greenplumn win32setlocale 源码

greenplumn win32setlocale 代码

文件路径：/src/port/win32setlocale.c

/*-------------------------------------------------------------------------
 *
 * win32setlocale.c
 *		Wrapper to work around bugs in Windows setlocale() implementation
 *
 * Copyright (c) 2011-2019, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *	  src/port/win32setlocale.c
 *
 *
 * The setlocale() function in Windows is broken in two ways. First, it
 * has a problem with locale names that have a dot in the country name. For
 * example:
 *
 * "Chinese (Traditional)_Hong Kong S.A.R..950"
 *
 * For some reason, setlocale() doesn't accept that as argument, even though
 * setlocale(LC_ALL, NULL) returns exactly that. Fortunately, it accepts
 * various alternative names for such countries, so to work around the broken
 * setlocale() function, we map the troublemaking locale names to accepted
 * aliases, before calling setlocale().
 *
 * The second problem is that the locale name for "Norwegian (Bokmål)"
 * contains a non-ASCII character. That's problematic, because it's not clear
 * what encoding the locale name itself is supposed to be in, when you
 * haven't yet set a locale. Also, it causes problems when the cluster
 * contains databases with different encodings, as the locale name is stored
 * in the pg_database system catalog. To work around that, when setlocale()
 * returns that locale name, map it to a pure-ASCII alias for the same
 * locale.
 *-------------------------------------------------------------------------
 */

#include "c.h"

#undef setlocale

struct locale_map
{
	/*
	 * String in locale name to replace. Can be a single string (end is NULL),
	 * or separate start and end strings. If two strings are given, the locale
	 * name must contain both of them, and everything between them is
	 * replaced. This is used for a poor-man's regexp search, allowing
	 * replacement of "start.*end".
	 */
	const char *locale_name_start;
	const char *locale_name_end;

	const char *replacement;	/* string to replace the match with */
};

/*
 * Mappings applied before calling setlocale(), to the argument.
 */
static const struct locale_map locale_map_argument[] = {
	/*
	 * "HKG" is listed here:
	 * http://msdn.microsoft.com/en-us/library/cdax410z%28v=vs.71%29.aspx
	 * (Country/Region Strings).
	 *
	 * "ARE" is the ISO-3166 three-letter code for U.A.E. It is not on the
	 * above list, but seems to work anyway.
	 */
	{"Hong Kong S.A.R.", NULL, "HKG"},
	{"U.A.E.", NULL, "ARE"},

	/*
	 * The ISO-3166 country code for Macau S.A.R. is MAC, but Windows doesn't
	 * seem to recognize that. And Macau isn't listed in the table of accepted
	 * abbreviations linked above. Fortunately, "ZHM" seems to be accepted as
	 * an alias for "Chinese (Traditional)_Macau S.A.R..950". I'm not sure
	 * where "ZHM" comes from, must be some legacy naming scheme. But hey, it
	 * works.
	 *
	 * Note that unlike HKG and ARE, ZHM is an alias for the *whole* locale
	 * name, not just the country part.
	 *
	 * Some versions of Windows spell it "Macau", others "Macao".
	 */
	{"Chinese (Traditional)_Macau S.A.R..950", NULL, "ZHM"},
	{"Chinese_Macau S.A.R..950", NULL, "ZHM"},
	{"Chinese (Traditional)_Macao S.A.R..950", NULL, "ZHM"},
	{"Chinese_Macao S.A.R..950", NULL, "ZHM"},
	{NULL, NULL, NULL}
};

/*
 * Mappings applied after calling setlocale(), to its return value.
 */
static const struct locale_map locale_map_result[] = {
	/*
	 * "Norwegian (Bokmål)" locale name contains the a-ring character.
	 * Map it to a pure-ASCII alias.
	 *
	 * It's not clear what encoding setlocale() uses when it returns the
	 * locale name, so to play it safe, we search for "Norwegian (Bok*l)".
	 */
	{"Norwegian (Bokm", "l)_Norway", "Norwegian_Norway"},
	{NULL, NULL, NULL}
};

#define MAX_LOCALE_NAME_LEN		100

static const char *
map_locale(const struct locale_map *map, const char *locale)
{
	static char aliasbuf[MAX_LOCALE_NAME_LEN];
	int			i;

	/* Check if the locale name matches any of the problematic ones. */
	for (i = 0; map[i].locale_name_start != NULL; i++)
	{
		const char *needle_start = map[i].locale_name_start;
		const char *needle_end = map[i].locale_name_end;
		const char *replacement = map[i].replacement;
		char	   *match;
		char	   *match_start = NULL;
		char	   *match_end = NULL;

		match = strstr(locale, needle_start);
		if (match)
		{
			/*
			 * Found a match for the first part. If this was a two-part
			 * replacement, find the second part.
			 */
			match_start = match;
			if (needle_end)
			{
				match = strstr(match_start + strlen(needle_start), needle_end);
				if (match)
					match_end = match + strlen(needle_end);
				else
					match_start = NULL;
			}
			else
				match_end = match_start + strlen(needle_start);
		}

		if (match_start)
		{
			/* Found a match. Replace the matched string. */
			int			matchpos = match_start - locale;
			int			replacementlen = strlen(replacement);
			char	   *rest = match_end;
			int			restlen = strlen(rest);

			/* check that the result fits in the static buffer */
			if (matchpos + replacementlen + restlen + 1 > MAX_LOCALE_NAME_LEN)
				return NULL;

			memcpy(&aliasbuf[0], &locale[0], matchpos);
			memcpy(&aliasbuf[matchpos], replacement, replacementlen);
			/* includes null terminator */
			memcpy(&aliasbuf[matchpos + replacementlen], rest, restlen + 1);

			return aliasbuf;
		}
	}

	/* no match, just return the original string */
	return locale;
}

char *
pgwin32_setlocale(int category, const char *locale)
{
	const char *argument;
	char	   *result;

	if (locale == NULL)
		argument = NULL;
	else
		argument = map_locale(locale_map_argument, locale);

	/* Call the real setlocale() function */
	result = setlocale(category, argument);

	/*
	 * setlocale() is specified to return a "char *" that the caller is
	 * forbidden to modify, so casting away the "const" is innocuous.
	 */
	if (result)
		result = unconstify(char *, map_locale(locale_map_result, result));

	return result;
}

相关信息

greenplumn 源码目录

相关文章

greenplumn chklocale 源码

greenplumn crypt 源码

greenplumn dirent 源码

greenplumn dirmod 源码

greenplumn dlopen 源码

greenplumn erand48 源码

greenplumn fls 源码

greenplumn fseeko 源码

greenplumn getaddrinfo 源码

greenplumn getopt 源码