/* intset.c - Source for a set of unsigned integers (implemented as a
* variable length bitfield)
*
* Copyright (C) 2005, 2006 Collabora Ltd. <http://www.collabora.co.uk/>
* Copyright (C) 2005, 2006 Nokia Corporation
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
/**
* SECTION:intset
* @title: TpIntSet
* @short_description: a set of unsigned integers
* @see_also: #TpHandleSet
*
* A #TpIntSet is a set of unsigned integers, implemented as a
* dynamically-allocated bitfield.
*/
#include <telepathy-glib/intset.h>
#include <string.h>
#include <glib.h>
#define DEFAULT_SIZE 16
#define DEFAULT_INCREMENT 8
#define DEFAULT_INCREMENT_LOG2 3
struct _TpIntSet
{
guint32 *bits;
guint size;
};
static TpIntSet *
_tp_intset_new_with_size (guint size)
{
TpIntSet *set = g_slice_new (TpIntSet);
set->size = MAX (size, DEFAULT_SIZE);
set->bits = g_new0 (guint32, set->size);
return set;
}
/**
* tp_intset_sized_new:
* @size: 1 more than the largest integer you expect to store
*
* Allocate an integer set just large enough to store the given number of bits,
* rounded up as necessary.
*
* The set will still expand automatically if you store larger integers;
* this is just an optimization to avoid wasting memory (if the set is too
* large) or time (if the set is too small and needs reallocation).
*
* Returns: a new, empty integer set to be destroyed with tp_intset_destroy()
*/
TpIntSet *
tp_intset_sized_new (guint size)
{
/* convert from a size in bits to a size in 32-bit words */
if (G_UNLIKELY (size == 0))
size = 1;
else
size = ((size - 1) >> 5) + 1;
return _tp_intset_new_with_size (size);
}
/**
* tp_intset_new:
*
* Allocate a new integer set with a default memory allocation.
*
* Returns: a new, empty integer set to be destroyed with tp_intset_destroy()
*/
TpIntSet *
tp_intset_new ()
{
return _tp_intset_new_with_size (DEFAULT_SIZE);
}
/**
* tp_intset_destroy:
* @set: set
*
* Free all memory used by the set.
*/
void
tp_intset_destroy (TpIntSet *set)
{
g_return_if_fail (set != NULL);
g_free (set->bits);
g_slice_free (TpIntSet, set);
}
/**
* tp_intset_clear:
* @set: set
*
* Unset every integer in the set.
*/
void
tp_intset_clear (TpIntSet *set)
{
g_return_if_fail (set != NULL);
memset (set->bits, 0, set->size * sizeof (guint32));
}
/**
* tp_intset_add:
* @set: set
* @element: integer to add
*
* Add an integer into a TpIntSet.
*/
void
tp_intset_add (TpIntSet *set, guint element)
{
guint offset;
guint newsize;
g_return_if_fail (set != NULL);
offset = element >> 5;
if (offset >= set->size)
{
newsize = ((offset>>DEFAULT_INCREMENT_LOG2) +1 ) << DEFAULT_INCREMENT_LOG2;
set->bits = g_renew (guint32, set->bits, newsize);
memset (set->bits + set->size, 0,
sizeof (guint32) * (newsize - set->size));
set->size = newsize;
g_assert (offset<newsize);
}
set->bits[offset] = set->bits[offset] | (1<<(element & 0x1f));
}
/**
* tp_intset_remove:
* @set: set
* @element: integer to add
*
* Remove an integer from a TpIntSet
*
* Returns: %TRUE if @element was previously in @set
*/
gboolean
tp_intset_remove (TpIntSet *set, guint element)
{
guint offset;
guint mask;
g_return_val_if_fail (set != NULL, FALSE);
offset = element >> 5;
mask = 1 << (element & 0x1f);
if (offset >= set->size)
return FALSE;
else if (!(set->bits[offset] & mask))
return FALSE;
else
{
set->bits[offset] &= ~mask;
return TRUE;
}
}
static inline gboolean
_tp_intset_is_member (const TpIntSet *set, guint element)
{
guint offset;
offset = element >> 5;
if (offset >= set->size)
return FALSE;
else
return (set->bits[offset] & (1 << (element & 0x1f))) != 0;
}
/**
* tp_intset_is_member:
* @set: set
* @element: integer to test
*
* Tests if @element is a member of @set
*
* Returns: %TRUE if @element is in @set
*/
gboolean
tp_intset_is_member (const TpIntSet *set, guint element)
{
g_return_val_if_fail (set != NULL, FALSE);
return _tp_intset_is_member (set, element);
}
/**
* tp_intset_foreach:
* @set: set
* @func: @TpIntFunc to use to iterate the set
* @userdata: user data to pass to each call of @func
*
* Call @func(element, @userdata) for each element of @set.
