In this example, memset() is called to initialize a new NullBitVector by setting all bytes to 0 after it has been allocated by the caller for an ARRAY of type phonenumbers_ary. The required information for these operations is retrieved by calling FNC_GetArrayTypeInfo. Then, FNC_SetNullBitVectorByElemIndex is called to set one of the bits to "not present".
The following example is based on the following 2-D ARRAY definition:
/* Oracle-compatible and Teradata syntax respectively: */
CREATE TYPE myArray AS VARRAY(1:20)(1:20) OF INTEGER;
CREATE TYPE myArray AS INTEGER ARRAY[1:20][1:20];
void ArrayUDF ( ARRAY_HANDLE *a,
char sqlstate[6])
{
NullBitVecType *NullBitVector;
array_info_t arrayInfo;
long nullVecBufSize;
int aryIndex[FNC_ARRAYMAXDIMENSIONS];
bounds_t arrayScope[FNC_ARRAYMAXDIMENSIONS];
/* Call FNC_GetArrayTypeInfo first to find out the number of */
/* elements in the array. */
FNC_GetArrayTypeInfo(*a,
&arrayInfo,
arrayScope);
(arrayInfo.totalNumElements % 8 == 0) ?
(nullVecBufSize = arrayInfo.totalNumElements / 8) :
(nullVecBufSize = arrayInfo.totalNumElements / 8) + 1;
/* Allocate a new NullBitVector array. */
NullBitVector = (NullBitVecType*)FNC_malloc(nullVecBufSize);
/* Initialize the NullBitVector to default values */
memset(NullBitVector, 0, nullVecBufSize);
/* Set one bit in NullBitVector to 1 (present) */
aryIndex[0] = 1;
aryIndex[1] = 1;
FNC_SetNullBitVectorByElemIndex(NullBitVector, aryIndex, 1,
nullVecBufSize, arrayScope, arrayInfo.numDimensions);
...
}