/* Copyright (C) 2002 MySQL AB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* ** example file of UDF (user definable functions) that are dynamicly loaded ** into the standard mysqld core. ** ** The functions name, type and shared library is saved in the new system ** table 'func'. To be able to create new functions one must have write ** privilege for the database 'mysql'. If one starts MySQL with ** --skip-grant, then UDF initialization will also be skipped. ** ** Syntax for the new commands are: ** create function returns {string|real|integer} ** soname ** drop function ** ** Each defined function may have a xxxx_init function and a xxxx_deinit ** function. The init function should alloc memory for the function ** and tell the main function about the max length of the result ** (for string functions), number of decimals (for double functions) and ** if the result may be a null value. ** ** If a function sets the 'error' argument to 1 the function will not be ** called anymore and mysqld will return NULL for all calls to this copy ** of the function. ** ** All strings arguments to functions are given as string pointer + length ** to allow handling of binary data. ** Remember that all functions must be thread safe. This means that one is not ** allowed to alloc any global or static variables that changes! ** If one needs memory one should alloc this in the init function and free ** this on the __deinit function. ** ** Note that the init and __deinit functions are only called once per ** SQL statement while the value function may be called many times ** ** Function 'metaphon' returns a metaphon string of the string argument. ** This is something like a soundex string, but it's more tuned for English. ** ** Function 'myfunc_double' returns summary of codes of all letters ** of arguments divided by summary length of all its arguments. ** ** Function 'myfunc_int' returns summary length of all its arguments. ** ** Function 'sequence' returns an sequence starting from a certain number. ** ** Function 'myfunc_argument_name' returns name of argument. ** ** On the end is a couple of functions that converts hostnames to ip and ** vice versa. ** ** A dynamicly loadable file should be compiled shared. ** (something like: gcc -shared -o my_func.so myfunc.cc). ** You can easily get all switches right by doing: ** cd sql ; make udf_example.o ** Take the compile line that make writes, remove the '-c' near the end of ** the line and add -shared -o udf_example.so to the end of the compile line. ** The resulting library (udf_example.so) should be copied to some dir ** searched by ld. (/usr/lib ?) ** If you are using gcc, then you should be able to create the udf_example.so ** by simply doing 'make udf_example.so'. ** ** After the library is made one must notify mysqld about the new ** functions with the commands: ** ** CREATE FUNCTION metaphon RETURNS STRING SONAME "udf_example.so"; ** CREATE FUNCTION myfunc_double RETURNS REAL SONAME "udf_example.so"; ** CREATE FUNCTION myfunc_int RETURNS INTEGER SONAME "udf_example.so"; ** CREATE FUNCTION sequence RETURNS INTEGER SONAME "udf_example.so"; ** CREATE FUNCTION lookup RETURNS STRING SONAME "udf_example.so"; ** CREATE FUNCTION reverse_lookup RETURNS STRING SONAME "udf_example.so"; ** CREATE AGGREGATE FUNCTION avgcost RETURNS REAL SONAME "udf_example.so"; ** CREATE FUNCTION myfunc_argument_name RETURNS STRING SONAME "udf_example.so"; ** ** After this the functions will work exactly like native MySQL functions. ** Functions should be created only once. ** ** The functions can be deleted by: ** ** DROP FUNCTION metaphon; ** DROP FUNCTION myfunc_double; ** DROP FUNCTION myfunc_int; ** DROP FUNCTION lookup; ** DROP FUNCTION