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Sourcecode: postgresql-8.4 version File versions

pg_locale.c

/*-----------------------------------------------------------------------
 *
 * PostgreSQL locale utilities
 *
 * Portions Copyright (c) 2002-2009, PostgreSQL Global Development Group
 *
 * $PostgreSQL$
 *
 *-----------------------------------------------------------------------
 */

/*----------
 * Here is how the locale stuff is handled: LC_COLLATE and LC_CTYPE
 * are fixed at CREATE DATABASE time, stored in pg_database, and cannot 
 * be changed. Thus, the effects of strcoll(), strxfrm(), isupper(),
 * toupper(), etc. are always in the same fixed locale.
 *
 * LC_MESSAGES is settable at run time and will take effect
 * immediately.
 *
 * The other categories, LC_MONETARY, LC_NUMERIC, and LC_TIME are also
 * settable at run-time.  However, we don't actually set those locale
 * categories permanently.    This would have bizarre effects like no
 * longer accepting standard floating-point literals in some locales.
 * Instead, we only set the locales briefly when needed, cache the
 * required information obtained from localeconv(), and set them back.
 * The cached information is only used by the formatting functions
 * (to_char, etc.) and the money type.    For the user, this should all be
 * transparent.
 *
 * !!! NOW HEAR THIS !!!
 *
 * We've been bitten repeatedly by this bug, so let's try to keep it in
 * mind in future: on some platforms, the locale functions return pointers
 * to static data that will be overwritten by any later locale function.
 * Thus, for example, the obvious-looking sequence
 *                save = setlocale(category, NULL);
 *                if (!setlocale(category, value))
 *                      fail = true;
 *                setlocale(category, save);
 * 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.
 *----------
 */


#include "postgres.h"

#include <locale.h>
#include <time.h>

#include "catalog/pg_control.h"
#include "mb/pg_wchar.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"

#ifdef WIN32
#include <shlwapi.h>
#endif

#define           MAX_L10N_DATA           80


/* GUC settings */
char     *locale_messages;
char     *locale_monetary;
char     *locale_numeric;
char     *locale_time;

/* lc_time localization cache */
char     *localized_abbrev_days[7];
char     *localized_full_days[7];
char     *localized_abbrev_months[12];
char     *localized_full_months[12];

/* indicates whether locale information cache is valid */
static bool CurrentLocaleConvValid = false;
static bool CurrentLCTimeValid = false;

/* Environment variable storage area */

#define LC_ENV_BUFSIZE (NAMEDATALEN + 20)

static char lc_collate_envbuf[LC_ENV_BUFSIZE];
static char lc_ctype_envbuf[LC_ENV_BUFSIZE];

#ifdef LC_MESSAGES
static char lc_messages_envbuf[LC_ENV_BUFSIZE];
#endif
static char lc_monetary_envbuf[LC_ENV_BUFSIZE];
static char lc_numeric_envbuf[LC_ENV_BUFSIZE];
static char lc_time_envbuf[LC_ENV_BUFSIZE];

#if defined(WIN32) && defined(LC_MESSAGES)
static char *IsoLocaleName(const char *); /* MSVC specific */
#endif


/*
 * pg_perm_setlocale
 *
 * This is identical to the libc function setlocale(), with the addition
 * that if the operation is successful, the corresponding LC_XXX environment
 * variable is set to match.  By setting the environment variable, we ensure
 * that any subsequent use of setlocale(..., "") will preserve the settings
 * made through this routine.  Of course, LC_ALL must also be unset to fully
 * ensure that, but that has to be done elsewhere after all the individual
 * LC_XXX variables have been set correctly.  (Thank you Perl for making this
 * kluge necessary.)
 */
char *
pg_perm_setlocale(int category, const char *locale)
{
      char     *result;
      const char *envvar;
      char     *envbuf;

#ifndef WIN32
      result = setlocale(category, locale);
#else

      /*
       * On Windows, setlocale(LC_MESSAGES) does not work, so just assume that
       * the given value is good and set it in the environment variables. We
       * must ignore attempts to set to "", which means "keep using the old
       * environment value".
       */
#ifdef LC_MESSAGES
      if (category == LC_MESSAGES)
      {
            result = (char *) locale;
            if (locale == NULL || locale[0] == '\0')
                  return result;
      }
      else
#endif
            result = setlocale(category, locale);
#endif   /* WIN32 */

      if (result == NULL)
            return result;                /* fall out immediately on failure */

