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bitmap: various clean-ups

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a) use memcmp() to compare bitmaps efficiently

b) use UINT64_C() macro instead of ULL suffixes to get right suffix for
   uint64_t constants

c) add a few assert()s

d) when comparing integers with 0 we generally try to make this explicit
   with "!= 0".

e) remove redundant bitmap_isset() if check, as we don't have it in
   bitmap_isset() either.

f) It should be fine to invoke bitmap_unset() on a NULL bitmap
This commit is contained in:
Lennart Poettering 2015-07-23 15:57:54 +02:00
parent b96c778a00
commit 370a2172ac
1 changed files with 14 additions and 13 deletions
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27
src/basic/bitmap.c
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@ -56,6 +56,8 @@ void bitmap_free(Bitmap *b) {
int bitmap_ensure_allocated(Bitmap **b) { int bitmap_ensure_allocated(Bitmap **b) {
Bitmap *a; Bitmap *a;
assert(b);
if (*b) if (*b)
return 0; return 0;
@ -87,7 +89,7 @@ int bitmap_set(Bitmap *b, unsigned n) {
b->n_bitmaps = offset + 1; b->n_bitmaps = offset + 1;
} }
bitmask = 1ULL << BITMAP_NUM_TO_REM(n); bitmask = UINT64_C(1) << BITMAP_NUM_TO_REM(n);
b->bitmaps[offset] |= bitmask; b->bitmaps[offset] |= bitmask;
@ -98,14 +100,15 @@ void bitmap_unset(Bitmap *b, unsigned n) {
uint64_t bitmask; uint64_t bitmask;
unsigned offset; unsigned offset;
assert(b); if (!b)
return;
offset = BITMAP_NUM_TO_OFFSET(n); offset = BITMAP_NUM_TO_OFFSET(n);
if (offset >= b->n_bitmaps) if (offset >= b->n_bitmaps)
return; return;
bitmask = 1ULL << BITMAP_NUM_TO_REM(n); bitmask = UINT64_C(1) << BITMAP_NUM_TO_REM(n);
b->bitmaps[offset] &= ~bitmask; b->bitmaps[offset] &= ~bitmask;
} }
@ -114,7 +117,7 @@ bool bitmap_isset(Bitmap *b, unsigned n) {
uint64_t bitmask; uint64_t bitmask;
unsigned offset; unsigned offset;
if (!b || !b->bitmaps) if (!b)
return false; return false;
offset = BITMAP_NUM_TO_OFFSET(n); offset = BITMAP_NUM_TO_OFFSET(n);
@ -122,7 +125,7 @@ bool bitmap_isset(Bitmap *b, unsigned n) {
if (offset >= b->n_bitmaps) if (offset >= b->n_bitmaps)
return false; return false;
bitmask = 1ULL << BITMAP_NUM_TO_REM(n); bitmask = UINT64_C(1) << BITMAP_NUM_TO_REM(n);
return !!(b->bitmaps[offset] & bitmask); return !!(b->bitmaps[offset] & bitmask);
} }
@ -133,7 +136,7 @@ bool bitmap_isclear(Bitmap *b) {
assert(b); assert(b);
for (i = 0; i < b->n_bitmaps; i++) for (i = 0; i < b->n_bitmaps; i++)
if (b->bitmaps[i]) if (b->bitmaps[i] != 0)
return false; return false;
return true; return true;
@ -149,12 +152,15 @@ bool bitmap_iterate(Bitmap *b, Iterator *i, unsigned *n) {
uint64_t bitmask; uint64_t bitmask;
unsigned offset, rem; unsigned offset, rem;
assert(i);
assert(n);
if (!b || i->idx == BITMAP_END) if (!b || i->idx == BITMAP_END)
return false; return false;
offset = BITMAP_NUM_TO_OFFSET(i->idx); offset = BITMAP_NUM_TO_OFFSET(i->idx);
rem = BITMAP_NUM_TO_REM(i->idx); rem = BITMAP_NUM_TO_REM(i->idx);
bitmask = 1ULL << rem; bitmask = UINT64_C(1) << rem;
for (; offset < b->n_bitmaps; offset ++) { for (; offset < b->n_bitmaps; offset ++) {
if (b->bitmaps[offset]) { if (b->bitmaps[offset]) {
@ -178,7 +184,6 @@ bool bitmap_iterate(Bitmap *b, Iterator *i, unsigned *n) {
} }
bool bitmap_equal(Bitmap *a, Bitmap *b) { bool bitmap_equal(Bitmap *a, Bitmap *b) {
unsigned i;
if (!a ^ !b) if (!a ^ !b)
return false; return false;
@ -189,9 +194,5 @@ bool bitmap_equal(Bitmap *a, Bitmap *b) {
if (a->n_bitmaps != b->n_bitmaps) if (a->n_bitmaps != b->n_bitmaps)
return false; return false;
for (i = 0; i < a->n_bitmaps; i++) return memcmp(a->bitmaps, b->bitmaps, sizeof(uint64_t) * a->n_bitmaps) == 0;
if (a->bitmaps[i] != b->bitmaps[i])
return false;
return true;
} }