gfx/harfbuzz/src/hb-number.cc

   1 /*
   2  * Copyright © 2019  Ebrahim Byagowi
   3  *
   4  *  This is part of HarfBuzz, a text shaping library.
   5  *
   6  * Permission is hereby granted, without written agreement and without
   7  * license or royalty fees, to use, copy, modify, and distribute this
   8  * software and its documentation for any purpose, provided that the
   9  * above copyright notice and the following two paragraphs appear in
  10  * all copies of this software.
  11  *
  12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  16  * DAMAGE.
  17  *
  18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  23  *
  24  */
  25
  26 #include "hb.hh"
  27 #include "hb-number.hh"
  28 #include "hb-number-parser.hh"
  29
  30 template<typename T, typename Func>
  31 static bool
  32 _parse_number (const char **pp, const char *end, T *pv,
  33                bool whole_buffer, Func f)
  34 {
  35   char buf[32];
  36   unsigned len = hb_min (ARRAY_LENGTH (buf) - 1, (unsigned) (end - *pp));
  37   strncpy (buf, *pp, len);
  38   buf[len] = '\0';
  39
  40   char *p = buf;
  41   char *pend = p;
  42
  43   errno = 0;
  44   *pv = f (p, &pend);
  45   if (unlikely (errno || p == pend ||
  46                 /* Check if consumed whole buffer if is requested */
  47                 (whole_buffer && pend - p != end - *pp)))
  48     return false;
  49
  50   *pp += pend - p;
  51   return true;
  52 }
  53
  54 bool
  55 hb_parse_int (const char **pp, const char *end, int *pv, bool whole_buffer)
  56 {
  57   return _parse_number<int> (pp, end, pv, whole_buffer,
  58                              [] (const char *p, char **end)
  59                              { return strtol (p, end, 10); });
  60 }
  61
  62 bool
  63 hb_parse_uint (const char **pp, const char *end, unsigned *pv,
  64                bool whole_buffer, int base)
  65 {
  66   return _parse_number<unsigned> (pp, end, pv, whole_buffer,
  67                                   [base] (const char *p, char **end)
  68                                   { return strtoul (p, end, base); });
  69 }
  70
  71 bool
  72 hb_parse_double (const char **pp, const char *end, double *pv, bool whole_buffer)
  73 {
  74   const char *pend = end;
  75   *pv = strtod_rl (*pp, &pend);
  76   if (unlikely (*pp == pend)) return false;
  77   *pp = pend;
  78   return !whole_buffer || end == pend;
  79 }