postgresql/contrib/cube/cubedata.h
Tom Lane f31a931fad Improve contrib/cube's handling of zero-D cubes, infinities, and NaNs.
It's always been possible to create a zero-dimensional cube by converting
from a zero-length float8 array, but cube_in failed to accept the '()'
representation that cube_out produced for that case, resulting in a
dump/reload hazard.  Make it accept the case.  Also fix a couple of
other places that didn't behave sanely for zero-dimensional cubes:
cube_size would produce 1.0 when surely the answer should be 0.0,
and g_cube_distance risked a divide-by-zero failure.

Likewise, it's always been possible to create cubes containing float8
infinity or NaN coordinate values, but cube_in couldn't parse such input,
and cube_out produced platform-dependent spellings of the values.  Convert
them to use float8in_internal and float8out_internal so that the behavior
will be the same as for float8, as we recently did for the core geometric
types (cf commit 50861cd68).  As in that commit, I don't pretend that this
patch fixes all insane corner-case behaviors that may exist for NaNs, but
it's a step forward.

(This change allows removal of the separate cube_1.out and cube_3.out
expected-files, as the platform dependency that previously required them
is now gone: an underflowing coordinate value will now produce an error
not plus or minus zero.)

Make errors from cube_in follow project conventions as to spelling
("invalid input syntax for cube" not "bad cube representation")
and errcode (INVALID_TEXT_REPRESENTATION not SYNTAX_ERROR).

Also a few marginal code cleanups and comment improvements.

Tom Lane, reviewed by Amul Sul

Discussion: <15085.1472494782@sss.pgh.pa.us>
2016-09-27 11:38:33 -04:00

70 lines
2.2 KiB
C

/* contrib/cube/cubedata.h */
/*
* This limit is pretty arbitrary, but don't make it so large that you
* risk overflow in sizing calculations.
*/
#define CUBE_MAX_DIM (100)
typedef struct NDBOX
{
/* varlena header (do not touch directly!) */
int32 vl_len_;
/*----------
* Header contains info about NDBOX. For binary compatibility with old
* versions, it is defined as "unsigned int".
*
* Following information is stored:
*
* bits 0-7 : number of cube dimensions;
* bits 8-30 : unused, initialize to zero;
* bit 31 : point flag. If set, the upper right coordinates are not
* stored, and are implicitly the same as the lower left
* coordinates.
*----------
*/
unsigned int header;
/*
* The lower left coordinates for each dimension come first, followed by
* upper right coordinates unless the point flag is set.
*/
double x[FLEXIBLE_ARRAY_MEMBER];
} NDBOX;
/* NDBOX access macros */
#define POINT_BIT 0x80000000
#define DIM_MASK 0x7fffffff
#define IS_POINT(cube) ( ((cube)->header & POINT_BIT) != 0 )
#define SET_POINT_BIT(cube) ( (cube)->header |= POINT_BIT )
#define DIM(cube) ( (cube)->header & DIM_MASK )
#define SET_DIM(cube, _dim) ( (cube)->header = ((cube)->header & ~DIM_MASK) | (_dim) )
#define LL_COORD(cube, i) ( (cube)->x[i] )
#define UR_COORD(cube, i) ( IS_POINT(cube) ? (cube)->x[i] : (cube)->x[(i) + DIM(cube)] )
#define POINT_SIZE(_dim) (offsetof(NDBOX, x) + sizeof(double)*(_dim))
#define CUBE_SIZE(_dim) (offsetof(NDBOX, x) + sizeof(double)*(_dim)*2)
/* fmgr interface macros */
#define DatumGetNDBOX(x) ((NDBOX *) PG_DETOAST_DATUM(x))
#define PG_GETARG_NDBOX(x) DatumGetNDBOX(PG_GETARG_DATUM(x))
#define PG_RETURN_NDBOX(x) PG_RETURN_POINTER(x)
/* GiST operator strategy numbers */
#define CubeKNNDistanceCoord 15 /* ~> */
#define CubeKNNDistanceTaxicab 16 /* <#> */
#define CubeKNNDistanceEuclid 17 /* <-> */
#define CubeKNNDistanceChebyshev 18 /* <=> */
/* in cubescan.l */
extern int cube_yylex(void);
extern void cube_yyerror(NDBOX **result, const char *message) pg_attribute_noreturn();
extern void cube_scanner_init(const char *str);
extern void cube_scanner_finish(void);
/* in cubeparse.y */
extern int cube_yyparse(NDBOX **result);