      switch (category)
      {
            case LC_COLLATE:
                  envvar = "LC_COLLATE";
                  envbuf = lc_collate_envbuf;
                  break;
            case LC_CTYPE:
                  envvar = "LC_CTYPE";
                  envbuf = lc_ctype_envbuf;
                  break;
#ifdef LC_MESSAGES
            case LC_MESSAGES:
                  envvar = "LC_MESSAGES";
                  envbuf = lc_messages_envbuf;
#ifdef WIN32
                  result = IsoLocaleName(locale);
                  if (result == NULL)
                        result = (char *) locale;
#endif /* WIN32 */
                  break;
#endif /* LC_MESSAGES */
            case LC_MONETARY:
                  envvar = "LC_MONETARY";
                  envbuf = lc_monetary_envbuf;
                  break;
            case LC_NUMERIC:
                  envvar = "LC_NUMERIC";
                  envbuf = lc_numeric_envbuf;
                  break;
            case LC_TIME:
                  envvar = "LC_TIME";
                  envbuf = lc_time_envbuf;
                  break;
            default:
                  elog(FATAL, "unrecognized LC category: %d", category);
                  envvar = NULL;          /* keep compiler quiet */
                  envbuf = NULL;
                  return NULL;
      }

      snprintf(envbuf, LC_ENV_BUFSIZE - 1, "%s=%s", envvar, result);

      if (putenv(envbuf))
            return NULL;

      return result;
}


/*
 * Is the locale name valid for the locale category?
 */
bool
check_locale(int category, const char *value)
{
      char     *save;
      bool        ret;

      save = setlocale(category, NULL);
      if (!save)
            return false;                 /* won't happen, we hope */

      /* save may be pointing at a modifiable scratch variable, see above */
      save = pstrdup(save);

      /* set the locale with setlocale, to see if it accepts it. */
      ret = (setlocale(category, value) != NULL);

      setlocale(category, save);    /* assume this won't fail */
      pfree(save);

      return ret;
}

/* GUC assign hooks */

/*
 * This is common code for several locale categories.  This doesn't
 * actually set the locale permanently, it only tests if the locale is
 * valid.  (See explanation at the top of this file.)
 *
 * Note: we accept value = "" as selecting the postmaster's environment
 * value, whatever it was (so long as the environment setting is legal).
 * This will have been locked down by an earlier call to pg_perm_setlocale.
 */
static const char *
locale_xxx_assign(int category, const char *value, bool doit, GucSource source)
{
      if (!check_locale(category, value))
            value = NULL;                 /* set failure return marker */

      /* need to reload cache next time? */
      if (doit && value != NULL)
      {
            CurrentLocaleConvValid = false;
            CurrentLCTimeValid = false;
      }

      return value;
}


const char *
locale_monetary_assign(const char *value, bool doit, GucSource source)
{
      return locale_xxx_assign(LC_MONETARY, value, doit, source);
}

const char *
locale_numeric_assign(const char *value, bool doit, GucSource source)
{
      return locale_xxx_assign(LC_NUMERIC, value, doit, source);
}

const char *
locale_time_assign(const char *value, bool doit, GucSource source)
{
      return locale_xxx_assign(LC_TIME, value, doit, source);
}


/*
 * We allow LC_MESSAGES to actually be set globally.
 *
 * Note: we normally disallow value = "" because it wouldn't have consistent
 * semantics (it'd effectively just use the previous value).  However, this
 * is the value passed for PGC_S_DEFAULT, so don't complain in that case,
 * not even if the attempted setting fails due to invalid environment value.
 * The idea there is just to accept the environment setting *if possible*
 * during startup, until we can read the proper value from postgresql.conf.
 */
const char *
locale_messages_assign(const char *value, bool doit, GucSource source)
{
      if (*value == '\0' && source != PGC_S_DEFAULT)
            return NULL;

      /*
       * LC_MESSAGES category does not exist everywhere, but accept it anyway
       *
       * On Windows, we can't even check the value, so the non-doit case is a
       * no-op
       */
#ifdef LC_MESSAGES
      if (doit)
      {
            if (!pg_perm_setlocale(LC_MESSAGES, value))
                  if (source != PGC_S_DEFAULT)
                        return NULL;
      }
#ifndef WIN32
      else
            value = locale_xxx_assign(LC_MESSAGES, value, false, source);
#endif   /* WIN32 */
#endif   /* LC_MESSAGES */
      return value;
}


/*
 * We'd like to cache whether LC_COLLATE is C (or POSIX), so we can
 * optimize a few code paths in various places.
 */
bool
lc_collate_is_c(void)
{
      /* Cache result so we only have to compute it once */
      static int  result = -1;
      char     *localeptr;

      if (result >= 0)
            return (bool) result;
      localeptr = setlocale(LC_COLLATE, NULL);
      if (!localeptr)
            elog(ERROR, "invalid LC_COLLATE setting");

      if (strcmp(localeptr, "C") == 0)
            result = true;
      else if (strcmp(localeptr, "POSIX") == 0)
            result = true;
      else
            result = false;
      return (bool) result;
}