reverse_lookup; ** DROP FUNCTION avgcost; ** DROP FUNCTION myfunc_argument_name; ** ** The CREATE FUNCTION and DROP FUNCTION update the func@mysql table. All ** Active function will be reloaded on every restart of server ** (if --skip-grant-tables is not given) ** ** If you ge problems with undefined symbols when loading the shared ** library, you should verify that mysqld is compiled with the -rdynamic ** option. ** ** If you can't get AGGREGATES to work, check that you have the column ** 'type' in the mysql.func table. If not, run 'mysql_fix_privilege_tables'. ** */ #ifdef STANDARD /* STANDARD is defined, don't use any mysql functions */ #include #include #include #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 #include #if defined(MYSQL_SERVER) #include /* To get strmov() */ #else /* when compiled as standalone */ #include #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 #include #ifdef HAVE_DLOPEN #if !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_SOLARIS_STYLE_GETHOST) static pthread_mutex_t LOCK_hostname; #endif /* These must be right or mysqld will not find the symbol! */ my_bool metaphon_init(UDF_INIT *initid, UDF_ARGS *args, char *message); void metaphon_deinit(UDF_INIT *initid); char *metaphon(UDF_INIT *initid, UDF_ARGS *args, char *result, unsigned long *length, char *is_null, char *error); my_bool myfunc_double_init(UDF_INIT *, UDF_ARGS *args, char *message); double myfunc_double(UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error); my_bool myfunc_int_init(UDF_INIT *initid, UDF_ARGS *args, char *message); longlong myfunc_int(UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error); my_bool sequence_init(UDF_INIT *initid, UDF_ARGS *args, char *message); void sequence_deinit(UDF_INIT *initid); longlong sequence(UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error); my_bool avgcost_init( UDF_INIT* initid, UDF_ARGS* args, char* message ); void avgcost_deinit( UDF_INIT* initid ); void avgcost_reset( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error ); void avgcost_clear( UDF_INIT* initid, char* is_null, char *error ); void avgcost_add( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error ); double avgcost( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error ); my_bool is_const_init(UDF_INIT *initid, UDF_ARGS *args, char *message); char *is_const(UDF_INIT *initid, UDF_ARGS *args, char *result, unsigned long *length, char *is_null, char *error); /************************************************************************* ** Example of init function ** Arguments: ** initid Points to a structure that the init function should fill. ** This argument is given to all other functions. ** my_bool maybe_null 1 if function can return NULL ** Default value is 1 if any of the arguments ** is declared maybe_null. ** unsigned int decimals Number of decimals. ** Default value is max decimals in any of the ** arguments. ** unsigned int max_length Length of string result. ** The default value for integer functions is 21 ** The default value for real functions is 13+ ** default number of decimals. ** The default value for string functions is ** the longest string argument. ** char *ptr; A pointer that the function can use. ** ** args Points to a structure which contains: ** unsigned int arg_count Number of arguments ** enum Item_result *arg_type Types for each argument. ** Types are STRING_RESULT, REAL_RESULT ** and INT_RESULT. ** char **args Pointer to constant arguments. ** Contains 0 for not constant argument. ** unsigned long *lengths; max string length for each argument ** char *maybe_null Information of which arguments ** may be NULL ** ** message Error message that should be passed to the user on fail. ** The