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Sourcecode: postgresql-8.4 version File versions

mbprint.c

/*
 * psql - the PostgreSQL interactive terminal
 *
 * Copyright (c) 2000-2009, PostgreSQL Global Development Group
 *
 * $PostgreSQL$
 *
 * XXX this file does not really belong in psql/.  Perhaps move to libpq?
 * It also seems that the mbvalidate function is redundant with existing
 * functionality.
 */

#include "postgres_fe.h"
#include "mbprint.h"
#include "libpq-fe.h"
#ifndef PGSCRIPTS
#include "settings.h"
#endif

/*
 * To avoid version-skew problems, this file must not use declarations
 * from pg_wchar.h: the encoding IDs we are dealing with are determined
 * by the libpq.so we are linked with, and that might not match the
 * numbers we see at compile time.  (If this file were inside libpq,
 * the problem would go away...)
 *
 * Hence, we have our own definition of pg_wchar, and we get the values
 * of any needed encoding IDs on-the-fly.
 */

typedef unsigned int pg_wchar;

static int
get_utf8_id(void)
{
      static int  utf8_id = -1;

      if (utf8_id < 0)
            utf8_id = pg_char_to_encoding("utf8");
      return utf8_id;
}

#define PG_UTF8         get_utf8_id()


static pg_wchar
utf2ucs(const unsigned char *c)
{
      /*
       * one char version of pg_utf2wchar_with_len. no control here, c must
       * point to a large enough string
       */
      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 & 0xf0) == 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;
      }
}


/*
 * Unicode 3.1 compliant validation : for each category, it checks the
 * combination of each byte to make sure it maps to a valid range. It also
 * returns -1 for the following UCS values: ucs > 0x10ffff ucs & 0xfffe =
 * 0xfffe 0xfdd0 < ucs < 0xfdef ucs & 0xdb00 = 0xd800 (surrogates)
 */
static int
utf_charcheck(const unsigned char *c)
{
      if ((*c & 0x80) == 0)
            return 1;
      else if ((*c & 0xe0) == 0xc0)
      {
            /* two-byte char */
            if (((c[1] & 0xc0) == 0x80) && ((c[0] & 0x1f) > 0x01))
                  return 2;
            return -1;
      }
      else if ((*c & 0xf0) == 0xe0)
      {
            /* three-byte char */
            if (((c[1] & 0xc0) == 0x80) &&
                  (((c[0] & 0x0f) != 0x00) || ((c[1] & 0x20) == 0x20)) &&
                  ((c[2] & 0xc0) == 0x80))
            {
                  int               z = c[0] & 0x0f;
                  int               yx = ((c[1] & 0x3f) << 6) | (c[0] & 0x3f);
                  int               lx = yx & 0x7f;

                  /* check 0xfffe/0xffff, 0xfdd0..0xfedf range, surrogates */
                  if (((z == 0x0f) &&
                         (((yx & 0xffe) == 0xffe) ||
                     (((yx & 0xf80) == 0xd80) && (lx >= 0x30) && (lx <= 0x4f)))) ||
                        ((z == 0x0d) && ((yx & 0xb00) == 0x800)))
                        return -1;
                  return 3;
            }
            return -1;
      }
      else if ((*c & 0xf8) == 0xf0)
      {
            int               u = ((c[0] & 0x07) << 2) | ((c[1] & 0x30) >> 4);

            /* four-byte char */
            if (((c[1] & 0xc0) == 0x80) &&
                  (u > 0x00) && (u <= 0x10) &&
                  ((c[2] & 0xc0) == 0x80) && ((c[3] & 0xc0) == 0x80))
            {
                  /* test for 0xzzzzfffe/0xzzzzfffff */
                  if (((c[1] & 0x0f) == 0x0f) && ((c[2] & 0x3f) == 0x3f) &&
                        ((c[3] & 0x3e) == 0x3e))
                        return -1;
                  return 4;
            }
            return -1;
      }
      return -1;
}


static void
mb_utf_validate(unsigned char *pwcs)
{
      unsigned char *p = pwcs;

      while (*pwcs)
      {
            int               len;

            if ((len = utf_charcheck(pwcs)) > 0)
            {
                  if (p != pwcs)
                  {
                        int               i;

                        for (i = 0; i < len; i++)
                              *p++ = *pwcs++;
                  }
                  else
                  {
                        pwcs += len;
                        p += len;
                  }
            }
            else
                  /* we skip the char */
                  pwcs++;
      }
      if (p != pwcs)
            *p = '\0';
}

/*
 * public functions : wcswidth and mbvalidate
 */

/*
 * pg_wcswidth is the dumb width function. It assumes that everything will
 * only appear on one line. OTOH it is easier to use if this applies to you.
 */
int
pg_wcswidth(const unsigned char *pwcs, size_t len, int encoding)
{
      int               width = 0;

      while (len > 0)
      {
            int               chlen,
                              chwidth;

            chlen = PQmblen((const char *) pwcs, encoding);
            if (chlen > len)
                  break;                        /* Invalid string */

            chwidth = PQdsplen((const char *) pwcs, encoding);

            if (chwidth > 0)
                  width += chwidth;
            pwcs += chlen;
      }
      return width;
}

