1 /*  Part of XPCE --- The SWI-Prolog GUI toolkit
2 
3     Author:        Jan Wielemaker and Anjo Anjewierden
4     E-mail:        wielemak@science.uva.nl
5     WWW:           http://www.swi-prolog.org/projects/xpce/
6     Copyright (c)  2011-2016, University of Amsterdam
7     All rights reserved.
8 
9     Redistribution and use in source and binary forms, with or without
10     modification, are permitted provided that the following conditions
11     are met:
12 
13     1. Redistributions of source code must retain the above copyright
14        notice, this list of conditions and the following disclaimer.
15 
16     2. Redistributions in binary form must reproduce the above copyright
17        notice, this list of conditions and the following disclaimer in
18        the documentation and/or other materials provided with the
19        distribution.
20 
21     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24     FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25     COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27     BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
29     CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30     LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
31     ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32     POSSIBILITY OF SUCH DAMAGE.
33 */
34 
35 typedef struct asymbol *ASymbol;
36 typedef struct table   *Table;
37 
38 struct asymbol
39 { atom_t	atom;
40   PceName	name;
41   ASymbol	next;
42 };
43 
44 struct table
45 { ASymbol      *symbols;
46   int		allocated;
47   int	        size;
48   int		mask;
49 };
50 
51 static struct table atom_to_name;
52 static struct table name_to_atom;
53 
54 #define AtomKey(t, a) (int)(((a)>>5) & (t)->mask)
55 #define NameKey(t, a) (int)(((uintptr_t)(a)>>2) & (t)->mask)
56 
57 static void
rehashTable(Table t,int aton)58 rehashTable(Table t, int aton)
59 { ASymbol *old   = t->symbols;
60   int oldentries = t->allocated;
61   int n;
62 
63   t->allocated *= 2;
64   t->mask = t->allocated - 1;
65   t->symbols    = malloc(t->allocated * sizeof(ASymbol));
66   memset(t->symbols, 0, t->allocated * sizeof(ASymbol));
67 
68   for(n=0; n<oldentries; n++)
69   { ASymbol s = old[n];
70     ASymbol n;
71 
72     for( ; s; s = n )
73     { int k;
74 
75       n = s->next;
76 
77       if ( aton )
78 	k = AtomKey(t, s->atom);
79       else
80 	k = NameKey(t, s->name);
81 
82       s->next = t->symbols[k];
83       t->symbols[k] = s;
84     }
85   }
86 
87   free(old);
88 }
89 
90 static PceName
atomToName(atom_t a)91 atomToName(atom_t a)
92 { int k = AtomKey(&atom_to_name, a);
93   ASymbol s = atom_to_name.symbols[k];
94   PceName name;
95   size_t len;
96   const char *textA;
97   const wchar_t *textW;
98 
99   for( ; s; s = s->next )
100   { if ( s->atom == a )
101       return s->name;
102   }
103 
104   PL_register_atom(a);
105   if ( (textA = PL_atom_nchars(a, &len)) )
106   { name = cToPceName_nA(textA, len);
107   } else if ( (textW = PL_atom_wchars(a, &len)) )
108   { name = cToPceName_nW(textW, len);
109   } else
110   { assert(0);
111     return NULL;
112   }
113 
114   s = pceAlloc(sizeof(struct asymbol));
115   s->atom = a;
116   s->name = name;
117   s->next = atom_to_name.symbols[k];
118   atom_to_name.symbols[k] = s;
119   if ( ++atom_to_name.size > 2*atom_to_name.allocated )
120     rehashTable(&atom_to_name, TRUE);
121 
122   return name;
123 }
124 
125 
126 static atom_t
CachedNameToAtom(PceName name)127 CachedNameToAtom(PceName name)
128 { int k = NameKey(&name_to_atom, name);
129   ASymbol s = name_to_atom.symbols[k];
130   atom_t a;
131   size_t len;
132   const char *textA;
133   const wchar_t *textW;
134 
135   for( ; s; s = s->next )
136   { if ( s->name == name )
137       return s->atom;
138   }
139 
140   if ( (textA = pceCharArrayToCA(name, &len)) )
141   { a = PL_new_atom_nchars(len, textA);
142   } else if ( (textW = pceCharArrayToCW(name, &len)) )
143   { a = PL_new_atom_wchars(len, textW);
144   } else
145   { assert(0);
146     return 0;
147   }
148 
149   s = pceAlloc(sizeof(struct asymbol));
150   s->atom = a;
151   s->name = name;
152   s->next = name_to_atom.symbols[k];
153   name_to_atom.symbols[k] = s;
154   if ( ++name_to_atom.size > 2*name_to_atom.allocated )
155     rehashTable(&name_to_atom, FALSE);
156 
157   return a;
158 }
159 
160 
161 static void
initTable(Table t)162 initTable(Table t)
163 { t->allocated = 1024;
164   t->size      = 0;
165   t->mask      = t->allocated-1;
166   t->symbols   = malloc(t->allocated * sizeof(ASymbol));
167   memset(t->symbols, 0, t->allocated * sizeof(ASymbol));
168 }
169 
170 
171 static void
initNameAtomTable()172 initNameAtomTable()
173 { initTable(&atom_to_name);
174   initTable(&name_to_atom);
175 }
176