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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3 Copyright (C) 1995, 1996 Ben Wing.
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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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25 #include <config.h>
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26 #include "lisp.h"
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27 #include "bytecode.h"
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28 #include "elhash.h"
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29
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30 Lisp_Object Qhash_tablep;
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31 static Lisp_Object Qhashtable, Qhash_table;
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442
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32 static Lisp_Object Qweakness, Qvalue, Qkey_or_value, Qkey_and_value;
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428
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33 static Lisp_Object Vall_weak_hash_tables;
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34 static Lisp_Object Qrehash_size, Qrehash_threshold;
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35 static Lisp_Object Q_size, Q_test, Q_weakness, Q_rehash_size, Q_rehash_threshold;
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36
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37 /* obsolete as of 19990901 in xemacs-21.2 */
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442
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38 static Lisp_Object Qweak, Qkey_weak, Qvalue_weak, Qkey_or_value_weak;
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39 static Lisp_Object Qnon_weak, Q_type;
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428
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40
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41 typedef struct hentry
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42 {
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43 Lisp_Object key;
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44 Lisp_Object value;
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45 } hentry;
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46
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47 struct Lisp_Hash_Table
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48 {
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49 struct lcrecord_header header;
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50 size_t size;
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51 size_t count;
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52 size_t rehash_count;
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53 double rehash_size;
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54 double rehash_threshold;
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55 size_t golden_ratio;
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56 hash_table_hash_function_t hash_function;
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57 hash_table_test_function_t test_function;
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58 hentry *hentries;
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59 enum hash_table_weakness weakness;
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60 Lisp_Object next_weak; /* Used to chain together all of the weak
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61 hash tables. Don't mark through this. */
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62 };
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63
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64 #define HENTRY_CLEAR_P(hentry) ((*(EMACS_UINT*)(&((hentry)->key))) == 0)
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65 #define CLEAR_HENTRY(hentry) \
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66 ((*(EMACS_UINT*)(&((hentry)->key))) = 0, \
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67 (*(EMACS_UINT*)(&((hentry)->value))) = 0)
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68
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69 #define HASH_TABLE_DEFAULT_SIZE 16
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70 #define HASH_TABLE_DEFAULT_REHASH_SIZE 1.3
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71 #define HASH_TABLE_MIN_SIZE 10
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72
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434
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73 #define HASH_CODE(key, ht) \
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444
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74 ((((ht)->hash_function ? (ht)->hash_function (key) : LISP_HASH (key)) \
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75 * (ht)->golden_ratio) \
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76 % (ht)->size)
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428
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77
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78 #define KEYS_EQUAL_P(key1, key2, testfun) \
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434
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79 (EQ (key1, key2) || ((testfun) && (testfun) (key1, key2)))
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428
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80
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81 #define LINEAR_PROBING_LOOP(probe, entries, size) \
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82 for (; \
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83 !HENTRY_CLEAR_P (probe) || \
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84 (probe == entries + size ? \
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85 (probe = entries, !HENTRY_CLEAR_P (probe)) : 0); \
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86 probe++)
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87
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88 #ifndef ERROR_CHECK_HASH_TABLE
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89 # ifdef ERROR_CHECK_TYPECHECK
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90 # define ERROR_CHECK_HASH_TABLE 1
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91 # else
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92 # define ERROR_CHECK_HASH_TABLE 0
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93 # endif
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94 #endif
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95
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96 #if ERROR_CHECK_HASH_TABLE
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97 static void
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98 check_hash_table_invariants (Lisp_Hash_Table *ht)
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99 {
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100 assert (ht->count < ht->size);
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101 assert (ht->count <= ht->rehash_count);
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102 assert (ht->rehash_count < ht->size);
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103 assert ((double) ht->count * ht->rehash_threshold - 1 <= (double) ht->rehash_count);
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104 assert (HENTRY_CLEAR_P (ht->hentries + ht->size));
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105 }
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106 #else
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107 #define check_hash_table_invariants(ht)
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108 #endif
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109
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110 /* We use linear probing instead of double hashing, despite its lack
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111 of blessing by Knuth and company, because, as a result of the
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112 increasing discrepancy between CPU speeds and memory speeds, cache
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113 behavior is becoming increasingly important, e.g:
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114
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115 For a trivial loop, the penalty for non-sequential access of an array is:
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116 - a factor of 3-4 on Pentium Pro 200 Mhz
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117 - a factor of 10 on Ultrasparc 300 Mhz */
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118
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119 /* Return a suitable size for a hash table, with at least SIZE slots. */
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120 static size_t
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121 hash_table_size (size_t requested_size)
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122 {
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123 /* Return some prime near, but greater than or equal to, SIZE.
