First Commit

For Azeroth!

dep/mysqllite/strings/int2str.c

@@ -0,0 +1,164 @@
+/* Copyright (C) 2000 MySQL AB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include <my_global.h>
+#include "m_string.h"
+
+/*
+  _dig_vec arrays are public because they are used in several outer places.
+*/
+char _dig_vec_upper[] =
+  "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+char _dig_vec_lower[] =
+  "0123456789abcdefghijklmnopqrstuvwxyz";
+
+
+/*
+  Convert integer to its string representation in given scale of notation.
+   
+  SYNOPSIS
+    int2str()
+      val     - value to convert
+      dst     - points to buffer where string representation should be stored
+      radix   - radix of scale of notation
+      upcase  - set to 1 if we should use upper-case digits
+
+  DESCRIPTION
+    Converts the (long) integer value to its character form and moves it to 
+    the destination buffer followed by a terminating NUL. 
+    If radix is -2..-36, val is taken to be SIGNED, if radix is  2..36, val is
+    taken to be UNSIGNED. That is, val is signed if and only if radix is. 
+    All other radixes treated as bad and nothing will be changed in this case.
+
+    For conversion to decimal representation (radix is -10 or 10) one can use
+    optimized int10_to_str() function.
+
+  RETURN VALUE
+    Pointer to ending NUL character or NullS if radix is bad.
+*/
+  
+char *
+int2str(register long int val, register char *dst, register int radix, 
+        int upcase)
+{
+  char buffer[65];
+  register char *p;
+  long int new_val;
+  char *dig_vec= upcase ? _dig_vec_upper : _dig_vec_lower;
+  ulong uval= (ulong) val;
+
+  if (radix < 0)
+  {
+    if (radix < -36 || radix > -2)
+      return NullS;
+    if (val < 0)
+    {
+      *dst++ = '-';
+      /* Avoid integer overflow in (-val) for LONGLONG_MIN (BUG#31799). */
+      uval = (ulong)0 - uval;
+    }
+    radix = -radix;
+  }
+  else if (radix > 36 || radix < 2)
+    return NullS;
+
+  /*
+    The slightly contorted code which follows is due to the fact that
+    few machines directly support unsigned long / and %.  Certainly
+    the VAX C compiler generates a subroutine call.  In the interests
+    of efficiency (hollow laugh) I let this happen for the first digit
+    only; after that "val" will be in range so that signed integer
+    division will do.  Sorry 'bout that.  CHECK THE CODE PRODUCED BY
+    YOUR C COMPILER.  The first % and / should be unsigned, the second
+    % and / signed, but C compilers tend to be extraordinarily
+    sensitive to minor details of style.  This works on a VAX, that's
+    all I claim for it.
+  */
+  p = &buffer[sizeof(buffer)-1];
+  *p = '\0';
+  new_val= uval / (ulong) radix;
+  *--p = dig_vec[(uchar) (uval- (ulong) new_val*(ulong) radix)];
+  val = new_val;
+#ifdef HAVE_LDIV
+  while (val != 0)
+  {
+    ldiv_t res;
+    res=ldiv(val,radix);
+    *--p = dig_vec[res.rem];
+    val= res.quot;
+  }
+#else
+  while (val != 0)
+  {
+    new_val=val/radix;
+    *--p = dig_vec[(uchar) (val-new_val*radix)];
+    val= new_val;
+  }
+#endif
+  while ((*dst++ = *p++) != 0) ;
+  return dst-1;
+}
+
+
+/*
+  Converts integer to its string representation in decimal notation.
+   
+  SYNOPSIS
+    int10_to_str()
+      val     - value to convert
+      dst     - points to buffer where string representation should be stored
+      radix   - flag that shows whenever val should be taken as signed or not
+
+  DESCRIPTION
+    This is version of int2str() function which is optimized for normal case
+    of radix 10/-10. It takes only sign of radix parameter into account and 
+    not its absolute value.
+
+  RETURN VALUE
+    Pointer to ending NUL character.
+*/
+
+char *int10_to_str(long int val,char *dst,int radix)
+{
+  char buffer[65];
+  register char *p;
+  long int new_val;
+  unsigned long int uval = (unsigned long int) val;
+
+  if (radix < 0)				/* -10 */
+  {
+    if (val < 0)
+    {
+      *dst++ = '-';
+      /* Avoid integer overflow in (-val) for LONGLONG_MIN (BUG#31799). */
+      uval = (unsigned long int)0 - uval;
+    }
+  }
+
+  p = &buffer[sizeof(buffer)-1];
+  *p = '\0';
+  new_val= (long) (uval / 10);
+  *--p = '0'+ (char) (uval - (unsigned long) new_val * 10);
+  val = new_val;
+
+  while (val != 0)
+  {
+    new_val=val/10;
+    *--p = '0' + (char) (val-new_val*10);
+    val= new_val;
+  }
+  while ((*dst++ = *p++) != 0) ;
+  return dst-1;
+}