/*
* Returns whether the Bloom filter contains the item or not
*/
Datum
bloom_contains(PG_FUNCTION_ARGS)
{
BloomFilter *bloom;
Datum elem = PG_GETARG_DATUM(1);
bool contains = false;
Oid val_type = get_fn_expr_argtype(fcinfo->flinfo, 1);
TypeCacheEntry *typ;
StringInfo buf;
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
if (PG_ARGISNULL(0))
PG_RETURN_BOOL(contains);
bloom = (BloomFilter *) PG_GETARG_VARLENA_P(0);
typ = lookup_type_cache(val_type, 0);
buf = makeStringInfo();
DatumToBytes(elem, typ, buf);
contains = BloomFilterContains(bloom, buf->data, buf->len);
pfree(buf->data);
pfree(buf);
PG_RETURN_BOOL(contains);
}
END_TEST
START_TEST(test_union)
{
BloomFilter *bf1 = BloomFilterCreate();
BloomFilter *bf2 = BloomFilterCreate();
int num_keys = 25000;
int *keys = palloc(sizeof(int) * num_keys * 2);
int i;
for (i = 0; i < num_keys; i++)
{
int k1 = rand();
int k2 = rand();
keys[i] = k1;
keys[num_keys + i] = k2;
BloomFilterAdd(bf1, &k1, sizeof(int));
BloomFilterAdd(bf2, &k2, sizeof(int));
}
bf1 = BloomFilterUnion(bf1, bf2);
for (i = 0; i < num_keys * 2; i++)
ck_assert(BloomFilterContains(bf1, &keys[i], sizeof(int)));
}
END_TEST
START_TEST(test_false_positives)
{
float p = 0.01;
int n = 10000;
BloomFilter *bf = BloomFilterCreateWithPAndN(p, n);
float fp = 0;
int i;
for (i = 0; i < n; i++)
BloomFilterAdd(bf, &i, sizeof(int));
for (i = 0; i < n; i++)
{
int r = rand();
if (BloomFilterContains(bf, &r, sizeof(int)))
fp++;
}
ck_assert_int_le(fp / n, p);
}