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124 Decades from the time of writing, someone will have a system large
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125 enough that the list below will be too short... */
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442
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126 static const size_t primes [] =
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428
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127 {
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128 19, 29, 41, 59, 79, 107, 149, 197, 263, 347, 457, 599, 787, 1031,
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129 1361, 1777, 2333, 3037, 3967, 5167, 6719, 8737, 11369, 14783,
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130 19219, 24989, 32491, 42257, 54941, 71429, 92861, 120721, 156941,
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131 204047, 265271, 344857, 448321, 582821, 757693, 985003, 1280519,
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132 1664681, 2164111, 2813353, 3657361, 4754591, 6180989, 8035301,
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133 10445899, 13579681, 17653589, 22949669, 29834603, 38784989,
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134 50420551, 65546729, 85210757, 110774011, 144006217, 187208107,
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135 243370577, 316381771, 411296309, 534685237, 695090819, 903618083,
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136 1174703521, 1527114613, 1985248999, 2580823717UL, 3355070839UL
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137 };
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138 /* We've heard of binary search. */
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139 int low, high;
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140 for (low = 0, high = countof (primes) - 1; high - low > 1;)
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141 {
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142 /* Loop Invariant: size < primes [high] */
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143 int mid = (low + high) / 2;
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144 if (primes [mid] < requested_size)
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145 low = mid;
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146 else
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147 high = mid;
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148 }
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149 return primes [high];
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150 }
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151
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152
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153 #if 0 /* I don't think these are needed any more.
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154 If using the general lisp_object_equal_*() functions
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155 causes efficiency problems, these can be resurrected. --ben */
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156 /* equality and hash functions for Lisp strings */
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157 int
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158 lisp_string_equal (Lisp_Object str1, Lisp_Object str2)
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159 {
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160 /* This is wrong anyway. You can't use strcmp() on Lisp strings,
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161 because they can contain zero characters. */
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162 return !strcmp ((char *) XSTRING_DATA (str1), (char *) XSTRING_DATA (str2));
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163 }
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164
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165 static hashcode_t
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166 lisp_string_hash (Lisp_Object obj)
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167 {
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168 return hash_string (XSTRING_DATA (str), XSTRING_LENGTH (str));
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169 }
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170
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171 #endif /* 0 */
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172
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173 static int
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174 lisp_object_eql_equal (Lisp_Object obj1, Lisp_Object obj2)
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175 {
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176 return EQ (obj1, obj2) || (FLOATP (obj1) && internal_equal (obj1, obj2, 0));
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177 }
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178
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179 static hashcode_t
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180 lisp_object_eql_hash (Lisp_Object obj)
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181 {
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182 return FLOATP (obj) ? internal_hash (obj, 0) : LISP_HASH (obj);
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183 }
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184
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185 static int
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186 lisp_object_equal_equal (Lisp_Object obj1, Lisp_Object obj2)
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187 {
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188 return internal_equal (obj1, obj2, 0);
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189 }
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190
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191 static hashcode_t
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192 lisp_object_equal_hash (Lisp_Object obj)
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193 {
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194 return internal_hash (obj, 0);
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195 }
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196
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197
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198 static Lisp_Object
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199 mark_hash_table (Lisp_Object obj)
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200 {
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201 Lisp_Hash_Table *ht = XHASH_TABLE (obj);
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202
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203 /* If the hash table is weak, we don't want to mark the keys and
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204 values (we scan over them after everything else has been marked,
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205 and mark or remove them as necessary). */
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206 if (ht->weakness == HASH_TABLE_NON_WEAK)
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207 {
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208 hentry *e, *sentinel;
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209
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210 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
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211 if (!HENTRY_CLEAR_P (e))
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212 {
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213 mark_object (e->key);
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214 mark_object (e->value);
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215 }
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216 }
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217 return Qnil;
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218 }
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219
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220 /* Equality of hash tables. Two hash tables are equal when they are of
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221 the same weakness and test function, they have the same number of
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222 elements, and for each key in the hash table, the values are `equal'.
