On lör, 2012-03-10 at 18:47 -0500, Tom Lane wrote:
> > void EncodeDateTime(struct pg_tm * tm, fsec_t fsec, const int *tzp, const
> > char *tzn, int style, char *str)
>
> It appears to me that null-ness of tzp and tzn are used as a 3-way flag
> to identify the style of timezone output wanted (none, numeric, or alpha).
> It would probably be better yet if it went like
>
> enum tzstyle, int tzp, const char *tzn
>
> where tzp or tzn would be examined only if tzstyle said so.
It's not quite a three-way flag, because it also depends on the style,
which time zone style is used. But I liked the idea of making "print
the time zone" more explicit and getting rid of the funny pointers. I
added a bit of documentation and code deduplication in the attached
patch, and it already looks much more understandable.
diff --git i/src/backend/utils/adt/date.c w/src/backend/utils/adt/date.c
index 85e8fd0..2da4e04 100644
--- i/src/backend/utils/adt/date.c
+++ w/src/backend/utils/adt/date.c
@@ -1131,7 +1131,7 @@ time_out(PG_FUNCTION_ARGS)
char buf[MAXDATELEN + 1];
time2tm(time, tm, &fsec);
- EncodeTimeOnly(tm, fsec, NULL, DateStyle, buf);
+ EncodeTimeOnly(tm, fsec, false, 0, DateStyle, buf);
result = pstrdup(buf);
PG_RETURN_CSTRING(result);
@@ -1918,7 +1918,7 @@ timetz_out(PG_FUNCTION_ARGS)
char buf[MAXDATELEN + 1];
timetz2tm(time, tm, &fsec, &tz);
- EncodeTimeOnly(tm, fsec, &tz, DateStyle, buf);
+ EncodeTimeOnly(tm, fsec, true, tz, DateStyle, buf);
result = pstrdup(buf);
PG_RETURN_CSTRING(result);
diff --git i/src/backend/utils/adt/datetime.c w/src/backend/utils/adt/datetime.c
index f495c3f..56515f1 100644
--- i/src/backend/utils/adt/datetime.c
+++ w/src/backend/utils/adt/datetime.c
@@ -3679,39 +3679,54 @@ EncodeDateOnly(struct pg_tm * tm, int style, char *str)
/* EncodeTimeOnly()
* Encode time fields only.
+ *
+ * tm and fsec are the value to encode, print_tz determines whether to include
+ * a time zone (the difference between time and timetz types), tz is the
+ * numeric time zone offset, style is the date style, str is where to write the
+ * output.
*/
void
-EncodeTimeOnly(struct pg_tm * tm, fsec_t fsec, int *tzp, int style, char *str)
+EncodeTimeOnly(struct pg_tm * tm, fsec_t fsec, bool print_tz, int tz, int style, char *str)
{
sprintf(str, "%02d:%02d:", tm->tm_hour, tm->tm_min);
str += strlen(str);
AppendSeconds(str, tm->tm_sec, fsec, MAX_TIME_PRECISION, true);
- if (tzp != NULL)
- EncodeTimezone(str, *tzp, style);
+ if (print_tz)
+ EncodeTimezone(str, tz, style);
}
/* EncodeDateTime()
* Encode date and time interpreted as local time.
- * Support several date styles:
+ *
+ * tm and fsec are the value to encode, print_tz determines whether to include
+ * a time zone (the difference between timestamp and timestamptz types), tz is
+ * the numeric time zone offset, tzn is the textual time zone, which if
+ * specified will be used instead of tz by some styles, style is the date
+ * style, str is where to write the output.
+ *
+ * Supported date styles:
* Postgres - day mon hh:mm:ss tz
* SQL - mm/dd/ hh:mm:ss.ss tz
* ISO - -mm-dd hh:mm:ss+/-tz
* German - dd.mm. hh:mm:ss tz
* XSD - -mm-ddThh:mm:ss.ss+/-tz
- * Variants (affects order of month and day for Postgres and SQL styles):
- * US - mm/dd/
- * European - dd/mm/
*/
void
-EncodeDateTime(struct pg_tm * tm, fsec_t fsec, int *tzp, char **tzn, int style, char *str)
+EncodeDateTime(struct pg_tm * tm, fsec_t fsec, bool print_tz, int tz, const char *tzn, int style, char *str)
{
int day;
Assert(tm->tm_mon >= 1 && tm->tm_mon <= MONTHS_PER_YEAR);
+ /*
+ * Negative tm_isdst means we have no valid time zone translation.
+ */
+ if (tm->tm_isdst < 0)
+ print_tz = false;
+
switch (style)
{
case USE_ISO_DATES:
@@ -3729,14 +3744,8 @@ EncodeDateTime(struct pg_tm * tm, fsec_t fsec, int *tzp, char **tzn, int style,
AppendTimestampSeconds(str + strlen(str), tm, fsec);
- /*
- * tzp == NULL indicates that we don't want *any* time zone info
- * in the output string. *tzn != NULL indicates that we have alpha
- * time zone info available. tm_isdst != -1 indicates that we have
- * a valid time zone translation.
- */
- if (tzp != NULL && tm->tm_isdst >= 0)
-EncodeTimezone(str, *tzp, style);
+ if (print_tz)
+EncodeTimezone(str, tz, style);
if (tm->tm_year <= 0)
sprintf(str + strlen(str), " BC");
@@ -3762,12 +3771,12 @@ EncodeDateTime(struct pg_tm * tm, fsec_t fsec, int *tzp, char **tzn, int style,
* TZ abbreviations in the Olson database are plain ASCII.
*/
- if (tzp != NULL && tm->tm_isdst >= 0)
+ if (print_tz)
{
-if (*tzn != NULL)
- sprintf(str + strlen(str), " %.*s", MAXTZLEN, *tzn);
+if (tzn)
+ sprintf(str + strlen(str), " %.*s", MAXTZLEN, tzn);
else
- EncodeTimezone(str, *tzp, style);
+ EncodeTimezone(str, tz, style);
}
if (tm->tm_year <= 0)
@@ -3785,12 +3794,12 @@
