summaryrefslogtreecommitdiffstats
path: root/src/common/wchar.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/common/wchar.c')
-rw-r--r--src/common/wchar.c1984
1 files changed, 1984 insertions, 0 deletions
diff --git a/src/common/wchar.c b/src/common/wchar.c
new file mode 100644
index 0000000..0636b87
--- /dev/null
+++ b/src/common/wchar.c
@@ -0,0 +1,1984 @@
+/*-------------------------------------------------------------------------
+ *
+ * wchar.c
+ * Functions for working with multibyte characters in various encodings.
+ *
+ * Portions Copyright (c) 1998-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/common/wchar.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "c.h"
+
+#include "mb/pg_wchar.h"
+
+
+/*
+ * Operations on multi-byte encodings are driven by a table of helper
+ * functions.
+ *
+ * To add an encoding support, define mblen(), dsplen(), verifychar() and
+ * verifystr() for the encoding. For server-encodings, also define mb2wchar()
+ * and wchar2mb() conversion functions.
+ *
+ * These functions generally assume that their input is validly formed.
+ * The "verifier" functions, further down in the file, have to be more
+ * paranoid.
+ *
+ * We expect that mblen() does not need to examine more than the first byte
+ * of the character to discover the correct length. GB18030 is an exception
+ * to that rule, though, as it also looks at second byte. But even that
+ * behaves in a predictable way, if you only pass the first byte: it will
+ * treat 4-byte encoded characters as two 2-byte encoded characters, which is
+ * good enough for all current uses.
+ *
+ * Note: for the display output of psql to work properly, the return values
+ * of the dsplen functions must conform to the Unicode standard. In particular
+ * the NUL character is zero width and control characters are generally
+ * width -1. It is recommended that non-ASCII encodings refer their ASCII
+ * subset to the ASCII routines to ensure consistency.
+ */
+
+/*
+ * SQL/ASCII
+ */
+static int
+pg_ascii2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+ int cnt = 0;
+
+ while (len > 0 && *from)
+ {
+ *to++ = *from++;
+ len--;
+ cnt++;
+ }
+ *to = 0;
+ return cnt;
+}
+
+static int
+pg_ascii_mblen(const unsigned char *s)
+{
+ return 1;
+}
+
+static int
+pg_ascii_dsplen(const unsigned char *s)
+{
+ if (*s == '\0')
+ return 0;
+ if (*s < 0x20 || *s == 0x7f)
+ return -1;
+
+ return 1;
+}
+
+/*
+ * EUC
+ */
+static int
+pg_euc2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+ int cnt = 0;
+
+ while (len > 0 && *from)
+ {
+ if (*from == SS2 && len >= 2) /* JIS X 0201 (so called "1 byte
+ * KANA") */
+ {
+ from++;
+ *to = (SS2 << 8) | *from++;
+ len -= 2;
+ }
+ else if (*from == SS3 && len >= 3) /* JIS X 0212 KANJI */
+ {
+ from++;
+ *to = (SS3 << 16) | (*from++ << 8);
+ *to |= *from++;
+ len -= 3;
+ }
+ else if (IS_HIGHBIT_SET(*from) && len >= 2) /* JIS X 0208 KANJI */
+ {
+ *to = *from++ << 8;
+ *to |= *from++;
+ len -= 2;
+ }
+ else /* must be ASCII */
+ {
+ *to = *from++;
+ len--;
+ }
+ to++;
+ cnt++;
+ }
+ *to = 0;
+ return cnt;
+}
+
+static inline int
+pg_euc_mblen(const unsigned char *s)
+{
+ int len;
+
+ if (*s == SS2)
+ len = 2;
+ else if (*s == SS3)
+ len = 3;
+ else if (IS_HIGHBIT_SET(*s))
+ len = 2;
+ else
+ len = 1;
+ return len;
+}
+
+static inline int
+pg_euc_dsplen(const unsigned char *s)
+{
+ int len;
+
+ if (*s == SS2)
+ len = 2;
+ else if (*s == SS3)
+ len = 2;
+ else if (IS_HIGHBIT_SET(*s))
+ len = 2;
+ else
+ len = pg_ascii_dsplen(s);
+ return len;
+}
+
+/*
+ * EUC_JP
+ */
+static int
+pg_eucjp2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+ return pg_euc2wchar_with_len(from, to, len);
+}
+
+static int
+pg_eucjp_mblen(const unsigned char *s)
+{
+ return pg_euc_mblen(s);
+}
+
+static int
+pg_eucjp_dsplen(const unsigned char *s)
+{
+ int len;
+
+ if (*s == SS2)
+ len = 1;
+ else if (*s == SS3)
+ len = 2;
+ else if (IS_HIGHBIT_SET(*s))
+ len = 2;
+ else
+ len = pg_ascii_dsplen(s);
+ return len;
+}
+
+/*
+ * EUC_KR
+ */
+static int
+pg_euckr2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+ return pg_euc2wchar_with_len(from, to, len);
+}
+
+static int
+pg_euckr_mblen(const unsigned char *s)
+{
+ return pg_euc_mblen(s);
+}
+
+static int
+pg_euckr_dsplen(const unsigned char *s)
+{
+ return pg_euc_dsplen(s);
+}
+
+/*
+ * EUC_CN
