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#include <stdio.h>
#include <stdlib.h>
typedef struct {
int size;
int nbits;
int allocated;
} bitarrayobject;
/* number of bytes necessary to store given bits */
#define BYTES(bits) (((bits) + 7) >> 3)
uint64_t s = 290797;
int bbs(void)
{
s *= s;
s %= 50515093;
return s % 8000;
}
void resize(bitarrayobject *self, int nbits)
{
int size = self->size, allocated = self->allocated;
int newsize = BYTES(nbits), new_allocated;
if (newsize == size) {
self->nbits = nbits;
return;
}
if (newsize == 0) {
/* free(self->ob_item) */
self->size = 0;
self->allocated = 0;
self->nbits = 0;
return;
}
if (allocated >= newsize) {
if (newsize >= allocated / 2) {
self->size = newsize;
self->nbits = nbits;
return;
}
new_allocated = newsize;
}
else {
new_allocated = newsize;
if (size != 0 && newsize / 2 <= allocated) {
new_allocated += (newsize >> 4) + (newsize < 8 ? 3 : 7);
new_allocated &= ~(int) 3;
}
}
/* realloc(self->ob_item) */
self->size = newsize;
self->allocated = new_allocated;
self->nbits = nbits;
}
int main()
{
int i, nbits, prev_alloc = -1;
bitarrayobject x;
#define SHOW printf("%d %d\n", x.size, x.allocated)
x.size = 0;
x.allocated = 0;
for (nbits = 0; nbits < 1000; nbits++) {
if (prev_alloc != x.allocated)
SHOW;
prev_alloc = x.allocated;
resize(&x, nbits);
}
resize(&x, 800000); SHOW;
resize(&x, 400000); SHOW;
resize(&x, 399992); SHOW;
resize(&x, 500000); SHOW;
resize(&x, 0); SHOW;
resize(&x, 0); SHOW;
resize(&x, 10000); SHOW;
resize(&x, 400); SHOW;
resize(&x, 600); SHOW;
resize(&x, 2000); SHOW;
for (nbits = 2000; nbits >= 0; nbits--) {
if (prev_alloc != x.allocated)
SHOW;
prev_alloc = x.allocated;
resize(&x, nbits);
}
SHOW;
for (nbits = 0; nbits < 100; nbits += 8) {
x.size = 0;
x.allocated = 0;
resize(&x, nbits);
SHOW;
}
for (i = 0; i < 100000; i++) {
resize(&x, bbs());
SHOW;
}
return 0;
}
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