/* 

 * 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/pool.h>

#include <pj/assert.h>

#include <pj/log.h>

#include <pj/string.h>

#include <pj/assert.h>

#include <pj/lock.h>

#include <pj/os.h>

#include <pj/pool_buf.h>

#if !PJ_HAS_POOL_ALT_API

static pj_pool_t* cpool_create_pool(pj_pool_factory *pf, 

                                    const char *name,

                                    pj_size_t initial_size, 

                                    pj_size_t increment_sz,

                                    pj_size_t alignment,

                                    pj_pool_callback *callback);

static void cpool_release_pool(pj_pool_factory *pf, pj_pool_t *pool);

static void cpool_dump_status(pj_pool_factory *factory, pj_bool_t detail );

static pj_bool_t cpool_on_block_alloc(pj_pool_factory *f, pj_size_t sz);

static void cpool_on_block_free(pj_pool_factory *f, pj_size_t sz);

static pj_size_t pool_sizes[PJ_CACHING_POOL_ARRAY_SIZE] = 

{

    256, 512, 1024, 2048, 4096, 8192, 12288, 16384, 

    20480, 24576, 28672, 32768, 40960, 49152, 57344, 65536

};

/* Index where the search for size should begin.

 * Start with pool_sizes[5], which is 8192.

 */

#define START_SIZE  5

PJ_DEF(void) pj_caching_pool_init( pj_caching_pool *cp, 

                                   const pj_pool_factory_policy *policy,

                                   pj_size_t max_capacity)

{

    int i;

    pj_pool_t *pool;

    pj_status_t status;

    PJ_CHECK_STACK();

    pj_bzero(cp, sizeof(*cp));

    cp->max_capacity = max_capacity;

    pj_list_init(&cp->used_list);

    for (i=0; i<PJ_CACHING_POOL_ARRAY_SIZE; ++i)

        pj_list_init(&cp->free_list[i]);

    if (policy == NULL) {

        policy = &pj_pool_factory_default_policy;

    }

    pj_memcpy(&cp->factory.policy, policy, sizeof(pj_pool_factory_policy));

    cp->factory.create_pool = &cpool_create_pool;

    cp->factory.release_pool = &cpool_release_pool;

    cp->factory.dump_status = &cpool_dump_status;

    /* Deprecated, these callbacks are only used for updating cp.used_size &

     * cp.peak_used_size which are no longer used.

     */

    //cp->factory.on_block_alloc = &cpool_on_block_alloc;

    //cp->factory.on_block_free = &cpool_on_block_free;

    PJ_UNUSED_ARG(cpool_on_block_alloc);

    PJ_UNUSED_ARG(cpool_on_block_free);

    pool = pj_pool_create_on_buf("cachingpool", cp->pool_buf, sizeof(cp->pool_buf));

    status = pj_lock_create_simple_mutex(pool, "cachingpool", &cp->lock);

    /* This mostly serves to silent coverity warning about unchecked 

     * return value. There's not much we can do if it fails. */

    PJ_ASSERT_ON_FAIL(status==PJ_SUCCESS, return);

}

PJ_DEF(void) pj_caching_pool_destroy( pj_caching_pool *cp )

{

    int i;

    pj_pool_t *pool;

    PJ_CHECK_STACK();

    /* Delete all pool in free list */

    for (i=0; i < PJ_CACHING_POOL_ARRAY_SIZE; ++i) {

        pj_pool_t *next;

        pool = (pj_pool_t*) cp->free_list[i].next;

        for (; pool != (void*)&cp->free_list[i]; pool = next) {

            next = pool->next;

            pj_list_erase(pool);

            pj_pool_destroy_int(pool);

        }

    }

    /* Delete all pools in used list */

    pool = (pj_pool_t*) cp->used_list.next;

    while (pool != (pj_pool_t*) &cp->used_list) {

        pj_pool_t *next = pool->next;

        pj_list_erase(pool);

        PJ_LOG(4,(pool->obj_name, 

                  "Pool is not released by application, releasing now"));

        pj_pool_destroy_int(pool);

        pool = next;

    }

    if (cp->lock) {

        pj_status_t status;

        pj_lock_destroy(cp->lock);

        status = pj_lock_create_null_mutex(NULL, "cachingpool", &cp->lock);

        PJ_ASSERT_ON_FAIL(status==PJ_SUCCESS, return);

