/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

/* This code kindly donated to APR by 
 *    Elrond  <elrond@samba-tng.org>
 *    Luke Kenneth Casson Leighton <lkcl@samba-tng.org>
 *    Sander Striker <striker@samba-tng.org>
 *
 * May 2001
 */
 
#ifndef APR_MEMORY_SYSTEM_H
#define APR_MEMORY_SYSTEM_H

#include "apr.h"
#include "apr_errno.h"
#include "apr_pools.h"
#include "apr_lock.h"

#ifdef __cplusplus
extern "C" {
#endif

/* The various types of cleanup's we can offer */
#define APR_ALL_CLEANUPS      0x0000
#define APR_CHILD_CLEANUP     0x0001
#define APR_PARENT_CLEANUP    0x0002

/* Alignment macro's */
#define APR_ALIGN(size, boundary) \
    ((size) + (((boundary) - ((size) & ((boundary) - 1))) & ((boundary) - 1)))

#define APR_ALIGN_DEFAULT(size) APR_ALIGN(size, 8)


/**
 * @package APR memory system
 */

struct apr_sms_cleanup;
typedef struct apr_sms_t    apr_sms_t;

/**
 * The memory system structure
 */
struct apr_sms_t
{
    apr_sms_t  *parent;
    apr_sms_t  *child;
    apr_sms_t  *sibling;
    apr_sms_t **ref;
    apr_sms_t  *accounting;
    const char *identity; /* a string identifying the module */

    apr_pool_t *pool;
    apr_lock_t *sms_lock;
    
    struct apr_sms_cleanup *cleanups;

    void * (*malloc_fn)            (apr_sms_t *sms, apr_size_t size);
    void * (*calloc_fn)            (apr_sms_t *sms, apr_size_t size);
    void * (*realloc_fn)           (apr_sms_t *sms, void *memory, 
                                    apr_size_t size);
    apr_status_t (*free_fn)        (apr_sms_t *sms, void *memory);
    apr_status_t (*reset_fn)       (apr_sms_t *sms);
    apr_status_t (*pre_destroy_fn) (apr_sms_t *sms);
    apr_status_t (*destroy_fn)     (apr_sms_t *sms);
    apr_status_t (*lock_fn)        (apr_sms_t *sms);
    apr_status_t (*unlock_fn)      (apr_sms_t *sms);
};

/*
 * memory allocation functions 
 */

/**
 * Allocate a block of memory using a certain memory system
 * @param sms The memory system to use
 * @param size The (minimal required) size of the block to be allocated
 * @return pointer to a newly allocated block of memory, NULL if insufficient
 *         memory available
 * @deffunc void *apr_sms_malloc(apr_sms_t *sms, apr_size_t size)
 */
APR_DECLARE(void *) apr_sms_malloc(apr_sms_t *sms, apr_size_t size);

/**
 * Allocate a block of zeroed memory using a certain memory system
 * @param sms The memory system to use
 * @param size The (minimal required) size of the block to be allocated
 * @return pointer to a newly allocated block of memory, NULL if insufficient
 *         memory available
 * @deffunc void *apr_sms_calloc(apr_sms_t *sms, apr_size_t size)
 */
APR_DECLARE(void *) apr_sms_calloc(apr_sms_t *sms, apr_size_t size);

/**
 * Change the size of a previously allocated block of memory
 * @param sms The memory system to use (should be the same as the
 *        one that returned the block)
 * @param mem Pointer to the previously allocated block. If NULL, this
 *        function acts like apr_sms_malloc.
 * @param size The (minimal required) size of the block to be allocated
 * @return pointer to a newly allocated block of memory, NULL if insufficient
 *         memory available
 * @deffunc void *apr_sms_realloc(apr_sms_t *sms, void *mem, apr_size_t size)
 */
APR_DECLARE(void *) apr_sms_realloc(apr_sms_t *sms, void *mem, apr_size_t size);

/**
 * Free a block of memory
 * @param sms The memory system to use (should be the same as the
 *        one that returned the block)
 * @param mem The block of memory to be freed
 * @deffunc void apr_sms_free(apr_sms_t *sms,
 *					void *mem)
 */
APR_DECLARE(apr_status_t) apr_sms_free(apr_sms_t *sms, void *mem);

/*
 * memory system functions
 */

/**
 * Initialize a memory system
 * @caution Call this function as soon as you have obtained a block of memory
 *          to serve as a memory system structure from your 
 *          apr_xxx_sms_create. Only use this function when you are
 *          implementing a memory system.
 * @param sms The memory system created
 * @param parent_sms The parent memory system
 * @deffunc apr_status_t apr_sms_init(apr_sms_t *sms,
 *				      apr_sms_t *parent_sms)
 */
APR_DECLARE(apr_status_t) apr_sms_init(apr_sms_t *sms, 
                                       apr_sms_t *parent_sms);

/**
 * Check if a memory system is obeying all rules. 
 * @caution Call this function as the last statement before returning a new
 *          memory system from your apr_xxx_sms_create.
 * @deffunc void apr_sms_validate(apr_sms_t *sms)
 */
#ifdef APR_ASSERT_MEMORY
APR_DECLARE(void) apr_sms_assert(apr_sms_t *sms);
#else
#ifdef apr_sms_assert
#undef apr_sms_assert
#endif
#define apr_sms_assert(sms)
#endif /* APR_ASSERT_MEMORY */