/*
 * pg_wcssize takes the given string in the given encoding and returns three
 * values:
 *      result_width: Width in display characters of the longest line in string
 *      result_height: Number of lines in display output
 *      result_format_size: Number of bytes required to store formatted
 *          representation of string
 *
 * This MUST be kept in sync with pg_wcsformat!
 */
void
pg_wcssize(unsigned char *pwcs, size_t len, int encoding,
               int *result_width, int *result_height, int *result_format_size)
{
      int               w,
                        chlen = 0,
                        linewidth = 0;
      int               width = 0;
      int               height = 1;
      int               format_size = 0;

      for (; *pwcs && len > 0; pwcs += chlen)
      {
            chlen = PQmblen((char *) pwcs, encoding);
            if (len < (size_t) chlen)
                  break;
            w = PQdsplen((char *) pwcs, encoding);

            if (chlen == 1)               /* single-byte char */
            {
                  if (*pwcs == '\n')      /* Newline */
                  {
                        if (linewidth > width)
                              width = linewidth;
                        linewidth = 0;
                        height += 1;
                        format_size += 1;       /* For NUL char */
                  }
                  else if (*pwcs == '\r')       /* Linefeed */
                  {
                        linewidth += 2;
                        format_size += 2;
                  }
                  else if (*pwcs == '\t')       /* Tab */
                  {
                        do
                        {
                              linewidth++;
                              format_size++;
                        } while (linewidth % 8 != 0);
                  }
                  else if (w < 0)         /* Other control char */
                  {
                        linewidth += 4;
                        format_size += 4;
                  }
                  else  /* Output it as-is */
                  {
                        linewidth += w;
                        format_size += 1;
                  }
            }
            else if (w < 0)               /* Non-ascii control char */
            {
                  linewidth += 6;         /* \u0000 */
                  format_size += 6;
            }
            else  /* All other chars */
            {
                  linewidth += w;
                  format_size += chlen;
            }
            len -= chlen;
      }
      if (linewidth > width)
            width = linewidth;
      format_size += 1;       /* For NUL char */

      /* Set results */
      if (result_width)
            *result_width = width;
      if (result_height)
            *result_height = height;
      if (result_format_size)
            *result_format_size = format_size;
}

/*
 *  Format a string into one or more "struct lineptr" lines.
 *  lines[i].ptr == NULL indicates the end of the array.
 *
 * This MUST be kept in sync with pg_wcssize!
 */
void
pg_wcsformat(unsigned char *pwcs, size_t len, int encoding,
                   struct lineptr *lines, int count)
{
      int               w,
                        chlen = 0;
      int               linewidth = 0;
      unsigned char *ptr = lines->ptr;    /* Pointer to data area */

      for (; *pwcs && len > 0; pwcs += chlen)
      {
            chlen = PQmblen((char *) pwcs, encoding);
            if (len < (size_t) chlen)
                  break;
            w = PQdsplen((char *) pwcs, encoding);

            if (chlen == 1)               /* single-byte char */
            {
                  if (*pwcs == '\n')      /* Newline */
                  {
                        *ptr++ = '\0';
                        lines->width = linewidth;
                        linewidth = 0;
                        lines++;
                        count--;
                        if (count <= 0)
                              exit(1);    /* Screwup */

                        /* make next line point to remaining memory */
                        lines->ptr = ptr;
                  }
                  else if (*pwcs == '\r')       /* Linefeed */
                  {
                        strcpy((char *) ptr, "\\r");
                        linewidth += 2;
                        ptr += 2;
                  }
                  else if (*pwcs == '\t')       /* Tab */
                  {
                        do
                        {
                              *ptr++ = ' ';
                              linewidth++;
                        } while (linewidth % 8 != 0);
                  }
                  else if (w < 0)         /* Other control char */
                  {
                        sprintf((char *) ptr, "\\x%02X", *pwcs);
                        linewidth += 4;
                        ptr += 4;
                  }
                  else  /* Output it as-is */
                  {
                        linewidth += w;
                        *ptr++ = *pwcs;
                  }
            }
            else if (w < 0)               /* Non-ascii control char */
            {
                  if (encoding == PG_UTF8)
                        sprintf((char *) ptr, "\\u%04X", utf2ucs(pwcs));
                  else
                  {
                        /*
                         * This case cannot happen in the current code because only
                         * UTF-8 signals multibyte control characters. But we may need
                         * to support it at some stage
                         */
                        sprintf((char *) ptr, "\\u????");
                  }
                  ptr += 6;
                  linewidth += 6;
            }
            else  /* All other chars */
            {
                  int               i;

                  for (i = 0; i < chlen; i++)
                        *ptr++ = pwcs[i];
                  linewidth += w;
            }
            len -= chlen;
      }
      lines->width = linewidth;
      *ptr++ = '\0';                /* Terminate formatted string */

      if (count <= 0)
            exit(1);    /* Screwup */

      (lines+1)->ptr = NULL;  /* terminate line array */
}

unsigned char *
mbvalidate(unsigned char *pwcs, int encoding)
{
      if (encoding == PG_UTF8)
            mb_utf_validate((unsigned char *) pwcs);
      else
      {
            /*
             * other encodings needing validation should add their own routines
             * here
             */
      }

      return pwcs;
}

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