    }

}

static pj_pool_t* cpool_create_pool(pj_pool_factory *pf, 

                                    const char *name, 

                                    pj_size_t initial_size, 

                                    pj_size_t increment_sz,

                                    pj_size_t alignment,

                                    pj_pool_callback *callback)

{

    pj_caching_pool *cp = (pj_caching_pool*)pf;

    pj_pool_t *pool;

    int idx;

    PJ_CHECK_STACK();

    pj_lock_acquire(cp->lock);

    /* Use pool factory's policy when callback is NULL */

    if (callback == NULL) {

        callback = pf->policy.callback;

    }

    /* Search the suitable size for the pool. 

     * We'll just do linear search to the size array, as the array size itself

     * is only a few elements. Binary search I suspect will be less efficient

     * for this purpose.

     */

    if (initial_size <= pool_sizes[START_SIZE]) {

        for (idx=START_SIZE-1; 

             idx >= 0 && pool_sizes[idx] >= initial_size;

             --idx)

            ;

        ++idx;

    } else {

        for (idx=START_SIZE+1; 

             idx < PJ_CACHING_POOL_ARRAY_SIZE && 

                  pool_sizes[idx] < initial_size;

             ++idx)

            ;

    }

    /* Check whether there's a pool in the list. */

    if (idx==PJ_CACHING_POOL_ARRAY_SIZE || pj_list_empty(&cp->free_list[idx])) {

        /* No pool is available. */

        /* Set minimum size. */

        if (idx < PJ_CACHING_POOL_ARRAY_SIZE)

            initial_size =  pool_sizes[idx];

        /* Create new pool */

        pool = pj_pool_create_int(&cp->factory, name, initial_size, 

                                  increment_sz, alignment, callback);

        if (!pool) {

            pj_lock_release(cp->lock);

            return NULL;

        }

    } else {

        /* Get one pool from the list. */

        pool = (pj_pool_t*) cp->free_list[idx].next;

        pj_list_erase(pool);

        /* Initialize the pool. */

        pj_pool_init_int(pool, name, increment_sz, alignment, callback);

        /* Update pool manager's free capacity. */

        if (cp->capacity > pj_pool_get_capacity(pool)) {

            cp->capacity -= pj_pool_get_capacity(pool);

        } else {

            cp->capacity = 0;

        }

        PJ_LOG(6, (pool->obj_name, "pool reused, size=%lu",

                   (unsigned long)pool->capacity));

    }

    /* Put in used list. */

    pj_list_insert_before( &cp->used_list, pool );

    /* Mark factory data */

    pool->factory_data = (void*) (pj_ssize_t) idx;

    /* Increment used count. */

    ++cp->used_count;

    pj_lock_release(cp->lock);

    return pool;

}

static void cpool_release_pool( pj_pool_factory *pf, pj_pool_t *pool)

{

    pj_caching_pool *cp = (pj_caching_pool*)pf;

    pj_size_t pool_capacity;

    unsigned i;

    PJ_CHECK_STACK();

    PJ_ASSERT_ON_FAIL(pf && pool, return);

    pj_lock_acquire(cp->lock);

#if PJ_SAFE_POOL

    /* Make sure pool is still in our used list */

    if (pj_list_find_node(&cp->used_list, pool) != pool) {

        pj_lock_release(cp->lock);

        pj_assert(!"Attempt to destroy pool that has been destroyed before");

        return;

    }

#endif

    /* Erase from the used list. */

    pj_list_erase(pool);

    /* Decrement used count. */

    --cp->used_count;

    pool_capacity = pj_pool_get_capacity(pool);

    /* Destroy the pool if the size is greater than our size or if the total

     * capacity in our recycle list (plus the size of the pool) exceeds 

     * maximum capacity.

   . */

    if (pool_capacity > pool_sizes[PJ_CACHING_POOL_ARRAY_SIZE-1] ||

        cp->capacity + pool_capacity > cp->max_capacity)

    {

        pj_pool_destroy_int(pool);

        pj_lock_release(cp->lock);

        return;

    }

    /* Reset pool. */

    PJ_LOG(6, (pool->obj_name, "recycle(): cap=%lu, used=%lu(%lu%%)", 

               (unsigned long)pool_capacity,

               (unsigned long)pj_pool_get_used_size(pool), 

               (unsigned long)(pj_pool_get_used_size(pool)*100/

                               pool_capacity)));

    pj_pool_reset(pool);

    pool_capacity = pj_pool_get_capacity(pool);

    /*

     * Otherwise put the pool in our recycle list.

