gtk/gtk/gtkallocatedbitmask.c
Neil Roberts 6044dfc35b bitmask: Don't allocate memory for small bitmasks
Code taken more or less verbatim from CoglBitmask.
2012-03-01 15:10:36 +01:00

344 lines
8.0 KiB
C

/*
* Copyright © 2011 Red Hat Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
* Authors: Benjamin Otte <otte@gnome.org>
*/
#include <config.h>
#include "gtk/gtkallocatedbitmaskprivate.h"
#define VALUE_TYPE gsize
#define VALUE_SIZE_BITS (sizeof (VALUE_TYPE) * 8)
#define VALUE_BIT(idx) (((VALUE_TYPE) 1) << (idx))
struct _GtkBitmask {
gsize len;
VALUE_TYPE data[1];
};
#define ENSURE_ALLOCATED(mask, heap_mask) G_STMT_START { \
if (!_gtk_bitmask_is_allocated (mask)) \
{ \
heap_mask.data[0] = _gtk_bitmask_to_bits (mask); \
heap_mask.len = heap_mask.data[0] ? 1 : 0; \
mask = &heap_mask; \
} \
} G_STMT_END
static GtkBitmask *
gtk_allocated_bitmask_resize (GtkBitmask *mask,
gsize size) G_GNUC_WARN_UNUSED_RESULT;
static GtkBitmask *
gtk_allocated_bitmask_resize (GtkBitmask *mask,
gsize size)
{
gsize i;
mask = g_realloc (mask, sizeof (GtkBitmask) + sizeof(VALUE_TYPE) * (size - 1));
for (i = mask->len; i < size; i++)
mask->data[i] = 0;
mask->len = size;
return mask;
}
static GtkBitmask *
gtk_allocated_bitmask_new_for_bits (gsize bits)
{
GtkBitmask *mask;
mask = g_malloc (sizeof (GtkBitmask));
mask->len = bits ? 1 : 0;
mask->data[0] = bits;
return mask;
}
static GtkBitmask *
gtk_bitmask_ensure_allocated (GtkBitmask *mask)
{
if (_gtk_bitmask_is_allocated (mask))
return mask;
else
return gtk_allocated_bitmask_new_for_bits (_gtk_bitmask_to_bits (mask));
}
GtkBitmask *
_gtk_allocated_bitmask_copy (const GtkBitmask *mask)
{
GtkBitmask *copy;
g_return_val_if_fail (mask != NULL, NULL);
copy = gtk_allocated_bitmask_new_for_bits (0);
return _gtk_allocated_bitmask_union (copy, mask);
}
void
_gtk_allocated_bitmask_free (GtkBitmask *mask)
{
g_return_if_fail (mask != NULL);
g_free (mask);
}
void
_gtk_allocated_bitmask_print (const GtkBitmask *mask,
GString *string)
{
GtkBitmask mask_allocated;
int i;
g_return_if_fail (mask != NULL);
g_return_if_fail (string != NULL);
ENSURE_ALLOCATED (mask, mask_allocated);
for (i = mask->len * VALUE_SIZE_BITS - 1; i >= 0; i--)
{
if (_gtk_allocated_bitmask_get (mask, i))
break;
}
if (i < 0)
{
g_string_append_c (string, '0');
return;
}
for (; i >= 0; i--)
{
g_string_append_c (string, _gtk_allocated_bitmask_get (mask, i) ? '1' : '0');
}
}
/* NB: Call this function whenever the
* array might have become too large.
* _gtk_allocated_bitmask_is_empty() depends on this.