+ *
+ */
+static int
+pg_euccn2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+ int cnt = 0;
+
+ while (len > 0 && *from)
+ {
+ if (*from == SS2 && len >= 3) /* code set 2 (unused?) */
+ {
+ from++;
+ *to = (SS2 << 16) | (*from++ << 8);
+ *to |= *from++;
+ len -= 3;
+ }
+ else if (*from == SS3 && len >= 3) /* code set 3 (unused ?) */
+ {
+ from++;
+ *to = (SS3 << 16) | (*from++ << 8);
+ *to |= *from++;
+ len -= 3;
+ }
+ else if (IS_HIGHBIT_SET(*from) && len >= 2) /* code set 1 */
+ {
+ *to = *from++ << 8;
+ *to |= *from++;
+ len -= 2;
+ }
+ else
+ {
+ *to = *from++;
+ len--;
+ }
+ to++;
+ cnt++;
+ }
+ *to = 0;
+ return cnt;
+}
+
+static int
+pg_euccn_mblen(const unsigned char *s)
+{
+ int len;
+
+ if (IS_HIGHBIT_SET(*s))
+ len = 2;
+ else
+ len = 1;
+ return len;
+}
+
+static int
+pg_euccn_dsplen(const unsigned char *s)
+{
+ int len;
+
+ if (IS_HIGHBIT_SET(*s))
+ len = 2;
+ else
+ len = pg_ascii_dsplen(s);
+ return len;
+}
+
+/*
+ * EUC_TW
+ *
+ */
+static int
+pg_euctw2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+ int cnt = 0;
+
+ while (len > 0 && *from)
+ {
+ if (*from == SS2 && len >= 4) /* code set 2 */
+ {
+ from++;
+ *to = (((uint32) SS2) << 24) | (*from++ << 16);
+ *to |= *from++ << 8;
+ *to |= *from++;
+ len -= 4;
+ }
+ else if (*from == SS3 && len >= 3) /* code set 3 (unused?) */
+ {
+ from++;
+ *to = (SS3 << 16) | (*from++ << 8);
+ *to |= *from++;
+ len -= 3;
+ }
+ else if (IS_HIGHBIT_SET(*from) && len >= 2) /* code set 2 */
+ {
+ *to = *from++ << 8;
+ *to |= *from++;
+ len -= 2;
+ }
+ else
+ {
+ *to = *from++;
+ len--;
+ }
+ to++;
+ cnt++;
+ }
+ *to = 0;
+ return cnt;
+}
+
+static int
+pg_euctw_mblen(const unsigned char *s)
+{
+ int len;
+
+ if (*s == SS2)
+ len = 4;
+ else if (*s == SS3)
+ len = 3;
+ else if (IS_HIGHBIT_SET(*s))
+ len = 2;
+ else
+ len = 1;
+ return len;
+}
+
+static int
+pg_euctw_dsplen(const unsigned char *s)
+{
+ int len;
+
+ if (*s == SS2)
+ len = 2;
+ else if (*s == SS3)
+ len = 2;
+ else if (IS_HIGHBIT_SET(*s))
+ len = 2;
+ else
+ len = pg_ascii_dsplen(s);
+ return len;
+}
+
+/*
+ * Convert pg_wchar to EUC_* encoding.
+ * caller must allocate enough space for "to", including a trailing zero!
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_wchar2euc_with_len(const pg_wchar *from, unsigned char *to, int len)
+{
+ int cnt = 0;
+
+ while (len > 0 && *from)
+ {
+ unsigned char c;
+
+ if ((c = (*from >> 24)))
+ {
+ *to++ = c;
+ *to++ = (*from >> 16) & 0xff;
+ *to++ = (*from >> 8) & 0xff;
+ *to++ = *from & 0xff;
+ cnt += 4;
+ }
+ else if ((c = (*from >> 16)))
+ {
+ *to++ = c;
+ *to++ = (*from >> 8) & 0xff;
+ *to++ = *from & 0xff;
+ cnt += 3;
+ }
+ else if ((c = (*from >> 8)))
+ {
+ *to++ = c;
+ *to++ = *from & 0xff;
+ cnt += 2;
+ }
+ else
+ {
+ *to++ = *from;
+ cnt++;
+ }
+ from++;
+ len--;
+ }
+ *to = 0;
+ return cnt;
+}
+
+
+/*
+ * JOHAB
+ */
+static int
+pg_johab_mblen(const unsigned char *s)
+{
+ return pg_euc_mblen(s);
+}
+
+static int
+pg_johab_dsplen(const unsigned char *s)
+{
+ return pg_euc_dsplen(s);
+}
+
+/*
+ * convert UTF8 string to pg_wchar (UCS-4)
+ * caller must allocate enough space for "to", including a trailing zero!
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_utf2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+ int cnt = 0;
+ uint32 c1,
+ c2,
+ c3,
+ c4;
+
+ while (len > 0 && *from)
+ {
+ if ((*from & 0x80) == 0)
+ {
+ *to = *from++;
+ len--;
+ }
+ else if ((*from & 0xe0) == 0xc0)
+ {
+ if (len < 2)
+ break; /* drop trailing incomplete char */
+ c1 = *from++ & 0x1f;
+ c2 = *from++ & 0x3f;
+ *to = (c1 << 6) | c2;
+ len -= 2;
+ }
+ else if ((*from & 0xf0) == 0xe0)
+ {
+ if (len < 3)
+ break; /* drop trailing incomplete char */
+ c1 = *from++ & 0x0f;
+ c2 = *from++ & 0x3f;
+ c3 = *from++ & 0x3f;
+ *to = (c1 << 12) | (c2 << 6) | c3;
+ len -= 3;
+ }
+ else if ((*from & 0xf8) == 0xf0)
+ {
+ if (len < 4)
+ break; /* drop trailing incomplete char */
+ c1 = *from++ & 0x07;
+ c2 = *from++ & 0x3f;
+ c3 = *from++ & 0x3f;
+ c4 = *from++ & 0x3f;
+ *to = (c1 << 18) | (c2 << 12) | (c3 << 6) | c4;
+ len -= 4;
+ }
+ else
+ {
+ /* treat a bogus char as length 1; not ours to raise error */
+ *to = *from++;
+ len--;
+ }
+ to++;
+ cnt++;
+ }
+ *to = 0;
+ return cnt;
+}
+
+
+/*
+ * Map a Unicode code point to UTF-8. utf8string must have 4 bytes of
+ * space allocated.
