src/libs/libgroff/ptable.cpp

   1 /* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
   2      Written by James Clark (jjc@jclark.com)
   3
   4 This file is part of groff.
   5
   6 groff is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 2, or (at your option) any later
   9 version.
  10
  11 groff is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License along
  17 with groff; see the file COPYING.  If not, write to the Free Software
  18 Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
  19
  20 #include "ptable.h"
  21 #include "errarg.h"
  22 #include "error.h"
  23
  24 unsigned long hash_string(const char *s)
  25 {
  26   assert(s != 0);
  27   unsigned long h = 0, g;
  28   while (*s != 0) {
  29     h <<= 4;
  30     h += *s++;
  31     if ((g = h & 0xf0000000) != 0) {
  32       h ^= g >> 24;
  33       h ^= g;
  34     }
  35   }
  36   return h;
  37 }
  38
  39 static const unsigned table_sizes[] = {
  40 101, 503, 1009, 2003, 3001, 4001, 5003, 10007, 20011, 40009,
  41 80021, 160001, 500009, 1000003, 2000003, 4000037, 8000009,
  42 16000057, 32000011, 64000031, 128000003, 0
  43 };
  44
  45 unsigned next_ptable_size(unsigned n)
  46 {
  47   const unsigned *p;
  48   for (p = table_sizes; *p <= n; p++)
  49     if (*p == 0)
  50       fatal("cannot expand table");
  51   return *p;
  52 }