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290 lines
6.4 KiB
C
290 lines
6.4 KiB
C
/*
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* This file contains public functions for conversion between
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* client encoding and server internal encoding.
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* (currently mule internal code (mic) is used)
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* Tatsuo Ishii
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* $Id: mbutils.c,v 1.10 2000/06/13 07:35:12 tgl Exp $ */
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#include "postgres.h"
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#include "miscadmin.h"
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#include "mb/pg_wchar.h"
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#include "utils/builtins.h"
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static int client_encoding = -1;
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static void (*client_to_mic) ();/* something to MIC */
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static void (*client_from_mic) (); /* MIC to something */
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static void (*server_to_mic) ();/* something to MIC */
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static void (*server_from_mic) (); /* MIC to something */
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/*
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* find encoding table entry by encoding
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*/
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static pg_encoding_conv_tbl *
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get_enc_ent(int encoding)
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{
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pg_encoding_conv_tbl *p = pg_conv_tbl;
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for (; p->encoding >= 0; p++)
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{
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if (p->encoding == encoding)
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return (p);
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}
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return (0);
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}
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/*
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* set the client encoding. if client/server encoding is
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* not supported, returns -1
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*/
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int
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pg_set_client_encoding(int encoding)
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{
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int current_server_encoding = GetDatabaseEncoding();
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client_encoding = encoding;
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if (client_encoding == current_server_encoding)
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{ /* server == client? */
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client_to_mic = client_from_mic = 0;
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server_to_mic = server_from_mic = 0;
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}
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else if (current_server_encoding == MULE_INTERNAL)
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{ /* server == MULE_INETRNAL? */
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client_to_mic = get_enc_ent(encoding)->to_mic;
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client_from_mic = get_enc_ent(encoding)->from_mic;
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server_to_mic = server_from_mic = 0;
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if (client_to_mic == 0 || client_from_mic == 0)
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return (-1);
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}
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else if (encoding == MULE_INTERNAL)
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{ /* client == MULE_INETRNAL? */
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client_to_mic = client_from_mic = 0;
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server_to_mic = get_enc_ent(current_server_encoding)->to_mic;
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server_from_mic = get_enc_ent(current_server_encoding)->from_mic;
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if (server_to_mic == 0 || server_from_mic == 0)
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return (-1);
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}
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else
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{
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client_to_mic = get_enc_ent(encoding)->to_mic;
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client_from_mic = get_enc_ent(encoding)->from_mic;
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server_to_mic = get_enc_ent(current_server_encoding)->to_mic;
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server_from_mic = get_enc_ent(current_server_encoding)->from_mic;
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if (client_to_mic == 0 || client_from_mic == 0)
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return (-1);
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if (server_to_mic == 0 || server_from_mic == 0)
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return (-1);
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}
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return (0);
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}
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/*
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* returns the current client encoding
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*/
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int
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pg_get_client_encoding()
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{
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if (client_encoding == -1)
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{
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/* this is the first time */
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client_encoding = GetDatabaseEncoding();
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}
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return (client_encoding);
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}
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/*
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* convert client encoding to server encoding.
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*
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* CASE 1: if no conversion is required, then the given pointer s is returned.
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*
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* CASE 2: if conversion is required, a palloc'd string is returned.
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*
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* Callers must check whether return value differs from passed value
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* to determine whether to pfree the result or not!
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*
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* Note: we assume that conversion cannot cause more than a 4-to-1 growth
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* in the length of the string --- is this enough?
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*/
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unsigned char *
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pg_client_to_server(unsigned char *s, int len)
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{
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unsigned char *result = s;
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unsigned char *buf;
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if (client_encoding == GetDatabaseEncoding())
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return result;
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if (client_to_mic)
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{
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buf = (unsigned char *) palloc(len * 4 + 1);
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(*client_to_mic) (result, buf, len);
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result = buf;
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len = strlen(result);
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}
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if (server_from_mic)
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{
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buf = (unsigned char *) palloc(len * 4 + 1);
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(*server_from_mic) (result, buf, len);
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if (result != s)
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pfree(result); /* release first buffer */
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result = buf;
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}
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return result;
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}
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/*
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* convert server encoding to client encoding.