+ */
+unsigned char *
+unicode_to_utf8(pg_wchar c, unsigned char *utf8string)
+{
+ if (c <= 0x7F)
+ {
+ utf8string[0] = c;
+ }
+ else if (c <= 0x7FF)
+ {
+ utf8string[0] = 0xC0 | ((c >> 6) & 0x1F);
+ utf8string[1] = 0x80 | (c & 0x3F);
+ }
+ else if (c <= 0xFFFF)
+ {
+ utf8string[0] = 0xE0 | ((c >> 12) & 0x0F);
+ utf8string[1] = 0x80 | ((c >> 6) & 0x3F);
+ utf8string[2] = 0x80 | (c & 0x3F);
+ }
+ else
+ {
+ utf8string[0] = 0xF0 | ((c >> 18) & 0x07);
+ utf8string[1] = 0x80 | ((c >> 12) & 0x3F);
+ utf8string[2] = 0x80 | ((c >> 6) & 0x3F);
+ utf8string[3] = 0x80 | (c & 0x3F);
+ }
+
+ return utf8string;
+}
+
+/*
+ * Trivial conversion from pg_wchar to UTF-8.
+ * caller should allocate enough space for "to"
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_wchar2utf_with_len(const pg_wchar *from, unsigned char *to, int len)
+{
+ int cnt = 0;
+
+ while (len > 0 && *from)
+ {
+ int char_len;
+
+ unicode_to_utf8(*from, to);
+ char_len = pg_utf_mblen(to);
+ cnt += char_len;
+ to += char_len;
+ from++;
+ len--;
+ }
+ *to = 0;
+ return cnt;
+}
+
+/*
+ * Return the byte length of a UTF8 character pointed to by s
+ *
+ * Note: in the current implementation we do not support UTF8 sequences
+ * of more than 4 bytes; hence do NOT return a value larger than 4.
+ * We return "1" for any leading byte that is either flat-out illegal or
+ * indicates a length larger than we support.
+ *
+ * pg_utf2wchar_with_len(), utf8_to_unicode(), pg_utf8_islegal(), and perhaps
+ * other places would need to be fixed to change this.
+ */
+int
+pg_utf_mblen(const unsigned char *s)
+{
+ int len;
+
+ if ((*s & 0x80) == 0)
+ len = 1;
+ else if ((*s & 0xe0) == 0xc0)
+ len = 2;
+ else if ((*s & 0xf0) == 0xe0)
+ len = 3;
+ else if ((*s & 0xf8) == 0xf0)
+ len = 4;
+#ifdef NOT_USED
+ else if ((*s & 0xfc) == 0xf8)
+ len = 5;
+ else if ((*s & 0xfe) == 0xfc)
+ len = 6;
+#endif
+ else
+ len = 1;
+ return len;
+}
+
+/*
+ * This is an implementation of wcwidth() and wcswidth() as defined in
+ * "The Single UNIX Specification, Version 2, The Open Group, 1997"
+ * <http://www.unix.org/online.html>
+ *
+ * Markus Kuhn -- 2001-09-08 -- public domain
+ *
+ * customised for PostgreSQL
+ *
+ * original available at : http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
+ */
+
+struct mbinterval
+{
+ unsigned short first;
+ unsigned short last;
+};
+
+/* auxiliary function for binary search in interval table */
+static int
+mbbisearch(pg_wchar ucs, const struct mbinterval *table, int max)
+{
+ int min = 0;
+ int mid;
+
+ if (ucs < table[0].first || ucs > table[max].last)
+ return 0;
+ while (max >= min)
+ {
+ mid = (min + max) / 2;
+ if (ucs > table[mid].last)
+ min = mid + 1;
+ else if (ucs < table[mid].first)
+ max = mid - 1;
+ else
+ return 1;
+ }
+
+ return 0;
+}
+
+
+/* The following functions define the column width of an ISO 10646
+ * character as follows:
+ *
+ * - The null character (U+0000) has a column width of 0.
+ *
+ * - Other C0/C1 control characters and DEL will lead to a return
+ * value of -1.
+ *
+ * - Non-spacing and enclosing combining characters (general
+ * category code Mn or Me in the Unicode database) have a
+ * column width of 0.
+ *
+ * - Other format characters (general category code Cf in the Unicode
+ * database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
+ *
+ * - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
+ * have a column width of 0.
+ *
+ * - Spacing characters in the East Asian Wide (W) or East Asian
+ * FullWidth (F) category as defined in Unicode Technical
+ * Report #11 have a column width of 2.
+ *
+ * - All remaining characters (including all printable
+ * ISO 8859-1 and WGL4 characters, Unicode control characters,
+ * etc.) have a column width of 1.
+ *
+ * This implementation assumes that wchar_t characters are encoded
+ * in ISO 10646.
+ */
+
+static int
+ucs_wcwidth(pg_wchar ucs)
+{
+#include "common/unicode_combining_table.h"
+
+ /* test for 8-bit control characters */
+ if (ucs == 0)
+ return 0;
+
+ if (ucs < 0x20 || (ucs >= 0x7f && ucs < 0xa0) || ucs > 0x0010ffff)
+ return -1;
+
+ /* binary search in table of non-spacing characters */
+ if (mbbisearch(ucs, combining,
+ sizeof(combining) / sizeof(struct mbinterval) - 1))
+ return 0;
+
+ /*
+ * if we arrive here, ucs is not a combining or C0/C1 control character
+ */
+
+ return 1 +
+ (ucs >= 0x1100 &&
+ (ucs <= 0x115f || /* Hangul Jamo init. consonants */
+ (ucs >= 0x2e80 && ucs <= 0xa4cf && (ucs & ~0x0011) != 0x300a &&
+ ucs != 0x303f) || /* CJK ... Yi */
+ (ucs >= 0xac00 && ucs <= 0xd7a3) || /* Hangul Syllables */
+ (ucs >= 0xf900 && ucs <= 0xfaff) || /* CJK Compatibility
+ * Ideographs */
+ (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
+ (ucs >= 0xff00 && ucs <= 0xff5f) || /* Fullwidth Forms */
+ (ucs >= 0xffe0 && ucs <= 0xffe6) ||
+ (ucs >= 0x20000 && ucs <= 0x2ffff)));
+}
+
+/*
+ * Convert a UTF-8 character to a Unicode code point.
