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Blarg.GameFramework/Blarg.GameFramework/Support/ObjectPools.cs

85 lines
2.1 KiB
C#

using System;
using System.Collections.Generic;
using System.Reflection;
namespace Blarg.GameFramework.Support
{
public static class ObjectPools
{
const int INITIAL_CAPACITY = 100;
class ObjectObjectPool : ObjectPool<Object>
{
Type _type;
ConstructorInfo _constructor;
public ObjectObjectPool(Type type, ConstructorInfo constructor)
: base(INITIAL_CAPACITY)
{
_type = type;
_constructor = constructor;
}
protected override object Allocate()
{
// TODO: use a compiled lambda expression instead?
// need to check if possible when AOT compiled
return _constructor.Invoke(null);
}
}
static Dictionary<Type, ObjectObjectPool> _pools = new Dictionary<Type, ObjectObjectPool>();
static ConstructorInfo GetParameterlessConstructor(Type type)
{
var constructors = type.GetConstructors();
for (int i = 0; i < constructors.Length; ++i)
{
if (constructors[i].GetParameters().Length == 0)
return constructors[i];
}
return null;
}
static ObjectObjectPool GetPool(Type type)
{
ObjectObjectPool pool = _pools.Get(type);
if (pool == null)
{
// why do we do this instead of just using a "new()" generic type constraint?
// because doing it this way saves us from having to litter that same type
// constraint on every other class method (in other classes) which might be
// using ObjectPools to auto manage their object pools. Sometimes it gets
// a bit restrictive ...0
var constructor = GetParameterlessConstructor(type);
if (constructor == null)
throw new InvalidOperationException("ObjectPools can only be used for types with parameterless constructors.");
pool = new ObjectObjectPool(type, constructor);
_pools.Add(type, pool);
}
return pool;
}
public static T Take<T>() where T : class
{
var pool = GetPool(typeof(T));
return (T)pool.Take();
}
public static void Free<T>(T obj) where T : class
{
var pool = GetPool(typeof(T));
pool.Free(obj);
}
public static void Free(Type type, object obj)
{
var pool = GetPool(type);
pool.Free(obj);
}
}
}