/*
 * We'd like to cache whether LC_CTYPE is C (or POSIX), so we can
 * optimize a few code paths in various places.
 */
bool
lc_ctype_is_c(void)
{
      /* Cache result so we only have to compute it once */
      static int  result = -1;
      char     *localeptr;

      if (result >= 0)
            return (bool) result;
      localeptr = setlocale(LC_CTYPE, NULL);
      if (!localeptr)
            elog(ERROR, "invalid LC_CTYPE setting");

      if (strcmp(localeptr, "C") == 0)
            result = true;
      else if (strcmp(localeptr, "POSIX") == 0)
            result = true;
      else
            result = false;
      return (bool) result;
}


/*
 * Frees the malloced content of a struct lconv.  (But not the struct
 * itself.)
 */
static void
free_struct_lconv(struct lconv * s)
{
      if (s == NULL)
            return;

      if (s->currency_symbol)
            free(s->currency_symbol);
      if (s->decimal_point)
            free(s->decimal_point);
      if (s->grouping)
            free(s->grouping);
      if (s->thousands_sep)
            free(s->thousands_sep);
      if (s->int_curr_symbol)
            free(s->int_curr_symbol);
      if (s->mon_decimal_point)
            free(s->mon_decimal_point);
      if (s->mon_grouping)
            free(s->mon_grouping);
      if (s->mon_thousands_sep)
            free(s->mon_thousands_sep);
      if (s->negative_sign)
            free(s->negative_sign);
      if (s->positive_sign)
            free(s->positive_sign);
}


/*
 * Return the POSIX lconv struct (contains number/money formatting
 * information) with locale information for all categories.
 */
struct lconv *
PGLC_localeconv(void)
{
      static struct lconv CurrentLocaleConv;
      struct lconv *extlconv;
      char     *save_lc_monetary;
      char     *save_lc_numeric;

      /* Did we do it already? */
      if (CurrentLocaleConvValid)
            return &CurrentLocaleConv;

      free_struct_lconv(&CurrentLocaleConv);

      /* Set 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);

      setlocale(LC_MONETARY, locale_monetary);
      setlocale(LC_NUMERIC, locale_numeric);

      /* Get formatting information */
      extlconv = localeconv();

      /*
       * Must copy all values since restoring internal settings may overwrite
       * localeconv()'s results.
       */
      CurrentLocaleConv = *extlconv;
      CurrentLocaleConv.currency_symbol = strdup(extlconv->currency_symbol);
      CurrentLocaleConv.decimal_point = strdup(extlconv->decimal_point);
      CurrentLocaleConv.grouping = strdup(extlconv->grouping);
      CurrentLocaleConv.thousands_sep = strdup(extlconv->thousands_sep);
      CurrentLocaleConv.int_curr_symbol = strdup(extlconv->int_curr_symbol);
      CurrentLocaleConv.mon_decimal_point = strdup(extlconv->mon_decimal_point);
      CurrentLocaleConv.mon_grouping = strdup(extlconv->mon_grouping);
      CurrentLocaleConv.mon_thousands_sep = strdup(extlconv->mon_thousands_sep);
      CurrentLocaleConv.negative_sign = strdup(extlconv->negative_sign);
      CurrentLocaleConv.positive_sign = strdup(extlconv->positive_sign);
      CurrentLocaleConv.n_sign_posn = extlconv->n_sign_posn;

      /* Try to restore internal settings */
      if (save_lc_monetary)
      {
            setlocale(LC_MONETARY, save_lc_monetary);
            pfree(save_lc_monetary);
      }

      if (save_lc_numeric)
      {
            setlocale(LC_NUMERIC, save_lc_numeric);
            pfree(save_lc_numeric);
      }

      CurrentLocaleConvValid = true;
      return &CurrentLocaleConv;
}

#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.
 *
 * Replace strftime() with a version that gets the string in UTF16 and then
 * converts it to the appropriate encoding as necessary.
 *
 * 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
 * pg_strftime(), which isn't locale-aware and does not need to be replaced.
 */
static size_t
strftime_win32(char *dst, size_t dstlen, const wchar_t *format, const struct tm *tm)
{
      size_t      len;
      wchar_t     wbuf[MAX_L10N_DATA];
      int         encoding;

      encoding = GetDatabaseEncoding();

      len = wcsftime(wbuf, MAX_L10N_DATA, format, tm);
      if (len == 0)
            /* strftime call failed - return 0 with the contents of dst unspecified */
            return 0;

      len = WideCharToMultiByte(CP_UTF8, 0, wbuf, len, dst, dstlen, NULL, NULL);
      if (len == 0)
            elog(ERROR,
                  "could not convert string to UTF-8:error %lu", GetLastError());

      dst[len] = '\0';
      if (encoding != PG_UTF8)
      {
            char *convstr = pg_do_encoding_conversion(dst, len, PG_UTF8, encoding);
            if (dst != convstr)
            {
                  strlcpy(dst, convstr, dstlen);
                  len = strlen(dst);
            }
      }

      return len;
}

#define strftime(a,b,c,d) strftime_win32(a,b,L##c,d)

