sebastienros.jint/Jint/Constraints/MemoryLimit.cs

using Jint.Runtime;

namespace Jint.Constraints
{
    internal sealed class MemoryLimit : IConstraint
    {
        private static readonly Func<long>? GetAllocatedBytesForCurrentThread;
        private readonly long _memoryLimit;
        private long _initialMemoryUsage;

        static MemoryLimit()
        {
            var methodInfo = typeof(GC).GetMethod("GetAllocatedBytesForCurrentThread");

            if (methodInfo != null)
            {
                GetAllocatedBytesForCurrentThread = (Func<long>)Delegate.CreateDelegate(typeof(Func<long>), null, methodInfo);
            }
        }

        public MemoryLimit(long memoryLimit)
        {
            _memoryLimit = memoryLimit;
        }

        public void Check()
        {
            if (_memoryLimit > 0)
            {
                if (GetAllocatedBytesForCurrentThread != null)
                {
                    var memoryUsage = GetAllocatedBytesForCurrentThread() - _initialMemoryUsage;
                    if (memoryUsage > _memoryLimit)
                    {
                        ExceptionHelper.ThrowMemoryLimitExceededException($"Script has allocated {memoryUsage} but is limited to {_memoryLimit}");
                    }
                }
                else
                {
                    ExceptionHelper.ThrowPlatformNotSupportedException("The current platform doesn't support MemoryLimit.");
                }
            }
        }

        public void Reset()
        {
            if (GetAllocatedBytesForCurrentThread != null)
            {
                _initialMemoryUsage = GetAllocatedBytesForCurrentThread();
            }
        }
    }
}