/**
 * Reset a memory system so it can be reused. 
 * This will also run all cleanup functions associated with the memory system
 * @warning This function will fail if there is no reset function available
 *          for the given memory system (i.e. the memory system is non-
 *          tracking).
 * @param sms The memory system to be reset
 * @deffunc apr_status_t apr_sms_reset(apr_sms_t *sms)
 */
APR_DECLARE(apr_status_t) apr_sms_reset(apr_sms_t *sms);

/**
 * Destroy a memory system, effectively freeing all of its memory, and itself. 
 * This will also run all cleanup functions associated with the memory system.
 * @caution Be carefull when using this function with a non-tracking memory
 *          system
 * @param sms The memory system to be destroyed
 * @deffunc apr_status_t apr_sms_destroy(apr_sms_t *sms)
 */
APR_DECLARE(apr_status_t) apr_sms_destroy(apr_sms_t *sms);

/**
 * Perform thread-safe locking required whilst this memory system is modified
 * @param sms The memory system to be locked for thread-safety
 */
APR_DECLARE(apr_status_t) apr_sms_lock(apr_sms_t *sms);

/**
 * Release thread-safe locking required whilst this memory system was
 * being modified
 * @param sms The memory system to be released from thread-safety
 */
APR_DECLARE(apr_status_t) apr_sms_unlock(apr_sms_t *sms);

/**
 * Determine if memory system a is an ancestor of memory system b
 * @param a The memory system to search
 * @param b The memory system to search for
 * @return APR_SUCCESS if a is an ancestor of b, 1 if it isn't
 * @deffunc apr_status_t apr_sms_is_ancestor(apr_sms_t *a,
 *						     apr_sms_t *b)
 */
APR_DECLARE(apr_status_t) apr_sms_is_ancestor(apr_sms_t *a, apr_sms_t *b);

/** 
 * Get the memory_system identity
 * @param sms The memory system to use
 * @deffunc const char * apr_sms_identity(apr_sms_t *sms);
 */
APR_DECLARE(const char *) apr_sms_identity(apr_sms_t *sms);

/**
 * Get the parent sms
 * @param sms the memory system to get the parent from
 */
APR_DECLARE(apr_sms_t *) apr_sms_get_parent(apr_sms_t *sms);

/*
 * memory system cleanup management functions
 */

/**
 * Register a function to be called when a memory system is reset or destroyed
 * @param sms The memory system to register the cleanup function with
 * @param type The type of cleanup to register
 * @param data The data to pass to the cleanup function
 * @param cleanup_fn The function to call when the memory system is reset or
 *        destroyed
 * @deffunc void apr_sms_cleanup_register(apr_sms_t *sms, apr_int32_t type,
 *		   void *data, apr_status_t (*cleanup_fn)(void *));
 */
APR_DECLARE(apr_status_t) apr_sms_cleanup_register(apr_sms_t *sms, apr_int32_t type,
                                                   void *data, 
                                                   apr_status_t (*cleanup_fn)(void *));

/**
 * Unregister a previously registered cleanup function
 * @param sms The memory system the cleanup function is registered
 *        with
 * @param type The type of the cleanup to unregister
 * @param data The data associated with the cleanup function
 * @param cleanup_fn The registered cleanup function
 * @deffunc void apr_sms_cleanup_unregister(apr_sms_t *sms,
 *		   void *data, apr_status_t (*cleanup_fn)(void *));
 */
APR_DECLARE(apr_status_t) apr_sms_cleanup_unregister(apr_sms_t *sms, apr_int32_t type,
                                                     void *data,
                                                     apr_status_t (*cleanup)(void *));

/**
 * Unregister all previously registered cleanup functions of the specified type
 * @param sms The memory system the cleanup functions are registered with
 * @param type The type associated with the cleanup function. Pass 0 to 
 *        unregister all cleanup functions.
 * @deffunc apr_status_t apr_sms_cleanup_unregister_type(apr_sms_t *sms,
 *                 apr_int32_t type);
 */
APR_DECLARE(apr_status_t) apr_sms_cleanup_unregister_type(apr_sms_t *sms,
                                                           apr_int32_t type);

/**
 * Run the specified cleanup function immediately and unregister it
 * @param sms The memory system the cleanup function is registered
 *        with
 * @param sms The memory system the cleanup function is registered with
 * @param type The type associated with the cleanup function. Pass 0 to ignore type.
 * @param data The data associated with the cleanup function
 * @param cleanup The registered cleanup function
 * @deffunc apr_status_t apr_sms_cleanup_run(apr_sms_t *sms, 
 *                 apr_int32_t type, void *data, apr_status_t (*cleanup)(void *));
 */
APR_DECLARE(apr_status_t) apr_sms_cleanup_run(apr_sms_t *sms, 
                                              apr_int32_t type, void *data,
                                              apr_status_t (*cleanup)(void *));

/**
 * Run the specified type of cleanup functions immediately and unregister them
 * @param sms The memory system the cleanup functions are registered with
 * @param type The category of cleanup functions to run. Pass 0 to run all
 *        cleanup functions.
 * @deffunc apr_status_t apr_sms_cleanup_run_type(apr_sms_t *sms,
 *	           apr_int32_t type);
 */
APR_DECLARE(apr_status_t) apr_sms_cleanup_run_type(apr_sms_t *sms, 
                                                   apr_int32_t type);

/**
 * Create a standard malloc/realloc/free memory system
 * @param sms A pointer to the created apr_sms_t*
 * @deffunc apr_status_t apr_sms_std_create(apr_sms_t **sms);
 */
APR_DECLARE(apr_status_t) apr_sms_std_create(apr_sms_t **sms);

#ifdef __cplusplus
}
#endif

#endif /* !APR_MEMORY_SYSTEM_H */