*/
void
tp_intset_foreach (const TpIntSet *set, TpIntFunc func, gpointer userdata)
{
guint i, j;
g_return_if_fail (set != NULL);
g_return_if_fail (func != NULL);
for (i = 0; i < set->size; i++)
{
if (set->bits[i])
for (j = 0; j < 32; j++)
{
if (set->bits[i] & 1 << j)
func (i * 32 + j, userdata);
}
}
}
static void
addint (guint i, gpointer data)
{
GArray *array = (GArray *) data;
g_array_append_val (array, i);
}
/**
* tp_intset_to_array:
* @set: set to convert
*
* <!--Returns: says it all-->
*
* Returns: a GArray of guint (which must be freed by the caller) containing
* the same integers as @set.
*/
GArray *
tp_intset_to_array (TpIntSet *set)
{
GArray *array;
g_return_val_if_fail (set != NULL, NULL);
array = g_array_new (FALSE, TRUE, sizeof (guint));
tp_intset_foreach (set, addint, array);
return array;
}
/**
* tp_intset_from_array:
* @array: An array of guint
*
* <!--Returns: says it all-->
*
* Returns: A set containing the same integers as @array.
*/
TpIntSet *
tp_intset_from_array (GArray *array)
{
TpIntSet *set;
guint max, i;
g_return_val_if_fail (array != NULL, NULL);
/* look at the 1st, last and middle values in the array to get an
* approximation of the largest */
max = 0;
if (array->len > 0)
max = g_array_index (array, guint, 0);
if (array->len > 1)
max = MAX (max, g_array_index (array, guint, array->len - 1));
if (array->len > 2)
max = MAX (max, g_array_index (array, guint, (array->len - 1) >> 1));
set = _tp_intset_new_with_size (1 + (max >> 5));
for (i = 0; i < array->len; i++)
{
tp_intset_add (set, g_array_index (array, guint, i));
}
return set;
}
/**
* tp_intset_size:
* @set: A set of integers
*
* <!--Returns: says it all-->
*
* Returns: The number of integers in @set
*/
guint
tp_intset_size (const TpIntSet *set)
{
guint i, count = 0;
guint32 n;
g_return_val_if_fail (set != NULL, 0);
for (i = 0; i < set->size; i++)
{
n = set->bits[i];
n = n - ((n >> 1) & 033333333333) - ((n >> 2) & 011111111111);
count += ((n + (n >> 3)) & 030707070707) % 63;
}
return count;
}
/**
* tp_intset_is_equal:
* @left: A set of integers
* @right: A set of integers
*
* <!--Returns: says it all-->
*
* Returns: %TRUE if @left and @right contain the same bits
*/
gboolean
tp_intset_is_equal (const TpIntSet *left, const TpIntSet *right)
{
const TpIntSet *large, *small;
guint i;
g_return_val_if_fail (left != NULL, FALSE);
g_return_val_if_fail (right != NULL, FALSE);
if (left->size > right->size)
{
large = left;
small = right;
}
else
{
large = right;
small = left;
}
for (i = 0; i < small->size; i++)
{
if (large->bits[i] != small->bits[i])
return FALSE;
}
for (i = small->size; i < large->size; i++)
{
if (large->bits[i] != 0)
return FALSE;
}
return TRUE;
}
/**
* tp_intset_copy:
* @orig: A set of integers
*
* <!--Returns: says it all-->
*
* Returns: A set containing the same integers as @orig, to be freed with
* tp_intset_destroy() by the caller
*/
TpIntSet *
tp_intset_copy (const TpIntSet *orig)
{
TpIntSet *ret;
g_return_val_if_fail (orig != NULL, NULL);
ret = _tp_intset_new_with_size (orig->size);
memcpy (ret->bits, orig->bits, (ret->size * sizeof (guint32)));
return ret;
}
/**
* tp_intset_intersection:
* @left: The left operand
* @right: The right operand
*
* <!--Returns: says it all-->
*
* Returns: The set of those integers which are in both @left and @right
* (analogous to the bitwise operation left & right), to be freed with
* tp_intset_destroy() by the caller
*/
TpIntSet *
tp_intset_intersection (const TpIntSet *left, const TpIntSet *right)
{
const TpIntSet *large, *small;
TpIntSet *ret;
guint i;
g_return_val_if_fail (left != NULL, NULL);
g_return_val_if_fail (right != NULL, NULL);
if (left->size > right->size)
{
large = left;
small = right;
}
else
{
large = right;
small = left;
}
