/*
* Measure distance between two range bounds.
*/
static float8
get_distance(TypeCacheEntry *typcache, RangeBound *bound1, RangeBound *bound2)
{
bool has_subdiff = OidIsValid(typcache->rng_subdiff_finfo.fn_oid);
if (!bound1->infinite && !bound2->infinite)
{
/*
* No bounds are infinite, use subdiff function or return default
* value of 1.0 if no subdiff is available.
*/
if (has_subdiff)
return
DatumGetFloat8(FunctionCall2Coll(&typcache->rng_subdiff_finfo,
typcache->rng_collation,
bound2->val,
bound1->val));
else
return 1.0;
}
else if (bound1->infinite && bound2->infinite)
{
/* Both bounds are infinite */
if (bound1->lower == bound2->lower)
return 0.0;
else
return get_float8_infinity();
}
else
{
/* One bound is infinite, another is not */
return get_float8_infinity();
}
}
/*
* The GiST MinDist method for boxes
*
*/
Datum
gist_box_mindistance(PG_FUNCTION_ARGS)
{
GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
BOX *query = PG_GETARG_BOX_P(1);
double d;
if (DatumGetBoxP(entry->key) == NULL || query == NULL) {
d = get_float8_infinity();
PG_RETURN_FLOAT8(d);
}
d = box_mindist_internal(DatumGetBoxP(entry->key), query);
PG_RETURN_FLOAT8(d);
}
static bool
check_special_value(char *ptr, double *retval, char **endptr)
{
if (pg_strncasecmp(ptr, "NaN", 3) == 0)
{
*retval = get_float8_nan();
*endptr = ptr + 3;
return true;
}
else if (pg_strncasecmp(ptr, "Infinity", 8) == 0)
{
*retval = get_float8_infinity();
*endptr = ptr + 8;
return true;
}
else if (pg_strncasecmp(ptr, "-Infinity", 9) == 0)
{
*retval = -get_float8_infinity();
*endptr = ptr + 9;
return true;
}
return false;
}
static float8
gbt_ts_dist(const void *a, const void *b)
{
const Timestamp *aa = (const Timestamp *) a;
const Timestamp *bb = (const Timestamp *) b;
Interval *i;
if (TIMESTAMP_NOT_FINITE(*aa) || TIMESTAMP_NOT_FINITE(*bb))
return get_float8_infinity();
i = DatumGetIntervalP(DirectFunctionCall2(timestamp_mi,
TimestampGetDatumFast(*aa),
TimestampGetDatumFast(*bb)));
return (float8) Abs(INTERVAL_TO_SEC(i));
}
/*
* Initialize the traversal value
*
* In the beginning, we don't have any restrictions. We have to
* initialize the struct to cover the whole 4D space.
*/
static RectBox *
initRectBox()
{
RectBox *rect_box = (RectBox *) palloc(sizeof(RectBox));
double infinity = get_float8_infinity();
rect_box->range_box_x.left.low = -infinity;
rect_box->range_box_x.left.high = infinity;
rect_box->range_box_x.right.low = -infinity;
rect_box->range_box_x.right.high = infinity;
rect_box->range_box_y.left.low = -infinity;
rect_box->range_box_y.left.high = infinity;
rect_box->range_box_y.right.low = -infinity;
rect_box->range_box_y.right.high = infinity;
return rect_box;
}
/*
* Size of a BOX for penalty-calculation purposes.
* The result can be +Infinity, but not NaN.
*/
static double
size_box(const BOX *box)
{
/*
* Check for zero-width cases. Note that we define the size of a zero-
* by-infinity box as zero. It's important to special-case this somehow,
* as naively multiplying infinity by zero will produce NaN.
*
* The less-than cases should not happen, but if they do, say "zero".
*/
if (FLOAT8_LE(box->high.x, box->low.x) ||
FLOAT8_LE(box->high.y, box->low.y))
return 0.0;
/*
* We treat NaN as larger than +Infinity, so any distance involving a NaN
* and a non-NaN is infinite. Note the previous check eliminated the
* possibility that the low fields are NaNs.
*/
if (isnan(box->high.x) || isnan(box->high.y))
return get_float8_infinity();
return (box->high.x - box->low.x) * (box->high.y - box->low.y);
}
/*
* gistindex_keytest() -- does this index tuple satisfy the scan key(s)?
*
* The index tuple might represent either a heap tuple or a lower index page,
* depending on whether the containing page is a leaf page or not.
*
* On success return for a heap tuple, *recheck_p is set to indicate
* whether recheck is needed. We recheck if any of the consistent() functions
* request it. recheck is not interesting when examining a non-leaf entry,
* since we must visit the lower index page if there's any doubt.
*
* If we are doing an ordered scan, so->distances[] is filled with distance
* data from the distance() functions before returning success.
*
* We must decompress the key in the IndexTuple before passing it to the
* sk_funcs (which actually are the opclass Consistent or Distance methods).
*
* Note that this function is always invoked in a short-lived memory context,
* so we don't need to worry about cleaning up allocated memory, either here
* or in the implementation of any Consistent or Distance methods.