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223
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224 This is similar to Common Lisp `equalp' of hash tables, with the
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225 difference that CL requires the keys to be compared with the test
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226 function, which we don't do. Doing that would require consing, and
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227 consing is a bad idea in `equal'. Anyway, our method should provide
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228 the same result -- if the keys are not equal according to the test
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229 function, then Fgethash() in hash_table_equal_mapper() will fail. */
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230 static int
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231 hash_table_equal (Lisp_Object hash_table1, Lisp_Object hash_table2, int depth)
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232 {
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233 Lisp_Hash_Table *ht1 = XHASH_TABLE (hash_table1);
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234 Lisp_Hash_Table *ht2 = XHASH_TABLE (hash_table2);
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235 hentry *e, *sentinel;
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236
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237 if ((ht1->test_function != ht2->test_function) ||
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238 (ht1->weakness != ht2->weakness) ||
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239 (ht1->count != ht2->count))
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240 return 0;
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241
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242 depth++;
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243
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244 for (e = ht1->hentries, sentinel = e + ht1->size; e < sentinel; e++)
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245 if (!HENTRY_CLEAR_P (e))
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246 /* Look up the key in the other hash table, and compare the values. */
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247 {
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248 Lisp_Object value_in_other = Fgethash (e->key, hash_table2, Qunbound);
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249 if (UNBOUNDP (value_in_other) ||
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250 !internal_equal (e->value, value_in_other, depth))
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251 return 0; /* Give up */
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252 }
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253
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254 return 1;
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255 }
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442
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256
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257 /* This is not a great hash function, but it _is_ correct and fast.
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258 Examining all entries is too expensive, and examining a random
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259 subset does not yield a correct hash function. */
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260 static hashcode_t
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261 hash_table_hash (Lisp_Object hash_table, int depth)
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262 {
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263 return XHASH_TABLE (hash_table)->count;
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264 }
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265
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428
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266
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267 /* Printing hash tables.
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268
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269 This is non-trivial, because we use a readable structure-style
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270 syntax for hash tables. This means that a typical hash table will be
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271 readably printed in the form of:
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272
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273 #s(hash-table size 2 data (key1 value1 key2 value2))
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274
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275 The supported hash table structure keywords and their values are:
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276 `test' (eql (or nil), eq or equal)
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277 `size' (a natnum or nil)
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278 `rehash-size' (a float)
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279 `rehash-threshold' (a float)
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442
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280 `weakness' (nil, key, value, key-and-value, or key-or-value)
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428
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281 `data' (a list)
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282
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430
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283 If `print-readably' is nil, then a simpler syntax is used, for example
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428
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284
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285 #<hash-table size 2/13 data (key1 value1 key2 value2) 0x874d>
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286
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287 The data is truncated to four pairs, and the rest is shown with
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288 `...'. This printer does not cons. */
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289
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290
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291 /* Print the data of the hash table. This maps through a Lisp
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292 hash table and prints key/value pairs using PRINTCHARFUN. */
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293 static void
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294 print_hash_table_data (Lisp_Hash_Table *ht, Lisp_Object printcharfun)
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295 {
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296 int count = 0;
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297 hentry *e, *sentinel;
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298
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299 write_c_string (" data (", printcharfun);
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300
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301 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
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302 if (!HENTRY_CLEAR_P (e))
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303 {
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304 if (count > 0)
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305 write_c_string (" ", printcharfun);
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306 if (!print_readably && count > 3)
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307 {
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308 write_c_string ("...", printcharfun);
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309 break;
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310 }
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311 print_internal (e->key, printcharfun, 1);
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312 write_c_string (" ", printcharfun);
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313 print_internal (e->value, printcharfun, 1);
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314 count++;
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315 }
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316
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317 write_c_string (")", printcharfun);
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318 }
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319
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320 static void
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321 print_hash_table (Lisp_Object obj, Lisp_Object printcharfun, int escapeflag)
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322 {
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323 Lisp_Hash_Table *ht = XHASH_TABLE (obj);
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324 char buf[128];
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325
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326 write_c_string (print_readably ? "#s(hash-table" : "#<hash-table",
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327 printcharfun);
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328
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329 /* These checks have a kludgy look to them, but they are safe.
