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5ded4bd214
The V0 convention is failure prone because we've so far assumed that a function is V0 if PG_FUNCTION_INFO_V1 is missing, leading to crashes if a function was coded against the V1 interface. V0 doesn't allow proper NULL, SRF and toast handling. V0 doesn't offer features that V1 doesn't. Thus remove V0 support and obsolete fmgr README contents relating to it. Author: Andres Freund, with contributions by Peter Eisentraut & Craig Ringer Reviewed-By: Peter Eisentraut, Craig Ringer Discussion: https://postgr.es/m/20161208213441.k3mbno4twhg2qf7g@alap3.anarazel.de
105 lines
2.3 KiB
C
105 lines
2.3 KiB
C
/* contrib/earthdistance/earthdistance.c */
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#include "postgres.h"
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#include <math.h>
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#include "utils/geo_decls.h" /* for Point */
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#ifndef M_PI
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#define M_PI 3.14159265358979323846
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#endif
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PG_MODULE_MAGIC;
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/* Earth's radius is in statute miles. */
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static const double EARTH_RADIUS = 3958.747716;
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static const double TWO_PI = 2.0 * M_PI;
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/******************************************************
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*
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* degtorad - convert degrees to radians
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*
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* arg: double, angle in degrees
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*
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* returns: double, same angle in radians
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******************************************************/
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static double
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degtorad(double degrees)
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{
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return (degrees / 360.0) * TWO_PI;
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}
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/******************************************************
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*
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* geo_distance_internal - distance between points
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*
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* args:
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* a pair of points - for each point,
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* x-coordinate is longitude in degrees west of Greenwich
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* y-coordinate is latitude in degrees above equator
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*
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* returns: double
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* distance between the points in miles on earth's surface
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******************************************************/
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static double
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geo_distance_internal(Point *pt1, Point *pt2)
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{
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double long1,
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lat1,
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long2,
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lat2;
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double longdiff;
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double sino;
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/* convert degrees to radians */
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long1 = degtorad(pt1->x);
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lat1 = degtorad(pt1->y);
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long2 = degtorad(pt2->x);
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lat2 = degtorad(pt2->y);
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/* compute difference in longitudes - want < 180 degrees */
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longdiff = fabs(long1 - long2);
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if (longdiff > M_PI)
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longdiff = TWO_PI - longdiff;
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sino = sqrt(sin(fabs(lat1 - lat2) / 2.) * sin(fabs(lat1 - lat2) / 2.) +
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cos(lat1) * cos(lat2) * sin(longdiff / 2.) * sin(longdiff / 2.));
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if (sino > 1.)
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sino = 1.;
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return 2. * EARTH_RADIUS * asin(sino);
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}
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/******************************************************
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*
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* geo_distance - distance between points
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*
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* args:
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* a pair of points - for each point,
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* x-coordinate is longitude in degrees west of Greenwich
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* y-coordinate is latitude in degrees above equator
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*
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* returns: float8
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* distance between the points in miles on earth's surface
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******************************************************/
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PG_FUNCTION_INFO_V1(geo_distance);
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Datum
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geo_distance(PG_FUNCTION_ARGS)
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{
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Point *pt1 = PG_GETARG_POINT_P(0);
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Point *pt2 = PG_GETARG_POINT_P(1);
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float8 result;
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result = geo_distance_internal(pt1, pt2);
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PG_RETURN_FLOAT8(result);
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}
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