*/
static GtkBitmask *
gtk_allocated_bitmask_shrink (GtkBitmask *mask) G_GNUC_WARN_UNUSED_RESULT;
static GtkBitmask *
gtk_allocated_bitmask_shrink (GtkBitmask *mask)
{
guint i;
for (i = mask->len; i; i--)
{
if (mask->data[i - 1])
break;
}
if (i == 0 ||
(i == 1 && mask->data[0] < VALUE_BIT (GTK_BITMASK_N_DIRECT_BITS)))
{
GtkBitmask *result = _gtk_bitmask_from_bits (i == 0 ? 0 : mask->data[0]);
_gtk_allocated_bitmask_free (mask);
return result;
}
return gtk_allocated_bitmask_resize (mask, i);
}
GtkBitmask *
_gtk_allocated_bitmask_intersect (GtkBitmask *mask,
const GtkBitmask *other)
{
GtkBitmask other_allocated;
guint i;
g_return_val_if_fail (mask != NULL, NULL);
g_return_val_if_fail (other != NULL, NULL);
mask = gtk_bitmask_ensure_allocated (mask);
ENSURE_ALLOCATED (other, other_allocated);
mask = gtk_allocated_bitmask_resize (mask, MIN (mask->len, other->len));
for (i = 0; i < mask->len; i++)
{
mask->data[i] &= other->data[i];
}
return gtk_allocated_bitmask_shrink (mask);
}
GtkBitmask *
_gtk_allocated_bitmask_union (GtkBitmask *mask,
const GtkBitmask *other)
{
GtkBitmask other_allocated;
guint i;
g_return_val_if_fail (mask != NULL, NULL);
g_return_val_if_fail (other != NULL, NULL);
mask = gtk_bitmask_ensure_allocated (mask);
ENSURE_ALLOCATED (other, other_allocated);
mask = gtk_allocated_bitmask_resize (mask, MAX (mask->len, other->len));
for (i = 0; i < other->len; i++)
{
mask->data[i] |= other->data[i];
}
return mask;
}
GtkBitmask *
_gtk_allocated_bitmask_subtract (GtkBitmask *mask,
const GtkBitmask *other)
{
GtkBitmask other_allocated;
guint i;
g_return_val_if_fail (mask != NULL, NULL);
g_return_val_if_fail (other != NULL, NULL);
mask = gtk_bitmask_ensure_allocated (mask);
ENSURE_ALLOCATED (other, other_allocated);
for (i = 0; i < other->len; i++)
{
mask->data[i] |= ~other->data[i];
}
return gtk_allocated_bitmask_shrink (mask);
}
static void
gtk_allocated_bitmask_indexes (guint index_,
guint *array_index,
guint *bit_index)
{
*array_index = index_ / VALUE_SIZE_BITS;
*bit_index = index_ % VALUE_SIZE_BITS;
}
gboolean
_gtk_allocated_bitmask_get (const GtkBitmask *mask,
guint index_)
{
guint array_index, bit_index;
g_return_val_if_fail (mask != NULL, FALSE);
gtk_allocated_bitmask_indexes (index_, &array_index, &bit_index);
if (array_index >= mask->len)
return FALSE;
return (mask->data[array_index] & VALUE_BIT (bit_index)) ? TRUE : FALSE;
}
GtkBitmask *
_gtk_allocated_bitmask_set (GtkBitmask *mask,
guint index_,
gboolean value)
{
guint array_index, bit_index;
g_return_val_if_fail (mask != NULL, NULL);
mask = gtk_bitmask_ensure_allocated (mask);
gtk_allocated_bitmask_indexes (index_, &array_index, &bit_index);
if (value)
{
if (array_index >= mask->len)
mask = gtk_allocated_bitmask_resize (mask, array_index + 1);
mask->data[array_index] |= VALUE_BIT (bit_index);
}
else
{
if (array_index < mask->len)
{
mask->data[array_index] &= ~ VALUE_BIT (bit_index);
mask = gtk_allocated_bitmask_shrink (mask);
}
}
return mask;
}
GtkBitmask *
_gtk_allocated_bitmask_invert_range (GtkBitmask *mask,
guint start,
guint end)
{
guint i;
g_return_val_if_fail (mask != NULL, NULL);
g_return_val_if_fail (start < end, NULL);
mask = gtk_bitmask_ensure_allocated (mask);
/* I CAN HAS SPEEDUP? */
for (i = start; i < end; i++)
mask = _gtk_allocated_bitmask_set (mask, i, !_gtk_allocated_bitmask_get (mask, i));
return mask;
}
gboolean
_gtk_allocated_bitmask_equals (const GtkBitmask *mask,
const GtkBitmask *other)
{
guint i;
g_return_val_if_fail (mask != NULL, FALSE);
g_return_val_if_fail (other != NULL, FALSE);
if (mask->len != other->len)
return FALSE;
for (i = 0; i < mask->len; i++)
{
if (mask->data[i] != other->data[i])
return FALSE;
}
return TRUE;
}
gboolean
_gtk_allocated_bitmask_intersects (const GtkBitmask *mask,
const GtkBitmask *other)
{
GtkBitmask mask_allocated, other_allocated;
int i;
g_return_val_if_fail (mask != NULL, FALSE);
g_return_val_if_fail (other != NULL, FALSE);
ENSURE_ALLOCATED (mask, mask_allocated);
ENSURE_ALLOCATED (other, other_allocated);
for (i = MIN (mask->len, other->len) - 1; i >= 0; i--)
{
if (mask->data[i] & other->data[i])
return TRUE;
}
return FALSE;
}