ret = tp_intset_copy (small);
for (i = 0; i < ret->size; i++)
{
ret->bits[i] &= large->bits[i];
}
return ret;
}
/**
* tp_intset_union:
* @left: The left operand
* @right: The right operand
*
* <!--Returns: says it all-->
*
* Returns: The set of those integers which are in either @left or @right
* (analogous to the bitwise operation left | right), to be freed with
* tp_intset_destroy() by the caller
*/
TpIntSet *
tp_intset_union (const TpIntSet *left, const TpIntSet *right)
{
const TpIntSet *large, *small;
TpIntSet *ret;
guint i;
g_return_val_if_fail (left != NULL, NULL);
g_return_val_if_fail (right != NULL, NULL);
if (left->size > right->size)
{
large = left;
small = right;
}
else
{
large = right;
small = left;
}
ret = tp_intset_copy (large);
for (i = 0; i < small->size; i++)
{
ret->bits[i] |= small->bits[i];
}
return ret;
}
/**
* tp_intset_difference:
* @left: The left operand
* @right: The right operand
*
* <!--Returns: says it all-->
*
* Returns: The set of those integers which are in @left and not in @right
* (analogous to the bitwise operation left & (~right)), to be freed with
* tp_intset_destroy() by the caller
*/
TpIntSet *
tp_intset_difference (const TpIntSet *left, const TpIntSet *right)
{
TpIntSet *ret;
guint i;
g_return_val_if_fail (left != NULL, NULL);
g_return_val_if_fail (right != NULL, NULL);
ret = tp_intset_copy (left);
for (i = 0; i < MIN (right->size, left->size); i++)
{
ret->bits[i] &= ~right->bits[i];
}
return ret;
}
/**
* tp_intset_symmetric_difference:
* @left: The left operand
* @right: The right operand
*
* <!--Returns: says it all-->
*
* Returns: The set of those integers which are in either @left or @right
* but not both (analogous to the bitwise operation left ^ right), to be freed
* with tp_intset_destroy() by the caller
*/
TpIntSet *
tp_intset_symmetric_difference (const TpIntSet *left, const TpIntSet *right)
{
const TpIntSet *large, *small;
TpIntSet *ret;
guint i;
g_return_val_if_fail (left != NULL, NULL);
g_return_val_if_fail (right != NULL, NULL);
if (left->size > right->size)
{
large = left;
small = right;
}
else
{
large = right;
small = left;
}
ret = tp_intset_copy (large);
for (i = 0; i < small->size; i++)
{
ret->bits[i] ^= small->bits[i];
}
return ret;
}
static void
_dump_foreach (guint i, gpointer data)
{
GString *tmp = (GString *) data;
if (tmp->len == 0)
g_string_append_printf (tmp, "%u", i);
else
g_string_append_printf (tmp, " %u", i);
}
/**
* tp_intset_dump:
* @set: An integer set
*
* <!--Returns: says it all-->
*
* Returns: a string which the caller must free with g_free, listing the
* numbers in @set in a human-readable format
*/
gchar *
tp_intset_dump (const TpIntSet *set)
{
GString *tmp = g_string_new ("");
tp_intset_foreach (set, _dump_foreach, tmp);
return g_string_free (tmp, FALSE);
}
/**
* tp_intset_iter_next:
* @iter: An iterator originally initialized with TP_INTSET_INIT(set)
*
* If there are integers in (@iter->set) higher than (@iter->element), set
* (iter->element) to the next one and return %TRUE. Otherwise return %FALSE.
*
* Usage:
*
* <informalexample><programlisting>
* TpIntSetIter iter = TP_INTSET_INIT (intset);
* while (tp_intset_iter_next (&iter))
* {
* printf ("%u is in the intset\n", iter.element);
* }
* </programlisting></informalexample>
*
* Returns: %TRUE if (@iter->element) has been advanced
*/
gboolean
tp_intset_iter_next (TpIntSetIter *iter)
{
g_return_val_if_fail (iter != NULL, FALSE);
g_return_val_if_fail (iter->set != NULL, FALSE);
do
{
if (iter->element == (guint)(-1))
{
/* only just started */
iter->element = 0;
}
else
{
++iter->element;
}
if (_tp_intset_is_member (iter->set, iter->element))
{
return TRUE;
}
}
while (iter->element < (iter->set->size << 5)
&& iter->element != (guint)(-1));
return FALSE;
}