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330 Due to nature of hashing, you cannot use arbitrary
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331 test functions anyway. */
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332 if (!ht->test_function)
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333 write_c_string (" test eq", printcharfun);
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334 else if (ht->test_function == lisp_object_equal_equal)
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335 write_c_string (" test equal", printcharfun);
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336 else if (ht->test_function == lisp_object_eql_equal)
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337 DO_NOTHING;
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338 else
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339 abort ();
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340
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341 if (ht->count || !print_readably)
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342 {
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343 if (print_readably)
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344 sprintf (buf, " size %lu", (unsigned long) ht->count);
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345 else
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346 sprintf (buf, " size %lu/%lu",
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347 (unsigned long) ht->count,
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348 (unsigned long) ht->size);
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349 write_c_string (buf, printcharfun);
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350 }
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351
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352 if (ht->weakness != HASH_TABLE_NON_WEAK)
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353 {
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354 sprintf (buf, " weakness %s",
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442
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355 (ht->weakness == HASH_TABLE_WEAK ? "key-and-value" :
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356 ht->weakness == HASH_TABLE_KEY_WEAK ? "key" :
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357 ht->weakness == HASH_TABLE_VALUE_WEAK ? "value" :
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358 ht->weakness == HASH_TABLE_KEY_VALUE_WEAK ? "key-or-value" :
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428
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359 "you-d-better-not-see-this"));
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360 write_c_string (buf, printcharfun);
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361 }
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362
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363 if (ht->count)
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364 print_hash_table_data (ht, printcharfun);
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365
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366 if (print_readably)
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367 write_c_string (")", printcharfun);
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368 else
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369 {
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370 sprintf (buf, " 0x%x>", ht->header.uid);
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371 write_c_string (buf, printcharfun);
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372 }
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373 }
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374
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375 static void
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376 finalize_hash_table (void *header, int for_disksave)
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377 {
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378 if (!for_disksave)
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379 {
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380 Lisp_Hash_Table *ht = (Lisp_Hash_Table *) header;
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381
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382 xfree (ht->hentries);
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383 ht->hentries = 0;
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384 }
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385 }
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386
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387 static const struct lrecord_description hentry_description_1[] = {
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440
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388 { XD_LISP_OBJECT, offsetof (hentry, key) },
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389 { XD_LISP_OBJECT, offsetof (hentry, value) },
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428
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390 { XD_END }
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391 };
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392
|
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393 static const struct struct_description hentry_description = {
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440
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394 sizeof (hentry),
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428
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395 hentry_description_1
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396 };
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397
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398 const struct lrecord_description hash_table_description[] = {
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440
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399 { XD_SIZE_T, offsetof (Lisp_Hash_Table, size) },
