database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-09-03 15:22:11 +03:00
Code Activity

Fix range_cmp_bounds for the case of equal-valued exclusive bounds.

Browse Source 
Also improve its comments and related regression tests.

Jeff Davis, with some further adjustments by Tom
This commit is contained in:
Tom Lane
2011-11-17 16:50:32 -05:00
parent ef27c81d89
commit bf4f96b5e2
3 changed files with 127 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

74
src/backend/utils/adt/rangetypes.c
View File

@@ -1622,33 +1622,89 @@ make_range(TypeCacheEntry *typcache, RangeBound *lower, RangeBound *upper,
return range;
}
/*
* Compare two range boundary points, returning <0, 0, or >0 according to
* whether b1 is less than, equal to, or greater than b2.
*
* The boundaries can be any combination of upper and lower; so it's useful
* for a variety of operators.
*
* The simple case is when b1 and b2 are both finite and inclusive, in which
* case the result is just a comparison of the values held in b1 and b2.
*
* If a bound is exclusive, then we need to know whether it's a lower bound,
* in which case we treat the boundary point as "just greater than" the held
* value; or an upper bound, in which case we treat the boundary point as
* "just less than" the held value.
*
* If a bound is infinite, it represents minus infinity (less than every other
* point) if it's a lower bound; or plus infinity (greater than every other
* point) if it's an upper bound.
*
* There is only one case where two boundaries compare equal but are not
* identical: when both bounds are inclusive and hold the same finite value,
* but one is an upper bound and the other a lower bound.
*/
int
range_cmp_bounds(TypeCacheEntry *typcache, RangeBound *b1, RangeBound *b2)
{
int32 result;
/*
* First, handle cases involving infinity, which don't require invoking
* the comparison proc.
*/
if (b1->infinite && b2->infinite)
{
/*
* Both are infinity, so they are equal unless one is lower and the
* other not.
*/
if (b1->lower == b2->lower)
return 0;
else
return (b1->lower) ? -1 : 1;
return b1->lower ? -1 : 1;
}
else if (b1->infinite && !b2->infinite)
return (b1->lower) ? -1 : 1;
else if (!b1->infinite && b2->infinite)
return (b2->lower) ? 1 : -1;
else if (b1->infinite)
return b1->lower ? -1 : 1;
else if (b2->infinite)
return b2->lower ? 1 : -1;
/*
* Both boundaries are finite, so compare the held values.
*/
result = DatumGetInt32(FunctionCall2Coll(&typcache->rng_cmp_proc_finfo,
typcache->rng_collation,
b1->val, b2->val));
/*
* If the comparison is anything other than equal, we're done. If they
* compare equal though, we still have to consider whether the boundaries
* are inclusive or exclusive.
*/
if (result == 0)
{
if (b1->inclusive && !b2->inclusive)
return (b2->lower) ? -1 : 1;
else if (!b1->inclusive && b2->inclusive)
return (b1->lower) ? 1 : -1;
if (!b1->inclusive && !b2->inclusive)
{
/* both are exclusive */
if (b1->lower == b2->lower)
return 0;
else
return b1->lower ? 1 : -1;
}
else if (!b1->inclusive)
return b1->lower ? 1 : -1;
else if (!b2->inclusive)
return b2->lower ? -1 : 1;
else
{
/*
* Both are inclusive and the values held are equal, so they are
* equal regardless of whether they are upper or lower boundaries,
* or a mix.
*/
return 0;
}
}
return result;