WriteLine($"error: {e}");
                Usage(stderr);
                return 1;
            }

            HashSet<string> namespaces = store.ListNamespaces().ToHashSet();
            if (namespaces.Count == 0)
            {
                stderr.WriteLine("error: There is no namespace at all.");
                Usage(stderr);
                return 1;
            }

            string ns;
            if (namespaces.Count == 1)
            {
                ns = namespaces.First();
                stderr.WriteLine(
                    $"There is only one namespace: {ns}; use this."
                );
            }
            else if (args.Length > 1)
            {
                ns = args[1];
            }
            else
            {
                stderr.WriteLine(
                    "error: There are multiple namespaces.  Please choose " +
                    "one in the following namespaces:"
                );
                foreach (string n in namespaces)
                {
                    stderr.WriteLine($"\t{n}");
                }
                Usage(stderr);
                return 1;
            }

            long tipIndex = store.CountIndex(ns) - 1;
            HashDigest<SHA256>? tipHash = store.IndexBlockHash(ns, tipIndex);
            if (tipIndex < 0 || !tipHash.HasValue)
            {
                stderr.WriteLine("error: There is no block at all.");
                return 1;
            }

            stderr.WriteLine(
                $"The tip before trimming: {tipHash.Value} ({tipIndex})."
            );
            bool deleted = store.DeleteIndex(ns, tipHash.Value);
            if (!deleted)
            {
                stderr.WriteLine(
                    $"error: Failed to trim the block {tipHash} ({tipIndex})."
                );
                return 1;
            }

            tipIndex = store.CountIndex(ns) - 1;
            tipHash = store.IndexBlockHash(ns, tipIndex);
            TextWriter stdout = Console.Out;
            stderr.Write("The tip after timmed: ");
            stderr.Flush();
            stdout.Write($"{tipHash} ({tipIndex})");
            stdout.Flush();
            stderr.WriteLine(".");
            return 0;
        }

        private static void Usage(TextWriter writer)
        {
            string name = System.Environment.GetCommandLineArgs()[0];
            writer.WriteLine($"usage: {name} [PATH] [NAMESPACE]");
        }
    }
}