428
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1 /* Implementation of the hash table lisp object type.
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2 Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc.
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800
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3 Copyright (C) 1995, 1996, 2002 Ben Wing.
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428
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4 Copyright (C) 1997 Free Software Foundation, Inc.
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5
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6 This file is part of XEmacs.
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7
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8 XEmacs is free software; you can redistribute it and/or modify it
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9 under the terms of the GNU General Public License as published by the
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10 Free Software Foundation; either version 2, or (at your option) any
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11 later version.
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12
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13 XEmacs is distributed in the hope that it will be useful, but WITHOUT
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14 ANY WARRANTY; without even the implied warranty of MERCNTABILITY or
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15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
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16 for more details.
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17
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18 You should have received a copy of the GNU General Public License
|
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19 along with XEmacs; see the file COPYING. If not, write to
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20 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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21 Boston, MA 02111-1307, USA. */
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22
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23 /* Synched up with: Not in FSF. */
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24
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1292
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25 /* Author: Lost in the mists of history. At least back to Lucid 19.3,
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26 circa Sep 1992. Early hash table implementation allowed only `eq' as a
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27 test -- other tests possible only when these objects were created from
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28 the C code.
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29
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30 Expansion to allow general `equal'-test Lisp-creatable tables, and hash
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31 methods for the various Lisp objects in existence at the time, added
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32 during 19.12 I think (early 1995?), by Ben Wing.
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33
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34 Weak hash tables added by Jamie (maybe?) early on, perhaps around 19.6,
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35 maybe earlier; again, only possible through the C code, and only
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36 supported fully weak hash tables. Expansion to other kinds of weakness,
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37 and exporting of the interface to Lisp, by Ben Wing during 19.12
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38 (early-mid 1995) or maybe 19.13 cycle (mid 1995).
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39
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40 Expansion to full Common Lisp spec and interface, redoing of the
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41 implementation, by Martin Buchholz, 1997? (Former hash table
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42 implementation used "double hashing", I'm pretty sure, and was weirdly
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43 tied into the generic hash.c code. Martin completely separated them.)
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44 */
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45
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489
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46 /* This file implements the hash table lisp object type.
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47
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504
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48 This implementation was mostly written by Martin Buchholz in 1997.
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49
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50 The Lisp-level API (derived from Common Lisp) is almost completely
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51 compatible with GNU Emacs 21, even though the implementations are
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52 totally independent.
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53
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489
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54 The hash table technique used is "linear probing". Collisions are
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55 resolved by putting the item in the next empty place in the array
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56 following the collision. Finding a hash entry performs a linear
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57 search in the cluster starting at the hash value.
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58
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59 On deletions from the hash table, the entries immediately following
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60 the deleted entry are re-entered in the hash table. We do not have
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61 a special way to mark deleted entries (known as "tombstones").
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62
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63 At the end of the hash entries ("hentries"), we leave room for an
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64 entry that is always empty (the "sentinel").
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65
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66 The traditional literature on hash table implementation
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67 (e.g. Knuth) suggests that too much "primary clustering" occurs
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68 with linear probing. However, this literature was written when
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69 locality of reference was not a factor. The discrepancy between
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70 CPU speeds and memory speeds is increasing, and the speed of access
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71 to memory is highly dependent on memory caches which work best when
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72 there is high locality of data reference. Random access to memory
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73 is up to 20 times as expensive as access to the nearest address
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74 (and getting worse). So linear probing makes sense.
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75
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76 But the representation doesn't actually matter that much with the
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77 current elisp engine. Funcall is sufficiently slow that the choice
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78 of hash table implementation is noise. */
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79
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428
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80 #include <config.h>
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81 #include "lisp.h"
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82 #include "bytecode.h"
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83 #include "elhash.h"
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489
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84 #include "opaque.h"
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428
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85
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86 Lisp_Object Qhash_tablep;
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87 static Lisp_Object Qhashtable, Qhash_table;
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442
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88 static Lisp_Object Qweakness, Qvalue, Qkey_or_value, Qkey_and_value;
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428
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89 static Lisp_Object Vall_weak_hash_tables;
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90 static Lisp_Object Qrehash_size, Qrehash_threshold;
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91 static Lisp_Object Q_size, Q_test, Q_weakness, Q_rehash_size, Q_rehash_threshold;
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92
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93 /* obsolete as of 19990901 in xemacs-21.2 */
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442
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94 static Lisp_Object Qweak, Qkey_weak, Qvalue_weak, Qkey_or_value_weak;
|
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95 static Lisp_Object Qnon_weak, Q_type;
|
428
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96
|
1204
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97 typedef struct htentry
|
428
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98 {
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99 Lisp_Object key;
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100 Lisp_Object value;
|
1204
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101 } htentry;
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428
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102
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103 struct Lisp_Hash_Table
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104 {
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105 struct lcrecord_header header;
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665
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106 Elemcount size;
|
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107 Elemcount count;
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108 Elemcount rehash_count;
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428
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109 double rehash_size;
|
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110 double rehash_threshold;
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665
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111 Elemcount golden_ratio;
|
428
|
112 hash_table_hash_function_t hash_function;
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113 hash_table_test_function_t test_function;
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1204
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114 htentry *hentries;
|
428
|
115 enum hash_table_weakness weakness;
|
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116 Lisp_Object next_weak; /* Used to chain together all of the weak
|
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117 hash tables. Don't mark through this. */
|
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118 };
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119
|
1204
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120 #define HTENTRY_CLEAR_P(htentry) ((*(EMACS_UINT*)(&((htentry)->key))) == 0)
|
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121 #define CLEAR_HTENTRY(htentry) \
|
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122 ((*(EMACS_UINT*)(&((htentry)->key))) = 0, \
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123 (*(EMACS_UINT*)(&((htentry)->value))) = 0)
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428
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124
|
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125 #define HASH_TABLE_DEFAULT_SIZE 16
|
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126 #define HASH_TABLE_DEFAULT_REHASH_SIZE 1.3
|
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127 #define HASH_TABLE_MIN_SIZE 10
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128
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665
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129 #define HASHCODE(key, ht) \
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444
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130 ((((ht)->hash_function ? (ht)->hash_function (key) : LISP_HASH (key)) \
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131 * (ht)->golden_ratio) \
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132 % (ht)->size)
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428
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133
|
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134 #define KEYS_EQUAL_P(key1, key2, testfun) \
|
434
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135 (EQ (key1, key2) || ((testfun) && (testfun) (key1, key2)))
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428
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136
|
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137 #define LINEAR_PROBING_LOOP(probe, entries, size) \
|
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138 for (; \
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1204
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139 !HTENTRY_CLEAR_P (probe) || \
|
428
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140 (probe == entries + size ? \
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1204
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141 (probe = entries, !HTENTRY_CLEAR_P (probe)) : 0); \
|
428
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142 probe++)
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143
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800
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144 #ifdef ERROR_CHECK_STRUCTURES
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428
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145 static void
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146 check_hash_table_invariants (Lisp_Hash_Table *ht)
|
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147 {
|
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148 assert (ht->count < ht->size);
|
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149 assert (ht->count <= ht->rehash_count);
|
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150 assert (ht->rehash_count < ht->size);
|
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151 assert ((double) ht->count * ht->rehash_threshold - 1 <= (double) ht->rehash_count);
|
1204
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152 assert (HTENTRY_CLEAR_P (ht->hentries + ht->size));
|
428
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153 }
|
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154 #else
|
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155 #define check_hash_table_invariants(ht)
|
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156 #endif
|
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157
|
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158 /* Return a suitable size for a hash table, with at least SIZE slots. */
|
665
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159 static Elemcount
|
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160 hash_table_size (Elemcount requested_size)
|
428
|
161 {
|
|
162 /* Return some prime near, but greater than or equal to, SIZE.
|
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163 Decades from the time of writing, someone will have a system large
|
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164 enough that the list below will be too short... */
|
665
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165 static const Elemcount primes [] =
|
428
|
166 {
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167 19, 29, 41, 59, 79, 107, 149, 197, 263, 347, 457, 599, 787, 1031,
|
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168 1361, 1777, 2333, 3037, 3967, 5167, 6719, 8737, 11369, 14783,
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169 19219, 24989, 32491, 42257, 54941, 71429, 92861, 120721, 156941,
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170 204047, 265271, 344857, 448321, 582821, 757693, 985003, 1280519,
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171 1664681, 2164111, 2813353, 3657361, 4754591, 6180989, 8035301,
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172 10445899, 13579681, 17653589, 22949669, 29834603, 38784989,
|
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173 50420551, 65546729, 85210757, 110774011, 144006217, 187208107,
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174 243370577, 316381771, 411296309, 534685237, 695090819, 903618083,
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647
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175 1174703521, 1527114613, 1985248999 /* , 2580823717UL, 3355070839UL */
|
428
|
176 };
|
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177 /* We've heard of binary search. */
|
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178 int low, high;
|
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179 for (low = 0, high = countof (primes) - 1; high - low > 1;)
|
|
180 {
|
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181 /* Loop Invariant: size < primes [high] */
|
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182 int mid = (low + high) / 2;
|
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183 if (primes [mid] < requested_size)
|
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184 low = mid;
|
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185 else
|
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186 high = mid;
|
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187 }
|
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188 return primes [high];
|
|
189 }
|
|
190
|
|
191
|
|
192 #if 0 /* I don't think these are needed any more.