+ * This is a one-character version of pg_utf2wchar_with_len.
+ *
+ * No error checks here, c must point to a long-enough string.
+ */
+pg_wchar
+utf8_to_unicode(const unsigned char *c)
+{
+ if ((*c & 0x80) == 0)
+ return (pg_wchar) c[0];
+ else if ((*c & 0xe0) == 0xc0)
+ return (pg_wchar) (((c[0] & 0x1f) << 6) |
+ (c[1] & 0x3f));
+ else if ((*c & 0xf0) == 0xe0)
+ return (pg_wchar) (((c[0] & 0x0f) << 12) |
+ ((c[1] & 0x3f) << 6) |
+ (c[2] & 0x3f));
+ else if ((*c & 0xf8) == 0xf0)
+ return (pg_wchar) (((c[0] & 0x07) << 18) |
+ ((c[1] & 0x3f) << 12) |
+ ((c[2] & 0x3f) << 6) |
+ (c[3] & 0x3f));
+ else
+ /* that is an invalid code on purpose */
+ return 0xffffffff;
+}
+
+static int
+pg_utf_dsplen(const unsigned char *s)
+{
+ return ucs_wcwidth(utf8_to_unicode(s));
+}
+
+/*
+ * convert mule internal code to pg_wchar
+ * caller should allocate enough space for "to"
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_mule2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+ int cnt = 0;
+
+ while (len > 0 && *from)
+ {
+ if (IS_LC1(*from) && len >= 2)
+ {
+ *to = *from++ << 16;
+ *to |= *from++;
+ len -= 2;
+ }
+ else if (IS_LCPRV1(*from) && len >= 3)
+ {
+ from++;
+ *to = *from++ << 16;
+ *to |= *from++;
+ len -= 3;
+ }
+ else if (IS_LC2(*from) && len >= 3)
+ {
+ *to = *from++ << 16;
+ *to |= *from++ << 8;
+ *to |= *from++;
+ len -= 3;
+ }
+ else if (IS_LCPRV2(*from) && len >= 4)
+ {
+ from++;
+ *to = *from++ << 16;
+ *to |= *from++ << 8;
+ *to |= *from++;
+ len -= 4;
+ }
+ else
+ { /* assume ASCII */
+ *to = (unsigned char) *from++;
+ len--;
+ }
+ to++;
+ cnt++;
+ }
+ *to = 0;
+ return cnt;
+}
+
+/*
+ * convert pg_wchar to mule internal code
+ * caller should allocate enough space for "to"
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_wchar2mule_with_len(const pg_wchar *from, unsigned char *to, int len)
+{
+ int cnt = 0;
+
+ while (len > 0 && *from)
+ {
+ unsigned char lb;
+
+ lb = (*from >> 16) & 0xff;
+ if (IS_LC1(lb))
+ {
+ *to++ = lb;
+ *to++ = *from & 0xff;
+ cnt += 2;
+ }
+ else if (IS_LC2(lb))
+ {
+ *to++ = lb;
+ *to++ = (*from >> 8) & 0xff;
+ *to++ = *from & 0xff;
+ cnt += 3;
+ }
+ else if (IS_LCPRV1_A_RANGE(lb))
+ {
+ *to++ = LCPRV1_A;
+ *to++ = lb;
+ *to++ = *from & 0xff;
+ cnt += 3;
+ }
+ else if (IS_LCPRV1_B_RANGE(lb))
+ {
+ *to++ = LCPRV1_B;
+ *to++ = lb;
+ *to++ = *from & 0xff;
+ cnt += 3;
+ }
+ else if (IS_LCPRV2_A_RANGE(lb))
+ {
+ *to++ = LCPRV2_A;
+ *to++ = lb;
+ *to++ = (*from >> 8) & 0xff;
+ *to++ = *from & 0xff;
+ cnt += 4;
+ }
+ else if (IS_LCPRV2_B_RANGE(lb))
+ {
+ *to++ = LCPRV2_B;
+ *to++ = lb;
+ *to++ = (*from >> 8) & 0xff;
+ *to++ = *from & 0xff;
+ cnt += 4;
+ }
+ else
+ {
+ *to++ = *from & 0xff;
+ cnt += 1;
+ }
+ from++;
+ len--;
+ }
+ *to = 0;
+ return cnt;
+}
+
+/* exported for direct use by conv.c */
+int
+pg_mule_mblen(const unsigned char *s)
+{
+ int len;
+
+ if (IS_LC1(*s))
+ len = 2;
+ else if (IS_LCPRV1(*s))
+ len = 3;
+ else if (IS_LC2(*s))
+ len = 3;
+ else if (IS_LCPRV2(*s))
+ len = 4;
+ else
+ len = 1; /* assume ASCII */
+ return len;
+}
+
+static int
+pg_mule_dsplen(const unsigned char *s)
+{
+ int len;
+
+ /*
+ * Note: it's not really appropriate to assume that all multibyte charsets
+ * are double-wide on screen. But this seems an okay approximation for
+ * the MULE charsets we currently support.
+ */
+
+ if (IS_LC1(*s))
+ len = 1;
+ else if (IS_LCPRV1(*s))
+ len = 1;
+ else if (IS_LC2(*s))
+ len = 2;
+ else if (IS_LCPRV2(*s))
+ len = 2;
+ else
+ len = 1; /* assume ASCII */
+
+ return len;
+}
+
+/*
+ * ISO8859-1
+ */
+static int
+pg_latin12wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+ int cnt = 0;
+
+ while (len > 0 && *from)
+ {
+ *to++ = *from++;
+ len--;
+ cnt++;
+ }
+ *to = 0;
+ return cnt;
+}
+
+/*
+ * Trivial conversion from pg_wchar to single byte encoding. Just ignores
+ * high bits.
