/*
  +----------------------------------------------------------------------+
  | Swoole                                                               |
  +----------------------------------------------------------------------+
  | This source file is subject to version 2.0 of the Apache license,    |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | http://www.apache.org/licenses/LICENSE-2.0.html                      |
  | If you did not receive a copy of the Apache2.0 license and are unable|
  | to obtain it through the world-wide-web, please send a note to       |
  | license@swoole.com so we can mail you a copy immediately.            |
  +----------------------------------------------------------------------+
  | Author: Tianfeng Han  <mikan.tenny@gmail.com>                        |
  +----------------------------------------------------------------------+
*/

#include "swoole.h"

static void swFixedPool_init(swFixedPool *object);
static void* swFixedPool_alloc(swMemoryPool *pool, uint32_t size);
static void swFixedPool_free(swMemoryPool *pool, void *ptr);
static void swFixedPool_destroy(swMemoryPool *pool);

void swFixedPool_debug_slice(swFixedPool_slice *slice);

/**
 * create new FixedPool, random alloc/free fixed size memory
 */
swMemoryPool* swFixedPool_new(uint32_t slice_num, uint32_t slice_size, uint8_t shared)
{
    size_t size = slice_size * slice_num + slice_num * sizeof(swFixedPool_slice);
    size_t alloc_size = size + sizeof(swFixedPool) + sizeof(swMemoryPool);
    void *memory = (shared == 1) ? sw_shm_malloc(alloc_size) : sw_malloc(alloc_size);

    swFixedPool *object = memory;
    memory += sizeof(swFixedPool);
    bzero(object, sizeof(swFixedPool));

    object->shared = shared;
    object->slice_num = slice_num;
    object->slice_size = slice_size;
    object->size = size;

    swMemoryPool *pool = memory;
    memory += sizeof(swMemoryPool);
    pool->object = object;
    pool->alloc = swFixedPool_alloc;
    pool->free = swFixedPool_free;
    pool->destroy = swFixedPool_destroy;

    object->memory = memory;

    /**
     * init linked list
     */
    swFixedPool_init(object);

    return pool;
}

/**
 * create new FixedPool, Using the given memory
 */
swMemoryPool* swFixedPool_new2(uint32_t slice_size, void *memory, size_t size)
{
    swFixedPool *object = memory;
    memory += sizeof(swFixedPool);
    bzero(object, sizeof(swFixedPool));

    object->slice_size = slice_size;
    object->size = size - sizeof(swMemoryPool) - sizeof(swFixedPool);
    object->slice_num = object->size / (slice_size + sizeof(swFixedPool_slice));

    swMemoryPool *pool = memory;
    memory += sizeof(swMemoryPool);
    bzero(pool, sizeof(swMemoryPool));

    pool->object = object;
    pool->alloc = swFixedPool_alloc;
    pool->free = swFixedPool_free;
    pool->destroy = swFixedPool_destroy;

    object->memory = memory;

    /**
     * init linked list
     */
    swFixedPool_init(object);

    return pool;
}

/**
 * linked list
 */
static void swFixedPool_init(swFixedPool *object)
{
    swFixedPool_slice *slice;
    void *cur = object->memory;
    void *max = object->memory + object->size;
    do
    {
        slice = (swFixedPool_slice *) cur;
        bzero(slice, sizeof(swFixedPool_slice));

        if (object->head != NULL)
        {
            object->head->pre = slice;
            slice->next = object->head;
        }
        else
        {
            object->tail = slice;
        }

        object->head = slice;
        cur += (sizeof(swFixedPool_slice) + object->slice_size);

        if (cur < max)
        {
            slice->pre = (swFixedPool_slice *) cur;
        }
        else
        {
            slice->pre = NULL;
            break;
        }

    } while (1);
}

static void* swFixedPool_alloc(swMemoryPool *pool, uint32_t size)
{
    swFixedPool *object = pool->object;
    swFixedPool_slice *slice;

    slice = object->head;

    if (slice->lock == 0)
    {
        slice->lock = 1;
        object->slice_use ++;
        /**
         * move next slice to head (idle list)
         */
        object->head = slice->next;
        slice->next->pre = NULL;

        /*
         * move this slice to tail (busy list)
         */
        object->tail->next = slice;
        slice->next = NULL;
        slice->pre = object->tail;
        object->tail = slice;

        return slice->data;
    }
    else
    {
        return NULL;
    }
}

static void swFixedPool_free(swMemoryPool *pool, void *ptr)
{
    swFixedPool *object = pool->object;
    swFixedPool_slice *slice;

    assert(ptr > object->memory && ptr < object->memory + object->size);

    slice = ptr - sizeof(swFixedPool_slice);

    if (slice->lock)
    {
        object->slice_use--;
    }

    slice->lock = 0;

    //list head, AB
    if (slice->pre == NULL)
    {
        return;
    }
    //list tail, DE
    if (slice->next == NULL)
    {
        slice->pre->next = NULL;
        object->tail = slice->pre;
    }
    //middle BCD
    else
    {
        slice->pre->next = slice->next;
        slice->next->pre = slice->pre;
    }

    slice->pre = NULL;
    slice->next = object->head;
    object->head->pre = slice;
    object->head = slice;
}

static void swFixedPool_destroy(swMemoryPool *pool)
{
    swFixedPool *object = pool->object;
    if (object->shared)
    {
        sw_shm_free(object);
    }
    else
    {
        sw_free(object);
    }
}

void swFixedPool_debug(swMemoryPool *pool)
{
    int line = 0;
    swFixedPool *object = pool->object;
    swFixedPool_slice *slice = object->head;

    printf("===============================%s=================================\n", __FUNCTION__);
    while (slice != NULL)
    {
        if (slice->next == slice)
        {
            printf("-------------------@@@@@@@@@@@@@@@@@@@@@@----------------\n");

        }
        printf("#%d\t", line);
        swFixedPool_debug_slice(slice);

        slice = slice->next;
        line++;
        if (line > 100)
            break;
    }
}

void swFixedPool_debug_slice(swFixedPool_slice *slice)
{
    printf("Slab[%p]\t", slice);
    printf("pre=%p\t", slice->pre);
    printf("next=%p\t", slice->next);
    printf("tag=%d\t", slice->lock);
    printf("data=%p\n", slice->data);
}