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400 { XD_STRUCT_PTR, offsetof (Lisp_Hash_Table, hentries), XD_INDIRECT(0, 1), &hentry_description },
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401 { XD_LO_LINK, offsetof (Lisp_Hash_Table, next_weak) },
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428
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402 { XD_END }
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403 };
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404
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405 DEFINE_LRECORD_IMPLEMENTATION ("hash-table", hash_table,
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406 mark_hash_table, print_hash_table,
|
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407 finalize_hash_table,
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442
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408 hash_table_equal, hash_table_hash,
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428
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409 hash_table_description,
|
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410 Lisp_Hash_Table);
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411
|
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412 static Lisp_Hash_Table *
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413 xhash_table (Lisp_Object hash_table)
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414 {
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415 if (!gc_in_progress)
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416 CHECK_HASH_TABLE (hash_table);
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417 check_hash_table_invariants (XHASH_TABLE (hash_table));
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418 return XHASH_TABLE (hash_table);
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419 }
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420
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421
|
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422 /************************************************************************/
|
|
423 /* Creation of Hash Tables */
|
|
424 /************************************************************************/
|
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425
|
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426 /* Creation of hash tables, without error-checking. */
|
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427 static void
|
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428 compute_hash_table_derived_values (Lisp_Hash_Table *ht)
|
|
429 {
|
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430 ht->rehash_count = (size_t)
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438
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431 ((double) ht->size * ht->rehash_threshold);
|
428
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432 ht->golden_ratio = (size_t)
|
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433 ((double) ht->size * (.6180339887 / (double) sizeof (Lisp_Object)));
|
|
434 }
|
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435
|
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436 Lisp_Object
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450
|
437 make_standard_lisp_hash_table (enum hash_table_test test,
|
|
438 size_t size,
|
|
439 double rehash_size,
|
|
440 double rehash_threshold,
|
|
441 enum hash_table_weakness weakness)
|
|
442 {
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462
|
443 hash_table_hash_function_t hash_function = 0;
|
450
|
444 hash_table_test_function_t test_function = 0;
|
|
445
|
|
446 switch (test)
|
|
447 {
|
|
448 case HASH_TABLE_EQ:
|
|
449 test_function = 0;
|
|
450 hash_function = 0;
|
|
451 break;
|
|
452
|
|
453 case HASH_TABLE_EQL:
|
|
454 test_function = lisp_object_eql_equal;
|
|
455 hash_function = lisp_object_eql_hash;
|
|
456 break;
|
|
457
|
|
458 case HASH_TABLE_EQUAL:
|
|
459 test_function = lisp_object_equal_equal;
|
|
460 hash_function = lisp_object_equal_hash;
|
|
461 break;
|
|
462
|
|
463 default:
|
|
464 abort ();
|
|
465 }
|
|
466
|
|
467 return make_general_lisp_hash_table (hash_function, test_function,
|
|
468 size, rehash_size, rehash_threshold,
|
|
469 weakness);
|
|
470 }
|
|
471
|
|
472 Lisp_Object
|
|
473 make_general_lisp_hash_table (hash_table_hash_function_t hash_function,
|
|
474 hash_table_test_function_t test_function,
|
428
|
475 size_t size,
|
|
476 double rehash_size,
|
|
477 double rehash_threshold,
|
|
478 enum hash_table_weakness weakness)
|
|
479 {
|
|
480 Lisp_Object hash_table;
|
|
481 Lisp_Hash_Table *ht = alloc_lcrecord_type (Lisp_Hash_Table, &lrecord_hash_table);
|
|
482
|
450
|
483 ht->test_function = test_function;
|
|
484 ht->hash_function = hash_function;
|
438
|
485 ht->weakness = weakness;
|
|
486
|
|
487 ht->rehash_size =
|
|
488 rehash_size > 1.0 ? rehash_size : HASH_TABLE_DEFAULT_REHASH_SIZE;
|
|
489
|
|
490 ht->rehash_threshold =
|
|
491 rehash_threshold > 0.0 ? rehash_threshold :
|
|
492 size > 4096 && !ht->test_function ? 0.7 : 0.6;
|
|
493
|
428
|
494 if (size < HASH_TABLE_MIN_SIZE)
|
|
495 size = HASH_TABLE_MIN_SIZE;
|
438
|
496 ht->size = hash_table_size ((size_t) (((double) size / ht->rehash_threshold)
|
|
497 + 1.0));
|
428
|
498 ht->count = 0;
|
438
|
499
|
428
|
500 compute_hash_table_derived_values (ht);
|
|
501
|
|
502 /* We leave room for one never-occupied sentinel hentry at the end. */
|
458
|
503 ht->hentries = xnew_array_and_zero (hentry, ht->size + 1);
|
428
|
504
|
|
505 XSETHASH_TABLE (hash_table, ht);
|
|
506
|
|
507 if (weakness == HASH_TABLE_NON_WEAK)
|
|
508 ht->next_weak = Qunbound;
|
|
509 else
|
|
510 ht->next_weak = Vall_weak_hash_tables, Vall_weak_hash_tables = hash_table;
|
|
511
|
|
512 return hash_table;
|
|
513 }
|
|
514
|
|
515 Lisp_Object
|
|
516 make_lisp_hash_table (size_t size,
|
|
517 enum hash_table_weakness weakness,
|
|
518 enum hash_table_test test)
|
|
519 {
|
450
|
520 return make_standard_lisp_hash_table (test, size, -1.0, -1.0, weakness);
|
428
|
521 }
|
|
522
|
|
523 /* Pretty reading of hash tables.