+ * caller should allocate enough space for "to"
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_wchar2single_with_len(const pg_wchar *from, unsigned char *to, int len)
+{
+ int cnt = 0;
+
+ while (len > 0 && *from)
+ {
+ *to++ = *from++;
+ len--;
+ cnt++;
+ }
+ *to = 0;
+ return cnt;
+}
+
+static int
+pg_latin1_mblen(const unsigned char *s)
+{
+ return 1;
+}
+
+static int
+pg_latin1_dsplen(const unsigned char *s)
+{
+ return pg_ascii_dsplen(s);
+}
+
+/*
+ * SJIS
+ */
+static int
+pg_sjis_mblen(const unsigned char *s)
+{
+ int len;
+
+ if (*s >= 0xa1 && *s <= 0xdf)
+ len = 1; /* 1 byte kana? */
+ else if (IS_HIGHBIT_SET(*s))
+ len = 2; /* kanji? */
+ else
+ len = 1; /* should be ASCII */
+ return len;
+}
+
+static int
+pg_sjis_dsplen(const unsigned char *s)
+{
+ int len;
+
+ if (*s >= 0xa1 && *s <= 0xdf)
+ len = 1; /* 1 byte kana? */
+ else if (IS_HIGHBIT_SET(*s))
+ len = 2; /* kanji? */
+ else
+ len = pg_ascii_dsplen(s); /* should be ASCII */
+ return len;
+}
+
+/*
+ * Big5
+ */
+static int
+pg_big5_mblen(const unsigned char *s)
+{
+ int len;
+
+ if (IS_HIGHBIT_SET(*s))
+ len = 2; /* kanji? */
+ else
+ len = 1; /* should be ASCII */
+ return len;
+}
+
+static int
+pg_big5_dsplen(const unsigned char *s)
+{
+ int len;
+
+ if (IS_HIGHBIT_SET(*s))
+ len = 2; /* kanji? */
+ else
+ len = pg_ascii_dsplen(s); /* should be ASCII */
+ return len;
+}
+
+/*
+ * GBK
+ */
+static int
+pg_gbk_mblen(const unsigned char *s)
+{
+ int len;
+
+ if (IS_HIGHBIT_SET(*s))
+ len = 2; /* kanji? */
+ else
+ len = 1; /* should be ASCII */
+ return len;
+}
+
+static int
+pg_gbk_dsplen(const unsigned char *s)
+{
+ int len;
+
+ if (IS_HIGHBIT_SET(*s))
+ len = 2; /* kanji? */
+ else
+ len = pg_ascii_dsplen(s); /* should be ASCII */
+ return len;
+}
+
+/*
+ * UHC
+ */
+static int
+pg_uhc_mblen(const unsigned char *s)
+{
+ int len;
+
+ if (IS_HIGHBIT_SET(*s))
+ len = 2; /* 2byte? */
+ else
+ len = 1; /* should be ASCII */
+ return len;
+}
+
+static int
+pg_uhc_dsplen(const unsigned char *s)
+{
+ int len;
+
+ if (IS_HIGHBIT_SET(*s))
+ len = 2; /* 2byte? */
+ else
+ len = pg_ascii_dsplen(s); /* should be ASCII */
+ return len;
+}
+
+/*
+ * GB18030
+ * Added by Bill Huang <bhuang@redhat.com>,<bill_huanghb@ybb.ne.jp>
+ */
+
+/*
+ * Unlike all other mblen() functions, this also looks at the second byte of
+ * the input. However, if you only pass the first byte of a multi-byte
+ * string, and \0 as the second byte, this still works in a predictable way:
+ * a 4-byte character will be reported as two 2-byte characters. That's
+ * enough for all current uses, as a client-only encoding. It works that
+ * way, because in any valid 4-byte GB18030-encoded character, the third and
+ * fourth byte look like a 2-byte encoded character, when looked at
+ * separately.
+ */
+static int
+pg_gb18030_mblen(const unsigned char *s)
+{
+ int len;
+
+ if (!IS_HIGHBIT_SET(*s))
+ len = 1; /* ASCII */
+ else if (*(s + 1) >= 0x30 && *(s + 1) <= 0x39)
+ len = 4;
+ else
+ len = 2;
+ return len;
+}
+
+static int
+pg_gb18030_dsplen(const unsigned char *s)
+{
+ int len;
+
+ if (IS_HIGHBIT_SET(*s))
+ len = 2;
+ else
+ len = pg_ascii_dsplen(s); /* ASCII */
+ return len;
+}
+
+/*
+ *-------------------------------------------------------------------
+ * multibyte sequence validators
+ *
+ * The verifychar functions accept "s", a pointer to the first byte of a
+ * string, and "len", the remaining length of the string. If there is a
+ * validly encoded character beginning at *s, return its length in bytes;
+ * else return -1.
+ *
+ * The verifystr functions also accept "s", a pointer to a string and "len",
+ * the length of the string. They verify the whole string, and return the
+ * number of input bytes (<= len) that are valid. In other words, if the
+ * whole string is valid, verifystr returns "len", otherwise it returns the
+ * byte offset of the first invalid character. The verifystr functions must
+ * test for and reject zeroes in the input.
+ *
+ * The verifychar functions can assume that len > 0 and that *s != '\0', but
+ * they must test for and reject zeroes in any additional bytes of a
+ * multibyte character. Note that this definition allows the function for a
+ * single-byte encoding to be just "return 1".
