飞线图案在这个简单的网核心Api使用更多的内存ram

Question

我试图在一个简单的.net核心Api中应用Flyweight方法模式，看看与不使用该模式相比节省了多少内存。

我有两种方法，第一种方法在不使用图案的情况下创建5000个对象，另一种方法使用图案创建5000个物体。在他们每个人创建对象后，他们调用一个方法，返回应用程序使用的当前内存。

public class MemoryService : IMemoryService
{
private readonly TreeFactory _treeFactory;
public MemoryService()
{
_treeFactory = new TreeFactory();
}
//create without pattern
public long SetObjectsMemory()
{
List<Tree> trees = new List<Tree>();
for (int i = 0; i < 5000; i++)
{
var tree = new Tree()
{
Id = new Random().Next(1, 9999999),
Part = new PartTree()
{
Name = "Nameany",
Bark = "Barkany",
Color = "Colorany"
}
};
trees.Add(tree);
};
return Utilities.GetCurrentMemoryUsed();
}
//crete with flyweight pattern
public long SetObjectsMemoryFactory()
{
List<Tree> trees = new List<Tree>();
for (int i = 0; i < 5000; i++)
{
var tree = new Tree()
{
Id = new Random().Next(1, 9999999),
Part = _treeFactory.GetPartTree("Nameany", "Barkany", "Colorany")
};
trees.Add(tree);
}
return Utilities.GetCurrentMemoryUsed();
}
}

我像使用零件列表的类一样使用该模式，并在存在的情况下返回零件对象。

public class TreeFactory
{
private static List<PartTree> _parts;
public TreeFactory() {
_parts = new List<PartTree>();
}
public PartTree GetPartTree(string name, string bark, string color)
{
if (_parts.Any(x => x.Name == name && x.Bark == bark && x.Color == color))
{
return _parts.Where(x => x.Name == name && x.Bark == bark && x.Color == color).FirstOrDefault();
}
else {
var newpart = new PartTree()
{
Name = name,
Bark = bark,
Color = color
};
_parts.Add(newpart);
return newpart;
}

}
}

获取应用程序使用的当前内存的方法是使用这种方式的进程(在实用程序类中(：

public static long GetCurrentMemoryUsed() {
Int64 memory;
using (Process proc = Process.GetCurrentProcess())
{
memory = proc.PrivateMemorySize64 / (1024 * 1024);
}
return memory;
}

在我的Startup中，我像Singleton一样注入MemoryService。在控制器中，我使用3种方法来调用函数：

[HttpGet, Route(nameof(WeatherForecastController.GenerateMemory))]
public IActionResult GenerateMemory()
{
var total=_memoryService.SetObjectsMemory();
return Ok(total);
}
[HttpGet, Route(nameof(WeatherForecastController.GenerateLiftMemory))]
public IActionResult GenerateLiftMemory()
{
var total = _memoryService.SetObjectsMemoryFactory();
return Ok(total);
}
[HttpGet, Route(nameof(WeatherForecastController.GetMemory))]
public IActionResult GetMemory()
{
var total = Utilities.GetCurrentMemoryUsed();
return Ok(total);
}

问题是：当我在导航器中调用控制器中没有模式(/wweatherForecast/GenerateMemory(的方法时，它会返回(当前(+2mb，但当我调用该方法时模式为(/wweatherForecast/GenerateLiftMemory(，返回(当前(+3mb。

为什么带模式flyweight的方法比不带模式的方法返回更多的MB(增长(

带有测试代码的存储库。Gitlab存储库内存api

Answer 1

使用TreeFactory的代码消耗更多内存，因为它的GetPartTree方法在循环中调用了多次，而Linq方法在其中调用了Any和Where。这两种方法都在引擎盖下创建了额外的Iterator对象，以便在集合中迭代，这会导致额外的内存消耗。