message buffer is MYSQL_ERRMSG_SIZE big, but one should ** try to keep the error message less than 80 bytes long! ** ** This function should return 1 if something goes wrong. In this case ** message should contain something useful! **************************************************************************/ #define MAXMETAPH 8 my_bool metaphon_init(UDF_INIT *initid, UDF_ARGS *args, char *message) { if (args->arg_count != 1 || args->arg_type[0] != STRING_RESULT) { strcpy(message,"Wrong arguments to metaphon; Use the source"); return 1; } initid->max_length=MAXMETAPH; return 0; } /**************************************************************************** ** Deinit function. This should free all resources allocated by ** this function. ** Arguments: ** initid Return value from xxxx_init ****************************************************************************/ void metaphon_deinit(UDF_INIT *initid __attribute__((unused))) { } /*************************************************************************** ** UDF string function. ** Arguments: ** initid Structure filled by xxx_init ** args The same structure as to xxx_init. This structure ** contains values for all parameters. ** Note that the functions MUST check and convert all ** to the type it wants! Null values are represented by ** a NULL pointer ** result Possible buffer to save result. At least 255 byte long. ** length Pointer to length of the above buffer. In this the function ** should save the result length ** is_null If the result is null, one should store 1 here. ** error If something goes fatally wrong one should store 1 here. ** ** This function should return a pointer to the result string. ** Normally this is 'result' but may also be an alloced string. ***************************************************************************/ /* Character coding array */ static char codes[26] = { 1,16,4,16,9,2,4,16,9,2,0,2,2,2,1,4,0,2,4,4,1,0,0,0,8,0 /* A B C D E F G H I J K L M N O P Q R S T U V W X Y Z*/ }; /*--- Macros to access character coding array -------------*/ #define ISVOWEL(x) (codes[(x) - 'A'] & 1) /* AEIOU */ /* Following letters are not changed */ #define NOCHANGE(x) (codes[(x) - 'A'] & 2) /* FJLMNR */ /* These form diphthongs when preceding H */ #define AFFECTH(x) (codes[(x) - 'A'] & 4) /* CGPST */ /* These make C and G soft */ #define MAKESOFT(x) (codes[(x) - 'A'] & 8) /* EIY */ /* These prevent GH from becoming F */ #define NOGHTOF(x) (codes[(x) - 'A'] & 16) /* BDH */ char *metaphon(UDF_INIT *initid __attribute__((unused)), UDF_ARGS *args, char *result, unsigned long *length, char *is_null, char *error __attribute__((unused))) { const char *word=args->args[0]; const char *w_end; char *org_result; char *n, *n_start, *n_end; /* pointers to string */ char *metaph_end; /* pointers to end of metaph */ char ntrans[32]; /* word with uppercase letters */ int KSflag; /* state flag for X to KS */ if (!word) /* Null argument */ { *is_null=1; return 0; } w_end=word+args->lengths[0]; org_result=result; /*-------------------------------------------------------- * Copy word to internal buffer, dropping non-alphabetic * characters and converting to uppercase. *-------------------------------------------------------*/ for (n = ntrans + 1, n_end = ntrans + sizeof(ntrans)-2; word != w_end && n < n_end; word++ ) if ( isalpha ( *word )) *n++ = toupper ( *word ); if ( n == ntrans + 1 ) /* return empty string if 0 bytes */ { *length=0; return result; } n_end = n; /* set n_end to end of string */ ntrans[0] = 'Z'; /* ntrans[0] should be a neutral char */ n[0]=n[1]=0; /* pad with nulls */ n = ntrans + 1; /* assign pointer to start */ /*------------------------------------------------------------ * check for all prefixes: * PN KN GN AE WR WH and X at start. *----------------------------------------------------------*/ switch ( *n ) { case 'P': case 'K': case 'G': if ( n[1] == 'N') *n++ = 0; break; case 'A': if ( n[1] == 'E') *n++ = 0; break; case 'W': if ( n[1] == 'R' ) *n++ = 0; else if ( *(n + 1) == 'H') { n[1] = *n; *n++ = 0; } break; case 'X': *n = 'S'; break; } /*------------------------------------------------------------ * Now, loop step through string, stopping at end of string * or when the computed metaph is MAXMETAPH characters long *----------------------------------------------------------*/ KSflag = 0; /* state flag for KS translation */ for (metaph_end = result + MAXMETAPH, n_start = n; n < n_end && result < metaph_end; n++ ) { if ( KSflag ) { KSflag = 0; *result++ = *n; } else { /* drop duplicates except for CC */ if ( *( n - 1 ) == *n && *n != 'C' ) continue; /* check for F J L M N R or first letter vowel */ if ( NOCHANGE ( *n ) || ( n == n_start && ISVOWEL ( *n ))) *result++ = *n; else switch ( *n ) { case 'B': /* check for -MB */ if ( n < n_end || *( n - 1 ) != 'M' ) *result++ = *n; break; case 'C': /* C = X ("sh" sound) in CH and CIA */ /* = S in CE CI and CY */ /* dropped in SCI SCE SCY */ /* else K */ if ( *( n - 1 ) != 'S' || !MAKESOFT ( n[1])) { if ( n[1] == 'I' && n[2] == 'A' ) *result++ = 'X'; else if ( MAKESOFT ( n[1])) *result++ = 'S'; else if ( n[1] == 'H' ) *result++ = (( n == n_start && !ISVOWEL ( n[2])) || *( n - 1 ) == 'S' ) ? (char)'K' : (char)'X'; else *result++ = 'K'; } break; case 'D': /* J before DGE, DGI, DGY, else T */ *result++ = ( n[1] == 'G' && MAKESOFT ( n[2])) ? (char)'J' : (char)'T'; break; case 'G': /* complicated, see table in text */ if (( n[1] != 'H' || ISVOWEL ( n[2])) && ( n[1] != 'N' || ( (n + 1) < n_end && ( n[2] != 'E' || *( n + 3 ) != 'D' ) ) ) && ( *( n - 1 ) != 'D' || !MAKESOFT ( n[1]) ) ) *result++ = ( MAKESOFT ( *( n + 1 )) && n[2] != 'G' ) ? (char)'J' : (char)'K'; else if ( n[1] == 'H' && !NOGHTOF( *( n - 3 )) && *( n - 4 ) != 'H') *result++ = 'F'; break; case 'H': /* H if before a vowel and not after */ /* C, G, P, S, T */ if ( !AFFECTH ( *( n - 1 )) && ( !ISVOWEL ( *( n - 1 )) || ISVOWEL ( n[1]))) *result++ = 'H'; break; case 'K': /* K = K, except dropped after C */ if ( *( n - 1 ) != 'C') *result++ = 'K'; break; case 'P': /* PH = F, else P = P */ *result++ = *( n + 1 ) == 'H' ? (char)'F' : (char)'P'; break; case 'Q': /* Q = K (U after Q is already gone */ *result++ = 'K'; break; case 'S': /* SH, SIO, SIA = X ("sh" sound) */ *result++ = ( n[1] == 'H' || ( *(n + 1) == 'I' && ( n[2] == 'O' || n[2] == 'A'))) ? (char)'X' : (char)'S'; break; case 'T': /* TIO, TIA = X ("sh" sound) */ /* TH = 0, ("th" sound ) */ if ( *( n + 1 ) == 'I' && ( n[2] == 'O' || n[2] == 'A') ) *result++ = 'X'; else if ( n[1] == 'H' ) *result++ = '0'; else if ( *( n + 1) != 'C' || n[2] != 'H') *result++ = 'T'; break; case 'V': /* V = F */ *result++ = 'F'; break; case 'W': /* only exist if a vowel follows */ case 'Y': if ( ISVOWEL ( n[1])) *result++ = *n; break; case 'X': /* X = KS, except at start */ if ( n == n_start ) *result++ = 'S'; else { *result++ = 'K'; /* insert K, then S */ KSflag = 1; /* this flag will cause S to be inserted on next pass thru loop */ } break; case 'Z': *result++ = 'S'; break; } } } *length= (unsigned long) (result - org_result); return org_result; } /*************************************************************************** ** UDF double function. ** Arguments: ** initid Structure filled by xxx_init ** args The same structure as to xxx_init. This structure ** contains values for all parameters. ** Note that the functions MUST check and convert all ** to the type it wants! Null values are represented by ** a NULL pointer ** is_null If the result is null, one should store 1 here. ** error If something goes fatally wrong one should store 1 here. ** ** This function should return the result. ***************************************************************************/ my_bool myfunc_double_init(UDF_INIT *initid, UDF_ARGS *args, char *message) { uint i; if (!args->arg_count) { strcpy(message,"myfunc_double must have at least one argument"); return 1; } /* ** As this function wants to have everything as strings, force all arguments ** to strings. */ for (i=0 ; i < args->arg_count; i++) args->arg_type[i]=STRING_RESULT; initid->maybe_null=1; /* The result may be null */ initid->decimals=2; /* We want 2 decimals in the result */ initid->max_length=6; /* 3 digits + . + 2 decimals */ return 0; } double myfunc_double(UDF_INIT *initid __attribute__((unused)), UDF_ARGS *args, char *is_null, char *error __attribute__((unused))) { unsigned long val = 0; unsigned long v = 0; uint i, j; for (i = 0; i < args->arg_count; i++) { if (args->args[i] == NULL) continue; val += args->lengths[i]; for (j=args->lengths[i] ; j-- > 0 ;) v += args->args[i][j]; } if (val) return (double) v/ (double) val; *is_null=1; return 0.0; } /*************************************************************************** ** UDF long long function. ** Arguments: ** initid Return value from xxxx_init ** args The same structure as to xxx_init. This structure ** contains values for all parameters. ** Note that the functions MUST check and convert all ** to the type it wants! Null values are represented by ** a NULL pointer ** is_null If the result is null, one should store 1 here. ** error If something goes fatally wrong one should store 1 here. ** ** This function should return the result as a long long ***************************************************************************/ /* This function returns the sum of all arguments */ longlong myfunc_int(UDF_INIT *initid __attribute__((unused)), UDF_ARGS *args, char *is_null __attribute__((unused)), char *error __attribute__((unused))) { longlong val = 0; uint i; for (i = 0; i < args->arg_count; i++) { if (args->args[i] == NULL) continue; switch (args->arg_type[i]) { case STRING_RESULT: /* Add string lengths */ val += args->lengths[i]; break; case INT_RESULT: /* Add numbers */ val += *((longlong*) args->args[i]); break; case REAL_RESULT: /* Add numers as longlong */ val += (longlong) *((double*) args->args[i]); break; default: break; } } return val; } /* At least one of _init/_deinit is needed unless the server is started with --allow_suspicious_udfs. */ my_bool myfunc_int_init(UDF_INIT *initid __attribute__((unused)), UDF_ARGS *args __attribute__((unused)), char *message __attribute__((unused))) { return 0; } /* Simple example of how to get a sequences starting from the first argument or 1 if no arguments have been given */ my_bool sequence_init(UDF_INIT *initid, UDF_ARGS *args, char *message) { if (args->arg_count > 1) { strmov(message,"This function takes none or 1 argument"); return 1; } if (args->arg_count) args->arg_type[0]= INT_RESULT; /* Force argument to int */ if (!(initid->ptr=(char*) malloc(sizeof(longlong)))) { strmov(message,"Couldn't allocate memory"); return 1; } bzero(initid->ptr,sizeof(longlong)); /* sequence() is a non-deterministic function : it has different value even if called with the same arguments. */ initid->const_item=0; return 0; } void sequence_deinit(UDF_INIT *initid) { if (initid->ptr) free(initid->ptr); } longlong sequence(UDF_INIT *initid __attribute__((unused)), UDF_ARGS *args, char *is_null __attribute__((unused)), char *error __attribute__((unused))) { ulonglong val=0; if (args->arg_count) val= *((longlong*) args->args[0]); return ++*((longlong*) initid->ptr) + val; } /**************************************************************************** ** Some functions that handles IP and hostname conversions ** The orignal function was from Zeev Suraski. ** ** CREATE FUNCTION lookup RETURNS STRING SONAME "udf_example.so"; ** CREATE FUNCTION reverse_lookup RETURNS STRING SONAME "udf_example.so"; ** ****************************************************************************/ #ifdef __WIN__ #include #else #include #include #include #include #endif my_bool lookup_init(UDF_INIT *initid, UDF_ARGS *args, char *message); void lookup_deinit(UDF_INIT *initid); char *lookup(UDF_INIT *initid, UDF_ARGS *args, char *result, unsigned long *length, char *null_value, char *error); my_bool reverse_lookup_init(UDF_INIT *initid, UDF_ARGS *args, char *message); void reverse_lookup_deinit(UDF_INIT *initid); char *reverse_lookup(UDF_INIT *initid, UDF_ARGS *args, char *result, unsigned long *length, char *null_value, char *error); /**************************************************************************** ** lookup IP for an hostname. ** ** This code assumes that gethostbyname_r exists and inet_ntoa() is thread ** safe (As it is in Solaris) ****************************************************************************/ my_bool lookup_init(UDF_INIT *initid, UDF_ARGS *args, char *message) { if (args->arg_count != 1 || args->arg_type[0] != STRING_RESULT) { strmov(message,"Wrong arguments to lookup; Use the source"); return 1; } initid->max_length=11; initid->maybe_null=1; #if !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_SOLARIS_STYLE_GETHOST) (void) pthread_mutex_init(&LOCK_hostname,MY_MUTEX_INIT_SLOW); #endif return 0; } void lookup_deinit(UDF_INIT *initid __attribute__((unused))) { #if !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_SOLARIS_STYLE_GETHOST) (void) pthread_mutex_destroy(&LOCK_hostname); #endif } char *lookup(UDF_INIT *initid __attribute__((unused)), UDF_ARGS *args, char *result, unsigned long *res_length, char *null_value, char *error __attribute__((unused))) { uint length; char name_buff[256]; struct hostent *hostent; #if defined(HAVE_GETHOSTBYADDR_R) && defined(HAVE_SOLARIS_STYLE_GETHOST) int tmp_errno; char hostname_buff[2048]; struct hostent tmp_hostent; #endif struct in_addr in; if (!args->args[0] || !(length=args->lengths[0])) { *null_value=1; return 0; } if (length >= sizeof(name_buff)) length=sizeof(name_buff)-1; memcpy(name_buff,args->args[0],length); name_buff[length]=0; #if defined(HAVE_GETHOSTBYADDR_R) && defined(HAVE_SOLARIS_STYLE_GETHOST) if (!(hostent=gethostbyname_r(name_buff,&tmp_hostent,hostname_buff, sizeof(hostname_buff), &tmp_errno))) { *null_value=1; return 0; } #else VOID(pthread_mutex_lock(&LOCK_hostname)); if (!(hostent= gethostbyname((char*) name_buff))) { VOID(pthread_mutex_unlock(&LOCK_hostname)); *null_value= 1; return 0; } VOID(pthread_mutex_unlock(&LOCK_hostname)); #endif memcpy_fixed((char*) &in,(char*) *hostent->h_addr_list, sizeof(in.s_addr)); *res_length= (ulong) (strmov(result, inet_ntoa(in)) - result); return result; } /**************************************************************************** ** return hostname for an IP number. ** The functions can take as arguments a string "xxx.xxx.xxx.xxx" or ** four numbers. ****************************************************************************/ my_bool reverse_lookup_init(UDF_INIT *initid, UDF_ARGS *args, char *message) { if (args->arg_count == 1) args->arg_type[0]= STRING_RESULT; else if (args->arg_count == 4) args->arg_type[0]=args->arg_type[1]=args->arg_type[2]=args->arg_type[3]= INT_RESULT; else { strmov(message, "Wrong number of arguments to reverse_lookup; Use the source"); return 1; } initid->max_length=32; initid->maybe_null=1; #if !