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/*
* This file contains public functions for conversion between
* client encoding and server internal encoding.
* (currently mule internal code (mic) is used)
* Tatsuo Ishii
* $Id: mbutils.c,v 1.16 2001/03/08 00:24:34 tgl Exp $
*/
#include "postgres.h"
#include "miscadmin.h"
#include "mb/pg_wchar.h"
#include "utils/builtins.h"
static int client_encoding = -1;
static void (*client_to_mic) ();/* something to MIC */
static void (*client_from_mic) (); /* MIC to something */
static void (*server_to_mic) ();/* something to MIC */
static void (*server_from_mic) (); /* MIC to something */
/*
* find encoding table entry by encoding
*/
pg_encoding_conv_tbl *
pg_get_enc_ent(int encoding)
{
pg_encoding_conv_tbl *p = pg_conv_tbl;
for (; p->encoding >= 0; p++)
{
if (p->encoding == encoding)
return (p);
}
return (0);
}
/*
* set the client encoding. if encoding conversion between
* client/server encoding is not supported, returns -1
*/
int
pg_set_client_encoding(int encoding)
{
int current_server_encoding = GetDatabaseEncoding();
client_encoding = encoding;
if (client_encoding == current_server_encoding)
{ /* server == client? */
client_to_mic = client_from_mic = 0;
server_to_mic = server_from_mic = 0;
}
else if (current_server_encoding == MULE_INTERNAL)
{ /* server == MULE_INETRNAL? */
client_to_mic = pg_get_enc_ent(encoding)->to_mic;
client_from_mic = pg_get_enc_ent(encoding)->from_mic;
server_to_mic = server_from_mic = 0;
if (client_to_mic == 0 || client_from_mic == 0)
return (-1);
}
else if (encoding == MULE_INTERNAL)
{ /* client == MULE_INETRNAL? */
client_to_mic = client_from_mic = 0;
server_to_mic = pg_get_enc_ent(current_server_encoding)->to_mic;
server_from_mic = pg_get_enc_ent(current_server_encoding)->from_mic;
if (server_to_mic == 0 || server_from_mic == 0)
return (-1);
}
else if (current_server_encoding == UNICODE)
{ /* server == UNICODE? */
client_to_mic = pg_get_enc_ent(encoding)->to_unicode;
client_from_mic = pg_get_enc_ent(encoding)->from_unicode;
server_to_mic = server_from_mic = 0;
if (client_to_mic == 0 || client_from_mic == 0)
return (-1);
}
else if (encoding == UNICODE)
{ /* client == UNICODE? */
client_to_mic = client_from_mic = 0;
server_to_mic = pg_get_enc_ent(current_server_encoding)->to_unicode;
server_from_mic = pg_get_enc_ent(current_server_encoding)->from_unicode;
if (server_to_mic == 0 || server_from_mic == 0)
return (-1);
}
else
{
client_to_mic = pg_get_enc_ent(encoding)->to_mic;
client_from_mic = pg_get_enc_ent(encoding)->from_mic;
server_to_mic = pg_get_enc_ent(current_server_encoding)->to_mic;
server_from_mic = pg_get_enc_ent(current_server_encoding)->from_mic;
if (client_to_mic == 0 || client_from_mic == 0)
return (-1);
if (server_to_mic == 0 || server_from_mic == 0)
return (-1);
}
return (0);
}
/*
* returns the current client encoding
*/
int
pg_get_client_encoding()
{
if (client_encoding == -1)
{
/* this is the first time */
client_encoding = GetDatabaseEncoding();
}
return (client_encoding);
}
/*
* convert client encoding to server encoding.
*
* CASE 1: if no conversion is required, then the given pointer s is returned.
*
* CASE 2: if conversion is required, a palloc'd string is returned.
*
* Callers must check whether return value differs from passed value
* to determine whether to pfree the result or not!
*
* Note: we assume that conversion cannot cause more than a 4-to-1 growth
* in the length of the string --- is this enough?
