database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-30 21:42:05 +03:00
Code Activity

Modernize to_char's Roman-numeral code, fixing overflow problems.

Browse Source 
int_to_roman() only accepts plain "int" input, which is fine since
we're going to produce '###############' for any value above 3999
anyway.  However, the numeric and int8 variants of to_char() would
throw an error if the given input exceeded the integer range, while
the float-input variants invoked undefined-per-C-standard behavior.
Fix things so that you uniformly get '###############' for out of
range input.

Also add test cases covering this code, plus the equally-untested
EEEE, V, and PL format codes.

Discussion: https://postgr.es/m/2956175.1725831136@sss.pgh.pa.us
This commit is contained in:
Tom Lane
2024-09-26 11:02:31 -04:00
parent e3a92ab070
commit 147bbc90f7
6 changed files with 231 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

92
src/backend/utils/adt/formatting.c
View File

@ -5189,6 +5189,11 @@ NUM_cache(int len, NUMDesc *Num, text *pars_str, bool *shouldFree)
}
/*
* Convert integer to Roman numerals
* Result is upper-case and not blank-padded (NUM_processor converts as needed)
* If input is out-of-range, produce '###############'
*/
static char *
int_to_roman(int number)
{
@ -5201,32 +5206,42 @@ int_to_roman(int number)
result = (char *) palloc(16);
*result = '\0';
/*
* This range limit is the same as in Oracle(TM). The difficulty with
* handling 4000 or more is that we'd need to use more than 3 "M"'s, and
* more than 3 of the same digit isn't considered a valid Roman string.
*/
if (number > 3999 || number < 1)
{
fill_str(result, '#', 15);
return result;
}
/* Convert to decimal, then examine each digit */
len = snprintf(numstr, sizeof(numstr), "%d", number);
Assert(len > 0 && len <= 4);
for (p = numstr; *p != '\0'; p++, --len)
{
num = *p - ('0' + 1);
if (num < 0)
continue;
if (len > 3)
continue; /* ignore zeroes */
/* switch on current column position */
switch (len)
{
while (num-- != -1)
strcat(result, "M");
}
else
{
if (len == 3)
case 4:
while (num-- >= 0)
strcat(result, "M");
break;
case 3:
strcat(result, rm100[num]);
else if (len == 2)
break;
case 2:
strcat(result, rm10[num]);
else if (len == 1)
break;
case 1:
strcat(result, rm1[num]);
break;
}
}
return result;
@ -6367,7 +6382,6 @@ numeric_to_char(PG_FUNCTION_ARGS)
char *numstr,
*orgnum,
*p;
Numeric x;
NUM_TOCHAR_prepare;
@ -6376,12 +6390,15 @@ numeric_to_char(PG_FUNCTION_ARGS)
*/
if (IS_ROMAN(&Num))
{
x = DatumGetNumeric(DirectFunctionCall2(numeric_round,
NumericGetDatum(value),
Int32GetDatum(0)));
numstr =
int_to_roman(DatumGetInt32(DirectFunctionCall1(numeric_int4,
NumericGetDatum(x))));
int32 intvalue;
bool err;
/* Round and convert to int */
intvalue = numeric_int4_opt_error(value, &err);
/* On overflow, just use PG_INT32_MAX; int_to_roman will cope */
if (err)
intvalue = PG_INT32_MAX;
numstr = int_to_roman(intvalue);
}
else if (IS_EEEE(&Num))
{
@ -6421,6 +6438,7 @@ numeric_to_char(PG_FUNCTION_ARGS)
{
int numstr_pre_len;
Numeric val = value;
Numeric x;
if (IS_MULTI(&Num))
{
@ -6589,12 +6607,18 @@ int8_to_char(PG_FUNCTION_ARGS)
NUM_TOCHAR_prepare;
/*
* On DateType depend part (int32)
* On DateType depend part (int64)
*/
if (IS_ROMAN(&Num))
{
/* Currently don't support int8 conversion to roman... */
numstr = int_to_roman(DatumGetInt32(DirectFunctionCall1(int84, Int64GetDatum(value))));
int32 intvalue;
/* On overflow, just use PG_INT32_MAX; int_to_roman will cope */
if (value <= PG_INT32_MAX && value >= PG_INT32_MIN)
intvalue = (int32) value;
else
intvalue = PG_INT32_MAX;
numstr = int_to_roman(intvalue);
}
else if (IS_EEEE(&Num))
{
@ -6695,7 +6719,18 @@ float4_to_char(PG_FUNCTION_ARGS)
NUM_TOCHAR_prepare;
if (IS_ROMAN(&Num))
numstr = int_to_roman((int) rint(value));
{
int32 intvalue;
/* See notes in ftoi4() */
value = rint(value);
/* On overflow, just use PG_INT32_MAX; int_to_roman will cope */
if (!isnan(value) && FLOAT4_FITS_IN_INT32(value))
intvalue = (int32) value;
else
intvalue = PG_INT32_MAX;
numstr = int_to_roman(intvalue);
}
else if (IS_EEEE(&Num))
{
if (isnan(value) || isinf(value))
@ -6797,7 +6832,18 @@ float8_to_char(PG_FUNCTION_ARGS)
NUM_TOCHAR_prepare;
if (IS_ROMAN(&Num))
numstr = int_to_roman((int) rint(value));
{
int32 intvalue;
/* See notes in dtoi4() */
value = rint(value);
/* On overflow, just use PG_INT32_MAX; int_to_roman will cope */
if (!isnan(value) && FLOAT8_FITS_IN_INT32(value))
intvalue = (int32) value;
else
intvalue = PG_INT32_MAX;
numstr = int_to_roman(intvalue);
}
else if (IS_EEEE(&Num))
{
if (isnan(value) || isinf(value))