I really hope that I haven't missed anything in this one...

From: t-ishii@sra.co.jp

Attached are patches to enhance the multi-byte support.  (patches are
against 7/18 snapshot)

* determine encoding at initdb/createdb rather than compile time

Now initdb/createdb has an option to specify the encoding. Also, I
modified the syntax of CREATE DATABASE to accept encoding option. See
README.mb for more details.

For this purpose I have added new column "encoding" to pg_database.
Also pg_attribute and pg_class are changed to catch up the
modification to pg_database.  Actually I haved added pg_database_mb.h,
pg_attribute_mb.h and pg_class_mb.h. These are used only when MB is
enabled. The reason having separate files is I couldn't find a way to
use ifdef or whatever in those files. I have to admit it looks
ugly. No way.

* support for PGCLIENTENCODING when issuing COPY command

commands/copy.c modified.

* support for SQL92 syntax "SET NAMES"

See gram.y.

* support for LATIN2-5
* add UNICODE regression test case
* new test suite for MB

New directory test/mb added.

* clean up source files

Basic idea is to have MB's own subdirectory for easier maintenance.
These are include/mb and backend/utils/mb.

1 files changed, 216 insertions, 0 deletions

diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c
new file mode 100644
index 00000000000..eb6cbc5262d
--- /dev/null
+++ b/src/backend/utils/mb/mbutils.c
@@ -0,0 +1,216 @@
+/*
+ * 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 1.1 1998/07/24 03:31:56 scrappy Exp $ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "mb/pg_wchar.h"
+
+static 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
+ */
+static pg_encoding_conv_tbl *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 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 = get_enc_ent(encoding)->to_mic;
+    client_from_mic = 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 = get_enc_ent(current_server_encoding)->to_mic;
+    server_from_mic = get_enc_ent(current_server_encoding)->from_mic;
+    if (server_to_mic == 0 || server_from_mic == 0) {
+      return(-1);
+    }
+  } else {
+    client_to_mic = get_enc_ent(encoding)->to_mic;
+    client_from_mic = get_enc_ent(encoding)->from_mic;
+    server_to_mic = get_enc_ent(current_server_encoding)->to_mic;
+    server_from_mic = 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. if server_encoding ==
+ * client_encoding or no conversion function exists,
+ * returns s. So be careful.
+ */
+unsigned char *pg_client_to_server(unsigned char *s, int len)
+{
+  static unsigned char b1[MAX_PARSE_BUFFER*4];	/* is this enough? */
+  static unsigned char b2[MAX_PARSE_BUFFER*4];	/* is this enough? */
+  unsigned char *p = s;
+
+  if (client_encoding == GetDatabaseEncoding()) {
+    return(p);
+  }
+  if (client_to_mic) {
+    (*client_to_mic)(s, b1, len);
+    len = strlen(b1);
+    p = b1;
+  }
+  if (server_from_mic) {
+    (*server_from_mic)(p, b2, len);
+    p = b2;
+  }
+  return(p);
+}
+
+/*
+ * convert server encoding to client encoding. if server_encoding ==
+ * client_encoding or no conversion function exists,
+ * returns s. So be careful.
+ */
+unsigned char *pg_server_to_client(unsigned char *s, int len)
+{
+  static unsigned char b1[MAX_PARSE_BUFFER*4];	/* is this enough? */
+  static unsigned char b2[MAX_PARSE_BUFFER*4];	/* is this enough? */
+  unsigned char *p = s;
+
+  if (client_encoding == GetDatabaseEncoding()) {
+    return(p);
+  }
+  if (server_to_mic) {
+    (*server_to_mic)(s, b1, len);
+    len = strlen(b1);
+    p = b1;
+  }
+  if (client_from_mic) {
+    (*client_from_mic)(p, b2, len);
+    p = b2;
+  }
+  return(p);
+}
+
+/* convert a multi-byte string to a wchar */
+void pg_mb2wchar(const unsigned char *from, pg_wchar *to)
+{
+  (*pg_wchar_table[GetDatabaseEncoding()].mb2wchar_with_len)(from,to,strlen(from));
+}
+
+/* convert a multi-byte string to a wchar with a limited length */
+void pg_mb2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+  (*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 (*mbstr && limit > 0) {
+    l = pg_mblen(mbstr);
+    limit -= l;
+    mbstr += l;
+    len++;
+  }
+  return(len);
+}
+
+/*
+ * fuctions for utils/init
+ */
+static int DatabaseEncoding = MB;
+void
+SetDatabaseEncoding(int encoding)
+{
+  DatabaseEncoding = encoding;
+}
+
+int
+GetDatabaseEncoding()
+{
+  return(DatabaseEncoding);
+}
+
+/* for builtin-function */
+const char *
+getdatabaseencoding()
+{
+  return(pg_encoding_to_char(DatabaseEncoding));
+}
+
+/* set and get template1 database encoding */
+static int templateEncoding;
+void SetTemplateEncoding(int encoding)
+{
+  templateEncoding = encoding;
+}
+
+int GetTemplateEncoding()
+{
+  return(templateEncoding);
+}