|
|
524
|
|
525 Here we use the existing structures mechanism (which is,
|
|
526 unfortunately, pretty cumbersome) for validating and instantiating
|
|
527 the hash tables. The idea is that the side-effect of reading a
|
|
528 #s(hash-table PLIST) object is creation of a hash table with desired
|
|
529 properties, and that the hash table is returned. */
|
|
530
|
|
531 /* Validation functions: each keyword provides its own validation
|
|
532 function. The errors should maybe be continuable, but it is
|
|
533 unclear how this would cope with ERRB. */
|
|
534 static int
|
|
535 hash_table_size_validate (Lisp_Object keyword, Lisp_Object value,
|
|
536 Error_behavior errb)
|
|
537 {
|
|
538 if (NATNUMP (value))
|
|
539 return 1;
|
|
540
|
|
541 maybe_signal_error (Qwrong_type_argument, list2 (Qnatnump, value),
|
|
542 Qhash_table, errb);
|
|
543 return 0;
|
|
544 }
|
|
545
|
|
546 static size_t
|
|
547 decode_hash_table_size (Lisp_Object obj)
|
|
548 {
|
|
549 return NILP (obj) ? HASH_TABLE_DEFAULT_SIZE : XINT (obj);
|
|
550 }
|
|
551
|
|
552 static int
|
|
553 hash_table_weakness_validate (Lisp_Object keyword, Lisp_Object value,
|
|
554 Error_behavior errb)
|
|
555 {
|
442
|
556 if (EQ (value, Qnil)) return 1;
|
|
557 if (EQ (value, Qt)) return 1;
|
|
558 if (EQ (value, Qkey)) return 1;
|
|
559 if (EQ (value, Qkey_and_value)) return 1;
|
|
560 if (EQ (value, Qkey_or_value)) return 1;
|
|
561 if (EQ (value, Qvalue)) return 1;
|
428
|
562
|
|
563 /* Following values are obsolete as of 19990901 in xemacs-21.2 */
|
442
|
564 if (EQ (value, Qnon_weak)) return 1;
|
|
565 if (EQ (value, Qweak)) return 1;
|
|
566 if (EQ (value, Qkey_weak)) return 1;
|
|
567 if (EQ (value, Qkey_or_value_weak)) return 1;
|
|
568 if (EQ (value, Qvalue_weak)) return 1;
|
428
|
569
|
|
570 maybe_signal_simple_error ("Invalid hash table weakness",
|
|
571 value, Qhash_table, errb);
|
|
572 return 0;
|
|
573 }
|
|
574
|
|
575 static enum hash_table_weakness
|
|
576 decode_hash_table_weakness (Lisp_Object obj)
|
|
577 {
|
442
|
578 if (EQ (obj, Qnil)) return HASH_TABLE_NON_WEAK;
|
|
579 if (EQ (obj, Qt)) return HASH_TABLE_WEAK;
|
|
580 if (EQ (obj, Qkey_and_value)) return HASH_TABLE_WEAK;
|
|
581 if (EQ (obj, Qkey)) return HASH_TABLE_KEY_WEAK;
|
|
582 if (EQ (obj, Qkey_or_value)) return HASH_TABLE_KEY_VALUE_WEAK;
|
|
583 if (EQ (obj, Qvalue)) return HASH_TABLE_VALUE_WEAK;
|
428
|
584
|
|
585 /* Following values are obsolete as of 19990901 in xemacs-21.2 */
|
442
|
586 if (EQ (obj, Qnon_weak)) return HASH_TABLE_NON_WEAK;
|
|
587 if (EQ (obj, Qweak)) return HASH_TABLE_WEAK;
|
|
588 if (EQ (obj, Qkey_weak)) return HASH_TABLE_KEY_WEAK;
|
|
589 if (EQ (obj, Qkey_or_value_weak)) return HASH_TABLE_KEY_VALUE_WEAK;
|
|
590 if (EQ (obj, Qvalue_weak)) return HASH_TABLE_VALUE_WEAK;
|
428
|
591
|
|
592 signal_simple_error ("Invalid hash table weakness", obj);
|
|
593 return HASH_TABLE_NON_WEAK; /* not reached */
|
|
594 }
|
|
595
|
|
596 static int
|
|
597 hash_table_test_validate (Lisp_Object keyword, Lisp_Object value,
|
|
598 Error_behavior errb)
|
|
599 {
|
|