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_SOLARIS_STYLE_GETHOST) (void) pthread_mutex_init(&LOCK_hostname,MY_MUTEX_INIT_SLOW); #endif return 0; } void reverse_lookup_deinit(UDF_INIT *initid __attribute__((unused))) { #if !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_SOLARIS_STYLE_GETHOST) (void) pthread_mutex_destroy(&LOCK_hostname); #endif } char *reverse_lookup(UDF_INIT *initid __attribute__((unused)), UDF_ARGS *args, char *result, unsigned long *res_length, char *null_value, char *error __attribute__((unused))) { #if defined(HAVE_GETHOSTBYADDR_R) && defined(HAVE_SOLARIS_STYLE_GETHOST) char name_buff[256]; struct hostent tmp_hostent; int tmp_errno; #endif struct hostent *hp; unsigned long taddr; uint length; if (args->arg_count == 4) { if (!args->args[0] || !args->args[1] ||!args->args[2] ||!args->args[3]) { *null_value=1; return 0; } sprintf(result,"%d.%d.%d.%d", (int) *((longlong*) args->args[0]), (int) *((longlong*) args->args[1]), (int) *((longlong*) args->args[2]), (int) *((longlong*) args->args[3])); } else { /* string argument */ if (!args->args[0]) /* Return NULL for NULL values */ { *null_value=1; return 0; } length=args->lengths[0]; if (length >= (uint) *res_length-1) length=(uint) *res_length; memcpy(result,args->args[0],length); result[length]=0; } taddr = inet_addr(result); if (taddr == (unsigned long) -1L) { *null_value=1; return 0; } #if defined(HAVE_GETHOSTBYADDR_R) && defined(HAVE_SOLARIS_STYLE_GETHOST) if (!(hp=gethostbyaddr_r((char*) &taddr,sizeof(taddr), AF_INET, &tmp_hostent, name_buff,sizeof(name_buff), &tmp_errno))) { *null_value=1; return 0; } #else VOID(pthread_mutex_lock(&LOCK_hostname)); if (!(hp= gethostbyaddr((char*) &taddr, sizeof(taddr), AF_INET))) { VOID(pthread_mutex_unlock(&LOCK_hostname)); *null_value= 1; return 0; } VOID(pthread_mutex_unlock(&LOCK_hostname)); #endif *res_length=(ulong) (strmov(result,hp->h_name) - result); return result; } /* ** Syntax for the new aggregate commands are: ** create aggregate function returns {string|real|integer} ** soname ** ** Syntax for avgcost: avgcost( t.quantity, t.price ) ** with t.quantity=integer, t.price=double ** (this example is provided by Andreas F. Bobak ) */ struct avgcost_data { ulonglong count; longlong totalquantity; double totalprice; }; /* ** Average Cost Aggregate Function. */ my_bool avgcost_init( UDF_INIT* initid, UDF_ARGS* args, char* message ) { struct avgcost_data* data; if (args->arg_count != 2) { strcpy( message, "wrong number of arguments: AVGCOST() requires two arguments" ); return 1; } if ((args->arg_type[0] != INT_RESULT) || (args->arg_type[1] != REAL_RESULT) ) { strcpy( message, "wrong argument type: AVGCOST() requires an INT and a REAL" ); return 1; } /* ** force arguments to double. */ /*args->arg_type[0] = REAL_RESULT; args->arg_type[1] = REAL_RESULT;*/ initid->maybe_null = 0; /* The result may be null */ initid->decimals = 4; /* We want 4 decimals in the result */ initid->max_length = 20; /* 6 digits + . + 10 decimals */ if (!(data = (struct avgcost_data*) malloc(sizeof(struct avgcost_data)))) { strmov(message,"Couldn't allocate memory"); return 1; } data->totalquantity = 0; data->totalprice = 0.0; initid->ptr = (char*)data; return 0; } void avgcost_deinit( UDF_INIT* initid ) { free(initid->ptr); } /* This is only for MySQL 4.0 compability */ void avgcost_reset(UDF_INIT* initid, UDF_ARGS* args, char* is_null, char* message) { avgcost_clear(initid, is_null, message); avgcost_add(initid, args, is_null, message); } /* This is needed to get things to work in MySQL 4.1.1 and above */ void avgcost_clear(UDF_INIT* initid, char* is_null __attribute__((unused)), char* message __attribute__((unused))) { struct