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193 If using the general lisp_object_equal_*() functions
|
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194 causes efficiency problems, these can be resurrected. --ben */
|
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195 /* equality and hash functions for Lisp strings */
|
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196 int
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197 lisp_string_equal (Lisp_Object str1, Lisp_Object str2)
|
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198 {
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199 /* This is wrong anyway. You can't use strcmp() on Lisp strings,
|
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200 because they can contain zero characters. */
|
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201 return !strcmp ((char *) XSTRING_DATA (str1), (char *) XSTRING_DATA (str2));
|
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202 }
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203
|
665
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204 static Hashcode
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428
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205 lisp_string_hash (Lisp_Object obj)
|
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206 {
|
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207 return hash_string (XSTRING_DATA (str), XSTRING_LENGTH (str));
|
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208 }
|
|
209
|
|
210 #endif /* 0 */
|
|
211
|
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212 static int
|
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213 lisp_object_eql_equal (Lisp_Object obj1, Lisp_Object obj2)
|
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214 {
|
|
215 return EQ (obj1, obj2) || (FLOATP (obj1) && internal_equal (obj1, obj2, 0));
|
|
216 }
|
|
217
|
665
|
218 static Hashcode
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428
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219 lisp_object_eql_hash (Lisp_Object obj)
|
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220 {
|
|
221 return FLOATP (obj) ? internal_hash (obj, 0) : LISP_HASH (obj);
|
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222 }
|
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223
|
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224 static int
|
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225 lisp_object_equal_equal (Lisp_Object obj1, Lisp_Object obj2)
|
|
226 {
|
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227 return internal_equal (obj1, obj2, 0);
|
|
228 }
|
|
229
|
665
|
230 static Hashcode
|
428
|
231 lisp_object_equal_hash (Lisp_Object obj)
|
|
232 {
|
|
233 return internal_hash (obj, 0);
|
|
234 }
|
|
235
|
|
236
|
|
237 static Lisp_Object
|
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238 mark_hash_table (Lisp_Object obj)
|
|
239 {
|
|
240 Lisp_Hash_Table *ht = XHASH_TABLE (obj);
|
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241
|
|
242 /* If the hash table is weak, we don't want to mark the keys and
|
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243 values (we scan over them after everything else has been marked,
|
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244 and mark or remove them as necessary). */
|
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245 if (ht->weakness == HASH_TABLE_NON_WEAK)
|
|
246 {
|
1204
|
247 htentry *e, *sentinel;
|
428
|
248
|
|
249 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
|
1204
|
250 if (!HTENTRY_CLEAR_P (e))
|
428
|
251 {
|
|
252 mark_object (e->key);
|
|
253 mark_object (e->value);
|
|
254 }
|
|
255 }
|
|
256 return Qnil;
|
|
257 }
|
|
258
|
|
259 /* Equality of hash tables. Two hash tables are equal when they are of
|
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260 the same weakness and test function, they have the same number of
|
|
261 elements, and for each key in the hash table, the values are `equal'.
|
|
262
|
|
263 This is similar to Common Lisp `equalp' of hash tables, with the
|
|
264 difference that CL requires the keys to be compared with the test
|
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265 function, which we don't do. Doing that would require consing, and
|
|
266 consing is a bad idea in `equal'. Anyway, our method should provide
|
|
267 the same result -- if the keys are not equal according to the test
|
|
268 function, then Fgethash() in hash_table_equal_mapper() will fail. */
|
|
269 static int
|
|
270 hash_table_equal (Lisp_Object hash_table1, Lisp_Object hash_table2, int depth)
|
|
271 {
|
|
272 Lisp_Hash_Table *ht1 = XHASH_TABLE (hash_table1);
|
|
273 Lisp_Hash_Table *ht2 = XHASH_TABLE (hash_table2);
|
1204
|
274 htentry *e, *sentinel;
|
428
|
275
|
|
276 if ((ht1->test_function != ht2->test_function) ||
|
|
277 (ht1->weakness != ht2->weakness) ||
|
|
278 (ht1->count != ht2->count))
|
|
279 return 0;
|
|
280
|
|
281 depth++;
|
|
282
|
|
283 for (e = ht1->hentries, sentinel = e + ht1->size; e < sentinel; e++)
|
1204
|
284 if (!HTENTRY_CLEAR_P (e))
|
428
|
285 /* Look up the key in the other hash table, and compare the values. */
|
|
286 {
|
|
287 Lisp_Object value_in_other = Fgethash (e->key, hash_table2, Qunbound);
|
|
288 if (UNBOUNDP (value_in_other) ||
|
|
289 !internal_equal (e->value, value_in_other, depth))
|
|
290 return 0; /* Give up */
|
|
291 }
|
|
292
|
|
293 return 1;
|
|
294 }
|
442
|
295
|
|
296 /* This is not a great hash function, but it _is_ correct and fast.
|
|
297 Examining all entries is too expensive, and examining a random
|
|
298 subset does not yield a correct hash function. */
|
665
|
299 static Hashcode
|
2286
|
300 hash_table_hash (Lisp_Object hash_table, int UNUSED (depth))
|
442
|
301 {
|
|
302 return XHASH_TABLE (hash_table)->count;
|
|
303 }
|
|
304
|
428
|
305
|
|
306 /* Printing hash tables.
|
|
307
|
|
308 This is non-trivial, because we use a readable structure-style
|
|
309 syntax for hash tables. This means that a typical hash table will be
|
|
310 readably printed in the form of:
|
|
311
|
|
312 #s(hash-table size 2 data (key1 value1 key2 value2))
|
|
313
|
|
314 The supported hash table structure keywords and their values are:
|
|
315 `test' (eql (or nil), eq or equal)
|
|
316 `size' (a natnum or nil)
|
|
317 `rehash-size' (a float)
|
|
318 `rehash-threshold' (a float)
|
442
|
319 `weakness' (nil, key, value, key-and-value, or key-or-value)
|
428
|
320 `data' (a list)
|
|
321
|
430
|
322 If `print-readably' is nil, then a simpler syntax is used, for example
|
428
|
323
|
|
324 #<hash-table size 2/13 data (key1 value1 key2 value2) 0x874d>
|
|
325
|
|
326 The data is truncated to four pairs, and the rest is shown with
|
|
327 `...'. This printer does not cons. */
|
|
328
|
|
329
|
|
330 /* Print the data of the hash table. This maps through a Lisp
|
|
331 hash table and prints key/value pairs using PRINTCHARFUN. */
|
|
332 static void
|
|
333 print_hash_table_data (Lisp_Hash_Table *ht, Lisp_Object printcharfun)
|
|
334 {
|
|
335 int count = 0;
|
1204
|
336 htentry *e, *sentinel;
|
428
|
337
|
826
|
338 write_c_string (printcharfun, " data (");
|
428
|
339
|
|
340 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
|
1204
|
341 if (!HTENTRY_CLEAR_P (e))
|
428
|
342 {
|
|
343 if (count > 0)
|
826
|
344 write_c_string (printcharfun, " ");
|
428
|
345 if (!print_readably && count > 3)
|
|
346 {
|
826
|
347 write_c_string (printcharfun, "...");
|
428
|
348 break;
|
|
349 }
|
|
350 print_internal (e->key, printcharfun, 1);
|
800
|
351 write_fmt_string_lisp (printcharfun, " %S", 1, e->value);
|
428
|
352 count++;
|
|
353 }
|
|
354
|
826
|
355 write_c_string (printcharfun, ")");
|
428
|
356 }
|
|
357
|
|
358 static void
|
2286
|
359 print_hash_table (Lisp_Object obj, Lisp_Object printcharfun,
|
|
360 int UNUSED (escapeflag))
|
428
|
361 {
|
|
362 Lisp_Hash_Table *ht = XHASH_TABLE (obj);
|
|
363
|
826
|
364 write_c_string (printcharfun,
|
|
365 print_readably ? "#s(hash-table" : "#<hash-table");
|
428
|
366
|
|
367 /* These checks have a kludgy look to them, but they are safe.
|
|
368 Due to nature of hashing, you cannot use arbitrary
|
|
369 test functions anyway. */
|
|
370 if (!ht->test_function)
|
826
|
371 write_c_string (printcharfun, " test eq");
|
428
|
372 else if (ht->test_function == lisp_object_equal_equal)
|
826
|
373 write_c_string (printcharfun, " test equal");
|
428
|
374 else if (ht->test_function == lisp_object_eql_equal)
|
|
375 DO_NOTHING;
|
|
376 else
|
|
377 abort ();
|
|
378
|
|
379 if (ht->count || !print_readably)
|
|
380 {
|
|
381 if (print_readably)
|
800
|
382 write_fmt_string (printcharfun, " size %ld", (long) ht->count);
|
428
|
383 else
|
800
|
384 write_fmt_string (printcharfun, " size %ld/%ld", (long) ht->count,
|
|
385 (long) ht->size);
|
428
|
386 }
|
|
387
|
|
388 if (ht->weakness != HASH_TABLE_NON_WEAK)
|
|
389 {
|
800
|
390 write_fmt_string
|
|
391 (printcharfun, " weakness %s",
|
|
392 (ht->weakness == HASH_TABLE_WEAK ? "key-and-value" :
