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mariadb/sql/udf_example.c
Sergei Golubchik 4f435bddfd 5.3 merge
2012-01-13 15:50:02 +01:00

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/*
Copyright (c) 2000, 2010, Oracle and/or its affiliates.
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 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 <function_name> returns {string|real|integer}
** soname <name_of_shared_library>
** drop function <function_name>
**
** 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_upgrade'.
**
*/
#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)
#endif
#endif
#include <mysql.h>
#include <ctype.h>
#ifdef _WIN32
/* inet_aton needs winsock library */
#pragma comment(lib, "ws2_32")
#endif
#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 <winsock2.h>
#else
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#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
pthread_mutex_lock(&LOCK_hostname);
if (!(hostent= gethostbyname((char*) name_buff)))
{
pthread_mutex_unlock(&LOCK_hostname);
*null_value= 1;
return 0;
}
pthread_mutex_unlock(&LOCK_hostname);
#endif
memcpy(&in, *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
pthread_mutex_lock(&LOCK_hostname);
if (!(hp= gethostbyaddr((char*) &taddr, sizeof(taddr), AF_INET)))
{
pthread_mutex_unlock(&LOCK_hostname);
*null_value= 1;
return 0;
}
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 <function_name> returns {string|real|integer}
** soname <name_of_shared_library>
**
** Syntax for avgcost: avgcost( t.quantity, t.price )
** with t.quantity=integer, t.price=double
** (this example is provided by Andreas F. Bobak <bobak@relog.ch>)
*/
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 */
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