/*

 * Memory Pool implementation logic.

 */

#include "cache.h"

#include "mem-pool.h"

static struct mp_block *mem_pool_alloc_block(struct mem_pool *mem_pool, size_t block_alloc)

{

	struct mp_block *p;

	mem_pool->pool_alloc += sizeof(struct mp_block) + block_alloc;

	p = xmalloc(st_add(sizeof(struct mp_block), block_alloc));

	p->next_block = mem_pool->mp_block;

	p->next_free = (char *)p->space;

	p->end = p->next_free + block_alloc;

	mem_pool->mp_block = p;

	return p;

}

void *mem_pool_alloc(struct mem_pool *mem_pool, size_t len)

{

	struct mp_block *p;

	void *r;

	/* round up to a 'uintmax_t' alignment */

	if (len & (sizeof(uintmax_t) - 1))

		len += sizeof(uintmax_t) - (len & (sizeof(uintmax_t) - 1));

	for (p = mem_pool->mp_block; p; p = p->next_block)

		if (p->end - p->next_free >= len)

			break;

	if (!p) {

		if (len >= (mem_pool->block_alloc / 2)) {

			mem_pool->pool_alloc += len;

			return xmalloc(len);

		}

		p = mem_pool_alloc_block(mem_pool, mem_pool->block_alloc);

	}

	r = p->next_free;

	p->next_free += len;

	return r;

}

void *mem_pool_calloc(struct mem_pool *mem_pool, size_t count, size_t size)

{

	size_t len = st_mult(count, size);

	void *r = mem_pool_alloc(mem_pool, len);

	memset(r, 0, len);

	return r;

}