#include "nw4r/snd/snd_InstancePool.h"

/* Original source:
 * kiwi515/ogws
 * src/nw4r/snd/snd_InstancePool.cpp
 */

/*******************************************************************************
 * headers
 */

#include "common.h"

#include "nw4r/ut/ut_Lock.h" // ut::AutoInterruptLock
#include "nw4r/ut/ut_algorithm.h" // ut::RoundUp

#include "nw4r/NW4RAssert.hpp"

/*******************************************************************************
 * functions
 */

namespace nw4r { namespace snd { namespace detail {

u32 PoolImpl::CreateImpl(void *buffer, u32 size, u32 objSize)
{
	NW4RAssertPointerNonnull_Line(38, buffer);

	ut::AutoInterruptLock lock;

	// alignas(4)
	char *ptr = static_cast<char *>(ut::RoundUp(buffer, 4));
	objSize = ut::RoundUp(objSize, 4);

	u32 numObjects = (size - (ptr - static_cast<char *>(buffer))) / objSize;

	for (u32 i = 0; i < numObjects; i++, ptr += objSize)
	{
		PoolImpl *head = reinterpret_cast<PoolImpl *>(ptr);

		head->mNext = mNext;
		mNext = head;
	}

	return numObjects;
}

void PoolImpl::DestroyImpl(void *buffer, u32 size)
{
	NW4RAssertPointerNonnull_Line(68, buffer);

	ut::AutoInterruptLock lock;

	void *begin = buffer;
	void *end = static_cast<char *>(begin) + size;

	for (PoolImpl *ptr = mNext, *prev = this; ptr; ptr = ptr->mNext)
	{
		if (begin <= ptr && ptr < end)
			prev->mNext = ptr->mNext;
		else
			prev = ptr;
	}
}

int PoolImpl::CountImpl() const
{
	ut::AutoInterruptLock lock;

	int count = 0;

	for (PoolImpl *ptr = mNext; ptr; ptr = ptr->mNext)
		count++;

	return count;
}

void *PoolImpl::AllocImpl()
{
	ut::AutoInterruptLock lock;

	if (!mNext)
		return nullptr;

	PoolImpl *head = mNext;

	mNext = head->mNext;

	return head;
}

void PoolImpl::FreeImpl(void *ptr)
{
	ut::AutoInterruptLock lock;

	PoolImpl *head = static_cast<PoolImpl *>(ptr);

	head->mNext = mNext;
	mNext = head;
}

}}} // namespace nw4r::snd::detail