/*
** Clear the i-th bit.
**
** pBuf must be a pointer to at least BITVEC_SZ bytes of temporary storage
** that BitvecClear can use to rebuilt its hash table.
*/
void sqlite3BitvecClear(Bitvec *p, u32 i, void *pBuf){
if( p==0 ) return;
assert( i>0 );
i--;
while( p->iDivisor ){
u32 bin = i/p->iDivisor;
i = i%p->iDivisor;
p = p->u.apSub[bin];
if (!p) {
return;
}
}
if( p->iSize<=BITVEC_NBIT ){
p->u.aBitmap[i/BITVEC_SZELEM] &= ~(1 << (i&(BITVEC_SZELEM-1)));
}else{
unsigned int j;
u32 *aiValues = pBuf;
memcpy(aiValues, p->u.aHash, sizeof(p->u.aHash));
memset(p->u.aHash, 0, sizeof(p->u.aHash));
p->nSet = 0;
for(j=0; j<BITVEC_NINT; j++){
if( aiValues[j] && aiValues[j]!=(i+1) ){
u32 h = BITVEC_HASH(aiValues[j]-1);
p->nSet++;
while( p->u.aHash[h] ){
h++;
if( h>=BITVEC_NINT ) h = 0;
}
p->u.aHash[h] = aiValues[j];
}
}
}
}
/*
** Set the i-th bit. Return 0 on success and an error code if
** anything goes wrong.
*/
int sqlite3BitvecSet(Bitvec *p, u32 i){
u32 h;
assert( p!=0 );
assert( i>0 );
assert( i<=p->iSize );
if( p->iSize<=BITVEC_NBIT ){
i--;
p->u.aBitmap[i/8] |= 1 << (i&7);
return SQLITE_OK;
}
if( p->iDivisor ){
u32 bin = (i-1)/p->iDivisor;
i = (i-1)%p->iDivisor + 1;
if( p->u.apSub[bin]==0 ){
sqlite3FaultBeginBenign(SQLITE_FAULTINJECTOR_MALLOC);
p->u.apSub[bin] = sqlite3BitvecCreate( p->iDivisor );
sqlite3FaultEndBenign(SQLITE_FAULTINJECTOR_MALLOC);
if( p->u.apSub[bin]==0 ) return SQLITE_NOMEM;
}
return sqlite3BitvecSet(p->u.apSub[bin], i);
}
h = BITVEC_HASH(i);
while( p->u.aHash[h] ){
if( p->u.aHash[h]==i ) return SQLITE_OK;
h++;
if( h==BITVEC_NINT ) h = 0;
}
p->nSet++;
if( p->nSet>=BITVEC_MXHASH ){
int j, rc;
u32 aiValues[BITVEC_NINT];
memcpy(aiValues, p->u.aHash, sizeof(aiValues));
memset(p->u.apSub, 0, sizeof(p->u.apSub[0])*BITVEC_NPTR);
p->iDivisor = (p->iSize + BITVEC_NPTR - 1)/BITVEC_NPTR;
rc = sqlite3BitvecSet(p, i);
for(j=0; j<BITVEC_NINT; j++){
if( aiValues[j] ) rc |= sqlite3BitvecSet(p, aiValues[j]);
}
return rc;
}
p->u.aHash[h] = i;
return SQLITE_OK;
}
/*
** Check to see if the i-th bit is set. Return true or false.
** If p is NULL (if the bitmap has not been created) or if
** i is out of range, then return false.
*/
int sqlite3BitvecTest(Bitvec *p, u32 i){
if( p==0 ) return 0;
if( i>p->iSize || i==0 ) return 0;
if( p->iSize<=BITVEC_NBIT ){
i--;
return (p->u.aBitmap[i/8] & (1<<(i&7)))!=0;
}
if( p->iDivisor>0 ){
u32 bin = (i-1)/p->iDivisor;
i = (i-1)%p->iDivisor + 1;
return sqlite3BitvecTest(p->u.apSub[bin], i);
}else{
u32 h = BITVEC_HASH(i);
while( p->u.aHash[h] ){
if( p->u.aHash[h]==i ) return 1;
h++;
if( h>=BITVEC_NINT ) h = 0;
}
return 0;