|
|
393 ht->weakness == HASH_TABLE_KEY_WEAK ? "key" :
|
|
394 ht->weakness == HASH_TABLE_VALUE_WEAK ? "value" :
|
|
395 ht->weakness == HASH_TABLE_KEY_VALUE_WEAK ? "key-or-value" :
|
|
396 "you-d-better-not-see-this"));
|
428
|
397 }
|
|
398
|
|
399 if (ht->count)
|
|
400 print_hash_table_data (ht, printcharfun);
|
|
401
|
|
402 if (print_readably)
|
826
|
403 write_c_string (printcharfun, ")");
|
428
|
404 else
|
|
405 {
|
800
|
406 write_fmt_string (printcharfun, " 0x%x>", ht->header.uid);
|
428
|
407 }
|
|
408 }
|
|
409
|
|
410 static void
|
2333
|
411 free_hentries (htentry *hentries,
|
|
412 #ifdef ERROR_CHECK_STRUCTURES
|
|
413 size_t size
|
|
414 #else
|
|
415 size_t UNUSED (size)
|
|
416 #endif
|
|
417 )
|
489
|
418 {
|
800
|
419 #ifdef ERROR_CHECK_STRUCTURES
|
489
|
420 /* Ensure a crash if other code uses the discarded entries afterwards. */
|
1204
|
421 htentry *e, *sentinel;
|
489
|
422
|
|
423 for (e = hentries, sentinel = e + size; e < sentinel; e++)
|
1204
|
424 * (unsigned long *) e = 0xdeadbeef; /* -559038737 base 10 */
|
489
|
425 #endif
|
|
426
|
|
427 if (!DUMPEDP (hentries))
|
1726
|
428 xfree (hentries, htentry *);
|
489
|
429 }
|
|
430
|
|
431 static void
|
428
|
432 finalize_hash_table (void *header, int for_disksave)
|
|
433 {
|
|
434 if (!for_disksave)
|
|
435 {
|
|
436 Lisp_Hash_Table *ht = (Lisp_Hash_Table *) header;
|
489
|
437 free_hentries (ht->hentries, ht->size);
|
428
|
438 ht->hentries = 0;
|
|
439 }
|
|
440 }
|
|
441
|
1204
|
442 static const struct memory_description htentry_description_1[] = {
|
|
443 { XD_LISP_OBJECT, offsetof (htentry, key) },
|
|
444 { XD_LISP_OBJECT, offsetof (htentry, value) },
|
428
|
445 { XD_END }
|
|
446 };
|
|
447
|
1204
|
448 static const struct sized_memory_description htentry_description = {
|
|
449 sizeof (htentry),
|
|
450 htentry_description_1
|
428
|
451 };
|
|
452
|
1204
|
453 static const struct memory_description htentry_union_description_1[] = {
|
|
454 /* Note: XD_INDIRECT in this table refers to the surrounding table,
|
|
455 and so this will work. */
|
|
456 { XD_STRUCT_PTR, HASH_TABLE_NON_WEAK, XD_INDIRECT (0, 1),
|
|
457 &htentry_description },
|
|
458 { XD_STRUCT_PTR, 0, XD_INDIRECT (0, 1), &htentry_description,
|
|
459 XD_FLAG_UNION_DEFAULT_ENTRY | XD_FLAG_NO_KKCC },
|
|
460 { XD_END }
|
|
461 };
|
|
462
|
|
463 static const struct sized_memory_description htentry_union_description = {
|
|
464 sizeof (htentry *),
|
|
465 htentry_union_description_1
|
|
466 };
|
|
467
|
|
468 const struct memory_description hash_table_description[] = {
|
|
469 { XD_ELEMCOUNT, offsetof (Lisp_Hash_Table, size) },
|
|
470 { XD_INT, offsetof (Lisp_Hash_Table, weakness) },
|
|
471 { XD_UNION, offsetof (Lisp_Hash_Table, hentries), XD_INDIRECT (1, 0),
|
|
472 &htentry_union_description },
|
440
|
473 { XD_LO_LINK, offsetof (Lisp_Hash_Table, next_weak) },
|
428
|
474 { XD_END }
|
|
475 };
|
|
476
|
934
|
477 DEFINE_LRECORD_IMPLEMENTATION ("hash-table", hash_table,
|
|
478 1, /*dumpable-flag*/
|
|
479 mark_hash_table, print_hash_table,
|
|
480 finalize_hash_table,
|
|
481 hash_table_equal, hash_table_hash,
|
|
482 hash_table_description,
|
|
483 Lisp_Hash_Table);
|
428
|
484
|
|
485 static Lisp_Hash_Table *
|
|
486 xhash_table (Lisp_Object hash_table)
|
|
487 {
|
1123
|
488 /* #### What's going on here? Why the gc_in_progress check? */
|
428
|
489 if (!gc_in_progress)
|
|
490 CHECK_HASH_TABLE (hash_table);
|
|
491 check_hash_table_invariants (XHASH_TABLE (hash_table));
|
|
492 return XHASH_TABLE (hash_table);
|
|
493 }
|
|
494
|
|
495
|
|
496 /************************************************************************/
|
|
497 /* Creation of Hash Tables */
|
|
498 /************************************************************************/
|
|
499
|
|
500 /* Creation of hash tables, without error-checking. */
|
|
501 static void
|
|
502 compute_hash_table_derived_values (Lisp_Hash_Table *ht)
|
|
503 {
|
665
|
504 ht->rehash_count = (Elemcount)
|
438
|
505 ((double) ht->size * ht->rehash_threshold);
|
665
|
506 ht->golden_ratio = (Elemcount)
|
428
|
507 ((double) ht->size * (.6180339887 / (double) sizeof (Lisp_Object)));
|
|
508 }
|
|
509
|
|
510 Lisp_Object
|
450
|
511 make_standard_lisp_hash_table (enum hash_table_test test,
|
665
|
512 Elemcount size,
|
450
|
513 double rehash_size,
|
|
514 double rehash_threshold,
|
|
515 enum hash_table_weakness weakness)
|
|
516 {
|
462
|
517 hash_table_hash_function_t hash_function = 0;
|
450
|
518 hash_table_test_function_t test_function = 0;
|
|
519
|
|
520 switch (test)
|
|
521 {
|
|
522 case HASH_TABLE_EQ:
|
|
523 test_function = 0;
|
|
524 hash_function = 0;
|
|
525 break;
|
|
526
|
|
527 case HASH_TABLE_EQL:
|
|
528 test_function = lisp_object_eql_equal;
|
|
529 hash_function = lisp_object_eql_hash;
|
|
530 break;
|
|
531
|
|
532 case HASH_TABLE_EQUAL:
|
|
533 test_function = lisp_object_equal_equal;
|
|
534 hash_function = lisp_object_equal_hash;
|
|
535 break;
|
|
536
|
|
537 default:
|
|
538 abort ();
|
|
539 }
|
|
540
|
|
541 return make_general_lisp_hash_table (hash_function, test_function,
|
|
542 size, rehash_size, rehash_threshold,
|
|
543 weakness);
|
|
544 }
|
|
545
|
|
546 Lisp_Object
|
|
547 make_general_lisp_hash_table (hash_table_hash_function_t hash_function,
|
|
548 hash_table_test_function_t test_function,
|
665
|
549 Elemcount size,
|
428
|
550 double rehash_size,
|
|
551 double rehash_threshold,
|
|
552 enum hash_table_weakness weakness)
|
|
553 {
|
|
554 Lisp_Object hash_table;
|
|
555 Lisp_Hash_Table *ht = alloc_lcrecord_type (Lisp_Hash_Table, &lrecord_hash_table);
|
|
556
|
450
|
557 ht->test_function = test_function;
|
|
558 ht->hash_function = hash_function;
|
438
|
559 ht->weakness = weakness;
|
|
560
|
|
561 ht->rehash_size =
|
|
562 rehash_size > 1.0 ? rehash_size : HASH_TABLE_DEFAULT_REHASH_SIZE;
|
|
563
|
|
564 ht->rehash_threshold =
|
|
565 rehash_threshold > 0.0 ? rehash_threshold :
|
|
566 size > 4096 && !ht->test_function ? 0.7 : 0.6;
|
|
567
|
428
|
568 if (size < HASH_TABLE_MIN_SIZE)
|
|
569 size = HASH_TABLE_MIN_SIZE;
|
665
|
570 ht->size = hash_table_size ((Elemcount) (((double) size / ht->rehash_threshold)
|
438
|
571 + 1.0));
|
428
|
572 ht->count = 0;
|
438
|
573
|
428
|
574 compute_hash_table_derived_values (ht);
|
|
575
|
1204
|
576 /* We leave room for one never-occupied sentinel htentry at the end. */
|
|
577 ht->hentries = xnew_array_and_zero (htentry, ht->size + 1);
|
428
|
578
|
793
|
579 hash_table = wrap_hash_table (ht);
|
428
|
580
|
|
581 if (weakness == HASH_TABLE_NON_WEAK)
|
|
582 ht->next_weak = Qunbound;
|
|
583 else
|
|
584 ht->next_weak = Vall_weak_hash_tables, Vall_weak_hash_tables = hash_table;
|
|
585
|
|
586 return hash_table;
|
|
587 }
|
|
588
|
|
589 Lisp_Object
|
665
|
590 make_lisp_hash_table (Elemcount size,
|
428
|
591 enum hash_table_weakness weakness,
|
|
592 enum hash_table_test test)
|
|
593 {
|
450
|
594 return make_standard_lisp_hash_table (test, size, -1.0, -1.0, weakness);
|
428
|
595 }
|
|
596
|
|
597 /* Pretty reading of hash tables.
|
|
598
|
|
599 Here we use the existing structures mechanism (which is,
|
|
600 unfortunately, pretty cumbersome) for validating and instantiating
|
|
601 the hash tables. The idea is that the side-effect of reading a
|
|
602 #s(hash-table PLIST) object is creation of a hash table with desired
|
|
603 properties, and that the hash table is returned. */
|
|
604
|
|
605 /* Validation functions: each keyword provides its own validation
|
|
606 function. The errors should maybe be continuable, but it is
|
|
607 unclear how this would cope with ERRB. */
|
|
608 static int
|
2286
|
609 hash_table_size_validate (Lisp_Object UNUSED (keyword), Lisp_Object value,
|
|
610 Error_Behavior errb)
|
428
|
611 {
|
|
612 if (NATNUMP (value))
|
|
613 return 1;
|
|
614
|
563
|
615 maybe_signal_error_1 (Qwrong_type_argument, list2 (Qnatnump, value),
|
2286
|
616 Qhash_table, errb);
|
428
|
617 return 0;
|
|
618 }
|
|
619
|
665
|
620 static Elemcount
|
428
|
621 decode_hash_table_size (Lisp_Object obj)
|
|
622 {
|
|
623 return NILP (obj) ? HASH_TABLE_DEFAULT_SIZE : XINT (obj);
|
|
624 }
|
|
625
|
|
626 static int
|
2286
|
627 hash_table_weakness_validate (Lisp_Object UNUSED (keyword), Lisp_Object value,
|
578
|
628 Error_Behavior errb)
|
428
|
629 {
|
442
|
630 if (EQ (value, Qnil)) return 1;
|
|
631 if (EQ (value, Qt)) return 1;
|
|
632 if (EQ (value, Qkey)) return 1;
|
|
633 if (EQ (value, Qkey_and_value)) return 1;
|
|
634 if (EQ (value, Qkey_or_value)) return 1;
|
|
635 if (EQ (value, Qvalue)) return 1;
|
428
|
636
|
|
637 /* Following values are obsolete as of 19990901 in xemacs-21.2 */
|
442
|
638 if (EQ (value, Qnon_weak)) return 1;
|
|
639 if (EQ (value, Qweak)) return 1;
|
|
640 if (EQ (value, Qkey_weak)) return 1;
|
|
641 if (EQ (value, Qkey_or_value_weak)) return 1;
|
|
642 if (EQ (value, Qvalue_weak)) return 1;
|
428
|
643
|
563
|
644 maybe_invalid_constant ("Invalid hash table weakness",
|
428
|
645 value, Qhash_table, errb);
|
|
646 return 0;
|
|
647 }
|
|
648
|
