Building MySQL UDF on MacOSX

lib_mysqludf_calc_distance.c

#ifdef STANDARD
/* STANDARD is defined, don't use any mysql functions */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#ifdef __WIN__
typedef unsigned __int64 ulonglong;/* Microsofts 64 bit types */
typedef __int64 longlong;
#else
typedef unsigned long long ulonglong;
typedef long long longlong;
#endif /*__WIN__*/
#else
#include <my_global.h>
#include <my_sys.h>
#if defined(MYSQL_SERVER)
#include <m_string.h>/* To get strmov() */
#else
/* when compiled as standalone */
#include <string.h>
#define strmov(a,b) stpcpy(a,b)
#define bzero(a,b) memset(a,0,b)
#define memcpy_fixed(a,b,c) memcpy(a,b,c)
#endif
#endif
#include <mysql.h>
#include <ctype.h>
   
#ifdef HAVE_DLOPEN
   
#if !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_SOLARIS_STYLE_GETHOST)
static pthread_mutex_t LOCK_hostname;
#endif
   
//                                                                        
// User #includes go here                                                 
//                                                                        
#include <lib_mysqludf_calc_distance.h>   
//                                                                        
// init, deinit and actual function prototypes here                       
//                                                                        

//                                                                        
// init function                                                          
//                                                                        
my_bool calc_distance_udf_init(UDF_INIT *initid, UDF_ARGS *args, char *message) {
    if(!(args->arg_count == 4)) {
        strcpy(message, "Expected four arguments (lat, lon, locate_lat, locate_lon)");
        return 1;
    }
   
    args->arg_type[0] = REAL_RESULT;
    args->arg_type[1] = REAL_RESULT;
    args->arg_type[2] = REAL_RESULT;
    args->arg_type[3] = REAL_RESULT;
   
    return 0;
}   
   
//                                                                        
// deinit function                                                        
//                                                                        
void calc_distance_udf_deinit(UDF_INIT *initid __attribute__((unused))) {}   
//                                                                        
// Actual function                                                        
//                                                                        
double calc_distance_udf(
    UDF_INIT* initid, UDF_ARGS* args __attribute__((unused)),
    char* is_null __attribute__((unused)), char* error __attribute__((unused))
) {
    double lat = *((double *)(args->args[0]));
    double lon = *((double *)(args->args[1]));
    double locate_lat = *((double *)(args->args[2]));
    double locate_lon = *((double *)(args->args[3]));
    
    lat = lat * M_PI / 180;
    lon = lon * M_PI / 180;
    locate_lat = locate_lat * M_PI / 180;
    locate_lon = locate_lon * M_PI / 180;
    
    return 3959 * acos(cos(lat) * cos(locate_lat) * cos(locate_lon - lon) + sin(lat) * sin(locate_lat));
}

#endif /* HAVE_DLOPEN */

lib_mysqludf_calc_distance.h

#ifndef __LIB_MYSQLUDF_CALC_DISTANCE
#define __LIB_MYSQLUDF_CALC_DISTANCE 1
#include <mysql.h>
my_bool calc_distance_udf_init(UDF_INIT *initid, UDF_ARGS *args, char *message);
void calc_distance_udf_deinit(UDF_INIT *initid __attribute__((unused)));
double calc_distance_udf(
    UDF_INIT* initid, 
    UDF_ARGS* args __attribute__((unused)), 
    char* is_null __attribute__((unused)), 
    char* error __attribute__((unused))
);
#endif

Makefile

MYSQL_BUILD_DIR =
MYSQL_PLUGIN_DIR = 
CC := gcc 
CPPFLAGS := -Iinclude -I$(MYSQL_BUILD_DIR)/include -dynamiclib 
LIB_FILE := lib_mysqludf_calc_distance.dylib
VPATH := src include

all: lib_mysqludf_calc_distance.dylib
lib_mysqludf_calc_distance.dylib: src/lib_mysqludf_calc_distance.c include/lib_mysqludf_calc_distance.h
	$(CC) $(CPPFLAGS) -o $@ src/lib_mysqludf_calc_distance.c
install: lib_mysqludf_calc_distance.dylib
	install -m 755 lib_mysqludf_calc_distance.dylib $(MYSQL_PLUGIN_DIR)