/*
 * Copyright © 2006 Joonas Pihlaja
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */
#ifndef CAIRO_FREELIST_H
#define CAIRO_FREELIST_H

#include "cairo-types-private.h"
#include "cairo-compiler-private.h"

/* for stand-alone compilation*/
#ifndef VG
#define VG(x)
#endif

#ifndef NULL
#define NULL (void *) 0
#endif

typedef struct _cairo_freelist_node cairo_freelist_node_t;
struct _cairo_freelist_node {
    cairo_freelist_node_t *next;
};

typedef struct _cairo_freelist {
    cairo_freelist_node_t *first_free_node;
    unsigned nodesize;
} cairo_freelist_t;

typedef struct _cairo_freelist_pool cairo_freelist_pool_t;
struct _cairo_freelist_pool {
    cairo_freelist_pool_t *next;
    unsigned size, rem;
    uint8_t *data;
};

typedef struct _cairo_freepool {
    cairo_freelist_node_t *first_free_node;
    cairo_freelist_pool_t *pools;
    unsigned nodesize;
    cairo_freelist_pool_t embedded_pool;
    uint8_t embedded_data[1000];
} cairo_freepool_t;


/* Initialise a freelist that will be responsible for allocating
 * nodes of size nodesize. */
cairo_private void
_cairo_freelist_init (cairo_freelist_t *freelist, unsigned nodesize);

/* Deallocate any nodes in the freelist. */
cairo_private void
_cairo_freelist_fini (cairo_freelist_t *freelist);

/* Allocate a new node from the freelist.  If the freelist contains no
 * nodes, a new one will be allocated using malloc().  The caller is
 * responsible for calling _cairo_freelist_free() or free() on the
 * returned node.  Returns %NULL on memory allocation error. */
cairo_private void *
_cairo_freelist_alloc (cairo_freelist_t *freelist);

/* Allocate a new node from the freelist.  If the freelist contains no
 * nodes, a new one will be allocated using calloc().  The caller is
 * responsible for calling _cairo_freelist_free() or free() on the
 * returned node.  Returns %NULL on memory allocation error. */
cairo_private void *
_cairo_freelist_calloc (cairo_freelist_t *freelist);

/* Return a node to the freelist. This does not deallocate the memory,
 * but makes it available for later reuse by
 * _cairo_freelist_alloc(). */
cairo_private void
_cairo_freelist_free (cairo_freelist_t *freelist, void *node);


cairo_private void
_cairo_freepool_init (cairo_freepool_t *freepool, unsigned nodesize);

cairo_private void
_cairo_freepool_fini (cairo_freepool_t *freepool);

cairo_private void *
_cairo_freepool_alloc_from_new_pool (cairo_freepool_t *freepool);

static inline void *
_cairo_freepool_alloc_from_pool (cairo_freepool_t *freepool)
{
    cairo_freelist_pool_t *pool;
    uint8_t *ptr;

    pool = freepool->pools;
    if (unlikely (freepool->nodesize > pool->rem))
	return _cairo_freepool_alloc_from_new_pool (freepool);

    ptr = pool->data;
    pool->data += freepool->nodesize;
    pool->rem -= freepool->nodesize;
    VG (VALGRIND_MAKE_MEM_UNDEFINED (ptr, freepool->nodesize));
    return ptr;
}

static inline void *
_cairo_freepool_alloc (cairo_freepool_t *freepool)
{
    cairo_freelist_node_t *node;

    node = freepool->first_free_node;
    if (unlikely (node == NULL))
	return _cairo_freepool_alloc_from_pool (freepool);

    VG (VALGRIND_MAKE_MEM_DEFINED (node, sizeof (node->next)));
    freepool->first_free_node = node->next;
    VG (VALGRIND_MAKE_MEM_UNDEFINED (node, freepool->nodesize));

    return node;
}

static inline void
_cairo_freepool_free (cairo_freepool_t *freepool, void *ptr)
{
    cairo_freelist_node_t *node = ptr;

    node->next = freepool->first_free_node;
    freepool->first_free_node = node;
    VG (VALGRIND_MAKE_MEM_NOACCESS (node, freepool->nodesize));
}

#endif /* CAIRO_FREELIST_H */