}
}
/*
** Check to see if the i-th bit is set. Return true or false.
** If p is NULL (if the bitmap has not been created) or if
** i is out of range, then return false.
*/
int sqlite3BitvecTest(Bitvec *p, u32 i){
if( p==0 ) return 0;
if( i>p->iSize || i==0 ) return 0;
i--;
while( p->iDivisor ){
u32 bin = i/p->iDivisor;
i = i%p->iDivisor;
p = p->u.apSub[bin];
if (!p) {
return 0;
}
}
if( p->iSize<=BITVEC_NBIT ){
return (p->u.aBitmap[i/BITVEC_SZELEM] & (1<<(i&(BITVEC_SZELEM-1))))!=0;
} else{
u32 h = BITVEC_HASH(i++);
while( p->u.aHash[h] ){
if( p->u.aHash[h]==i ) return 1;
h = (h+1) % BITVEC_NINT;
}
return 0;
}
}
/*
** Set the i-th bit. Return 0 on success and an error code if
** anything goes wrong.
**
** This routine might cause sub-bitmaps to be allocated. Failing
** to get the memory needed to hold the sub-bitmap is the only
** that can go wrong with an insert, assuming p and i are valid.
**
** The calling function must ensure that p is a valid Bitvec object
** and that the value for "i" is within range of the Bitvec object.
** Otherwise the behavior is undefined.
*/
int sqlite3BitvecSet(Bitvec *p, u32 i){
u32 h;
if( p==0 ) return SQLITE_OK;
assert( i>0 );
assert( i<=p->iSize );
i--;
while((p->iSize > BITVEC_NBIT) && p->iDivisor) {
u32 bin = i/p->iDivisor;
i = i%p->iDivisor;
if( p->u.apSub[bin]==0 ){
p->u.apSub[bin] = sqlite3BitvecCreate( p->iDivisor );
if( p->u.apSub[bin]==0 ) return SQLITE_NOMEM;
}
p = p->u.apSub[bin];
}
if( p->iSize<=BITVEC_NBIT ){
p->u.aBitmap[i/BITVEC_SZELEM] |= 1 << (i&(BITVEC_SZELEM-1));
return SQLITE_OK;
}
h = BITVEC_HASH(i++);
/* if there wasn't a hash collision, and this doesn't */
/* completely fill the hash, then just add it without */
/* worring about sub-dividing and re-hashing. */
if( !p->u.aHash[h] ){
if (p->nSet<(BITVEC_NINT-1)) {
goto bitvec_set_end;
} else {
goto bitvec_set_rehash;
}
}
/* there was a collision, check to see if it's already */
/* in hash, if not, try to find a spot for it */
do {
if( p->u.aHash[h]==i ) return SQLITE_OK;
h++;
if( h>=BITVEC_NINT ) h = 0;
} while( p->u.aHash[h] );
/* we didn't find it in the hash. h points to the first */
/* available free spot. check to see if this is going to */
/* make our hash too "full". */
bitvec_set_rehash:
if( p->nSet>=BITVEC_MXHASH ){
unsigned int j;
int rc;
u32 *aiValues = sqlite3StackAllocRaw(0, sizeof(p->u.aHash));
if( aiValues==0 ){
return SQLITE_NOMEM;
}else{
memcpy(aiValues, p->u.aHash, sizeof(p->u.aHash));
memset(p->u.apSub, 0, sizeof(p->u.apSub));
p->iDivisor = (p->iSize + BITVEC_NPTR - 1)/BITVEC_NPTR;
rc = sqlite3BitvecSet(p, i);
for(j=0; j<BITVEC_NINT; j++){
if( aiValues[j] ) rc |= sqlite3BitvecSet(p, aiValues[j]);
}
sqlite3StackFree(0, aiValues);
return rc;
}
}
bitvec_set_end:
p->nSet++;
p->u.aHash[h] = i;
return SQLITE_OK;
}
