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Begin adding new SQL functions that depend on -lm: ceil(), ceiling(),

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floor(), ln(), log(), and log10() so far.  More to follow.

FossilOrigin-Name: 4db5f2f7875f6df78630a7816fc018141a6eee2e295b44fc7627eb66d07881ea
This commit is contained in:
drh
2020-12-07 17:15:32 +00:00
parent aeb6bc5628
commit f6e904bd92
10 changed files with 249 additions and 27 deletions
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78
src/func.c
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@@ -1904,6 +1904,75 @@ int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){
return 1;
}
/* Extra math functions that require linking with -lm
*/
#ifdef SQLITE_ENABLE_MATH_FUNCTIONS
/*
** Implementation SQL functions:
**
** ceil(X)
** ceiling(X)
** floor(X)
**
** The sqlite3_user_data() pointer is a pointer to the libm implementation
** of the underlying C function.
*/
static void ceilingFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
assert( argc==1 );
switch( sqlite3_value_type(argv[0]) ){
case SQLITE_INTEGER:
sqlite3_result_int64(context, sqlite3_value_int64(argv[0]));
break;
case SQLITE_NULL:
break;
default: {
double (*x)(double) = (double(*)(double))sqlite3_user_data(context);
sqlite3_result_double(context, x(sqlite3_value_double(argv[0])));
break;
}
}
}
/*
** Implementation of SQL functions:
**
** ln(X) - natural logarithm
** log(X) - log base 10
** log10(X) - log base 10
** log(X,Y) - log base Y
*/
static void logFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
double x, y, ans;
assert( argc==1 || argc==2 );
if( sqlite3_value_type(argv[0])==SQLITE_NULL
|| (x = sqlite3_value_double(argv[0]))<0.0
){
return; /* Return NULL for a domain error */
}
ans = log(x);
if( argc==2 ){
if( sqlite3_value_type(argv[1])==SQLITE_NULL
|| (y = sqlite3_value_double(argv[1]))<0.0
){
return; /* Return NULL for a domain error */
}
ans /= log(y);
}else if( sqlite3_user_data(context)!=0 ){
/* Convert from natural logarithm to log base 10 */
ans *= 0.43429448190325178672;
}
sqlite3_result_double(context, ans);
}
#endif /* SQLITE_ENABLE_MATH_FUNCTIONS */
/*
** All of the FuncDef structures in the aBuiltinFunc[] array above
** to the global function hash table. This occurs at start-time (as
@@ -2024,6 +2093,15 @@ void sqlite3RegisterBuiltinFunctions(void){
FUNCTION(coalesce, 0, 0, 0, 0 ),
INLINE_FUNC(coalesce, -1, INLINEFUNC_coalesce, 0 ),
INLINE_FUNC(iif, 3, INLINEFUNC_iif, 0 ),
#ifdef SQLITE_ENABLE_MATH_FUNCTIONS
MFUNCTION(ceil, 1, ceil, ceilingFunc ),
MFUNCTION(ceiling, 1, ceil, ceilingFunc ),
MFUNCTION(floor, 1, floor, ceilingFunc ),
FUNCTION(ln, 1, 0, 0, logFunc ),
FUNCTION(log, 1, 1, 0, logFunc ),
FUNCTION(log10, 1, 1, 0, logFunc ),
FUNCTION(log, 2, 0, 0, logFunc ),
#endif /* SQLITE_ENABLE_MATH_FUNCTIONS */
};
#ifndef SQLITE_OMIT_ALTERTABLE
sqlite3AlterFunctions();