/** Memory pool for fixed size objects.
 *
 * @author Steffen Vogel <post@steffenvogel.de>
 * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
 * @license Apache 2.0
 *********************************************************************************/

#include <villas/utils.hpp>
#include <villas/exceptions.hpp>
#include <villas/pool.hpp>
#include <villas/node/memory.hpp>
#include <villas/kernel/kernel.hpp>
#include <villas/log.hpp>

using namespace villas;

int villas::node::pool_init(struct Pool *p, size_t cnt, size_t blocksz, struct memory::Type *m)
{
	int ret;
	auto logger = logging.get("pool");

	/* Make sure that we use a block size that is aligned to the size of a cache line */
	p->alignment = kernel::getCachelineSize();
	p->blocksz = p->alignment * CEIL(blocksz, p->alignment);
	p->len = cnt * p->blocksz;

	logger->debug("New memory pool: alignment={}, blocksz={}, len={}, memory={}", p->alignment, p->blocksz, p->len, m->name);

	void *buffer = memory::alloc_aligned(p->len, p->alignment, m);
	if (!buffer)
		throw MemoryAllocationError();

	logger->debug("Allocated {:#x} bytes for memory pool", p->len);

	p->buffer_off = (char*) buffer - (char*) p;

	ret = queue_init(&p->queue, LOG2_CEIL(cnt), m);
	if (ret)
		return ret;

	for (unsigned i = 0; i < cnt; i++)
		queue_push(&p->queue, (char *) buffer + i * p->blocksz);

	p->state = State::INITIALIZED;

	return 0;
}

int villas::node::pool_destroy(struct Pool *p)
{
	int ret;

	if (p->state == State::DESTROYED)
		return 0;

	ret = queue_destroy(&p->queue);
	if (ret)
		return ret;

	void *buffer = (char *) p + p->buffer_off;
	ret = memory::free(buffer);
	if (ret == 0)
		p->state = State::DESTROYED;

	return ret;
}

ssize_t villas::node::pool_get_many(struct Pool *p, void *blocks[], size_t cnt)
{
	return queue_pull_many(&p->queue, blocks, cnt);
}

ssize_t villas::node::pool_put_many(struct Pool *p, void *blocks[], size_t cnt)
{
	return queue_push_many(&p->queue, blocks, cnt);
}

void * villas::node::pool_get(struct Pool *p)
{
	void *ptr;
	return queue_pull(&p->queue, &ptr) == 1 ? ptr : nullptr;
}

int villas::node::pool_put(struct Pool *p, void *buf)
{
	return queue_push(&p->queue, buf);
}