/**
* virBitmapSetBit:
* @bitmap: Pointer to bitmap
* @b: bit position to set
*
* Set bit position @b in @bitmap
*
* Returns 0 on if bit is successfully set, -1 on error.
*/
int virBitmapSetBit(virBitmapPtr bitmap, size_t b)
{
if (bitmap->max_bit <= b)
return -1;
bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] |= VIR_BITMAP_BIT(b);
return 0;
}
/**
* virBitmapSetBitExpand:
* @bitmap: Pointer to bitmap
* @b: bit position to set
*
* Set bit position @b in @bitmap. Expands the bitmap as necessary so that @b is
* included in the map.
*
* Returns 0 on if bit is successfully set, -1 on error.
*/
int virBitmapSetBitExpand(virBitmapPtr bitmap, size_t b)
{
if (bitmap->max_bit <= b && virBitmapExpand(bitmap, b) < 0)
return -1;
bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] |= VIR_BITMAP_BIT(b);
return 0;
}
/**
* virBitmapLastSetBit:
* @bitmap: the bitmap
*
* Search for the last set bit in bitmap @bitmap.
*
* Returns the position of the found bit, or -1 if no bit is set.
*/
ssize_t
virBitmapLastSetBit(virBitmapPtr bitmap)
{
ssize_t i;
int unusedBits;
ssize_t sz;
unsigned long bits;
/* If bitmap is empty then there is no set bit */
if (bitmap->map_len == 0)
return -1;
unusedBits = bitmap->map_len * VIR_BITMAP_BITS_PER_UNIT - bitmap->nbits;
sz = bitmap->map_len - 1;
if (unusedBits > 0) {
bits = bitmap->map[sz] & (VIR_BITMAP_BIT(VIR_BITMAP_BITS_PER_UNIT - unusedBits) - 1);
if (bits != 0)
goto found;
sz--;
}
for (; sz >= 0; sz--) {
bits = bitmap->map[sz];
if (bits != 0)
goto found;
}
/* Only reached if no set bit was found */
return -1;
found:
for (i = VIR_BITMAP_BITS_PER_UNIT - 1; i >= 0; i--) {
if (bits & 1UL << i)
return i + sz * VIR_BITMAP_BITS_PER_UNIT;
}
return -1;
}
/**
* virBitmapLastSetBit:
* @bitmap: the bitmap
*
* Search for the last set bit in bitmap @bitmap.
*
* Returns the position of the found bit, or -1 if no bit is set.
*/
ssize_t
virBitmapLastSetBit(virBitmapPtr bitmap)
{
ssize_t i;
int unusedBits;
ssize_t sz;
unsigned long bits = 0;
unusedBits = bitmap->map_len * VIR_BITMAP_BITS_PER_UNIT - bitmap->max_bit;
sz = bitmap->map_len - 1;
if (unusedBits > 0) {
bits = bitmap->map[sz] & (VIR_BITMAP_BIT(VIR_BITMAP_BITS_PER_UNIT - unusedBits) - 1);
if (bits != 0)
goto found;
sz--;
}
for (; sz >= 0; sz--) {
bits = bitmap->map[sz];
if (bits != 0)
goto found;
}
if (bits == 0)
return -1;
found:
for (i = VIR_BITMAP_BITS_PER_UNIT - 1; i >= 0; i--) {
if (bits & 1UL << i)
return i + sz * VIR_BITMAP_BITS_PER_UNIT;
}
return -1;
}
/* Helper function. caller must ensure b < bitmap->max_bit */
static bool virBitmapIsSet(virBitmapPtr bitmap, size_t b)
{
return !!(bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] & VIR_BITMAP_BIT(b));
}