*/
static bool
gistindex_keytest(IndexScanDesc scan,
IndexTuple tuple,
Page page,
OffsetNumber offset,
bool *recheck_p)
{
GISTScanOpaque so = (GISTScanOpaque) scan->opaque;
GISTSTATE *giststate = so->giststate;
ScanKey key = scan->keyData;
int keySize = scan->numberOfKeys;
double *distance_p;
Relation r = scan->indexRelation;
*recheck_p = false;
/*
* If it's a leftover invalid tuple from pre-9.1, treat it as a match with
* minimum possible distances. This means we'll always follow it to the
* referenced page.
*
* GPDB: the virtual TIDs created for AO tables use the full range of
* offset numbers from 0 to 65535. So a tuple on leaf page that looks like
* an invalid tuple, is actually ok.
*/
if (!GistPageIsLeaf(page) && GistTupleIsInvalid(tuple))
{
int i;
for (i = 0; i < scan->numberOfOrderBys; i++)
so->distances[i] = -get_float8_infinity();
return true;
}
/* Check whether it matches according to the Consistent functions */
while (keySize > 0)
{
Datum datum;
bool isNull;
datum = index_getattr(tuple,
key->sk_attno,
giststate->tupdesc,
&isNull);
if (key->sk_flags & SK_ISNULL)
{
/*
* On non-leaf page we can't conclude that child hasn't NULL
* values because of assumption in GiST: union (VAL, NULL) is VAL.
* But if on non-leaf page key IS NULL, then all children are
* NULL.
*/
if (key->sk_flags & SK_SEARCHNULL)
{
if (GistPageIsLeaf(page) && !isNull)
return false;
}
else
{
Assert(key->sk_flags & SK_SEARCHNOTNULL);
if (isNull)
return false;
}
}
else if (isNull)
{
return false;
}
else
{
Datum test;
bool recheck;
GISTENTRY de;
gistdentryinit(giststate, key->sk_attno - 1, &de,
datum, r, page, offset,
FALSE, isNull);
/*
* Call the Consistent function to evaluate the test. The
* arguments are the index datum (as a GISTENTRY*), the comparison
* datum, the comparison operator's strategy number and subtype
* from pg_amop, and the recheck flag.
*
* (Presently there's no need to pass the subtype since it'll
* always be zero, but might as well pass it for possible future
* use.)
*
* We initialize the recheck flag to true (the safest assumption)
* in case the Consistent function forgets to set it.
*/
recheck = true;
test = FunctionCall5Coll(&key->sk_func,
key->sk_collation,
PointerGetDatum(&de),
key->sk_argument,
Int32GetDatum(key->sk_strategy),
ObjectIdGetDatum(key->sk_subtype),
PointerGetDatum(&recheck));
if (!DatumGetBool(test))
return false;
*recheck_p |= recheck;
}
key++;
keySize--;
}
/* OK, it passes --- now let's compute the distances */
key = scan->orderByData;
distance_p = so->distances;
keySize = scan->numberOfOrderBys;
while (keySize > 0)
{
Datum datum;
bool isNull;
datum = index_getattr(tuple,
key->sk_attno,
giststate->tupdesc,
&isNull);
if ((key->sk_flags & SK_ISNULL) || isNull)
{
/* Assume distance computes as null and sorts to the end */
*distance_p = get_float8_infinity();
}
else
{
Datum dist;
GISTENTRY de;
gistdentryinit(giststate, key->sk_attno - 1, &de,
datum, r, page, offset,
FALSE, isNull);
/*
* Call the Distance function to evaluate the distance. The
* arguments are the index datum (as a GISTENTRY*), the comparison
* datum, and the ordering operator's strategy number and subtype
* from pg_amop.
*
* (Presently there's no need to pass the subtype since it'll
* always be zero, but might as well pass it for possible future
* use.)
*
* Note that Distance functions don't get a recheck argument. We
* can't tolerate lossy distance calculations on leaf tuples;
* there is no opportunity to re-sort the tuples afterwards.
*/
dist = FunctionCall4Coll(&key->sk_func,
key->sk_collation,
PointerGetDatum(&de),
key->sk_argument,
Int32GetDatum(key->sk_strategy),
ObjectIdGetDatum(key->sk_subtype));
*distance_p = DatumGetFloat8(dist);
}
key++;
distance_p++;
keySize--;
}
return true;
}
/*
* gistindex_keytest() -- does this index tuple satisfy the scan key(s)?
*
* The index tuple might represent either a heap tuple or a lower index page,
* depending on whether the containing page is a leaf page or not.
*
* On success return for a heap tuple, *recheck_p is set to indicate whether
* the quals need to be rechecked. We recheck if any of the consistent()
* functions request it. recheck is not interesting when examining a non-leaf
* entry, since we must visit the lower index page if there's any doubt.
* Similarly, *recheck_distances_p is set to indicate whether the distances
* need to be rechecked, and it is also ignored for non-leaf entries.
*
* If we are doing an ordered scan, so->distances[] is filled with distance
* data from the distance() functions before returning success.