|
649 static enum hash_table_weakness
|
|
650 decode_hash_table_weakness (Lisp_Object obj)
|
|
651 {
|
442
|
652 if (EQ (obj, Qnil)) return HASH_TABLE_NON_WEAK;
|
|
653 if (EQ (obj, Qt)) return HASH_TABLE_WEAK;
|
|
654 if (EQ (obj, Qkey_and_value)) return HASH_TABLE_WEAK;
|
|
655 if (EQ (obj, Qkey)) return HASH_TABLE_KEY_WEAK;
|
|
656 if (EQ (obj, Qkey_or_value)) return HASH_TABLE_KEY_VALUE_WEAK;
|
|
657 if (EQ (obj, Qvalue)) return HASH_TABLE_VALUE_WEAK;
|
428
|
658
|
|
659 /* Following values are obsolete as of 19990901 in xemacs-21.2 */
|
442
|
660 if (EQ (obj, Qnon_weak)) return HASH_TABLE_NON_WEAK;
|
|
661 if (EQ (obj, Qweak)) return HASH_TABLE_WEAK;
|
|
662 if (EQ (obj, Qkey_weak)) return HASH_TABLE_KEY_WEAK;
|
|
663 if (EQ (obj, Qkey_or_value_weak)) return HASH_TABLE_KEY_VALUE_WEAK;
|
|
664 if (EQ (obj, Qvalue_weak)) return HASH_TABLE_VALUE_WEAK;
|
428
|
665
|
563
|
666 invalid_constant ("Invalid hash table weakness", obj);
|
1204
|
667 RETURN_NOT_REACHED (HASH_TABLE_NON_WEAK);
|
428
|
668 }
|
|
669
|
|
670 static int
|
2286
|
671 hash_table_test_validate (Lisp_Object UNUSED (keyword), Lisp_Object value,
|
|
672 Error_Behavior errb)
|
428
|
673 {
|
|
674 if (EQ (value, Qnil)) return 1;
|
|
675 if (EQ (value, Qeq)) return 1;
|
|
676 if (EQ (value, Qequal)) return 1;
|
|
677 if (EQ (value, Qeql)) return 1;
|
|
678
|
563
|
679 maybe_invalid_constant ("Invalid hash table test",
|
2286
|
680 value, Qhash_table, errb);
|
428
|
681 return 0;
|
|
682 }
|
|
683
|
|
684 static enum hash_table_test
|
|
685 decode_hash_table_test (Lisp_Object obj)
|
|
686 {
|
|
687 if (EQ (obj, Qnil)) return HASH_TABLE_EQL;
|
|
688 if (EQ (obj, Qeq)) return HASH_TABLE_EQ;
|
|
689 if (EQ (obj, Qequal)) return HASH_TABLE_EQUAL;
|
|
690 if (EQ (obj, Qeql)) return HASH_TABLE_EQL;
|
|
691
|
563
|
692 invalid_constant ("Invalid hash table test", obj);
|
1204
|
693 RETURN_NOT_REACHED (HASH_TABLE_EQ);
|
428
|
694 }
|
|
695
|
|
696 static int
|
2286
|
697 hash_table_rehash_size_validate (Lisp_Object UNUSED (keyword),
|
|
698 Lisp_Object value, Error_Behavior errb)
|
428
|
699 {
|
|
700 if (!FLOATP (value))
|
|
701 {
|
563
|
702 maybe_signal_error_1 (Qwrong_type_argument, list2 (Qfloatp, value),
|
428
|
703 Qhash_table, errb);
|
|
704 return 0;
|
|
705 }
|
|
706
|
|
707 {
|
|
708 double rehash_size = XFLOAT_DATA (value);
|
|
709 if (rehash_size <= 1.0)
|
|
710 {
|
563
|
711 maybe_invalid_argument
|
428
|
712 ("Hash table rehash size must be greater than 1.0",
|
|
713 value, Qhash_table, errb);
|
|
714 return 0;
|
|
715 }
|
|
716 }
|
|
717
|
|
718 return 1;
|
|
719 }
|
|
720
|
|
721 static double
|
|
722 decode_hash_table_rehash_size (Lisp_Object rehash_size)
|
|
723 {
|
|
724 return NILP (rehash_size) ? -1.0 : XFLOAT_DATA (rehash_size);
|
|
725 }
|
|
726
|
|
727 static int
|
2286
|
728 hash_table_rehash_threshold_validate (Lisp_Object UNUSED (keyword),
|
|
729 Lisp_Object value, Error_Behavior errb)
|
428
|
730 {
|
|
731 if (!FLOATP (value))
|
|
732 {
|
563
|
733 maybe_signal_error_1 (Qwrong_type_argument, list2 (Qfloatp, value),
|
428
|
734 Qhash_table, errb);
|
|
735 return 0;
|
|
736 }
|
|
737
|
|
738 {
|
|
739 double rehash_threshold = XFLOAT_DATA (value);
|
|
740 if (rehash_threshold <= 0.0 || rehash_threshold >= 1.0)
|
|
741 {
|
563
|
742 maybe_invalid_argument
|
428
|
743 ("Hash table rehash threshold must be between 0.0 and 1.0",
|
|
744 value, Qhash_table, errb);
|
|
745 return 0;
|
|
746 }
|
|
747 }
|
|
748
|
|
749 return 1;
|
|
750 }
|
|
751
|
|
752 static double
|
|
753 decode_hash_table_rehash_threshold (Lisp_Object rehash_threshold)
|
|
754 {
|
|
755 return NILP (rehash_threshold) ? -1.0 : XFLOAT_DATA (rehash_threshold);
|
|
756 }
|
|
757
|
|
758 static int
|
2286
|
759 hash_table_data_validate (Lisp_Object UNUSED (keyword), Lisp_Object value,
|
|
760 Error_Behavior errb)
|
428
|
761 {
|
|
762 int len;
|
|
763
|
|
764 GET_EXTERNAL_LIST_LENGTH (value, len);
|
|
765
|
|
766 if (len & 1)
|
|
767 {
|
563
|
768 maybe_sferror
|
428
|
769 ("Hash table data must have alternating key/value pairs",
|
|
770 value, Qhash_table, errb);
|
|
771 return 0;
|
|
772 }
|
|
773 return 1;
|
|
774 }
|
|
775
|
|
776 /* The actual instantiation of a hash table. This does practically no
|
|
777 error checking, because it relies on the fact that the paranoid
|
|
778 functions above have error-checked everything to the last details.
|
|
779 If this assumption is wrong, we will get a crash immediately (with
|
|
780 error-checking compiled in), and we'll know if there is a bug in
|
|
781 the structure mechanism. So there. */
|
|
782 static Lisp_Object
|
|
783 hash_table_instantiate (Lisp_Object plist)
|
|
784 {
|
|
785 Lisp_Object hash_table;
|
|
786 Lisp_Object test = Qnil;
|
|
787 Lisp_Object size = Qnil;
|
|
788 Lisp_Object rehash_size = Qnil;
|
|
789 Lisp_Object rehash_threshold = Qnil;
|
|
790 Lisp_Object weakness = Qnil;
|
|
791 Lisp_Object data = Qnil;
|
|
792
|
|
793 while (!NILP (plist))
|
|
794 {
|
|
795 Lisp_Object key, value;
|
|
796 key = XCAR (plist); plist = XCDR (plist);
|
|
797 value = XCAR (plist); plist = XCDR (plist);
|
|
798
|
|
799 if (EQ (key, Qtest)) test = value;
|
|
800 else if (EQ (key, Qsize)) size = value;
|
|
801 else if (EQ (key, Qrehash_size)) rehash_size = value;
|
|
802 else if (EQ (key, Qrehash_threshold)) rehash_threshold = value;
|
|
803 else if (EQ (key, Qweakness)) weakness = value;
|
|
804 else if (EQ (key, Qdata)) data = value;
|
|
805 else if (EQ (key, Qtype))/*obsolete*/ weakness = value;
|
|
806 else
|
|
807 abort ();
|
|
808 }
|
|
809
|
|
810 /* Create the hash table. */
|
450
|
811 hash_table = make_standard_lisp_hash_table
|
428
|
812 (decode_hash_table_test (test),
|
|
813 decode_hash_table_size (size),
|
|
814 decode_hash_table_rehash_size (rehash_size),
|
|
815 decode_hash_table_rehash_threshold (rehash_threshold),
|
|
816 decode_hash_table_weakness (weakness));
|
|
817
|
|
818 /* I'm not sure whether this can GC, but better safe than sorry. */
|
|
819 {
|
|
820 struct gcpro gcpro1;
|
|
821 GCPRO1 (hash_table);
|
|
822
|
|
823 /* And fill it with data. */
|
|
824 while (!NILP (data))
|
|
825 {
|
|
826 Lisp_Object key, value;
|
|
827 key = XCAR (data); data = XCDR (data);
|
|
828 value = XCAR (data); data = XCDR (data);
|
|
829 Fputhash (key, value, hash_table);
|
|
830 }
|
|
831 UNGCPRO;
|
|
832 }
|
|
833
|
|
834 return hash_table;
|
|
835 }
|
|
836
|
|
837 static void
|
|
838 structure_type_create_hash_table_structure_name (Lisp_Object structure_name)
|
|
839 {
|
|
840 struct structure_type *st;
|
|
841
|
|
842 st = define_structure_type (structure_name, 0, hash_table_instantiate);
|
|
843 define_structure_type_keyword (st, Qtest, hash_table_test_validate);
|
|
844 define_structure_type_keyword (st, Qsize, hash_table_size_validate);
|
|
845 define_structure_type_keyword (st, Qrehash_size, hash_table_rehash_size_validate);
|
|
846 define_structure_type_keyword (st, Qrehash_threshold, hash_table_rehash_threshold_validate);
|
|
847 define_structure_type_keyword (st, Qweakness, hash_table_weakness_validate);
|
|
848 define_structure_type_keyword (st, Qdata, hash_table_data_validate);
|
|
849
|
|
850 /* obsolete as of 19990901 in xemacs-21.2 */
|
|
851 define_structure_type_keyword (st, Qtype, hash_table_weakness_validate);
|
|
852 }
|
|
853
|
|
854 /* Create a built-in Lisp structure type named `hash-table'.
|
|
855 We make #s(hashtable ...) equivalent to #s(hash-table ...),
|
|
856 for backward compatibility.
|
|
857 This is called from emacs.c. */
|
|
858 void
|
|
859 structure_type_create_hash_table (void)
|
|
860 {
|
|
861 structure_type_create_hash_table_structure_name (Qhash_table);
|
|
862 structure_type_create_hash_table_structure_name (Qhashtable); /* compat */
|
|
863 }
|
|
864
|
|
865
|
|
866 /************************************************************************/
|
|
867 /* Definition of Lisp-visible methods */
|
|
868 /************************************************************************/
|
|
869
|
|
870 DEFUN ("hash-table-p", Fhash_table_p, 1, 1, 0, /*
|
|
871 Return t if OBJECT is a hash table, else nil.
|
|
872 */
|
|
873 (object))
|
|
874 {
|
|
875 return HASH_TABLEP (object) ? Qt : Qnil;
|
|
876 }
|
|
877
|
|
878 DEFUN ("make-hash-table", Fmake_hash_table, 0, MANY, 0, /*
|
|
879 Return a new empty hash table object.
|
|
880 Use Common Lisp style keywords to specify hash table properties.
|
|
881 (make-hash-table &key test size rehash-size rehash-threshold weakness)
|
|
882
|
|
883 Keyword :test can be `eq', `eql' (default) or `equal'.
|
|
884 Comparison between keys is done using this function.
|
|
885 If speed is important, consider using `eq'.
|
|
886 When storing strings in the hash table, you will likely need to use `equal'.
|
|
887
|
|
888 Keyword :size specifies the number of keys likely to be inserted.
|
|
889 This number of entries can be inserted without enlarging the hash table.
|
|
890
|
|
891 Keyword :rehash-size must be a float greater than 1.0, and specifies
|
|
892 the factor by which to increase the size of the hash table when enlarging.
