/* 

 * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)

 * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 

 */

#include <pj/string.h>

#define PJ_POOL_ALIGN_PTR(PTR,ALIGNMENT)    (PTR + (-(pj_ssize_t)(PTR) & (ALIGNMENT-1)))

#define PJ_IS_POWER_OF_TWO(val)             (((val)>0) && ((val) & ((val)-1))==0)

#define PJ_IS_ALIGNED(PTR, ALIGNMENT)       (!((pj_ssize_t)(PTR) & ((ALIGNMENT)-1)))

PJ_IDEF(pj_size_t) pj_pool_get_capacity( pj_pool_t *pool )

{

    return pool->capacity;

}

PJ_IDEF(pj_size_t) pj_pool_get_used_size( pj_pool_t *pool )

{

    pj_pool_block *b = pool->block_list.next;

    pj_size_t used_size = sizeof(pj_pool_t);

    while (b != &pool->block_list) {

        used_size += (b->cur - b->buf) + sizeof(pj_pool_block);

        b = b->next;

    }

    return used_size;

}

PJ_IDEF(void*) pj_pool_alloc_from_block( pj_pool_block *block, pj_size_t alignment,

                                         pj_size_t size )

{

    unsigned char *ptr;

    pj_assert(PJ_IS_POWER_OF_TWO(alignment));

    // Size should be already aligned.

    // this code was moved up to pj_pool_aligned_alloc. 

    // ...and then removed there

    //

    ///* The operation below is valid for size==0. 

    // * When size==0, the function will return the pointer to the pool

    // * memory address, but no memory will be allocated.

    // */

    //if (size & (alignment -1)) {

    //    size = (size + alignment) & ~(alignment -1);

    //}

    ptr = PJ_POOL_ALIGN_PTR(block->cur, alignment);

    if (block->cur <= ptr && /* check pointer overflow */

        block->end - ptr >= (pj_ssize_t)size) /* check available size */

    {

    //if (ptr + size <= block->end &&

    //    /* here we check pointer overflow */

    //    block->cur <= ptr && ptr <= ptr + size) {

        block->cur = ptr + size;

        return ptr;

    }

    return NULL;

}

PJ_IDEF(void*) pj_pool_alloc( pj_pool_t *pool, pj_size_t size)

{

    return pj_pool_aligned_alloc(pool, 0, size);

}

PJ_IDEF(void*) pj_pool_aligned_alloc(pj_pool_t *pool, pj_size_t alignment,

                                     pj_size_t size)

{

    void *ptr;

    PJ_ASSERT_RETURN(!alignment || PJ_IS_POWER_OF_TWO(alignment), NULL);

    if (!alignment)

        alignment = pool->alignment;

#if 0

    //Rounding up is the compiler's job, not the allocator's.

    /* The operation below is valid for size==0. 

     * When size==0, the function will return the pointer to the pool

     * memory address, but no memory will be allocated.

     */

    if (size & (alignment -1)) {

        size = (size + alignment) & ~(alignment -1);

    }

    pj_assert(PJ_IS_ALIGNED(size, alignment));

#endif

    ptr = pj_pool_alloc_from_block(pool->block_list.next, 

                                   alignment, size);

    if (!ptr)

        ptr = pj_pool_allocate_find(pool, alignment, size);

    return ptr;

}

PJ_IDEF(void*) pj_pool_calloc( pj_pool_t *pool, pj_size_t count, pj_size_t size)

{

    void *buf = pj_pool_alloc( pool, size*count);

    if (buf)

        pj_bzero(buf, size * count);

    return buf;

}

PJ_IDEF(const char *) pj_pool_getobjname( const pj_pool_t *pool )

{

    return pool->obj_name;

}

PJ_IDEF(pj_pool_t*) pj_pool_create( pj_pool_factory *f, 

                                    const char *name,

                                    pj_size_t initial_size, 

                                    pj_size_t increment_size,

                                    pj_pool_callback *callback)

{

    return pj_pool_aligned_create(f, name, initial_size, increment_size, 0, callback);

}

PJ_IDEF(pj_pool_t*) pj_pool_aligned_create(pj_pool_factory *f,

                                           const char *name,

                                           pj_size_t initial_size,

                                           pj_size_t increment_size,

                                           pj_size_t alignment,

                                           pj_pool_callback *callback)

{

    return (*f->create_pool)(f, name, initial_size, increment_size, alignment, callback);

}

PJ_IDEF(void) pj_pool_release( pj_pool_t *pool )

{

#if PJ_POOL_RELEASE_WIPE_DATA

    pj_pool_block *b;

    b = pool->block_list.next;

    while (b != &pool->block_list) {

        volatile unsigned char *p = b->buf;

        while (p < b->end) *p++ = 0;

        b = b->next;

    }

#endif

    if (pool->factory->release_pool)

        (*pool->factory->release_pool)(pool->factory, pool);

}

PJ_IDEF(void) pj_pool_safe_release( pj_pool_t **ppool )

{

    pj_pool_t *pool = *ppool;

    *ppool = NULL;

    if (pool)

        pj_pool_release(pool);

}

PJ_IDEF(void) pj_pool_secure_release( pj_pool_t **ppool )

{

    pj_pool_block *b;

    pj_pool_t *pool = *ppool;

    *ppool = NULL;

    if (!pool)

        return;

    b = pool->block_list.next;

    while (b != &pool->block_list) {

        volatile unsigned char *p = b->buf;

        while (p < b->end) *p++ = 0;

        b = b->next;

    }

    pj_pool_release(pool);

}