+ *-------------------------------------------------------------------
+ */
+static int
+pg_ascii_verifychar(const unsigned char *s, int len)
+{
+ return 1;
+}
+
+static int
+pg_ascii_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *nullpos = memchr(s, 0, len);
+
+ if (nullpos == NULL)
+ return len;
+ else
+ return nullpos - s;
+}
+
+#define IS_EUC_RANGE_VALID(c) ((c) >= 0xa1 && (c) <= 0xfe)
+
+static int
+pg_eucjp_verifychar(const unsigned char *s, int len)
+{
+ int l;
+ unsigned char c1,
+ c2;
+
+ c1 = *s++;
+
+ switch (c1)
+ {
+ case SS2: /* JIS X 0201 */
+ l = 2;
+ if (l > len)
+ return -1;
+ c2 = *s++;
+ if (c2 < 0xa1 || c2 > 0xdf)
+ return -1;
+ break;
+
+ case SS3: /* JIS X 0212 */
+ l = 3;
+ if (l > len)
+ return -1;
+ c2 = *s++;
+ if (!IS_EUC_RANGE_VALID(c2))
+ return -1;
+ c2 = *s++;
+ if (!IS_EUC_RANGE_VALID(c2))
+ return -1;
+ break;
+
+ default:
+ if (IS_HIGHBIT_SET(c1)) /* JIS X 0208? */
+ {
+ l = 2;
+ if (l > len)
+ return -1;
+ if (!IS_EUC_RANGE_VALID(c1))
+ return -1;
+ c2 = *s++;
+ if (!IS_EUC_RANGE_VALID(c2))
+ return -1;
+ }
+ else
+ /* must be ASCII */
+ {
+ l = 1;
+ }
+ break;
+ }
+
+ return l;
+}
+
+static int
+pg_eucjp_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_eucjp_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+static int
+pg_euckr_verifychar(const unsigned char *s, int len)
+{
+ int l;
+ unsigned char c1,
+ c2;
+
+ c1 = *s++;
+
+ if (IS_HIGHBIT_SET(c1))
+ {
+ l = 2;
+ if (l > len)
+ return -1;
+ if (!IS_EUC_RANGE_VALID(c1))
+ return -1;
+ c2 = *s++;
+ if (!IS_EUC_RANGE_VALID(c2))
+ return -1;
+ }
+ else
+ /* must be ASCII */
+ {
+ l = 1;
+ }
+
+ return l;
+}
+
+static int
+pg_euckr_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_euckr_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+/* EUC-CN byte sequences are exactly same as EUC-KR */
+#define pg_euccn_verifychar pg_euckr_verifychar
+#define pg_euccn_verifystr pg_euckr_verifystr
+
+static int
+pg_euctw_verifychar(const unsigned char *s, int len)
+{
+ int l;
+ unsigned char c1,
+ c2;
+
+ c1 = *s++;
+
+ switch (c1)
+ {
+ case SS2: /* CNS 11643 Plane 1-7 */
+ l = 4;
+ if (l > len)
+ return -1;
+ c2 = *s++;
+ if (c2 < 0xa1 || c2 > 0xa7)
+ return -1;
+ c2 = *s++;
+ if (!IS_EUC_RANGE_VALID(c2))
+ return -1;
+ c2 = *s++;
+ if (!IS_EUC_RANGE_VALID(c2))
+ return -1;
+ break;
+
+ case SS3: /* unused */
+ return -1;
+
+ default:
+ if (IS_HIGHBIT_SET(c1)) /* CNS 11643 Plane 1 */
+ {
+ l = 2;
+ if (l > len)
+ return -1;
+ /* no further range check on c1? */
+ c2 = *s++;
+ if (!IS_EUC_RANGE_VALID(c2))
+ return -1;
+ }
+ else
+ /* must be ASCII */
+ {
+ l = 1;
+ }
+ break;
+ }
+ return l;
+}
+
+static int
+pg_euctw_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_euctw_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+static int
+pg_johab_verifychar(const unsigned char *s, int len)
+{
+ int l,
+ mbl;
+ unsigned char c;
+
+ l = mbl = pg_johab_mblen(s);
+
+ if (len < l)
+ return -1;
+
+ if (!IS_HIGHBIT_SET(*s))
+ return mbl;
+
+ while (--l > 0)
+ {
+ c = *++s;
+ if (!IS_EUC_RANGE_VALID(c))
+ return -1;
+ }
+ return mbl;
+}
+
+static int
+pg_johab_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_johab_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+static int
+pg_mule_verifychar(const unsigned char *s, int len)
+{
+ int l,
+ mbl;
+ unsigned char c;
+
+ l = mbl = pg_mule_mblen(s);
+
+ if (len < l)
+ return -1;
+
+ while (--l > 0)
+ {
+ c = *++s;
+ if (!IS_HIGHBIT_SET(c))
+ return -1;
+ }
+ return mbl;
+}
+
+static int
+pg_mule_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_mule_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+static int
+pg_latin1_verifychar(const unsigned char *s, int len)
+{
+ return 1;
+}
+
+static int
+pg_latin1_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *nullpos = memchr(s, 0, len);
+
+ if (nullpos == NULL)
+ return len;
+ else
+ return nullpos - s;
+}
+
+static int
+pg_sjis_verifychar(const unsigned char *s, int len)
+{
+ int l,
+ mbl;
+ unsigned char c1,
+ c2;
+
+ l = mbl = pg_sjis_mblen(s);
+
+ if (len < l)
+ return -1;
+
+ if (l == 1) /* pg_sjis_mblen already verified it */
+ return mbl;
+
+ c1 = *s++;
+ c2 = *s;
+ if (!ISSJISHEAD(c1) || !ISSJISTAIL(c2))
+ return -1;
+ return mbl;
+}
+
+static int
+pg_sjis_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_sjis_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+static int
+pg_big5_verifychar(const unsigned char *s, int len)
+{
+ int l,
+ mbl;
+
+ l = mbl = pg_big5_mblen(s);
+
+ if (len < l)
+ return -1;
+
+ while (--l > 0)
+ {
+ if (*++s == '\0')
+ return -1;
+ }
+
+ return mbl;
+}
+
+static int
+pg_big5_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_big5_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+static int
+pg_gbk_verifychar(const unsigned char *s, int len)
+{
+ int l,
+ mbl;
+
+ l = mbl = pg_gbk_mblen(s);
+
+ if (len < l)
+ return -1;
+
+ while (--l > 0)
+ {