我使用BenchmarkDotNet编写了简单的基准测试，并提供了更多选项来演示问题

扩展内存服务

public class MemoryService : IMemoryService
{
private const int TreeCount = 50000;
private readonly TreeFactory _treeFactory;
public MemoryService()
{
_treeFactory = new TreeFactory();
}
//crea objetos en memoria sin patrones
public decimal SetObjectsMemory()
{
List<Tree> trees = new List<Tree>();
for (int i = 0; i < TreeCount; i++)
{
var tree = new Tree()
{
Id = 1,
Part = new PartTree()
{
Name = "Nameany",
Bark = "Barkany",
Color = "Colorany"
}
};
trees.Add(tree);
};
return Utilities.GetCurrentMemoryUsed();
}
//crea objetos en memoria usando patron flyweight
public decimal SetObjectsMemoryFactory()
{
List<Tree> trees = new List<Tree>();
for (int i = 0; i < TreeCount; i++)
{
var tree = new Tree()
{
Id = 1,
Part = _treeFactory.GetPartTree("Nameany", "Barkany", "Colorany")
};
trees.Add(tree);
}
return Utilities.GetCurrentMemoryUsed();
}
public decimal SetObjectsMemoryFactoryImproved()
{
List<Tree> trees = new List<Tree>();
for (int i = 0; i < TreeCount; i++)
{
var tree = new Tree()
{
Id = 1,
Part = _treeFactory.GetPartTreeImproved("Nameany", "Barkany", "Colorany")
};
trees.Add(tree);
}
return Utilities.GetCurrentMemoryUsed();
}
//crea objetos en memoria usando patron flyweight
public decimal SetObjectsMemoryFactoryWithoutLambda()
{
List<Tree> trees = new List<Tree>();
for (int i = 0; i < TreeCount; i++)
{
var tree = new Tree()
{
Id = 1,
Part = _treeFactory.GetPartTreeWithoutLambda("Nameany", "Barkany", "Colorany")
};
trees.Add(tree);
}
return Utilities.GetCurrentMemoryUsed();
}
}

扩展树工厂

public class TreeFactory
{
private static List<PartTree> _parts;
public TreeFactory()
{
_parts = new List<PartTree>();
}
public PartTree GetPartTree(string name, string bark, string color)
{
if (_parts.Any(x => x.Name == name && x.Bark == bark && x.Color == color))
{
return _parts.Where(x => x.Name == name && x.Bark == bark && x.Color == color).FirstOrDefault();
}
var newpart = new PartTree()
{
Name = name,
Bark = bark,
Color = color
};
_parts.Add(newpart);
return newpart;
}
public PartTree GetPartTreeImproved(string name, string bark, string color)
{
var existingPart = _parts.Where(x => x.Name == name && x.Bark == bark && x.Color == color).FirstOrDefault();
if (existingPart != null)
return existingPart;
var newpart = new PartTree()
{
Name = name,
Bark = bark,
Color = color
};
_parts.Add(newpart);
return newpart;
}
public PartTree GetPartTreeWithoutLambda(string name, string bark, string color)
{
for (int i = 0; i < _parts.Count; i++)
{
var x = _parts[i];
if (x.Name == name && x.Bark == bark && x.Color == color)
return x;
}
var newpart = new PartTree()
{
Name = name,
Bark = bark,
Color = color
};
_parts.Add(newpart);
return newpart;
}
}

在单独的控制台项目中进行基准测试

class Program
{
static void Main(string[] args)
{
var result = BenchmarkRunner.Run<MemoryBenchmark>();
}
}

[MemoryDiagnoser]
public class MemoryBenchmark
{
private IMemoryService memoryService;
[GlobalSetup]
public void Setup()
{
memoryService = new MemoryService();
}
[Benchmark]
public object SimpleTrees()
{
var trees = memoryService.SetObjectsMemory();
return trees;
}
[Benchmark]
public object FlyTrees()
{
var trees = memoryService.SetObjectsMemoryFactory();
return trees;
}
[Benchmark]
public object FlyTreesImproved()
{
var trees = memoryService.SetObjectsMemoryFactoryImproved();
return trees;
}
[Benchmark]
public object FlyTreesWithoutLambda()
{
var trees = memoryService.SetObjectsMemoryFactoryWithoutLambda();
return trees;
}
}

及其结果

>StdDev：right；">已分配>>>>>

方法	平均值	错误
SimpleTrees	9.040毫秒
FlyTrees	19.701毫秒		FlyTrees改进	18.075毫秒	0.2869毫秒	0.2684毫秒	1781.2500	625.0000	312.5000/tr>
FlyTreeWithoutLambda	4.919毫秒	0.0273毫秒	0.0242毫秒	421.8750	281.2500	281.2500 MB