*/
unsigned char *
pg_client_to_server(unsigned char *s, int len)
{
unsigned char *result = s;
unsigned char *buf;
if (client_encoding == GetDatabaseEncoding())
return result;
if (client_to_mic)
{
buf = (unsigned char *) palloc(len * 4 + 1);
(*client_to_mic) (result, buf, len);
result = buf;
len = strlen(result);
}
if (server_from_mic)
{
buf = (unsigned char *) palloc(len * 4 + 1);
(*server_from_mic) (result, buf, len);
if (result != s)
pfree(result); /* release first buffer */
result = buf;
}
return result;
}
/*
* convert server encoding to client encoding.
*
* CASE 1: if no conversion is required, then the given pointer s is returned.
*
* CASE 2: if conversion is required, a palloc'd string is returned.
*
* Callers must check whether return value differs from passed value
* to determine whether to pfree the result or not!
*
* Note: we assume that conversion cannot cause more than a 4-to-1 growth
* in the length of the string --- is this enough?
*/
unsigned char *
pg_server_to_client(unsigned char *s, int len)
{
unsigned char *result = s;
unsigned char *buf;
if (client_encoding == GetDatabaseEncoding())
return result;
if (server_to_mic)
{
buf = (unsigned char *) palloc(len * 4 + 1);
(*server_to_mic) (result, buf, len);
result = buf;
len = strlen(result);
}
if (client_from_mic)
{
buf = (unsigned char *) palloc(len * 4 + 1);
(*client_from_mic) (result, buf, len);
if (result != s)
pfree(result); /* release first buffer */
result = buf;
}
return result;
}
/* convert a multi-byte string to a wchar */
int
pg_mb2wchar(const unsigned char *from, pg_wchar * to)
{
return (*pg_wchar_table[GetDatabaseEncoding()].mb2wchar_with_len) (from, to, strlen(from));
}
/* convert a multi-byte string to a wchar with a limited length */
int
pg_mb2wchar_with_len(const unsigned char *from, pg_wchar * to, int len)
{
return (*pg_wchar_table[GetDatabaseEncoding()].mb2wchar_with_len) (from, to, len);
}
/* returns the byte length of a multi-byte word */
int
pg_mblen(const unsigned char *mbstr)
{
return ((*pg_wchar_table[GetDatabaseEncoding()].mblen) (mbstr));
}
/* returns the length (counted as a wchar) of a multi-byte string */
int
pg_mbstrlen(const unsigned char *mbstr)
{
int len = 0;
while (*mbstr)
{
mbstr += pg_mblen(mbstr);
len++;
}
return (len);
}
/* returns the length (counted as a wchar) of a multi-byte string
(not necessarily NULL terminated) */
int
pg_mbstrlen_with_len(const unsigned char *mbstr, int limit)
{
int len = 0;
int l;
while (limit > 0 && *mbstr)
{
l = pg_mblen(mbstr);
limit -= l;
mbstr += l;
len++;
}
return (len);
}
/*
* returns the length of a multi-byte string
* (not necessarily NULL terminated)
* that is not longer than limit.
* this function does not break multi-byte word boundary.
*/
int
pg_mbcliplen(const unsigned char *mbstr, int len, int limit)
{
int clen = 0;
int l;
while (len > 0 && *mbstr)
{
l = pg_mblen(mbstr);
if ((clen + l) > limit)
break;
clen += l;
if (clen == limit)
break;
len -= l;
mbstr += l;
}
return (clen);
}
/*
* functions for utils/init
*/
static int DatabaseEncoding = MULTIBYTE;
void
SetDatabaseEncoding(int encoding)
{
DatabaseEncoding = encoding;
}
int
GetDatabaseEncoding()
{
return (DatabaseEncoding);
}
/* for builtin-function */
Datum
getdatabaseencoding(PG_FUNCTION_ARGS)
{
PG_RETURN_NAME(pg_encoding_to_char(DatabaseEncoding));
}
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