/*
** Clear the i-th bit. Return 0 on success and an error code if
** anything goes wrong.
*/
void sqlite3BitvecClear(Bitvec *p, u32 i){
assert( p!=0 );
assert( i>0 );
if( p->iSize<=BITVEC_NBIT ){
i--;
p->u.aBitmap[i/8] &= ~(1 << (i&7));
}else if( p->iDivisor ){
u32 bin = (i-1)/p->iDivisor;
i = (i-1)%p->iDivisor + 1;
if( p->u.apSub[bin] ){
sqlite3BitvecClear(p->u.apSub[bin], i);
}
}else{
int j;
u32 aiValues[BITVEC_NINT];
memcpy(aiValues, p->u.aHash, sizeof(aiValues));
memset(p->u.aHash, 0, sizeof(p->u.aHash[0])*BITVEC_NINT);
p->nSet = 0;
for(j=0; j<BITVEC_NINT; j++){
if( aiValues[j] && aiValues[j]!=i ){
sqlite3BitvecSet(p, aiValues[j]);
}
}
}
}
static SQRESULT sq_BitVector_clear(HSQUIRRELVM v){
SQ_FUNC_VARS_NO_TOP(v);
GET_BitVector_INSTANCE();
SQ_GET_INTEGER(v, 2, int_pos);
BV_CHECK_RANGE();
// void sqlite3BitvecClear(Bitvec*, u32, void*)
SQChar *bv_buf = sq_getscratchpad(v, sqlite3BITVEC_SZ());
sqlite3BitvecClear(self, (u32)int_pos, bv_buf);
return 0;
}
/*
** This routine runs an extensive test of the Bitvec code.
**
** The input is an array of integers that acts as a program
** to test the Bitvec. The integers are opcodes followed
** by 0, 1, or 3 operands, depending on the opcode. Another
** opcode follows immediately after the last operand.
**
** There are 6 opcodes numbered from 0 through 5. 0 is the
** "halt" opcode and causes the test to end.
**
** 0 Halt and return the number of errors
** 1 N S X Set N bits beginning with S and incrementing by X
** 2 N S X Clear N bits beginning with S and incrementing by X
** 3 N Set N randomly chosen bits
** 4 N Clear N randomly chosen bits
** 5 N S X Set N bits from S increment X in array only, not in bitvec
**
** The opcodes 1 through 4 perform set and clear operations are performed
** on both a Bitvec object and on a linear array of bits obtained from malloc.
** Opcode 5 works on the linear array only, not on the Bitvec.
** Opcode 5 is used to deliberately induce a fault in order to
** confirm that error detection works.
**
** At the conclusion of the test the linear array is compared
** against the Bitvec object. If there are any differences,
** an error is returned. If they are the same, zero is returned.
**
** If a memory allocation error occurs, return -1.
*/
int sqlite3BitvecBuiltinTest(int sz, int *aOp){
Bitvec *pBitvec = 0;
unsigned char *pV = 0;
int rc = -1;
int i, nx, pc, op;
void *pTmpSpace;
/* Allocate the Bitvec to be tested and a linear array of
** bits to act as the reference */
pBitvec = sqlite3BitvecCreate( sz );
pV = sqlite3MallocZero( (sz+7)/8 + 1 );
pTmpSpace = sqlite3_malloc(BITVEC_SZ);
if( pBitvec==0 || pV==0 || pTmpSpace==0 ) goto bitvec_end;
/* NULL pBitvec tests */
sqlite3BitvecSet(0, 1);
sqlite3BitvecClear(0, 1, pTmpSpace);
/* Run the program */
pc = 0;
while( (op = aOp[pc])!=0 ){
switch( op ){
case 1:
case 2:
case 5: {
nx = 4;
i = aOp[pc+2] - 1;
aOp[pc+2] += aOp[pc+3];
break;
}
case 3:
case 4:
default: {
nx = 2;
sqlite3_randomness(sizeof(i), &i);
break;
}
}
if( (--aOp[pc+1]) > 0 ) nx = 0;
pc += nx;
i = (i & 0x7fffffff)%sz;
if( (op & 1)!=0 ){
SETBIT(pV, (i+1));
if( op!=5 ){
if( sqlite3BitvecSet(pBitvec, i+1) ) goto bitvec_end;
}
}else{
CLEARBIT(pV, (i+1));
sqlite3BitvecClear(pBitvec, i+1, pTmpSpace);
}
}
/* Test to make sure the linear array exactly matches the
** Bitvec object. Start with the assumption that they do
** match (rc==0). Change rc to non-zero if a discrepancy
** is found.
*/
rc = sqlite3BitvecTest(0,0) + sqlite3BitvecTest(pBitvec, sz+1)
+ sqlite3BitvecTest(pBitvec, 0)
+ (sqlite3BitvecSize(pBitvec) - sz);
for(i=1; i<=sz; i++){
if( (TESTBIT(pV,i))!=sqlite3BitvecTest(pBitvec,i) ){
rc = i;
break;
}
}
/* Free allocated structure */
bitvec_end:
sqlite3_free(pTmpSpace);
sqlite3_free(pV);
sqlite3BitvecDestroy(pBitvec);
return rc;
}
