database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-09 22:41:56 +03:00
Code Activity

Per-column collation support

Browse Source 
This adds collation support for columns and domains, a COLLATE clause
to override it per expression, and B-tree index support.

Peter Eisentraut
reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch
This commit is contained in:
Peter Eisentraut
2011-02-08 23:04:18 +02:00
parent 1703f0e8da
commit 414c5a2ea6
156 changed files with 4519 additions and 582 deletions
Download Patch File Download Diff File Expand all files Collapse all files

219
src/backend/utils/adt/pg_locale.c
View File

@ -54,10 +54,13 @@
#include <locale.h>
#include <time.h>
#include "catalog/pg_collation.h"
#include "catalog/pg_control.h"
#include "mb/pg_wchar.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"
#include "utils/syscache.h"
#ifdef WIN32
#include <shlwapi.h>
@ -100,6 +103,11 @@ static char lc_time_envbuf[LC_ENV_BUFSIZE];
static char *IsoLocaleName(const char *); /* MSVC specific */
#endif
static HTAB *locale_cness_cache = NULL;
#ifdef HAVE_LOCALE_T
static HTAB *locale_t_cache = NULL;
#endif
/*
* pg_perm_setlocale
@ -305,16 +313,90 @@ locale_messages_assign(const char *value, bool doit, GucSource source)
/*
* We'd like to cache whether LC_COLLATE is C (or POSIX), so we can
* optimize a few code paths in various places.
* We'd like to cache whether LC_COLLATE or LC_CTYPE is C (or POSIX),
* so we can optimize a few code paths in various places.
*
* Note that some code relies on this not reporting false negatives
* (that is, saying it's not C when it is). For example, char2wchar()
* could fail if the locale is C, so str_tolower() shouldn't call it
* in that case.
*/
struct locale_cness_cache_entry
{
Oid collid;
bool collate_is_c;
bool ctype_is_c;
};
static void
init_locale_cness_cache(void)
{
HASHCTL ctl;
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(struct locale_cness_cache_entry);
ctl.hash = oid_hash;
locale_cness_cache = hash_create("locale C-ness cache", 1000, &ctl, HASH_ELEM | HASH_FUNCTION);
}
/*
* Handle caching of locale "C-ness" for nondefault collation objects.
* Relying on the system cache directly isn't fast enough.
*/
static bool
lookup_collation_cness(Oid collation, int category)
{
struct locale_cness_cache_entry *cache_entry;
bool found;
HeapTuple tp;
char *localeptr;
Assert(OidIsValid(collation));
Assert(category == LC_COLLATE || category == LC_CTYPE);
if (!locale_cness_cache)
init_locale_cness_cache();
cache_entry = hash_search(locale_cness_cache, &collation, HASH_ENTER, &found);
if (found)
{
if (category == LC_COLLATE)
return cache_entry->collate_is_c;
else
return cache_entry->ctype_is_c;
}
tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collation));
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for collation %u", collation);
localeptr = NameStr(((Form_pg_collation) GETSTRUCT(tp))->collcollate);
cache_entry->collate_is_c = (strcmp(localeptr, "C") == 0) || (strcmp(localeptr, "POSIX") == 0);
localeptr = NameStr(((Form_pg_collation) GETSTRUCT(tp))->collctype);
cache_entry->ctype_is_c = (strcmp(localeptr, "C") == 0) || (strcmp(localeptr, "POSIX") == 0);
ReleaseSysCache(tp);
return category == LC_COLLATE ? cache_entry->collate_is_c : cache_entry->ctype_is_c;
}
bool
lc_collate_is_c(void)
lc_collate_is_c(Oid collation)
{
/* Cache result so we only have to compute it once */
static int result = -1;
char *localeptr;
if (!OidIsValid(collation))
return false;
if (collation != DEFAULT_COLLATION_OID)
return lookup_collation_cness(collation, LC_COLLATE);
if (result >= 0)
return (bool) result;
localeptr = setlocale(LC_COLLATE, NULL);
@ -331,17 +413,19 @@ lc_collate_is_c(void)
}
/*
* 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)
lc_ctype_is_c(Oid collation)
{
/* Cache result so we only have to compute it once */
static int result = -1;
char *localeptr;
if (!OidIsValid(collation))
return false;
if (collation != DEFAULT_COLLATION_OID)