|
|
893
|
|
894 Keyword :rehash-threshold must be a float between 0.0 and 1.0,
|
|
895 and specifies the load factor of the hash table which triggers enlarging.
|
|
896
|
442
|
897 Non-standard keyword :weakness can be `nil' (default), `t', `key-and-value',
|
|
898 `key', `value' or `key-or-value'. `t' is an alias for `key-and-value'.
|
428
|
899
|
442
|
900 A key-and-value-weak hash table, also known as a fully-weak or simply
|
|
901 as a weak hash table, is one whose pointers do not count as GC
|
|
902 referents: for any key-value pair in the hash table, if the only
|
|
903 remaining pointer to either the key or the value is in a weak hash
|
|
904 table, then the pair will be removed from the hash table, and the key
|
|
905 and value collected. A non-weak hash table (or any other pointer)
|
|
906 would prevent the object from being collected.
|
428
|
907
|
|
908 A key-weak hash table is similar to a fully-weak hash table except that
|
|
909 a key-value pair will be removed only if the key remains unmarked
|
|
910 outside of weak hash tables. The pair will remain in the hash table if
|
|
911 the key is pointed to by something other than a weak hash table, even
|
|
912 if the value is not.
|
|
913
|
|
914 A value-weak hash table is similar to a fully-weak hash table except
|
|
915 that a key-value pair will be removed only if the value remains
|
|
916 unmarked outside of weak hash tables. The pair will remain in the
|
|
917 hash table if the value is pointed to by something other than a weak
|
|
918 hash table, even if the key is not.
|
442
|
919
|
|
920 A key-or-value-weak hash table is similar to a fully-weak hash table except
|
|
921 that a key-value pair will be removed only if the value and the key remain
|
|
922 unmarked outside of weak hash tables. The pair will remain in the
|
|
923 hash table if the value or key are pointed to by something other than a weak
|
|
924 hash table, even if the other is not.
|
428
|
925 */
|
|
926 (int nargs, Lisp_Object *args))
|
|
927 {
|
|
928 int i = 0;
|
|
929 Lisp_Object test = Qnil;
|
|
930 Lisp_Object size = Qnil;
|
|
931 Lisp_Object rehash_size = Qnil;
|
|
932 Lisp_Object rehash_threshold = Qnil;
|
|
933 Lisp_Object weakness = Qnil;
|
|
934
|
|
935 while (i + 1 < nargs)
|
|
936 {
|
|
937 Lisp_Object keyword = args[i++];
|
|
938 Lisp_Object value = args[i++];
|
|
939
|
|
940 if (EQ (keyword, Q_test)) test = value;
|
|
941 else if (EQ (keyword, Q_size)) size = value;
|
|
942 else if (EQ (keyword, Q_rehash_size)) rehash_size = value;
|
|
943 else if (EQ (keyword, Q_rehash_threshold)) rehash_threshold = value;
|
|
944 else if (EQ (keyword, Q_weakness)) weakness = value;
|
|
945 else if (EQ (keyword, Q_type))/*obsolete*/ weakness = value;
|
563
|
946 else invalid_constant ("Invalid hash table property keyword", keyword);
|
428
|
947 }
|
|
948
|
|
949 if (i < nargs)
|
563
|
950 sferror ("Hash table property requires a value", args[i]);
|
428
|
951
|
|
952 #define VALIDATE_VAR(var) \
|
|
953 if (!NILP (var)) hash_table_##var##_validate (Q##var, var, ERROR_ME);
|
|
954
|
|
955 VALIDATE_VAR (test);
|
|
956 VALIDATE_VAR (size);
|
|
957 VALIDATE_VAR (rehash_size);
|
|
958 VALIDATE_VAR (rehash_threshold);
|
|
959 VALIDATE_VAR (weakness);
|
|
960
|
450
|
961 return make_standard_lisp_hash_table
|
428
|
962 (decode_hash_table_test (test),
|
|
963 decode_hash_table_size (size),
|
|
964 decode_hash_table_rehash_size (rehash_size),
|
|
965 decode_hash_table_rehash_threshold (rehash_threshold),
|
|
966 decode_hash_table_weakness (weakness));
|
|
967 }
|
|
968
|
|
969 DEFUN ("copy-hash-table", Fcopy_hash_table, 1, 1, 0, /*
|
|
970 Return a new hash table containing the same keys and values as HASH-TABLE.
|
|
971 The keys and values will not themselves be copied.
|
|
972 */
|
|
973 (hash_table))
|
|
974 {
|
442
|
975 const Lisp_Hash_Table *ht_old = xhash_table (hash_table);
|
428
|
976 Lisp_Hash_Table *ht = alloc_lcrecord_type (Lisp_Hash_Table, &lrecord_hash_table);
|
|
977
|
|
978 copy_lcrecord (ht, ht_old);
|
|
979
|
1204
|
980 ht->hentries = xnew_array (htentry, ht_old->size + 1);
|
|
981 memcpy (ht->hentries, ht_old->hentries, (ht_old->size + 1) * sizeof (htentry));
|
428
|
982
|
793
|
983 hash_table = wrap_hash_table (ht);
|
428
|
984
|
|
985 if (! EQ (ht->next_weak, Qunbound))
|
|
986 {
|
|
987 ht->next_weak = Vall_weak_hash_tables;
|
|
988 Vall_weak_hash_tables = hash_table;
|
|
989 }
|
|
990
|
|
991 return hash_table;
|
|
992 }
|
|
993
|
|
994 static void
|
665
|
995 resize_hash_table (Lisp_Hash_Table *ht, Elemcount new_size)
|
428
|
996 {
|
1204
|
997 htentry *old_entries, *new_entries, *sentinel, *e;
|
665
|
998 Elemcount old_size;
|
428
|
999
|
|
1000 old_size = ht->size;
|
|
1001 ht->size = new_size;
|
|
1002
|
|
1003 old_entries = ht->hentries;
|
|
1004
|
1204
|
1005 ht->hentries = xnew_array_and_zero (htentry, new_size + 1);
|
428
|
1006 new_entries = ht->hentries;
|
|
1007
|
|
1008 compute_hash_table_derived_values (ht);
|
|
1009
|
440
|
1010 for (e = old_entries, sentinel = e + old_size; e < sentinel; e++)
|
1204
|
1011 if (!HTENTRY_CLEAR_P (e))
|
428
|
1012 {
|
1204
|
1013 htentry *probe = new_entries + HASHCODE (e->key, ht);
|
428
|
1014 LINEAR_PROBING_LOOP (probe, new_entries, new_size)
|
|
1015 ;
|
|
1016 *probe = *e;
|
|
1017 }
|
|
1018
|
489
|
1019 free_hentries (old_entries, old_size);
|
428
|
1020 }
|
|
1021
|
440
|
1022 /* After a hash table has been saved to disk and later restored by the
|
|
1023 portable dumper, it contains the same objects, but their addresses
|
665
|
1024 and thus their HASHCODEs have changed. */
|
428
|
1025 void
|
440
|
1026 pdump_reorganize_hash_table (Lisp_Object hash_table)
|
428
|
1027 {
|
442
|
1028 const Lisp_Hash_Table *ht = xhash_table (hash_table);
|
1204
|
1029 htentry *new_entries = xnew_array_and_zero (htentry, ht->size + 1);
|
|
1030 htentry *e, *sentinel;
|
440
|
1031
|
|
1032 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
|
1204
|
1033 if (!HTENTRY_CLEAR_P (e))
|
440
|
1034 {
|
1204
|
1035 htentry *probe = new_entries + HASHCODE (e->key, ht);
|
440
|
1036 LINEAR_PROBING_LOOP (probe, new_entries, ht->size)
|
|
1037 ;
|
|
1038 *probe = *e;
|
|
1039 }
|
|
1040
|
1204
|
1041 memcpy (ht->hentries, new_entries, ht->size * sizeof (htentry));
|
440
|
1042
|
1726
|
1043 xfree (new_entries, htentry *);
|
428
|
1044 }
|
|
1045
|
|
1046 static void
|
|
1047 enlarge_hash_table (Lisp_Hash_Table *ht)
|
|
1048 {
|
665
|
1049 Elemcount new_size =
|
|
1050 hash_table_size ((Elemcount) ((double) ht->size * ht->rehash_size));
|
428
|
1051 resize_hash_table (ht, new_size);
|
|
1052 }
|
|
1053
|
1204
|
1054 static htentry *
|
|
1055 find_htentry (Lisp_Object key, const Lisp_Hash_Table *ht)
|
428
|
1056 {
|
|
1057 hash_table_test_function_t test_function = ht->test_function;
|
1204
|
1058 htentry *entries = ht->hentries;
|
|
1059 htentry *probe = entries + HASHCODE (key, ht);
|
428
|
1060
|
|
1061 LINEAR_PROBING_LOOP (probe, entries, ht->size)
|
|
1062 if (KEYS_EQUAL_P (probe->key, key, test_function))
|
|
1063 break;
|
|
1064
|
|
1065 return probe;
|
|
1066 }
|
|
1067
|
|
1068 DEFUN ("gethash", Fgethash, 2, 3, 0, /*
|
|
1069 Find hash value for KEY in HASH-TABLE.
|
|
1070 If there is no corresponding value, return DEFAULT (which defaults to nil).
|
|
1071 */
|
|
1072 (key, hash_table, default_))
|
|
1073 {
|
442
|
1074 const Lisp_Hash_Table *ht = xhash_table (hash_table);
|
1204
|
1075 htentry *e = find_htentry (key, ht);
|
428
|
1076
|
1204
|
1077 return HTENTRY_CLEAR_P (e) ? default_ : e->value;
|
428
|
1078 }
|
|
1079
|
|
1080 DEFUN ("puthash", Fputhash, 3, 3, 0, /*
|
|
1081 Hash KEY to VALUE in HASH-TABLE.
|
|
1082 */
|
|
1083 (key, value, hash_table))
|
|
1084 {
|
|
1085 Lisp_Hash_Table *ht = xhash_table (hash_table);
|
1204
|
1086 htentry *e = find_htentry (key, ht);
|
428
|
1087
|
1204
|
1088 if (!HTENTRY_CLEAR_P (e))
|
428
|
1089 return e->value = value;
|
|
1090
|
|
1091 e->key = key;
|
|
1092 e->value = value;
|
|
1093
|
|
1094 if (++ht->count >= ht->rehash_count)
|
|
1095 enlarge_hash_table (ht);
|
|
1096
|
|
1097 return value;
|
|
1098 }
|
|
1099
|
1204
|
1100 /* Remove htentry pointed at by PROBE.