600 if (EQ (value, Qnil)) return 1;
|
|
601 if (EQ (value, Qeq)) return 1;
|
|
602 if (EQ (value, Qequal)) return 1;
|
|
603 if (EQ (value, Qeql)) return 1;
|
|
604
|
|
605 maybe_signal_simple_error ("Invalid hash table test",
|
|
606 value, Qhash_table, errb);
|
|
607 return 0;
|
|
608 }
|
|
609
|
|
610 static enum hash_table_test
|
|
611 decode_hash_table_test (Lisp_Object obj)
|
|
612 {
|
|
613 if (EQ (obj, Qnil)) return HASH_TABLE_EQL;
|
|
614 if (EQ (obj, Qeq)) return HASH_TABLE_EQ;
|
|
615 if (EQ (obj, Qequal)) return HASH_TABLE_EQUAL;
|
|
616 if (EQ (obj, Qeql)) return HASH_TABLE_EQL;
|
|
617
|
|
618 signal_simple_error ("Invalid hash table test", obj);
|
|
619 return HASH_TABLE_EQ; /* not reached */
|
|
620 }
|
|
621
|
|
622 static int
|
|
623 hash_table_rehash_size_validate (Lisp_Object keyword, Lisp_Object value,
|
|
624 Error_behavior errb)
|
|
625 {
|
|
626 if (!FLOATP (value))
|
|
627 {
|
|
628 maybe_signal_error (Qwrong_type_argument, list2 (Qfloatp, value),
|
|
629 Qhash_table, errb);
|
|
630 return 0;
|
|
631 }
|
|
632
|
|
633 {
|
|
634 double rehash_size = XFLOAT_DATA (value);
|
|
635 if (rehash_size <= 1.0)
|
|
636 {
|
|
637 maybe_signal_simple_error
|
|
638 ("Hash table rehash size must be greater than 1.0",
|
|
639 value, Qhash_table, errb);
|
|
640 return 0;
|
|
641 }
|
|
642 }
|
|
643
|
|
644 return 1;
|
|
645 }
|
|
646
|
|
647 static double
|
|
648 decode_hash_table_rehash_size (Lisp_Object rehash_size)
|
|
649 {
|
|
650 return NILP (rehash_size) ? -1.0 : XFLOAT_DATA (rehash_size);
|
|
651 }
|
|
652
|
|
653 static int
|
|
654 hash_table_rehash_threshold_validate (Lisp_Object keyword, Lisp_Object value,
|
|
655 Error_behavior errb)
|
|
656 {
|
|
657 if (!FLOATP (value))
|
|
658 {
|
|
659 maybe_signal_error (Qwrong_type_argument, list2 (Qfloatp, value),
|
|
660 Qhash_table, errb);
|
|
661 return 0;
|
|
662 }
|
|
663
|
|
664 {
|
|
665 double rehash_threshold = XFLOAT_DATA (value);
|
|
666 if (rehash_threshold <= 0.0 || rehash_threshold >= 1.0)
|
|
667 {
|
|
668 maybe_signal_simple_error
|
|
669 ("Hash table rehash threshold must be between 0.0 and 1.0",
|
|
670 value, Qhash_table, errb);
|
|
671 return 0;
|
|
672 }
|
|
673 }
|
|
674
|
|
675 return 1;
|
|
676 }
|
|
677
|
|
678 static double
|
|
679 decode_hash_table_rehash_threshold (Lisp_Object rehash_threshold)
|
|
680 {
|
|
681 return NILP (rehash_threshold) ? -1.0 : XFLOAT_DATA (rehash_threshold);
|
|
682 }
|
|
683
|
|
684 static int
|
|
685 hash_table_data_validate (Lisp_Object keyword, Lisp_Object value,
|
|
686 Error_behavior errb)
|
|
687 {
|
|
688 int len;
|
|
689
|
|
690 GET_EXTERNAL_LIST_LENGTH (value, len);
|
|
691
|
|
692 if (len & 1)
|
|
693 {
|
|
694 maybe_signal_simple_error
|
|
695 ("Hash table data must have alternating key/value pairs",
|
|
696 value, Qhash_table, errb);
|
|
697 return 0;
|
|
698 }
|
|
699 return 1;
|
|
700 }
|
|
701
|
|
702 /* The actual instantiation of a hash table. This does practically no
|
|
703 error checking, because it relies on the fact that the paranoid
|
|
704 functions above have error-checked everything to the last details.
