lib/ptable.h

   1 // -*- C++ -*-
   2 /* Copyright (C) 1989, 1990, 1991 Free Software Foundation, Inc.
   3      Written by James Clark (jjc@jclark.uucp)
   4
   5 This file is part of groff.
   6
   7 groff is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 1, or (at your option) any later
  10 version.
  11
  12 groff is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License along
  18 with groff; see the file LICENSE.  If not, write to the Free Software
  19 Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
  20
  21 #include <assert.h>
  22 #include <generic.h>
  23 #include <string.h>
  24
  25 #ifdef __BORLANDC__
  26 #ifndef name2
  27 #define name2 _Paste2
  28 #endif
  29 #endif
  30
  31 #define PTABLE(T) name2(T,_ptable)
  32 #define PASSOC(T) name2(T,_passoc)
  33 #define PTABLE_ITERATOR(T) name2(T,_ptable_iterator)
  34
  35 extern unsigned next_ptable_size(unsigned);
  36 extern unsigned long hash_string(const char *);
  37
  38 #define declare_ptable(T)                                                     \
  39                                                                               \
  40 struct PASSOC(T) {                                                            \
  41   char *key;                                                                  \
  42   T *val;                                                                     \
  43   PASSOC(T)();                                                                \
  44 };                                                                            \
  45                                                                               \
  46 struct PTABLE(T);                                                             \
  47                                                                               \
  48 class PTABLE_ITERATOR(T) {                                                    \
  49   PTABLE(T) *p;                                                               \
  50   unsigned i;                                                                 \
  51 public:                                                                       \
  52   PTABLE_ITERATOR(T)(PTABLE(T) *);                                            \
  53   int next(const char **, T **);                                              \
  54 };                                                                            \
  55                                                                               \
  56 class PTABLE(T) {                                                             \
  57   PASSOC(T) *v;                                                               \
  58   unsigned size;                                                              \
  59   unsigned used;                                                              \
  60   enum { FULL_NUM = 2, FULL_DEN = 3, INITIAL_SIZE = 17 };                     \
  61 public:                                                                       \
  62   PTABLE(T)();                                                                \
  63   ~PTABLE(T)();                                                               \
  64   void define(const char *, T *);                                             \
  65   T *lookup(const char *);                                                    \
  66   friend class PTABLE_ITERATOR(T);                                            \
  67 };
  68
  69
  70 #define implement_ptable(T)                                                   \
  71                                                                               \
  72 PASSOC(T)::PASSOC(T)()                                                        \
  73 : key(0), val(0)                                                              \
  74 {                                                                             \
  75 }                                                                             \
  76                                                                               \
  77 PTABLE(T)::PTABLE(T)()                                                        \
  78 {                                                                             \
  79   v = new PASSOC(T)[size = INITIAL_SIZE];                                     \
  80   used = 0;                                                                   \
  81 }                                                                             \
  82                                                                               \
  83 PTABLE(T)::~PTABLE(T)()                                                       \
  84 {                                                                             \
  85   for (unsigned i = 0; i < size; i++) {                                       \
  86     a_delete v[i].key;                                                        \
  87     delete v[i].val;                                                          \
  88   }                                                                           \
  89 }                                                                             \
  90                                                                               \
  91 void PTABLE(T)::define(const char *key, T *val)                               \
  92 {                                                                             \
  93   assert(key != 0);                                                           \
  94   unsigned long h = hash_string(key);                                         \
  95   for (unsigned n = unsigned(h % size);                                       \
  96        v[n].key != 0;                                                         \
  97        n = (n == 0 ? size - 1 : n - 1))                                       \
  98     if (strcmp(v[n].key, key) == 0) {                                         \
  99       delete v[n].val;                                                        \
 100       v[n].val = val;                                                         \
 101       return;                                                                 \
 102     }                                                                         \
 103   if (val == 0)                                                               \
 104     return;                                                                   \
 105   if (used*FULL_DEN >= size*FULL_NUM) {                                       \
 106     PASSOC(T) *oldv = v;                                                      \
 107     unsigned old_size = size;                                                 \
 108     size = next_ptable_size(size);                                            \
 109     v = new PASSOC(T)[size];                                                  \
 110     for (unsigned i = 0; i < old_size; i++)                                   \
 111       if (oldv[i].key != 0) {                                                 \
 112         if (oldv[i].val == 0)                                                 \
 113           a_delete oldv[i].key;                                               \
 114         else {                                                                \
 115           for (unsigned j = unsigned(hash_string(oldv[i].key) % size);        \
 116                v[j].key != 0;                                                 \
 117                j = (j == 0 ? size - 1 : j - 1))                               \
 118                  ;                                                            \
 119           v[j].key = oldv[i].key;                                             \
 120           v[j].val = oldv[i].val;                                             \
 121         }                                                                     \
 122       }                                                                       \
 123     for (n = unsigned(h % size);                                              \
 124          v[n].key != 0;                                                       \
 125          n = (n == 0 ? size - 1 : n - 1))                                     \
 126       ;                                                                       \
 127     a_delete oldv;                                                            \
 128   }                                                                           \
 129   char *temp = new char[strlen(key)+1];                                       \
 130   strcpy(temp, key);                                                          \
 131   v[n].key = temp;                                                            \
 132   v[n].val = val;                                                             \
 133   used++;                                                                     \
 134 }                                                                             \
 135                                                                               \
 136 T *PTABLE(T)::lookup(const char *key)                                         \
 137 {                                                                             \
 138   assert(key != 0);                                                           \
 139   for (unsigned n = unsigned(hash_string(key) % size);                        \
 140        v[n].key != 0;                                                         \
 141        n = (n == 0 ? size - 1 : n - 1))                                       \
 142     if (strcmp(v[n].key, key) == 0)                                           \
 143       return v[n].val;                                                        \
 144   return 0;                                                                   \
 145 }                                                                             \
 146                                                                               \
 147 PTABLE_ITERATOR(T)::PTABLE_ITERATOR(T)(PTABLE(T) *t)                          \
 148 : p(t), i(0)                                                                  \
 149 {                                                                             \
 150 }                                                                             \
 151                                                                               \
 152 int PTABLE_ITERATOR(T)::next(const char **keyp, T **valp)                     \
 153 {                                                                             \
 154   unsigned size = p->size;                                                    \
 155   PASSOC(T) *v = p->v;                                                        \
 156   for (; i < size; i++)                                                       \
 157     if (v[i].key != 0) {                                                      \
 158       *keyp = v[i].key;                                                       \
 159       *valp = v[i].val;                                                       \
 160       i++;                                                                    \
 161       return 1;                                                               \
 162     }                                                                         \
 163   return 0;                                                                   \
 164 }
 165