+ if (*++s == '\0')
+ return -1;
+ }
+
+ return mbl;
+}
+
+static int
+pg_gbk_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_gbk_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+static int
+pg_uhc_verifychar(const unsigned char *s, int len)
+{
+ int l,
+ mbl;
+
+ l = mbl = pg_uhc_mblen(s);
+
+ if (len < l)
+ return -1;
+
+ while (--l > 0)
+ {
+ if (*++s == '\0')
+ return -1;
+ }
+
+ return mbl;
+}
+
+static int
+pg_uhc_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_uhc_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+static int
+pg_gb18030_verifychar(const unsigned char *s, int len)
+{
+ int l;
+
+ if (!IS_HIGHBIT_SET(*s))
+ l = 1; /* ASCII */
+ else if (len >= 4 && *(s + 1) >= 0x30 && *(s + 1) <= 0x39)
+ {
+ /* Should be 4-byte, validate remaining bytes */
+ if (*s >= 0x81 && *s <= 0xfe &&
+ *(s + 2) >= 0x81 && *(s + 2) <= 0xfe &&
+ *(s + 3) >= 0x30 && *(s + 3) <= 0x39)
+ l = 4;
+ else
+ l = -1;
+ }
+ else if (len >= 2 && *s >= 0x81 && *s <= 0xfe)
+ {
+ /* Should be 2-byte, validate */
+ if ((*(s + 1) >= 0x40 && *(s + 1) <= 0x7e) ||
+ (*(s + 1) >= 0x80 && *(s + 1) <= 0xfe))
+ l = 2;
+ else
+ l = -1;
+ }
+ else
+ l = -1;
+ return l;
+}
+
+static int
+pg_gb18030_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_gb18030_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+static int
+pg_utf8_verifychar(const unsigned char *s, int len)
+{
+ int l;
+
+ if ((*s & 0x80) == 0)
+ {
+ if (*s == '\0')
+ return -1;
+ return 1;
+ }
+ else if ((*s & 0xe0) == 0xc0)
+ l = 2;
+ else if ((*s & 0xf0) == 0xe0)
+ l = 3;
+ else if ((*s & 0xf8) == 0xf0)
+ l = 4;
+ else
+ l = 1;
+
+ if (l > len)
+ return -1;
+
+ if (!pg_utf8_islegal(s, l))
+ return -1;
+
+ return l;
+}
+
+static int
+pg_utf8_verifystr(const unsigned char *s, int len)
+{
+ const unsigned char *start = s;
+
+ while (len > 0)
+ {
+ int l;
+
+ /* fast path for ASCII-subset characters */
+ if (!IS_HIGHBIT_SET(*s))
+ {
+ if (*s == '\0')
+ break;
+ l = 1;
+ }
+ else
+ {
+ l = pg_utf8_verifychar(s, len);
+ if (l == -1)
+ break;
+ }
+ s += l;
+ len -= l;
+ }
+
+ return s - start;
+}
+
+/*
+ * Check for validity of a single UTF-8 encoded character
+ *
+ * This directly implements the rules in RFC3629. The bizarre-looking
+ * restrictions on the second byte are meant to ensure that there isn't
+ * more than one encoding of a given Unicode character point; that is,
+ * you may not use a longer-than-necessary byte sequence with high order
+ * zero bits to represent a character that would fit in fewer bytes.
+ * To do otherwise is to create security hazards (eg, create an apparent
+ * non-ASCII character that decodes to plain ASCII).
+ *
+ * length is assumed to have been obtained by pg_utf_mblen(), and the
+ * caller must have checked that that many bytes are present in the buffer.
+ */
+bool
+pg_utf8_islegal(const unsigned char *source, int length)
+{
+ unsigned char a;
+
+ switch (length)
+ {
+ default:
+ /* reject lengths 5 and 6 for now */
+ return false;
+ case 4:
+ a = source[3];
+ if (a < 0x80 || a > 0xBF)
+ return false;
+ /* FALL THRU */
+ case 3:
+ a = source[2];
+ if (a < 0x80 || a > 0xBF)
+ return false;
+ /* FALL THRU */
+ case 2:
+ a = source[1];
+ switch (*source)
+ {
+ case 0xE0:
+ if (a < 0xA0 || a > 0xBF)
+ return false;
+ break;
+ case 0xED:
+ if (a < 0x80 || a > 0x9F)
+ return false;
+ break;
+ case 0xF0:
+ if (a < 0x90 || a > 0xBF)
+ return false;
+ break;
+ case 0xF4:
+ if (a < 0x80 || a > 0x8F)
+ return false;
+ break;
+ default:
+ if (a < 0x80 || a > 0xBF)
+ return false;
+ break;
+ }
+ /* FALL THRU */
+ case 1:
+ a = *source;
+ if (a >= 0x80 && a < 0xC2)
+ return false;
+ if (a > 0xF4)
+ return false;
+ break;
+ }
+ return true;
+}
+
+
+/*
+ *-------------------------------------------------------------------
+ * encoding info table
+ * XXX must be sorted by the same order as enum pg_enc (in mb/pg_wchar.h)
+ *-------------------------------------------------------------------
+ */
+const pg_wchar_tbl pg_wchar_table[] = {
+ {pg_ascii2wchar_with_len, pg_wchar2single_with_len, pg_ascii_mblen, pg_ascii_dsplen, pg_ascii_verifychar, pg_ascii_verifystr, 1}, /* PG_SQL_ASCII */
+ {pg_eucjp2wchar_with_len, pg_wchar2euc_with_len, pg_eucjp_mblen, pg_eucjp_dsplen, pg_eucjp_verifychar, pg_eucjp_verifystr, 3}, /* PG_EUC_JP */
+ {pg_euccn2wchar_with_len, pg_wchar2euc_with_len, pg_euccn_mblen, pg_euccn_dsplen, pg_euccn_verifychar, pg_euccn_verifystr, 2}, /* PG_EUC_CN */
+ {pg_euckr2wchar_with_len, pg_wchar2euc_with_len, pg_euckr_mblen, pg_euckr_dsplen, pg_euckr_verifychar, pg_euckr_verifystr, 3}, /* PG_EUC_KR */
+ {pg_euctw2wchar_with_len, pg_wchar2euc_with_len, pg_euctw_mblen, pg_euctw_dsplen, pg_euctw_verifychar, pg_euctw_verifystr, 4}, /* PG_EUC_TW */
+ {pg_eucjp2wchar_with_len, pg_wchar2euc_with_len, pg_eucjp_mblen, pg_eucjp_dsplen, pg_eucjp_verifychar, pg_eucjp_verifystr, 3}, /* PG_EUC_JIS_2004 */
