Improve decompression memory management

[yallie]

Zyan unpacks the compressed payload using MemoryStream.
When the buffer overflows, MemoryStream allocates the larger block and moves the data:
https://referencesource.microsoft.com/#mscorlib/system/io/memorystream.cs,283

Reallocation can be avoided if the required capacity is specified upfront:
https://referencesource.microsoft.com/#mscorlib/system/io/memorystream.cs,70

Or we can use chunked memory stream instead. Something like this perhaps:
https://github.com/Aethon/SmallBlockMemoryStream

[yallie]

Benchmark code:

//
// Compile server using:
// csc test.cs /r:Zyan.Communication.dll /platform:anycpu /debug /out:server.exe
//
// Compile client using:
// csc.exe test.cs /r:Zyan.Communication.dll /platform:x86 /debug /out:client.exe
//
// Start up server.exe, then run client.exe.
//

using System;
using System.Collections.Concurrent;
using System.Diagnostics;
using System.Linq;
using Zyan.Communication;
using Zyan.Communication.ChannelSinks.Compression;
using Zyan.Communication.Protocols.Tcp;
using Zyan.Communication.Toolbox;

class CanceledSubscriptionTest
{
	static void Main()
	{
		try
		{
			StartServer();
		}
		catch
		{
			StartClient();
		}
	}

	// ------------ Server code --------------

	static void StartServer()
	{
		Console.Title = $"Server, PID: {Process.GetCurrentProcess().Id}";

		var proto = new TcpDuplexServerProtocolSetup(4321)
		{
		    CompressionMethod = CompressionMethod.Default
		};

		using (var host = new ZyanComponentHost(nameof(CanceledSubscriptionTest), proto))
		{
			host.RegisterComponent<IService, Service>();
			Console.WriteLine("Server started. Press ENTER to quit.");
			Console.ReadLine();
		}
	}

	public class Service : IService
	{
		public byte[][] GetPayload(int count)
		{
			var chunkSize = 8192;
			var arraySize = count / chunkSize;
			Console.WriteLine($"Generating {count} bytes of payload, that is, byte[{chunkSize}][{arraySize}].");

			var result = Enumerable.Range(1, arraySize).Select(i => new byte[chunkSize]).ToArray();

			Console.WriteLine($"Returning approx. {chunkSize * arraySize} bytes.");
			GC.Collect();
			GC.WaitForPendingFinalizers();
			GC.Collect();

			return result;
		}
	}

	// ------------ Shared code --------------

	public interface IService
	{
		byte[][] GetPayload(int count);
	}

	// ------------ Client code --------------

	static void StartClient()
	{
		Console.Title = $"Client, PID: {Process.GetCurrentProcess().Id}";

		var proto = new TcpDuplexClientProtocolSetup()
		{
		    CompressionMethod = CompressionMethod.Default
		};

		var url = proto.FormatUrl("localhost", 4321, nameof(CanceledSubscriptionTest));
		using (var conn = new ZyanConnection(url))
		{
			Console.WriteLine("Client started. Hit ENTER for 10 runs, ^C to quit.");

			var proxy = conn.CreateProxy<IService>();
            while (true)
			{
				var command = Console.ReadLine();
				var count = 0;
				if (!int.TryParse(command, out count))
				{
					count = 10;
				}

				try
				{
					var size = 2_343_750;
					for (var i = 0; i < count; i++)
					{
						Console.Write($"Get payload: {size} bytes...");
						var data = proxy.GetPayload(size);

						Console.WriteLine($"done!");
						size *= 2;
					}
				}
				catch (Exception ex)
				{
					Console.WriteLine($"Exception: {ex}");
					throw;
				}
			}
		}
	}
}

Plain MemoryStream, x86 — crashes on 300 Mb:

Get payload: 2343750 bytes...done!
Get payload: 4687500 bytes...done!
Get payload: 9375000 bytes...done!
Get payload: 18750000 bytes...done!
Get payload: 37500000 bytes...done!
Get payload: 75000000 bytes...done!
Get payload: 150000000 bytes...done!
Get payload: 300000000 bytes...Exception: System.OutOfMemoryException

Custom SmallBlockMemoryStream, x86 — crashes on 1200 Mb:

Get payload: 2343750 bytes...done!
Get payload: 4687500 bytes...done!
Get payload: 9375000 bytes...done!
Get payload: 18750000 bytes...done!
Get payload: 37500000 bytes...done!
Get payload: 75000000 bytes...done!
Get payload: 150000000 bytes...done!
Get payload: 300000000 bytes...done!
Get payload: 600000000 bytes...done!
Get payload: 1200000000 bytes...Exception: System.OutOfMemoryException

Custom SmallBlockMemoryStream, x64 — doesn't crash on 1200 Mb:

Get payload: 2343750 bytes...done!
Get payload: 4687500 bytes...done!
Get payload: 9375000 bytes...done!
Get payload: 18750000 bytes...done!
Get payload: 37500000 bytes...done!
Get payload: 75000000 bytes...done!
Get payload: 150000000 bytes...done!
Get payload: 300000000 bytes...done!
Get payload: 600000000 bytes...done!
Get payload: 1200000000 bytes...done!

[yallie]

Implemented in 1554ef0.