|
428
|
1101 Subsequent entries are removed and reinserted.
|
|
1102 We don't use tombstones - too wasteful. */
|
|
1103 static void
|
1204
|
1104 remhash_1 (Lisp_Hash_Table *ht, htentry *entries, htentry *probe)
|
428
|
1105 {
|
665
|
1106 Elemcount size = ht->size;
|
1204
|
1107 CLEAR_HTENTRY (probe);
|
428
|
1108 probe++;
|
|
1109 ht->count--;
|
|
1110
|
|
1111 LINEAR_PROBING_LOOP (probe, entries, size)
|
|
1112 {
|
|
1113 Lisp_Object key = probe->key;
|
1204
|
1114 htentry *probe2 = entries + HASHCODE (key, ht);
|
428
|
1115 LINEAR_PROBING_LOOP (probe2, entries, size)
|
|
1116 if (EQ (probe2->key, key))
|
1204
|
1117 /* htentry at probe doesn't need to move. */
|
428
|
1118 goto continue_outer_loop;
|
1204
|
1119 /* Move htentry from probe to new home at probe2. */
|
428
|
1120 *probe2 = *probe;
|
1204
|
1121 CLEAR_HTENTRY (probe);
|
428
|
1122 continue_outer_loop: continue;
|
|
1123 }
|
|
1124 }
|
|
1125
|
|
1126 DEFUN ("remhash", Fremhash, 2, 2, 0, /*
|
|
1127 Remove the entry for KEY from HASH-TABLE.
|
|
1128 Do nothing if there is no entry for KEY in HASH-TABLE.
|
617
|
1129 Return non-nil if an entry was removed.
|
428
|
1130 */
|
|
1131 (key, hash_table))
|
|
1132 {
|
|
1133 Lisp_Hash_Table *ht = xhash_table (hash_table);
|
1204
|
1134 htentry *e = find_htentry (key, ht);
|
428
|
1135
|
1204
|
1136 if (HTENTRY_CLEAR_P (e))
|
428
|
1137 return Qnil;
|
|
1138
|
|
1139 remhash_1 (ht, ht->hentries, e);
|
|
1140 return Qt;
|
|
1141 }
|
|
1142
|
|
1143 DEFUN ("clrhash", Fclrhash, 1, 1, 0, /*
|
|
1144 Remove all entries from HASH-TABLE, leaving it empty.
|
|
1145 */
|
|
1146 (hash_table))
|
|
1147 {
|
|
1148 Lisp_Hash_Table *ht = xhash_table (hash_table);
|
1204
|
1149 htentry *e, *sentinel;
|
428
|
1150
|
|
1151 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
|
1204
|
1152 CLEAR_HTENTRY (e);
|
428
|
1153 ht->count = 0;
|
|
1154
|
|
1155 return hash_table;
|
|
1156 }
|
|
1157
|
|
1158 /************************************************************************/
|
|
1159 /* Accessor Functions */
|
|
1160 /************************************************************************/
|
|
1161
|
|
1162 DEFUN ("hash-table-count", Fhash_table_count, 1, 1, 0, /*
|
|
1163 Return the number of entries in HASH-TABLE.
|
|
1164 */
|
|
1165 (hash_table))
|
|
1166 {
|
|
1167 return make_int (xhash_table (hash_table)->count);
|
|
1168 }
|
|
1169
|
|
1170 DEFUN ("hash-table-test", Fhash_table_test, 1, 1, 0, /*
|
|
1171 Return the test function of HASH-TABLE.
|
|
1172 This can be one of `eq', `eql' or `equal'.
|
|
1173 */
|
|
1174 (hash_table))
|
|
1175 {
|
|
1176 hash_table_test_function_t fun = xhash_table (hash_table)->test_function;
|
|
1177
|
|
1178 return (fun == lisp_object_eql_equal ? Qeql :
|
|
1179 fun == lisp_object_equal_equal ? Qequal :
|
|
1180 Qeq);
|
|
1181 }
|
|
1182
|
|
1183 DEFUN ("hash-table-size", Fhash_table_size, 1, 1, 0, /*
|
|
1184 Return the size of HASH-TABLE.
|
|
1185 This is the current number of slots in HASH-TABLE, whether occupied or not.
|
|
1186 */
|
|
1187 (hash_table))
|
|
1188 {
|
|
1189 return make_int (xhash_table (hash_table)->size);
|
|
1190 }
|
|
1191
|
|
1192 DEFUN ("hash-table-rehash-size", Fhash_table_rehash_size, 1, 1, 0, /*
|
|
1193 Return the current rehash size of HASH-TABLE.
|
|
1194 This is a float greater than 1.0; the factor by which HASH-TABLE
|
|
1195 is enlarged when the rehash threshold is exceeded.
|
|
1196 */
|
|
1197 (hash_table))
|
|
1198 {
|
|
1199 return make_float (xhash_table (hash_table)->rehash_size);
|
|
1200 }
|
|
1201
|
|
1202 DEFUN ("hash-table-rehash-threshold", Fhash_table_rehash_threshold, 1, 1, 0, /*
|
|
1203 Return the current rehash threshold of HASH-TABLE.
|
|
1204 This is a float between 0.0 and 1.0; the maximum `load factor' of HASH-TABLE,
|
|
1205 beyond which the HASH-TABLE is enlarged by rehashing.
|
|
1206 */
|
|
1207 (hash_table))
|
|
1208 {
|
438
|
1209 return make_float (xhash_table (hash_table)->rehash_threshold);
|
428
|
1210 }
|
|
1211
|
|
1212 DEFUN ("hash-table-weakness", Fhash_table_weakness, 1, 1, 0, /*
|
|
1213 Return the weakness of HASH-TABLE.
|
442
|
1214 This can be one of `nil', `key-and-value', `key-or-value', `key' or `value'.
|
428
|
1215 */
|
|
1216 (hash_table))
|
|
1217 {
|
|
1218 switch (xhash_table (hash_table)->weakness)
|
|
1219 {
|
442
|
1220 case HASH_TABLE_WEAK: return Qkey_and_value;
|
|
1221 case HASH_TABLE_KEY_WEAK: return Qkey;
|
|
1222 case HASH_TABLE_KEY_VALUE_WEAK: return Qkey_or_value;
|
|
1223 case HASH_TABLE_VALUE_WEAK: return Qvalue;
|
|
1224 default: return Qnil;
|
428
|
1225 }
|
|
1226 }
|
|
1227
|
|
1228 /* obsolete as of 19990901 in xemacs-21.2 */
|
|
1229 DEFUN ("hash-table-type", Fhash_table_type, 1, 1, 0, /*
|
|
1230 Return the type of HASH-TABLE.
|
|
1231 This can be one of `non-weak', `weak', `key-weak' or `value-weak'.
|
|
1232 */
|
|
1233 (hash_table))
|
|
1234 {
|
|
1235 switch (xhash_table (hash_table)->weakness)
|
|
1236 {
|
442
|
1237 case HASH_TABLE_WEAK: return Qweak;
|
|
1238 case HASH_TABLE_KEY_WEAK: return Qkey_weak;
|
|
1239 case HASH_TABLE_KEY_VALUE_WEAK: return Qkey_or_value_weak;
|
|
1240 case HASH_TABLE_VALUE_WEAK: return Qvalue_weak;
|
|
1241 default: return Qnon_weak;
|
428
|
1242 }
|
|
1243 }
|
|
1244
|
|
1245 /************************************************************************/
|
|
1246 /* Mapping Functions */
|
|
1247 /************************************************************************/
|
489
|
1248
|
|
1249 /* We need to be careful when mapping over hash tables because the
|
|
1250 hash table might be modified during the mapping operation:
|
|
1251 - by the mapping function
|
|
1252 - by gc (if the hash table is weak)
|
|
1253
|
|
1254 So we make a copy of the hentries at the beginning of the mapping
|
497
|
1255 operation, and iterate over the copy. Naturally, this is
|
|
1256 expensive, but not as expensive as you might think, because no
|
|
1257 actual memory has to be collected by our notoriously inefficient
|
|
1258 GC; we use an unwind-protect instead to free the memory directly.
|
|
1259
|
|
1260 We could avoid the copying by having the hash table modifiers
|
|
1261 puthash and remhash check for currently active mapping functions.
|
|
1262 Disadvantages: it's hard to get right, and IMO hash mapping
|
|
1263 functions are basically rare, and no extra space in the hash table
|
|
1264 object and no extra cpu in puthash or remhash should be wasted to
|
|
1265 make maphash 3% faster. From a design point of view, the basic
|
|
1266 functions gethash, puthash and remhash should be implementable
|
|
1267 without having to think about maphash.
|
|
1268
|
|
1269 Note: We don't (yet) have Common Lisp's with-hash-table-iterator.
|
|
1270 If you implement this naively, you cannot have more than one
|
|
1271 concurrently active iterator over the same hash table. The `each'
|
|
1272 function in perl has this limitation.
|
|
1273
|
|
1274 Note: We GCPRO memory on the heap, not on the stack. There is no
|
|
1275 obvious reason why this is bad, but as of this writing this is the
|
|
1276 only known occurrence of this technique in the code.
|
504
|
1277
|
|
1278 -- Martin
|
|
1279 */
|
|
1280
|
|
1281 /* Ben disagrees with the "copying hentries" design, and says:
|
|
1282
|
|
1283 Another solution is the same as I've already proposed -- when
|
|
1284 mapping, mark the table as "change-unsafe", and in this case, use a
|
|
1285 secondary table to maintain changes. this could be basically a
|
|
1286 standard hash table, but with entries only for added or deleted
|
|
1287 entries in the primary table, and a marker like Qunbound to
|
|
1288 indicate a deleted entry. puthash, gethash and remhash need a
|
|
1289 single extra check for this secondary table -- totally
|
|
1290 insignificant speedwise. if you really cared about making
|
|
1291 recursive maphashes completely correct, you'd have to do a bit of
|
|
1292 extra work here -- when maphashing, if the secondary table exists,
|
|
1293 make a copy of it, and use the copy in conjunction with the primary
|
|
1294 table when mapping. the advantages of this are
|
|
1295
|
|
1296 [a] easy to demonstrate correct, even with weak hashtables.
|
|
1297
|
|
1298 [b] no extra overhead in the general maphash case -- only when you
|
|
1299 modify the table while maphashing, and even then the overhead is
|
|
1300 very small.