     */

    i = (unsigned) (unsigned long) (pj_ssize_t) pool->factory_data;

    pj_assert(i<PJ_CACHING_POOL_ARRAY_SIZE);

    if (i >= PJ_CACHING_POOL_ARRAY_SIZE ) {

        /* Something has gone wrong with the pool. */

        pj_pool_destroy_int(pool);

        pj_lock_release(cp->lock);

        return;

    }

    pj_list_insert_after(&cp->free_list[i], pool);

    cp->capacity += pool_capacity;

    pj_lock_release(cp->lock);

}

static void cpool_dump_status(pj_pool_factory *factory, pj_bool_t detail )

{

#if PJ_LOG_MAX_LEVEL >= 3

    pj_caching_pool *cp = (pj_caching_pool*)factory;

    pj_lock_acquire(cp->lock);

    PJ_LOG(3,("cachpool", " Dumping caching pool:"));

    PJ_LOG(3,("cachpool", "   Capacity=%lu, max_capacity=%lu, used_cnt=%lu",

              (unsigned long)cp->capacity, (unsigned long)cp->max_capacity,

              (unsigned long)cp->used_count));

    if (detail) {

        pj_pool_t *pool = (pj_pool_t*) cp->used_list.next;

        pj_size_t total_used = 0, total_capacity = 0;

        PJ_LOG(3,("cachpool", "  Dumping all active pools:"));

        while (pool != (void*)&cp->used_list) {

            pj_size_t pool_capacity = pj_pool_get_capacity(pool);

            pj_pool_block *block = pool->block_list.next;

            unsigned nblocks = 0;

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

#if 0

                PJ_LOG(6, ("cachpool", "   %16s block %u, size %ld",

                                       pj_pool_getobjname(pool), nblocks,

                                       (long)(block->end - block->buf + 1)));

#endif

                nblocks++;

                block = block->next;

            }

            PJ_LOG(3,("cachpool", "   %16s: %8lu of %8lu (%lu%%) used, "

                                  "nblocks: %d",

                                  pj_pool_getobjname(pool), 

                                  (unsigned long)pj_pool_get_used_size(pool), 

                                  (unsigned long)pool_capacity,

                                  (unsigned long)(pj_pool_get_used_size(pool)*

                                                  100/pool_capacity),

                                  nblocks));

#if PJ_POOL_MAX_SEARCH_BLOCK_COUNT == 0

            if (nblocks >= 10) {

                PJ_LOG(3,("cachpool", "   %16s has too many blocks (%d), "

                                      "consider increasing its initial and/or "

                                      "increment size for better performance",

                                      pj_pool_getobjname(pool), nblocks));

            }

#endif

            total_used += pj_pool_get_used_size(pool);

            total_capacity += pool_capacity;

            pool = pool->next;

        }

        if (total_capacity) {

            PJ_LOG(3,("cachpool", "  Total %9lu of %9lu (%lu %%) used!",

                                  (unsigned long)total_used,

                                  (unsigned long)total_capacity,

                                  (unsigned long)(total_used * 100 /

                                                  total_capacity)));

        }

    }

    pj_lock_release(cp->lock);

#else

    PJ_UNUSED_ARG(factory);

    PJ_UNUSED_ARG(detail);

#endif

}

static pj_bool_t cpool_on_block_alloc(pj_pool_factory *f, pj_size_t sz)

{

    pj_caching_pool *cp = (pj_caching_pool*)f;

    //Can't lock because mutex is not recursive

    //if (cp->mutex) pj_mutex_lock(cp->mutex);

    cp->used_size += sz;

    if (cp->used_size > cp->peak_used_size)

        cp->peak_used_size = cp->used_size;

    //if (cp->mutex) pj_mutex_unlock(cp->mutex);

    return PJ_TRUE;

}

static void cpool_on_block_free(pj_pool_factory *f, pj_size_t sz)

{

    pj_caching_pool *cp = (pj_caching_pool*)f;

    //pj_mutex_lock(cp->mutex);

    cp->used_size -= sz;

    //pj_mutex_unlock(cp->mutex);

}

#endif  /* PJ_HAS_POOL_ALT_API */