+ {pg_utf2wchar_with_len, pg_wchar2utf_with_len, pg_utf_mblen, pg_utf_dsplen, pg_utf8_verifychar, pg_utf8_verifystr, 4}, /* PG_UTF8 */
+ {pg_mule2wchar_with_len, pg_wchar2mule_with_len, pg_mule_mblen, pg_mule_dsplen, pg_mule_verifychar, pg_mule_verifystr, 4}, /* PG_MULE_INTERNAL */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_LATIN1 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_LATIN2 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_LATIN3 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_LATIN4 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_LATIN5 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_LATIN6 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_LATIN7 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_LATIN8 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_LATIN9 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_LATIN10 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN1256 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN1258 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN866 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN874 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_KOI8R */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN1251 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN1252 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* ISO-8859-5 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* ISO-8859-6 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* ISO-8859-7 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* ISO-8859-8 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN1250 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN1253 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN1254 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN1255 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_WIN1257 */
+ {pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1}, /* PG_KOI8U */
+ {0, 0, pg_sjis_mblen, pg_sjis_dsplen, pg_sjis_verifychar, pg_sjis_verifystr, 2}, /* PG_SJIS */
+ {0, 0, pg_big5_mblen, pg_big5_dsplen, pg_big5_verifychar, pg_big5_verifystr, 2}, /* PG_BIG5 */
+ {0, 0, pg_gbk_mblen, pg_gbk_dsplen, pg_gbk_verifychar, pg_gbk_verifystr, 2}, /* PG_GBK */
+ {0, 0, pg_uhc_mblen, pg_uhc_dsplen, pg_uhc_verifychar, pg_uhc_verifystr, 2}, /* PG_UHC */
+ {0, 0, pg_gb18030_mblen, pg_gb18030_dsplen, pg_gb18030_verifychar, pg_gb18030_verifystr, 4}, /* PG_GB18030 */
+ {0, 0, pg_johab_mblen, pg_johab_dsplen, pg_johab_verifychar, pg_johab_verifystr, 3}, /* PG_JOHAB */
+ {0, 0, pg_sjis_mblen, pg_sjis_dsplen, pg_sjis_verifychar, pg_sjis_verifystr, 2} /* PG_SHIFT_JIS_2004 */
+};
+
+/*
+ * Returns the byte length of a multibyte character.
+ *
+ * Caution: when dealing with text that is not certainly valid in the
+ * specified encoding, the result may exceed the actual remaining
+ * string length. Callers that are not prepared to deal with that
+ * should use pg_encoding_mblen_bounded() instead.
+ */
+int
+pg_encoding_mblen(int encoding, const char *mbstr)
+{
+ return (PG_VALID_ENCODING(encoding) ?
+ pg_wchar_table[encoding].mblen((const unsigned char *) mbstr) :
+ pg_wchar_table[PG_SQL_ASCII].mblen((const unsigned char *) mbstr));
+}
+
+/*
+ * Returns the byte length of a multibyte character; but not more than
+ * the distance to end of string.
+ */
+int
+pg_encoding_mblen_bounded(int encoding, const char *mbstr)
+{
+ return strnlen(mbstr, pg_encoding_mblen(encoding, mbstr));
+}
+
+/*
+ * Returns the display length of a multibyte character.
+ */
+int
+pg_encoding_dsplen(int encoding, const char *mbstr)
+{
+ return (PG_VALID_ENCODING(encoding) ?
+ pg_wchar_table[encoding].dsplen((const unsigned char *) mbstr) :
+ pg_wchar_table[PG_SQL_ASCII].dsplen((const unsigned char *) mbstr));
+}
+
+/*
+ * Verify the first multibyte character of the given string.
+ * Return its byte length if good, -1 if bad. (See comments above for
+ * full details of the mbverifychar API.)
+ */
+int
+pg_encoding_verifymbchar(int encoding, const char *mbstr, int len)
+{
+ return (PG_VALID_ENCODING(encoding) ?
+ pg_wchar_table[encoding].mbverifychar((const unsigned char *) mbstr, len) :
+ pg_wchar_table[PG_SQL_ASCII].mbverifychar((const unsigned char *) mbstr, len));
+}
+
+/*
+ * Verify that a string is valid for the given encoding.
+ * Returns the number of input bytes (<= len) that form a valid string.
+ * (See comments above for full details of the mbverifystr API.)
+ */
+int
+pg_encoding_verifymbstr(int encoding, const char *mbstr, int len)
+{
+ return (PG_VALID_ENCODING(encoding) ?
+ pg_wchar_table[encoding].mbverifystr((const unsigned char *) mbstr, len) :
+ pg_wchar_table[PG_SQL_ASCII].mbverifystr((const unsigned char *) mbstr, len));
+}
+
+/*
+ * fetch maximum length of a given encoding
+ */
+int
+pg_encoding_max_length(int encoding)
+{
+ Assert(PG_VALID_ENCODING(encoding));
+
+ return pg_wchar_table[encoding].maxmblen;
+}