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Revise the API for user-defined functions. (CVS 398)

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FossilOrigin-Name: 633951f0fa11c91f93aa2862df84691750c01e73
This commit is contained in:
drh
2002-02-27 19:00:20 +00:00
parent 4e0f995347
commit 1350b030c1
10 changed files with 331 additions and 146 deletions
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src/func.c
+13 -21
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@@ -16,7 +16,7 @@
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.3 2002/02/26 23:55:31 drh Exp $
** $Id: func.c,v 1.4 2002/02/27 19:00:22 drh Exp $
*/
#include <ctype.h>
#include <math.h>
@@ -26,7 +26,7 @@
/*
** Implementation of the upper() and lower() SQL functions.
*/
static void upperFunc(void *context, int argc, const char **argv){
static void upperFunc(sqlite_func *context, int argc, const char **argv){
char *z;
int i;
if( argc<1 || argv[0]==0 ) return;
@@ -36,7 +36,7 @@ static void upperFunc(void *context, int argc, const char **argv){
if( islower(z[i]) ) z[i] = toupper(z[i]);
}
}
static void lowerFunc(void *context, int argc, const char **argv){
static void lowerFunc(sqlite_func *context, int argc, const char **argv){
char *z;
int i;
if( argc<1 || argv[0]==0 ) return;
@@ -61,32 +61,24 @@ struct StdDevCtx {
/*
** Routines used to compute the standard deviation as an aggregate.
*/
static void *stdDevStep(void *stddev, int argc, char **argv){
static void stdDevStep(sqlite_func *context, int argc, const char **argv){
StdDevCtx *p;
double x;
if( argc<1 ) return 0;
if( stddev==0 ){
p = malloc( sizeof(*p) );
p->n = 0;
p->sum = 0.0;
p->sum2 = 0.0;
}else{
p = (StdDevCtx*)stddev;
}
if( argc<1 ) return;
p = sqlite_aggregate_context(context, sizeof(*p));
if( p==0 ) return;
x = atof(argv[0]);
p->sum += x;
p->sum2 += x*x;
p->n++;
return p;
}
static void stdDevFinalize(void *stddev, void *context){
StdDevCtx *p = (StdDevCtx*)stddev;
if( context && p && p->n>1 ){
static void stdDevFinalize(sqlite_func *context){
StdDevCtx *p = sqlite_aggregate_context(context, sizeof(*p));
if( p && p->n>1 ){
double rN = p->n;
sqlite_set_result_double(context,
sqrt((p->sum2 - p->sum*p->sum/rN)/(rN-1.0)));
}
if( stddev ) free(stddev);
}
/*
@@ -95,7 +87,7 @@ static void stdDevFinalize(void *stddev, void *context){
** external linkage.
*/
void sqliteRegisterBuildinFunctions(sqlite *db){
sqlite_create_function(db, "upper", 1, upperFunc);
sqlite_create_function(db, "lower", 1, lowerFunc);
sqlite_create_aggregate(db, "stddev", 1, stdDevStep, stdDevFinalize);
sqlite_create_function(db, "upper", 1, upperFunc, 0);
sqlite_create_function(db, "lower", 1, lowerFunc, 0);
sqlite_create_aggregate(db, "stddev", 1, stdDevStep, stdDevFinalize, 0);
}