|
497
|
1301 */
|
|
1302
|
489
|
1303 static Lisp_Object
|
|
1304 maphash_unwind (Lisp_Object unwind_obj)
|
|
1305 {
|
|
1306 void *ptr = (void *) get_opaque_ptr (unwind_obj);
|
1726
|
1307 xfree (ptr, void *);
|
489
|
1308 free_opaque_ptr (unwind_obj);
|
|
1309 return Qnil;
|
|
1310 }
|
|
1311
|
|
1312 /* Return a malloced array of alternating key/value pairs from HT. */
|
|
1313 static Lisp_Object *
|
|
1314 copy_compress_hentries (const Lisp_Hash_Table *ht)
|
|
1315 {
|
|
1316 Lisp_Object * const objs =
|
|
1317 /* If the hash table is empty, ht->count could be 0. */
|
|
1318 xnew_array (Lisp_Object, 2 * (ht->count > 0 ? ht->count : 1));
|
1204
|
1319 const htentry *e, *sentinel;
|
489
|
1320 Lisp_Object *pobj;
|
|
1321
|
|
1322 for (e = ht->hentries, sentinel = e + ht->size, pobj = objs; e < sentinel; e++)
|
1204
|
1323 if (!HTENTRY_CLEAR_P (e))
|
489
|
1324 {
|
|
1325 *(pobj++) = e->key;
|
|
1326 *(pobj++) = e->value;
|
|
1327 }
|
|
1328
|
|
1329 type_checking_assert (pobj == objs + 2 * ht->count);
|
|
1330
|
|
1331 return objs;
|
|
1332 }
|
|
1333
|
428
|
1334 DEFUN ("maphash", Fmaphash, 2, 2, 0, /*
|
|
1335 Map FUNCTION over entries in HASH-TABLE, calling it with two args,
|
|
1336 each key and value in HASH-TABLE.
|
|
1337
|
489
|
1338 FUNCTION must not modify HASH-TABLE, with the one exception that FUNCTION
|
428
|
1339 may remhash or puthash the entry currently being processed by FUNCTION.
|
|
1340 */
|
|
1341 (function, hash_table))
|
|
1342 {
|
489
|
1343 const Lisp_Hash_Table * const ht = xhash_table (hash_table);
|
|
1344 Lisp_Object * const objs = copy_compress_hentries (ht);
|
|
1345 Lisp_Object args[3];
|
|
1346 const Lisp_Object *pobj, *end;
|
|
1347 int speccount = specpdl_depth ();
|
|
1348 struct gcpro gcpro1;
|
|
1349
|
|
1350 record_unwind_protect (maphash_unwind, make_opaque_ptr ((void *)objs));
|
|
1351 GCPRO1 (objs[0]);
|
|
1352 gcpro1.nvars = 2 * ht->count;
|
428
|
1353
|
489
|
1354 args[0] = function;
|
|
1355
|
|
1356 for (pobj = objs, end = pobj + 2 * ht->count; pobj < end; pobj += 2)
|
|
1357 {
|
|
1358 args[1] = pobj[0];
|
|
1359 args[2] = pobj[1];
|
|
1360 Ffuncall (countof (args), args);
|
|
1361 }
|
|
1362
|
771
|
1363 unbind_to (speccount);
|
489
|
1364 UNGCPRO;
|
428
|
1365
|
|
1366 return Qnil;
|
|
1367 }
|
|
1368
|
489
|
1369 /* Map *C* function FUNCTION over the elements of a non-weak lisp hash table.
|
|
1370 FUNCTION must not modify HASH-TABLE, with the one exception that FUNCTION
|
|
1371 may puthash the entry currently being processed by FUNCTION.
|
|
1372 Mapping terminates if FUNCTION returns something other than 0. */
|
428
|
1373 void
|
489
|
1374 elisp_maphash_unsafe (maphash_function_t function,
|
428
|
1375 Lisp_Object hash_table, void *extra_arg)
|
|
1376 {
|
442
|
1377 const Lisp_Hash_Table *ht = XHASH_TABLE (hash_table);
|
1204
|
1378 const htentry *e, *sentinel;
|
428
|
1379
|
|
1380 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
|
1204
|
1381 if (!HTENTRY_CLEAR_P (e))
|
489
|
1382 if (function (e->key, e->value, extra_arg))
|
|
1383 return;
|
428
|
1384 }
|
|
1385
|
489
|
1386 /* Map *C* function FUNCTION over the elements of a lisp hash table.
|
|
1387 It is safe for FUNCTION to modify HASH-TABLE.
|
|
1388 Mapping terminates if FUNCTION returns something other than 0. */
|
|
1389 void
|
|
1390 elisp_maphash (maphash_function_t function,
|
|
1391 Lisp_Object hash_table, void *extra_arg)
|
|
1392 {
|
|
1393 const Lisp_Hash_Table * const ht = xhash_table (hash_table);
|
|
1394 Lisp_Object * const objs = copy_compress_hentries (ht);
|
|
1395 const Lisp_Object *pobj, *end;
|
|
1396 int speccount = specpdl_depth ();
|
|
1397 struct gcpro gcpro1;
|
|
1398
|
|
1399 record_unwind_protect (maphash_unwind, make_opaque_ptr ((void *)objs));
|
|
1400 GCPRO1 (objs[0]);
|
|
1401 gcpro1.nvars = 2 * ht->count;
|
|
1402
|
|
1403 for (pobj = objs, end = pobj + 2 * ht->count; pobj < end; pobj += 2)
|
|
1404 if (function (pobj[0], pobj[1], extra_arg))
|
|
1405 break;
|
|
1406
|
771
|
1407 unbind_to (speccount);
|
489
|
1408 UNGCPRO;
|
|
1409 }
|
|
1410
|
|
1411 /* Remove all elements of a lisp hash table satisfying *C* predicate PREDICATE.
|
|
1412 PREDICATE must not modify HASH-TABLE. */
|
428
|
1413 void
|
|
1414 elisp_map_remhash (maphash_function_t predicate,
|
|
1415 Lisp_Object hash_table, void *extra_arg)
|
|
1416 {
|
489
|
1417 const Lisp_Hash_Table * const ht = xhash_table (hash_table);
|
|
1418 Lisp_Object * const objs = copy_compress_hentries (ht);
|
|
1419 const Lisp_Object *pobj, *end;
|
|
1420 int speccount = specpdl_depth ();
|
|
1421 struct gcpro gcpro1;
|
428
|
1422
|
489
|
1423 record_unwind_protect (maphash_unwind, make_opaque_ptr ((void *)objs));
|
|
1424 GCPRO1 (objs[0]);
|
|
1425 gcpro1.nvars = 2 * ht->count;
|
|
1426
|
|
1427 for (pobj = objs, end = pobj + 2 * ht->count; pobj < end; pobj += 2)
|
|
1428 if (predicate (pobj[0], pobj[1], extra_arg))
|
|
1429 Fremhash (pobj[0], hash_table);
|
|
1430
|
771
|
1431 unbind_to (speccount);
|
489
|
1432 UNGCPRO;
|
428
|
1433 }
|
|
1434
|
|
1435
|
|
1436 /************************************************************************/
|
|
1437 /* garbage collecting weak hash tables */
|
|
1438 /************************************************************************/
|
1598
|
1439 #ifdef USE_KKCC
|
|
1440 #define MARK_OBJ(obj) do { \
|
|
1441 Lisp_Object mo_obj = (obj); \
|
|
1442 if (!marked_p (mo_obj)) \
|
|
1443 { \
|
|
1444 kkcc_gc_stack_push_lisp_object (mo_obj); \
|
|
1445 did_mark = 1; \
|
|
1446 } \
|
|
1447 } while (0)
|
|
1448
|
|
1449 #else /* NO USE_KKCC */
|
|
1450
|
442
|
1451 #define MARK_OBJ(obj) do { \
|
|
1452 Lisp_Object mo_obj = (obj); \
|
|
1453 if (!marked_p (mo_obj)) \
|
|
1454 { \
|
|
1455 mark_object (mo_obj); \
|
|
1456 did_mark = 1; \
|
|
1457 } \
|
|
1458 } while (0)
|
1598
|
1459 #endif /*NO USE_KKCC */
|
442
|
1460
|
428
|
1461
|
|
1462 /* Complete the marking for semi-weak hash tables. */
|
|
1463 int
|
|
1464 finish_marking_weak_hash_tables (void)
|
|
1465 {
|
|
1466 Lisp_Object hash_table;
|
|
1467 int did_mark = 0;
|
|
1468
|
|
1469 for (hash_table = Vall_weak_hash_tables;
|
|
1470 !NILP (hash_table);
|
|
1471 hash_table = XHASH_TABLE (hash_table)->next_weak)
|
|
1472 {
|
442
|
1473 const Lisp_Hash_Table *ht = XHASH_TABLE (hash_table);
|
1204
|
1474 const htentry *e = ht->hentries;
|
|
1475 const htentry *sentinel = e + ht->size;
|
428
|
1476
|
|
1477 if (! marked_p (hash_table))
|
|
1478 /* The hash table is probably garbage. Ignore it. */
|
|
1479 continue;
|
|
1480
|
|
1481 /* Now, scan over all the pairs. For all pairs that are
|
|
1482 half-marked, we may need to mark the other half if we're
|
|
1483 keeping this pair. */
|
|
1484 switch (ht->weakness)
|
|
1485 {
|
|
1486 case HASH_TABLE_KEY_WEAK:
|
|
1487 for (; e < sentinel; e++)
|
1204
|
1488 if (!HTENTRY_CLEAR_P (e))
|
428
|
1489 if (marked_p (e->key))
|
|
1490 MARK_OBJ (e->value);
|
|
1491 break;
|
|
1492
|
|
1493 case HASH_TABLE_VALUE_WEAK:
|
|
1494 for (; e < sentinel; e++)
|
1204
|
1495 if (!HTENTRY_CLEAR_P (e))
|
428
|
1496 if (marked_p (e->value))
|
|
1497 MARK_OBJ (e->key);
|
|
1498 break;
|
|
1499
|
442
|
1500 case HASH_TABLE_KEY_VALUE_WEAK:
|
|
1501 for (; e < sentinel; e++)
|
1204
|
1502 if (!HTENTRY_CLEAR_P (e))
|
442
|
1503 {
|
|
1504 if (marked_p (e->value))
|
|
1505 MARK_OBJ (e->key);
|
|
1506 else if (marked_p (e->key))
|
|
1507 MARK_OBJ (e->value);
|
|
1508 }
|
|
1509 break;
|
|
1510
|
428
|
1511 case HASH_TABLE_KEY_CAR_WEAK:
|
|
1512 for (; e < sentinel; e++)
|
1204
|
1513 if (!HTENTRY_CLEAR_P (e))
|
428
|
1514 if (!CONSP (e->key) || marked_p (XCAR (e->key)))
|
|
1515 {
|
|
1516 MARK_OBJ (e->key);