#endif /* WIN32 */


/*
 * Update the lc_time localization cache variables if needed.
 */
void
cache_locale_time(void)
{
      char        *save_lc_time;
      time_t            timenow;
      struct tm   *timeinfo;
      char        buf[MAX_L10N_DATA];
      char     *ptr;
      int               i;
#ifdef WIN32
      char     *save_lc_ctype;
#endif

      /* did we do this already? */
      if (CurrentLCTimeValid)
            return;

      elog(DEBUG3, "cache_locale_time() executed; locale: \"%s\"", locale_time);

#ifdef WIN32
      /* set user's value of ctype locale */
      save_lc_ctype = setlocale(LC_CTYPE, NULL);
      if (save_lc_ctype)
            save_lc_ctype = pstrdup(save_lc_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);
      timeinfo = localtime(&timenow);

      /* localized days */
      for (i = 0; i < 7; i++)
      {
            timeinfo->tm_wday = i;
            strftime(buf, MAX_L10N_DATA, "%a", timeinfo);
            ptr = MemoryContextStrdup(TopMemoryContext, buf);
            if (localized_abbrev_days[i])
                  pfree(localized_abbrev_days[i]);
            localized_abbrev_days[i] = ptr;

            strftime(buf, MAX_L10N_DATA, "%A", timeinfo);
            ptr = MemoryContextStrdup(TopMemoryContext, buf);
            if (localized_full_days[i])
                  pfree(localized_full_days[i]);
            localized_full_days[i] = ptr;
      }

      /* localized months */
      for (i = 0; i < 12; i++)
      {
            timeinfo->tm_mon = i;
            timeinfo->tm_mday = 1;  /* make sure we don't have invalid date */
            strftime(buf, MAX_L10N_DATA, "%b", timeinfo);
            ptr = MemoryContextStrdup(TopMemoryContext, buf);
            if (localized_abbrev_months[i])
                  pfree(localized_abbrev_months[i]);
            localized_abbrev_months[i] = ptr;

            strftime(buf, MAX_L10N_DATA, "%B", timeinfo);
            ptr = MemoryContextStrdup(TopMemoryContext, buf);
            if (localized_full_months[i])
                  pfree(localized_full_months[i]);
            localized_full_months[i] = ptr;
      }

      /* try to restore internal settings */
      if (save_lc_time)
      {
            setlocale(LC_TIME, save_lc_time);
            pfree(save_lc_time);
      }

#ifdef WIN32
      /* try to restore internal ctype settings */
      if (save_lc_ctype)
      {
            setlocale(LC_CTYPE, save_lc_ctype);
            pfree(save_lc_ctype);
      }
#endif

      CurrentLCTimeValid = true;
}


#if defined(WIN32) && defined(LC_MESSAGES)
/*
 *    Convert Windows locale name to the ISO formatted one
 *    if possible.
 *
 *    This function returns NULL if conversion is impossible,
 *    otherwise returns the pointer to a static area which
 *    contains the iso formatted locale name.
 */
static
char *IsoLocaleName(const char *winlocname)
{
#if (_MSC_VER >= 1400) /* VC8.0 or later */
      static char iso_lc_messages[32];
      _locale_t   loct = NULL;

      if (pg_strcasecmp("c", winlocname) == 0 ||
            pg_strcasecmp("posix", winlocname) == 0)
      {
            strcpy(iso_lc_messages, "C");
            return iso_lc_messages;
      }

      loct = _create_locale(LC_CTYPE, winlocname);
      if (loct != NULL)
      {
            char  isolang[32], isocrty[32];
            LCID  lcid;

            lcid = loct->locinfo->lc_handle[LC_CTYPE];
            if (lcid == 0)
                  lcid = MAKELCID(MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US), SORT_DEFAULT);
            _free_locale(loct);

            if (!GetLocaleInfoA(lcid, LOCALE_SISO639LANGNAME, isolang, sizeof(isolang)))
                  return NULL;
            if (!GetLocaleInfoA(lcid, LOCALE_SISO3166CTRYNAME, isocrty, sizeof(isocrty)))
                  return NULL;
            snprintf(iso_lc_messages, sizeof(iso_lc_messages) - 1, "%s_%s", isolang, isocrty);
            return iso_lc_messages;
      }
      return NULL;
#else
      return NULL; /* Not supported on this version of msvc/mingw */
#endif /* _MSC_VER >= 1400 */
}
#endif /* WIN32 && LC_MESSAGES */


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