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*
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* CASE 1: if no conversion is required, then the given pointer s is returned.
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*
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* CASE 2: if conversion is required, a palloc'd string is returned.
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*
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* Callers must check whether return value differs from passed value
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* to determine whether to pfree the result or not!
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*
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* Note: we assume that conversion cannot cause more than a 4-to-1 growth
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* in the length of the string --- is this enough?
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*/
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unsigned char *
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pg_server_to_client(unsigned char *s, int len)
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{
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unsigned char *result = s;
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unsigned char *buf;
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if (client_encoding == GetDatabaseEncoding())
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return result;
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if (server_to_mic)
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{
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buf = (unsigned char *) palloc(len * 4 + 1);
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(*server_to_mic) (result, buf, len);
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result = buf;
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len = strlen(result);
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}
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if (client_from_mic)
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{
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buf = (unsigned char *) palloc(len * 4 + 1);
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(*client_from_mic) (result, buf, len);
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if (result != s)
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pfree(result); /* release first buffer */
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result = buf;
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}
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return result;
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}
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/* convert a multi-byte string to a wchar */
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void
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pg_mb2wchar(const unsigned char *from, pg_wchar * to)
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{
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(*pg_wchar_table[GetDatabaseEncoding()].mb2wchar_with_len) (from, to, strlen(from));
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}
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/* convert a multi-byte string to a wchar with a limited length */
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void
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pg_mb2wchar_with_len(const unsigned char *from, pg_wchar * to, int len)
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{
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(*pg_wchar_table[GetDatabaseEncoding()].mb2wchar_with_len) (from, to, len);
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}
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/* returns the byte length of a multi-byte word */
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int
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pg_mblen(const unsigned char *mbstr)
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{
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return ((*pg_wchar_table[GetDatabaseEncoding()].mblen) (mbstr));
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}
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/* returns the length (counted as a wchar) of a multi-byte string */
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int
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pg_mbstrlen(const unsigned char *mbstr)
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{
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int len = 0;
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while (*mbstr)
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{
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mbstr += pg_mblen(mbstr);
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len++;
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}
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return (len);
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}
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/* returns the length (counted as a wchar) of a multi-byte string
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(not necessarily NULL terminated) */
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int
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pg_mbstrlen_with_len(const unsigned char *mbstr, int limit)
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{
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int len = 0;
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int l;
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while (*mbstr && limit > 0)
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{
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l = pg_mblen(mbstr);
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limit -= l;
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mbstr += l;
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len++;
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}
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return (len);
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}
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/*
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* returns the length of a multi-byte string
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* (not necessarily NULL terminated)
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* that is not longer than limit.
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* this function does not break multi-byte word boundary.
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*/
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int
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pg_mbcliplen(const unsigned char *mbstr, int len, int limit)
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{
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int clen = 0;
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int l;
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while (*mbstr && len > 0)
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{
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l = pg_mblen(mbstr);
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if ((clen + l) > limit)
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break;
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clen += l;
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if (clen == limit)
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break;
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len -= l;
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mbstr += l;
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}
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return (clen);
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}
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/*
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* fuctions for utils/init
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*/
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static int DatabaseEncoding = MULTIBYTE;
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void
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SetDatabaseEncoding(int encoding)
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{
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DatabaseEncoding = encoding;
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}
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int
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GetDatabaseEncoding()
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{
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return (DatabaseEncoding);
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}
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/* for builtin-function */
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Datum
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getdatabaseencoding(PG_FUNCTION_ARGS)
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{
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PG_RETURN_NAME(pg_encoding_to_char(DatabaseEncoding));
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}
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/* set and get template1 database encoding */
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static int templateEncoding;
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void
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SetTemplateEncoding(int encoding)
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{
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templateEncoding = encoding;
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}
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int
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GetTemplateEncoding()
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{
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return (templateEncoding);
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}
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