src/include/ptable.h

   1 // -*- C++ -*-
   2 /* Copyright (C) 1989, 1990, 1991, 1992, 2003, 2004
   3    Free Software Foundation, Inc.
   4      Written by James Clark (jjc@jclark.com)
   5
   6 This file is part of groff.
   7
   8 groff is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 2, or (at your option) any later
  11 version.
  12
  13 groff is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License along
  19 with groff; see the file COPYING.  If not, write to the Free Software
  20 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
  21
  22 #include <assert.h>
  23 #include <string.h>
  24
  25 #ifdef TRADITIONAL_CPP
  26 #define name2(a,b) a/**/b
  27 #else /* not TRADITIONAL_CPP */
  28 #define name2(a,b) name2x(a,b)
  29 #define name2x(a,b) a ## b
  30 #endif /* not TRADITIONAL_CPP */
  31
  32 #define PTABLE(T) name2(T,_ptable)
  33 #define PASSOC(T) name2(T,_passoc)
  34 #define PTABLE_ITERATOR(T) name2(T,_ptable_iterator)
  35
  36 extern unsigned next_ptable_size(unsigned);
  37 extern unsigned long hash_string(const char *);
  38
  39 #define declare_ptable(T)                                                     \
  40                                                                               \
  41 struct PASSOC(T) {                                                            \
  42   char *key;                                                                  \
  43   T *val;                                                                     \
  44   PASSOC(T)();                                                                \
  45 };                                                                            \
  46                                                                               \
  47 class PTABLE(T);                                                              \
  48                                                                               \
  49 class PTABLE_ITERATOR(T) {                                                    \
  50   PTABLE(T) *p;                                                               \
  51   unsigned i;                                                                 \
  52 public:                                                                       \
  53   PTABLE_ITERATOR(T)(PTABLE(T) *);                                            \
  54   int next(const char **, T **);                                              \
  55 };                                                                            \
  56                                                                               \
  57 class PTABLE(T) {                                                             \
  58   PASSOC(T) *v;                                                               \
  59   unsigned size;                                                              \
  60   unsigned used;                                                              \
  61   enum { FULL_NUM = 2, FULL_DEN = 3, INITIAL_SIZE = 17 };                     \
  62 public:                                                                       \
  63   PTABLE(T)();                                                                \
  64   ~PTABLE(T)();                                                               \
  65   void define(const char *, T *);                                             \
  66   T *lookup(const char *);                                                    \
  67   friend class PTABLE_ITERATOR(T);                                            \
  68 };
  69
  70
  71 // Keys (which are strings) are allocated and freed by PTABLE.
  72 // Values must be allocated by the caller (always using new[], not new)
  73 // and are freed by PTABLE.
  74
  75 #define implement_ptable(T)                                                   \
  76                                                                               \
  77 PASSOC(T)::PASSOC(T)()                                                        \
  78 : key(0), val(0)                                                              \
  79 {                                                                             \
  80 }                                                                             \
  81                                                                               \
  82 PTABLE(T)::PTABLE(T)()                                                        \
  83 {                                                                             \
  84   v = new PASSOC(T)[size = INITIAL_SIZE];                                     \
  85   used = 0;                                                                   \
  86 }                                                                             \
  87                                                                               \
  88 PTABLE(T)::~PTABLE(T)()                                                       \
  89 {                                                                             \
  90   for (unsigned i = 0; i < size; i++) {                                       \
  91     a_delete v[i].key;                                                        \
  92     a_delete v[i].val;                                                        \
  93   }                                                                           \
  94   a_delete v;                                                                 \
  95 }                                                                             \
  96                                                                               \
  97 void PTABLE(T)::define(const char *key, T *val)                               \
  98 {                                                                             \
  99   assert(key != 0);                                                           \
 100   unsigned long h = hash_string(key);                                         \
 101   unsigned n;                                                                 \
 102   for (n = unsigned(h % size);                                                \
 103        v[n].key != 0;                                                         \
 104        n = (n == 0 ? size - 1 : n - 1))                                       \
 105     if (strcmp(v[n].key, key) == 0) {                                         \
 106       a_delete v[n].val;                                                      \
 107       v[n].val = val;                                                         \
 108       return;                                                                 \
 109     }                                                                         \
 110   if (val == 0)                                                               \
 111     return;                                                                   \
 112   if (used*FULL_DEN >= size*FULL_NUM) {                                       \
 113     PASSOC(T) *oldv = v;                                                      \
 114     unsigned old_size = size;                                                 \
 115     size = next_ptable_size(size);                                            \
 116     v = new PASSOC(T)[size];                                                  \
 117     for (unsigned i = 0; i < old_size; i++)                                   \
 118       if (oldv[i].key != 0) {                                                 \
 119         if (oldv[i].val == 0)                                                 \
 120           a_delete oldv[i].key;                                               \
 121         else {                                                                \
 122           unsigned j;                                                         \
 123           for (j = unsigned(hash_string(oldv[i].key) % size);                 \
 124                v[j].key != 0;                                                 \
 125                j = (j == 0 ? size - 1 : j - 1))                               \
 126                  ;                                                            \
 127           v[j].key = oldv[i].key;                                             \
 128           v[j].val = oldv[i].val;                                             \
 129         }                                                                     \
 130       }                                                                       \
 131     for (n = unsigned(h % size);                                              \
 132          v[n].key != 0;                                                       \
 133          n = (n == 0 ? size - 1 : n - 1))                                     \
 134       ;                                                                       \
 135     a_delete oldv;                                                            \
 136   }                                                                           \
 137   char *temp = new char[strlen(key)+1];                                       \
 138   strcpy(temp, key);                                                          \
 139   v[n].key = temp;                                                            \
 140   v[n].val = val;                                                             \
 141   used++;                                                                     \
 142 }                                                                             \
 143                                                                               \
 144 T *PTABLE(T)::lookup(const char *key)                                         \
 145 {                                                                             \
 146   assert(key != 0);                                                           \
 147   for (unsigned n = unsigned(hash_string(key) % size);                        \
 148        v[n].key != 0;                                                         \
 149        n = (n == 0 ? size - 1 : n - 1))                                       \
 150     if (strcmp(v[n].key, key) == 0)                                           \
 151       return v[n].val;                                                        \
 152   return 0;                                                                   \
 153 }                                                                             \
 154                                                                               \
 155 PTABLE_ITERATOR(T)::PTABLE_ITERATOR(T)(PTABLE(T) *t)                          \
 156 : p(t), i(0)                                                                  \
 157 {                                                                             \
 158 }                                                                             \
 159                                                                               \
 160 int PTABLE_ITERATOR(T)::next(const char **keyp, T **valp)                     \
 161 {                                                                             \
 162   unsigned size = p->size;                                                    \
 163   PASSOC(T) *v = p->v;                                                        \
 164   for (; i < size; i++)                                                       \
 165     if (v[i].key != 0) {                                                      \
 166       *keyp = v[i].key;                                                       \
 167       *valp = v[i].val;                                                       \
 168       i++;                                                                    \
 169       return 1;                                                               \
 170     }                                                                         \
 171   return 0;                                                                   \
 172 }