From 22da73198f87e04dc0f978dd2507ebf5c7ae6ee8 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Sat, 24 Apr 2010 22:54:56 +0000
Subject: [PATCH] Add C comments for recent to_char('L') fix for Win32.
---
src/backend/utils/adt/pg_locale.c | 78 ++++++++++++++++++++++---------
1 file changed, 55 insertions(+), 23 deletions(-)
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 171431fbd4..33297accab 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -4,7 +4,7 @@
*
* Portions Copyright (c) 2002-2010, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/backend/utils/adt/pg_locale.c,v 1.54 2010/04/22 01:55:52 itagaki Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/pg_locale.c,v 1.55 2010/04/24 22:54:56 momjian Exp $
*
*-----------------------------------------------------------------------
*/
@@ -41,6 +41,10 @@
* DOES NOT WORK RELIABLY: on some platforms the second setlocale() call
* will change the memory save is pointing at. To do this sort of thing
* safely, you *must* pstrdup what setlocale returns the first time.
+ *
+ * FYI, The Open Group locale standard is defined here:
+ *
+ * http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap07.html
*----------
*/
@@ -424,7 +428,6 @@ PGLC_localeconv(void)
char *grouping;
char *thousands_sep;
int encoding;
-
#ifdef WIN32
char *save_lc_ctype;
#endif
@@ -435,25 +438,48 @@ PGLC_localeconv(void)
free_struct_lconv(&CurrentLocaleConv);
- /* Set user's values of monetary and numeric locales */
+ /* Save user's values of monetary and numeric locales */
save_lc_monetary = setlocale(LC_MONETARY, NULL);
if (save_lc_monetary)
save_lc_monetary = pstrdup(save_lc_monetary);
+
save_lc_numeric = setlocale(LC_NUMERIC, NULL);
if (save_lc_numeric)
save_lc_numeric = pstrdup(save_lc_numeric);
#ifdef WIN32
- /* set user's value of ctype locale */
+ /*
+ * Ideally, monetary and numeric local symbols could be returned in
+ * any server encoding. Unfortunately, the WIN32 API does not allow
+ * setlocale() to return values in a codepage/CTYPE that uses more
+ * than two bytes per character, like UTF-8:
+ *
+ * http://msdn.microsoft.com/en-us/library/x99tb11d.aspx
+ *
+ * Evidently, LC_CTYPE allows us to control the encoding used
+ * for strings returned by localeconv(). The Open Group
+ * standard, mentioned at the top of this C file, doesn't
+ * explicitly state this.
+ *
+ * Therefore, we set LC_CTYPE to match LC_NUMERIC or LC_MONETARY
+ * (which cannot be UTF8), call localeconv(), and then convert from
+ * the numeric/monitary LC_CTYPE to the server encoding. One
+ * example use of this is for the Euro symbol.
+ *
+ * Perhaps someday we will use GetLocaleInfoW() which returns values
+ * in UTF16 and convert from that.
+ */
+
+ /* save user's value of ctype locale */
save_lc_ctype = setlocale(LC_CTYPE, NULL);
if (save_lc_ctype)
save_lc_ctype = pstrdup(save_lc_ctype);
-#endif
- /* Get formatting information for numeric */
-#ifdef WIN32
+ /* use numeric to set the ctype */
setlocale(LC_CTYPE, locale_numeric);
#endif
+
+ /* Get formatting information for numeric */
setlocale(LC_NUMERIC, locale_numeric);
extlconv = localeconv();
encoding = pg_get_encoding_from_locale(locale_numeric);
@@ -462,10 +488,12 @@ PGLC_localeconv(void)
thousands_sep = db_encoding_strdup(encoding, extlconv->thousands_sep);
grouping = strdup(extlconv->grouping);
- /* Get formatting information for monetary */
#ifdef WIN32
+ /* use monetary to set the ctype */
setlocale(LC_CTYPE, locale_monetary);
#endif
+
+ /* Get formatting information for monetary */
setlocale(LC_MONETARY, locale_monetary);
extlconv = localeconv();
encoding = pg_get_encoding_from_locale(locale_monetary);
@@ -500,7 +528,7 @@ PGLC_localeconv(void)
}
#ifdef WIN32
- /* try to restore internal ctype settings */
+ /* Try to restore internal ctype settings */
if (save_lc_ctype)
{
setlocale(LC_CTYPE, save_lc_ctype);
@@ -514,13 +542,15 @@ PGLC_localeconv(void)
#ifdef WIN32
/*
- * On win32, strftime() returns the encoding in CP_ACP, which is likely
- * different from SERVER_ENCODING. This is especially important in Japanese
- * versions of Windows which will use SJIS encoding, which we don't support
- * as a server encoding.
+ * On WIN32, strftime() returns the encoding in CP_ACP (the default
+ * operating system codpage for that computer), which is likely different
+ * from SERVER_ENCODING. This is especially important in Japanese versions
+ * of Windows which will use SJIS encoding, which we don't support as a
+ * server encoding.
*
- * Replace strftime() with a version that gets the string in UTF16 and then
- * converts it to the appropriate encoding as necessary.
+ * So, instead of using strftime(), use wcsftime() to return the value in
+ * wide characters (internally UTF16) and then convert it to the appropriate
+ * database encoding.
*
* Note that this only affects the calls to strftime() in this file, which are
* used to get the locale-aware strings. Other parts of the backend use
@@ -537,7 +567,6 @@ strftime_win32(char *dst, size_t dstlen, const wchar_t *format, const struct tm
len = wcsftime(wbuf, MAX_L10N_DATA, format, tm);
if (len == 0)
-
/*
* strftime call failed - return 0 with the contents of dst
* unspecified
@@ -564,7 +593,9 @@ strftime_win32(char *dst, size_t dstlen, const wchar_t *format, const struct tm
return len;
}
+/* redefine strftime() */
#define strftime(a,b,c,d) strftime_win32(a,b,L##c,d)
+
#endif /* WIN32 */
@@ -580,7 +611,6 @@ cache_locale_time(void)
char buf[MAX_L10N_DATA];
char *ptr;
int i;
-
#ifdef WIN32
char *save_lc_ctype;
#endif
@@ -591,20 +621,22 @@ cache_locale_time(void)
elog(DEBUG3, "cache_locale_time() executed; locale: \"%s\"", locale_time);
+ /* save user's value of time locale */
+ save_lc_time = setlocale(LC_TIME, NULL);
+ if (save_lc_time)
+ save_lc_time = pstrdup(save_lc_time);
+
#ifdef WIN32
- /* set user's value of ctype locale */
+ /* See the WIN32 comment near the top of PGLC_localeconv() */
+ /* save user's value of ctype locale */
save_lc_ctype = setlocale(LC_CTYPE, NULL);
if (save_lc_ctype)
save_lc_ctype = pstrdup(save_lc_ctype);
+ /* use lc_time to set the ctype */
setlocale(LC_CTYPE, locale_time);
#endif
- /* set user's value of time locale */
- save_lc_time = setlocale(LC_TIME, NULL);
- if (save_lc_time)
- save_lc_time = pstrdup(save_lc_time);
-
setlocale(LC_TIME, locale_time);
timenow = time(NULL);
--
2.40.0