*
* We must decompress the key in the IndexTuple before passing it to the
* sk_funcs (which actually are the opclass Consistent or Distance methods).
*
* Note that this function is always invoked in a short-lived memory context,
* so we don't need to worry about cleaning up allocated memory, either here
* or in the implementation of any Consistent or Distance methods.
*/
static bool
gistindex_keytest(IndexScanDesc scan,
IndexTuple tuple,
Page page,
OffsetNumber offset,
bool *recheck_p,
bool *recheck_distances_p)
{
GISTScanOpaque so = (GISTScanOpaque) scan->opaque;
GISTSTATE *giststate = so->giststate;
ScanKey key = scan->keyData;
int keySize = scan->numberOfKeys;
double *distance_p;
Relation r = scan->indexRelation;
*recheck_p = false;
*recheck_distances_p = false;
/*
* If it's a leftover invalid tuple from pre-9.1, treat it as a match with
* minimum possible distances. This means we'll always follow it to the
* referenced page.
*/
if (GistTupleIsInvalid(tuple))
{
int i;
if (GistPageIsLeaf(page)) /* shouldn't happen */
elog(ERROR, "invalid GiST tuple found on leaf page");
for (i = 0; i < scan->numberOfOrderBys; i++)
so->distances[i] = -get_float8_infinity();
return true;
}
/* Check whether it matches according to the Consistent functions */
while (keySize > 0)
{
Datum datum;
bool isNull;
datum = index_getattr(tuple,
key->sk_attno,
giststate->tupdesc,
&isNull);
if (key->sk_flags & SK_ISNULL)
{
/*
* On non-leaf page we can't conclude that child hasn't NULL
* values because of assumption in GiST: union (VAL, NULL) is VAL.
* But if on non-leaf page key IS NULL, then all children are
* NULL.
*/
if (key->sk_flags & SK_SEARCHNULL)
{
if (GistPageIsLeaf(page) && !isNull)
return false;
}
else
{
Assert(key->sk_flags & SK_SEARCHNOTNULL);
if (isNull)
return false;
}
}
else if (isNull)
{
return false;
}
else
{
Datum test;
bool recheck;
GISTENTRY de;
gistdentryinit(giststate, key->sk_attno - 1, &de,
datum, r, page, offset,
false, isNull);
/*
* Call the Consistent function to evaluate the test. The
* arguments are the index datum (as a GISTENTRY*), the comparison
* datum, the comparison operator's strategy number and subtype
* from pg_amop, and the recheck flag.
*
* (Presently there's no need to pass the subtype since it'll
* always be zero, but might as well pass it for possible future
* use.)
*
* We initialize the recheck flag to true (the safest assumption)
* in case the Consistent function forgets to set it.
*/
recheck = true;
test = FunctionCall5Coll(&key->sk_func,
key->sk_collation,
PointerGetDatum(&de),
key->sk_argument,
Int16GetDatum(key->sk_strategy),
ObjectIdGetDatum(key->sk_subtype),
PointerGetDatum(&recheck));
if (!DatumGetBool(test))
return false;
*recheck_p |= recheck;
}
key++;
keySize--;
}
/* OK, it passes --- now let's compute the distances */
key = scan->orderByData;
distance_p = so->distances;
keySize = scan->numberOfOrderBys;
while (keySize > 0)
{
Datum datum;
bool isNull;
datum = index_getattr(tuple,
key->sk_attno,
giststate->tupdesc,
&isNull);
if ((key->sk_flags & SK_ISNULL) || isNull)
{
/* Assume distance computes as null and sorts to the end */
*distance_p = get_float8_infinity();
}
else
{
Datum dist;
bool recheck;
GISTENTRY de;
gistdentryinit(giststate, key->sk_attno - 1, &de,
datum, r, page, offset,
false, isNull);
/*
* Call the Distance function to evaluate the distance. The
* arguments are the index datum (as a GISTENTRY*), the comparison
* datum, the ordering operator's strategy number and subtype from
* pg_amop, and the recheck flag.
*
* (Presently there's no need to pass the subtype since it'll
* always be zero, but might as well pass it for possible future
* use.)
*
* If the function sets the recheck flag, the returned distance is
* a lower bound on the true distance and needs to be rechecked.
* We initialize the flag to 'false'. This flag was added in
* version 9.5; distance functions written before that won't know
* about the flag, but are expected to never be lossy.
*/
recheck = false;
dist = FunctionCall5Coll(&key->sk_func,
key->sk_collation,
PointerGetDatum(&de),
key->sk_argument,
Int16GetDatum(key->sk_strategy),
ObjectIdGetDatum(key->sk_subtype),
PointerGetDatum(&recheck));
*recheck_distances_p |= recheck;
*distance_p = DatumGetFloat8(dist);
}
key++;
distance_p++;
keySize--;
}
return true;
}
static Datum
leftmostvalue_float8(void)
{
return Float8GetDatum(-get_float8_infinity());
}
Datum gist_infinite_mindistance(PG_FUNCTION_ARGS)
{
double d = get_float8_infinity();
PG_RETURN_FLOAT8(d);
}