|
|
1517 MARK_OBJ (e->value);
|
|
1518 }
|
|
1519 break;
|
|
1520
|
450
|
1521 /* We seem to be sprouting new weakness types at an alarming
|
|
1522 rate. At least this is not externally visible - and in
|
|
1523 fact all of these KEY_CAR_* types are only used by the
|
|
1524 glyph code. */
|
|
1525 case HASH_TABLE_KEY_CAR_VALUE_WEAK:
|
|
1526 for (; e < sentinel; e++)
|
1204
|
1527 if (!HTENTRY_CLEAR_P (e))
|
450
|
1528 {
|
|
1529 if (!CONSP (e->key) || marked_p (XCAR (e->key)))
|
|
1530 {
|
|
1531 MARK_OBJ (e->key);
|
|
1532 MARK_OBJ (e->value);
|
|
1533 }
|
|
1534 else if (marked_p (e->value))
|
|
1535 MARK_OBJ (e->key);
|
|
1536 }
|
|
1537 break;
|
|
1538
|
428
|
1539 case HASH_TABLE_VALUE_CAR_WEAK:
|
|
1540 for (; e < sentinel; e++)
|
1204
|
1541 if (!HTENTRY_CLEAR_P (e))
|
428
|
1542 if (!CONSP (e->value) || marked_p (XCAR (e->value)))
|
|
1543 {
|
|
1544 MARK_OBJ (e->key);
|
|
1545 MARK_OBJ (e->value);
|
|
1546 }
|
|
1547 break;
|
|
1548
|
|
1549 default:
|
|
1550 break;
|
|
1551 }
|
|
1552 }
|
|
1553
|
|
1554 return did_mark;
|
|
1555 }
|
|
1556
|
|
1557 void
|
|
1558 prune_weak_hash_tables (void)
|
|
1559 {
|
|
1560 Lisp_Object hash_table, prev = Qnil;
|
|
1561 for (hash_table = Vall_weak_hash_tables;
|
|
1562 !NILP (hash_table);
|
|
1563 hash_table = XHASH_TABLE (hash_table)->next_weak)
|
|
1564 {
|
|
1565 if (! marked_p (hash_table))
|
|
1566 {
|
|
1567 /* This hash table itself is garbage. Remove it from the list. */
|
|
1568 if (NILP (prev))
|
|
1569 Vall_weak_hash_tables = XHASH_TABLE (hash_table)->next_weak;
|
|
1570 else
|
|
1571 XHASH_TABLE (prev)->next_weak = XHASH_TABLE (hash_table)->next_weak;
|
|
1572 }
|
|
1573 else
|
|
1574 {
|
|
1575 /* Now, scan over all the pairs. Remove all of the pairs
|
|
1576 in which the key or value, or both, is unmarked
|
|
1577 (depending on the weakness of the hash table). */
|
|
1578 Lisp_Hash_Table *ht = XHASH_TABLE (hash_table);
|
1204
|
1579 htentry *entries = ht->hentries;
|
|
1580 htentry *sentinel = entries + ht->size;
|
|
1581 htentry *e;
|
428
|
1582
|
|
1583 for (e = entries; e < sentinel; e++)
|
1204
|
1584 if (!HTENTRY_CLEAR_P (e))
|
428
|
1585 {
|
|
1586 again:
|
|
1587 if (!marked_p (e->key) || !marked_p (e->value))
|
|
1588 {
|
|
1589 remhash_1 (ht, entries, e);
|
1204
|
1590 if (!HTENTRY_CLEAR_P (e))
|
428
|
1591 goto again;
|
|
1592 }
|
|
1593 }
|
|
1594
|
|
1595 prev = hash_table;
|
|
1596 }
|
|
1597 }
|
|
1598 }
|
|
1599
|
|
1600 /* Return a hash value for an array of Lisp_Objects of size SIZE. */
|
|
1601
|
665
|
1602 Hashcode
|
428
|
1603 internal_array_hash (Lisp_Object *arr, int size, int depth)
|
|
1604 {
|
|
1605 int i;
|
665
|
1606 Hashcode hash = 0;
|
442
|
1607 depth++;
|
428
|
1608
|
|
1609 if (size <= 5)
|
|
1610 {
|
|
1611 for (i = 0; i < size; i++)
|
442
|
1612 hash = HASH2 (hash, internal_hash (arr[i], depth));
|
428
|
1613 return hash;
|
|
1614 }
|
|
1615
|
|
1616 /* just pick five elements scattered throughout the array.
|
|
1617 A slightly better approach would be to offset by some
|
|
1618 noise factor from the points chosen below. */
|
|
1619 for (i = 0; i < 5; i++)
|
442
|
1620 hash = HASH2 (hash, internal_hash (arr[i*size/5], depth));
|
428
|
1621
|
|
1622 return hash;
|
|
1623 }
|
|
1624
|
|
1625 /* Return a hash value for a Lisp_Object. This is for use when hashing
|
|
1626 objects with the comparison being `equal' (for `eq', you can just
|
|
1627 use the Lisp_Object itself as the hash value). You need to make a
|
|
1628 tradeoff between the speed of the hash function and how good the
|
|
1629 hashing is. In particular, the hash function needs to be FAST,
|
|
1630 so you can't just traipse down the whole tree hashing everything
|
|
1631 together. Most of the time, objects will differ in the first
|
|
1632 few elements you hash. Thus, we only go to a short depth (5)
|
|
1633 and only hash at most 5 elements out of a vector. Theoretically
|
|
1634 we could still take 5^5 time (a big big number) to compute a
|
|
1635 hash, but practically this won't ever happen. */
|
|
1636
|
665
|
1637 Hashcode
|
428
|
1638 internal_hash (Lisp_Object obj, int depth)
|
|
1639 {
|
|
1640 if (depth > 5)
|
|
1641 return 0;
|
|
1642 if (CONSP (obj))
|
|
1643 {
|
|
1644 /* no point in worrying about tail recursion, since we're not
|
|
1645 going very deep */
|
|
1646 return HASH2 (internal_hash (XCAR (obj), depth + 1),
|
|
1647 internal_hash (XCDR (obj), depth + 1));
|
|
1648 }
|
|
1649 if (STRINGP (obj))
|
|
1650 {
|
|
1651 return hash_string (XSTRING_DATA (obj), XSTRING_LENGTH (obj));
|
|
1652 }
|
|
1653 if (LRECORDP (obj))
|
|
1654 {
|
442
|
1655 const struct lrecord_implementation
|
428
|
1656 *imp = XRECORD_LHEADER_IMPLEMENTATION (obj);
|
|
1657 if (imp->hash)
|
|
1658 return imp->hash (obj, depth);
|
|
1659 }
|
|
1660
|
|
1661 return LISP_HASH (obj);
|
|
1662 }
|
|
1663
|
|
1664 DEFUN ("sxhash", Fsxhash, 1, 1, 0, /*
|
|
1665 Return a hash value for OBJECT.
|
444
|
1666 \(equal obj1 obj2) implies (= (sxhash obj1) (sxhash obj2)).
|
428
|
1667 */
|
|
1668 (object))
|
|
1669 {
|
|
1670 return make_int (internal_hash (object, 0));
|
|
1671 }
|
|
1672
|
|
1673 #if 0
|
826
|
1674 DEFUN ("internal-hash-value", Finternal_hash_value, 1, 1, 0, /*
|
428
|
1675 Hash value of OBJECT. For debugging.
|
|
1676 The value is returned as (HIGH . LOW).
|
|
1677 */
|
|
1678 (object))
|
|
1679 {
|
|
1680 /* This function is pretty 32bit-centric. */
|
665
|
1681 Hashcode hash = internal_hash (object, 0);
|
428
|
1682 return Fcons (hash >> 16, hash & 0xffff);
|
|
1683 }
|
|
1684 #endif
|
|
1685
|
|
1686
|
|
1687 /************************************************************************/
|
|
1688 /* initialization */
|
|
1689 /************************************************************************/
|
|
1690
|
|
1691 void
|
|
1692 syms_of_elhash (void)
|
|
1693 {
|
|
1694 DEFSUBR (Fhash_table_p);
|
|
1695 DEFSUBR (Fmake_hash_table);
|
|
1696 DEFSUBR (Fcopy_hash_table);
|
|
1697 DEFSUBR (Fgethash);
|
|
1698 DEFSUBR (Fremhash);
|
|
1699 DEFSUBR (Fputhash);
|
|
1700 DEFSUBR (Fclrhash);
|
|
1701 DEFSUBR (Fmaphash);
|
|
1702 DEFSUBR (Fhash_table_count);
|
|
1703 DEFSUBR (Fhash_table_test);
|
|
1704 DEFSUBR (Fhash_table_size);
|
|
1705 DEFSUBR (Fhash_table_rehash_size);
|
|
1706 DEFSUBR (Fhash_table_rehash_threshold);
|
|
1707 DEFSUBR (Fhash_table_weakness);
|
|
1708 DEFSUBR (Fhash_table_type); /* obsolete */
|
|
1709 DEFSUBR (Fsxhash);
|
|
1710 #if 0
|
|
1711 DEFSUBR (Finternal_hash_value);
|
|
1712 #endif
|
|
1713
|
563
|
1714 DEFSYMBOL_MULTIWORD_PREDICATE (Qhash_tablep);
|
|
1715 DEFSYMBOL (Qhash_table);
|
|
1716 DEFSYMBOL (Qhashtable);
|
|
1717 DEFSYMBOL (Qweakness);
|
|
1718 DEFSYMBOL (Qvalue);
|
|
1719 DEFSYMBOL (Qkey_or_value);
|
|
1720 DEFSYMBOL (Qkey_and_value);
|
|
1721 DEFSYMBOL (Qrehash_size);
|
|
1722 DEFSYMBOL (Qrehash_threshold);
|
428
|
1723
|
563
|
1724 DEFSYMBOL (Qweak); /* obsolete */
|
|
1725 DEFSYMBOL (Qkey_weak); /* obsolete */
|
|
1726 DEFSYMBOL (Qkey_or_value_weak); /* obsolete */
|
|
1727 DEFSYMBOL (Qvalue_weak); /* obsolete */
|
|
1728 DEFSYMBOL (Qnon_weak); /* obsolete */
|
428
|
1729
|
563
|
1730 DEFKEYWORD (Q_test);
|
|
1731 DEFKEYWORD (Q_size);
|
|
1732 DEFKEYWORD (Q_rehash_size);
|
|
1733 DEFKEYWORD (Q_rehash_threshold);
|
|
1734 DEFKEYWORD (Q_weakness);
|
|
1735 DEFKEYWORD (Q_type); /* obsolete */
|
428
|
1736 }
|
|
1737
|
|
1738 void
|
771
|
1739 init_elhash_once_early (void)
|
428
|
1740 {
|
771
|
1741 INIT_LRECORD_IMPLEMENTATION (hash_table);
|
|
1742
|
428
|
1743 /* This must NOT be staticpro'd */
|
|
1744 Vall_weak_hash_tables = Qnil;
|
452
|
1745 dump_add_weak_object_chain (&Vall_weak_hash_tables);
|
428
|
1746 }
|