return lookup_collation_cness(collation, LC_CTYPE);
if (result >= 0)
return (bool) result;
localeptr = setlocale(LC_CTYPE, NULL);
@ -483,7 +567,7 @@ PGLC_localeconv(void)
/* Get formatting information for numeric */
setlocale(LC_NUMERIC, locale_numeric);
extlconv = localeconv();
encoding = pg_get_encoding_from_locale(locale_numeric);
encoding = pg_get_encoding_from_locale(locale_numeric, true);
decimal_point = db_encoding_strdup(encoding, extlconv->decimal_point);
thousands_sep = db_encoding_strdup(encoding, extlconv->thousands_sep);
@ -497,7 +581,7 @@ PGLC_localeconv(void)
/* Get formatting information for monetary */
setlocale(LC_MONETARY, locale_monetary);
extlconv = localeconv();
encoding = pg_get_encoding_from_locale(locale_monetary);
encoding = pg_get_encoding_from_locale(locale_monetary, true);
/*
* Must copy all values since restoring internal settings may overwrite
@ -758,3 +842,118 @@ IsoLocaleName(const char *winlocname)
}
#endif /* WIN32 && LC_MESSAGES */
#ifdef HAVE_LOCALE_T
struct locale_t_cache_entry
{
Oid collid;
locale_t locale;
};
static void
init_locale_t_cache(void)
{
HASHCTL ctl;
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(struct locale_t_cache_entry);
ctl.hash = oid_hash;
locale_t_cache = hash_create("locale_t cache", 1000, &ctl, HASH_ELEM | HASH_FUNCTION);
}
#endif /* HAVE_LOCALE_T */
/*
* Create a locale_t from a collation OID. Results are cached for the
* lifetime of the backend. Thus, do not free the result with
* freelocale().
*
* As a special optimization, the default/database collation returns
* 0. Callers should then revert to the non-locale_t-enabled code
* path. In fact, they shouldn't call this function at all when they
* are dealing with the default locale. That can save quite a bit in
* hotspots.
*
* For simplicity, we always generate COLLATE + CTYPE even though we
* might only need one of them. Since this is called only once per
* session, it shouldn't cost much.
*/
pg_locale_t
pg_newlocale_from_collation(Oid collid)
{
#ifdef HAVE_LOCALE_T
HeapTuple tp;
const char *collcollate;
const char *collctype;
locale_t result;
struct locale_t_cache_entry *cache_entry;
bool found;
if (collid == DEFAULT_COLLATION_OID)
return (locale_t) 0;
if (!OidIsValid(collid))
elog(ERROR, "locale operation to be invoked, but no collation was derived");
if (!locale_t_cache)
init_locale_t_cache();
cache_entry = hash_search(locale_t_cache, &collid, HASH_ENTER, &found);
if (found)
return cache_entry->locale;
tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid));
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for collation %u", collid);
collcollate = NameStr(((Form_pg_collation) GETSTRUCT(tp))->collcollate);
collctype = NameStr(((Form_pg_collation) GETSTRUCT(tp))->collctype);
if (strcmp(collcollate, collctype) == 0)
{
result = newlocale(LC_COLLATE_MASK | LC_CTYPE_MASK, collcollate, NULL);
if (!result)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not create locale \"%s\": %m", collcollate)));
}
else
{
locale_t loc1;
loc1 = newlocale(LC_COLLATE_MASK, collcollate, NULL);
if (!loc1)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not create locale \"%s\": %m", collcollate)));
result = newlocale(LC_CTYPE_MASK, collctype, loc1);
if (!result)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not create locale \"%s\": %m", collctype)));
}
ReleaseSysCache(tp);
cache_entry->locale = result;
return result;
#else /* not HAVE_LOCALE_T */
/*
* For platforms that don't support locale_t, check that we are
* dealing with the default locale. It's unlikely that we'll get
* here, but it's possible if users are creating collations even
* though they are not supported, or they are mixing builds in odd
* ways.
*/
if (!OidIsValid(collid))
elog(ERROR, "locale operation to be invoked, but no collation was derived");
else if (collid != DEFAULT_COLLATION_OID)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("nondefault collations are not supported on this platform")));
return 0;
#endif /* not HAVE_LOCALE_T */
}