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ofono
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Code Issues Releases Activity

Add idmap_from_range constructor

This commit is contained in:
Denis Kenzior 2010-01-07 13:20:48 -06:00
parent 6051d0bdde
commit af007cde66
2 changed files with 37 additions and 11 deletions
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45
src/idmap.c
View File

@ -36,6 +36,8 @@
struct idmap {
unsigned long *bits;
unsigned int size;
unsigned int min;
unsigned int max;
};
static inline int ffz(unsigned long word)
@ -97,35 +99,43 @@ found_middle:
return result + ffz(tmp);
}
struct idmap *idmap_new(unsigned int size)
struct idmap *idmap_new_from_range(unsigned int min, unsigned int max)
{
struct idmap *ret = g_new0(struct idmap, 1);
unsigned int size = max - min + 1;
ret->bits = g_new0(unsigned long,
(size + BITS_PER_LONG - 1) / BITS_PER_LONG);
ret->size = size;
ret->min = min;
ret->max = max;
return ret;
}
struct idmap *idmap_new(unsigned int size)
{
return idmap_new_from_range(1, size);
}
void idmap_free(struct idmap *idmap)
{
g_free(idmap->bits);
g_free(idmap);
}
void idmap_put(struct idmap *idmap, unsigned int bit)
void idmap_put(struct idmap *idmap, unsigned int id)
{
unsigned int offset = (bit - 1) / BITS_PER_LONG;
unsigned int offset = (id - idmap->min) / BITS_PER_LONG;
bit -= 1;
id -= idmap->min;
if (bit > idmap->size)
if (id > idmap->size)
return;
bit %= BITS_PER_LONG;
id %= BITS_PER_LONG;
idmap->bits[offset] &= ~(1 << bit);
idmap->bits[offset] &= ~(1 << id);
}
unsigned int idmap_alloc(struct idmap *idmap)
@ -141,18 +151,21 @@ unsigned int idmap_alloc(struct idmap *idmap)
offset = bit / BITS_PER_LONG;
idmap->bits[offset] |= 1 << (bit % BITS_PER_LONG);
return bit + 1;
return bit + idmap->min;
}
/*
* Allocate the next bit skipping the first last bits
* Allocate the next bit skipping the ids up to and including last. If there
* is no free ids until the max id is encountered, the counter is wrapped back
* to min and the search starts again.
*/
unsigned int idmap_alloc_next(struct idmap *idmap, unsigned int last)
{
unsigned int bit;
unsigned int offset;
bit = find_next_zero_bit(idmap->bits, idmap->size, last);
bit = find_next_zero_bit(idmap->bits, idmap->size,
last - idmap->min + 1);
if (bit >= idmap->size)
return idmap_alloc(idmap);
@ -160,5 +173,15 @@ unsigned int idmap_alloc_next(struct idmap *idmap, unsigned int last)
offset = bit / BITS_PER_LONG;
idmap->bits[offset] |= 1 << (bit % BITS_PER_LONG);
return bit + 1;
return bit + idmap->min;
}
unsigned int idmap_get_min(struct idmap *idmap)
{
return idmap->min;
}
unsigned int idmap_get_max(struct idmap *idmap)
{
return idmap->max;
}

3
src/idmap.h
View File

@ -26,3 +26,6 @@ void idmap_free(struct idmap *idmap);
void idmap_put(struct idmap *idmap, unsigned int bit);
unsigned int idmap_alloc(struct idmap *idmap);
unsigned int idmap_alloc_next(struct idmap *idmap, unsigned int last);
struct idmap *idmap_new_from_range(unsigned int min, unsigned int max);
unsigned int idmap_get_min(struct idmap *idmap);
unsigned int idmap_get_max(struct idmap *idmap);