avgcost_data* data = (struct avgcost_data*)initid->ptr; data->totalprice= 0.0; data->totalquantity= 0; data->count= 0; } void avgcost_add(UDF_INIT* initid, UDF_ARGS* args, char* is_null __attribute__((unused)), char* message __attribute__((unused))) { if (args->args[0] && args->args[1]) { struct avgcost_data* data = (struct avgcost_data*)initid->ptr; longlong quantity = *((longlong*)args->args[0]); longlong newquantity = data->totalquantity + quantity; double price = *((double*)args->args[1]); data->count++; if ( ((data->totalquantity >= 0) && (quantity < 0)) || ((data->totalquantity < 0) && (quantity > 0)) ) { /* ** passing from + to - or from - to + */ if ( ((quantity < 0) && (newquantity < 0)) || ((quantity > 0) && (newquantity > 0)) ) { data->totalprice = price * (double)newquantity; } /* ** sub q if totalq > 0 ** add q if totalq < 0 */ else { price = data->totalprice / (double)data->totalquantity; data->totalprice = price * (double)newquantity; } data->totalquantity = newquantity; } else { data->totalquantity += quantity; data->totalprice += price * (double)quantity; } if (data->totalquantity == 0) data->totalprice = 0.0; } } double avgcost( UDF_INIT* initid, UDF_ARGS* args __attribute__((unused)), char* is_null, char* error __attribute__((unused))) { struct avgcost_data* data = (struct avgcost_data*)initid->ptr; if (!data->count || !data->totalquantity) { *is_null = 1; return 0.0; } *is_null = 0; return data->totalprice/(double)data->totalquantity; } my_bool myfunc_argument_name_init(UDF_INIT *initid, UDF_ARGS *args, char *message); char *myfunc_argument_name(UDF_INIT *initid, UDF_ARGS *args, char *result, unsigned long *length, char *null_value, char *error); my_bool myfunc_argument_name_init(UDF_INIT *initid, UDF_ARGS *args, char *message) { if (args->arg_count != 1) { strmov(message,"myfunc_argument_name_init accepts only one argument"); return 1; } initid->max_length= args->attribute_lengths[0]; initid->maybe_null= 1; initid->const_item= 1; return 0; } char *myfunc_argument_name(UDF_INIT *initid __attribute__((unused)), UDF_ARGS *args, char *result, unsigned long *length, char *null_value, char *error __attribute__((unused))) { if (!args->attributes[0]) { *null_value= 1; return 0; } (*length)--; /* space for ending \0 (for debugging purposes) */ if (*length > args->attribute_lengths[0]) *length= args->attribute_lengths[0]; memcpy(result, args->attributes[0], *length); result[*length]= 0; return result; } my_bool is_const_init(UDF_INIT *initid, UDF_ARGS *args, char *message) { if (args->arg_count != 1) { strmov(message, "IS_CONST accepts only one argument"); return 1; } initid->ptr= (char*)((args->args[0] != NULL) ? 1UL : 0); return 0; } char * is_const(UDF_INIT *initid, UDF_ARGS *args __attribute__((unused)), char *result, unsigned long *length, char *is_null, char *error __attribute__((unused))) { if (initid->ptr != 0) { sprintf(result, "const"); } else { sprintf(result, "not const"); } *is_null= 0; *length= (uint) strlen(result); return result; } my_bool check_const_len_init(UDF_INIT *initid, UDF_ARGS *args, char *message) { if (args->arg_count != 1) { strmov(message, "CHECK_CONST_LEN accepts only one argument"); return 1; } if (args->args[0] == 0) { initid->ptr= (char*)"Not constant"; } else if(strlen(args->args[0]) == args->lengths[0]) { initid->ptr= (char*)"Correct length"; } else { initid->ptr= (char*)"Wrong length"; } initid->max_length = 100; return 0; } char * check_const_len(UDF_INIT *initid, UDF_ARGS *args __attribute__((unused)), char *result, unsigned long *length, char *is_null, char *error __attribute__((unused))) { strmov(result, initid->ptr); *length= (uint) strlen(result); *is_null= 0; return result; } #endif /* HAVE_DLOPEN */