|
|
705 If this assumption is wrong, we will get a crash immediately (with
|
|
706 error-checking compiled in), and we'll know if there is a bug in
|
|
707 the structure mechanism. So there. */
|
|
708 static Lisp_Object
|
|
709 hash_table_instantiate (Lisp_Object plist)
|
|
710 {
|
|
711 Lisp_Object hash_table;
|
|
712 Lisp_Object test = Qnil;
|
|
713 Lisp_Object size = Qnil;
|
|
714 Lisp_Object rehash_size = Qnil;
|
|
715 Lisp_Object rehash_threshold = Qnil;
|
|
716 Lisp_Object weakness = Qnil;
|
|
717 Lisp_Object data = Qnil;
|
|
718
|
|
719 while (!NILP (plist))
|
|
720 {
|
|
721 Lisp_Object key, value;
|
|
722 key = XCAR (plist); plist = XCDR (plist);
|
|
723 value = XCAR (plist); plist = XCDR (plist);
|
|
724
|
|
725 if (EQ (key, Qtest)) test = value;
|
|
726 else if (EQ (key, Qsize)) size = value;
|
|
727 else if (EQ (key, Qrehash_size)) rehash_size = value;
|
|
728 else if (EQ (key, Qrehash_threshold)) rehash_threshold = value;
|
|
729 else if (EQ (key, Qweakness)) weakness = value;
|
|
730 else if (EQ (key, Qdata)) data = value;
|
|
731 else if (EQ (key, Qtype))/*obsolete*/ weakness = value;
|
|
732 else
|
|
733 abort ();
|
|
734 }
|
|
735
|
|
736 /* Create the hash table. */
|
450
|
737 hash_table = make_standard_lisp_hash_table
|
428
|
738 (decode_hash_table_test (test),
|
|
739 decode_hash_table_size (size),
|
|
740 decode_hash_table_rehash_size (rehash_size),
|
|
741 decode_hash_table_rehash_threshold (rehash_threshold),
|
|
742 decode_hash_table_weakness (weakness));
|
|
743
|
|
744 /* I'm not sure whether this can GC, but better safe than sorry. */
|
|
745 {
|
|
746 struct gcpro gcpro1;
|
|
747 GCPRO1 (hash_table);
|
|
748
|
|
749 /* And fill it with data. */
|
|
750 while (!NILP (data))
|
|
751 {
|
|
752 Lisp_Object key, value;
|
|
753 key = XCAR (data); data = XCDR (data);
|
|
754 value = XCAR (data); data = XCDR (data);
|
|
755 Fputhash (key, value, hash_table);
|
|
756 }
|
|
757 UNGCPRO;
|
|
758 }
|
|
759
|
|
760 return hash_table;
|
|
761 }
|
|
762
|
|
763 static void
|
|
764 structure_type_create_hash_table_structure_name (Lisp_Object structure_name)
|
|
765 {
|
|
766 struct structure_type *st;
|
|
767
|
|
768 st = define_structure_type (structure_name, 0, hash_table_instantiate);
|
|
769 define_structure_type_keyword (st, Qtest, hash_table_test_validate);
|
|
770 define_structure_type_keyword (st, Qsize, hash_table_size_validate);
|
|
771 define_structure_type_keyword (st, Qrehash_size, hash_table_rehash_size_validate);
|
|
772 define_structure_type_keyword (st, Qrehash_threshold, hash_table_rehash_threshold_validate);
|
|
773 define_structure_type_keyword (st, Qweakness, hash_table_weakness_validate);
|
|
774 define_structure_type_keyword (st, Qdata, hash_table_data_validate);
|
|
775
|
|
776 /* obsolete as of 19990901 in xemacs-21.2 */
|
|
777 define_structure_type_keyword (st, Qtype, hash_table_weakness_validate);
|
|
778 }
|
|
779
|
|
780 /* Create a built-in Lisp structure type named `hash-table'.
|
|
781 We make #s(hashtable ...) equivalent to #s(hash-table ...),
|
|
782 for backward compatibility.
|
|
783 This is called from emacs.c. */
|
|
784 void
|
|
785 structure_type_create_hash_table (void)
|
|
786 {
|
|
787 structure_type_create_hash_table_structure_name (Qhash_table);
|
|
788 structure_type_create_hash_table_structure_name (Qhashtable); /* compat */
|
|
789 }
|
|
790
|
|
791
|
|
792 /************************************************************************/
|
|
793 /* Definition of Lisp-visible methods */
|
|
794 /************************************************************************/
|
|
795
|
|
796 DEFUN ("hash-table-p", Fhash_table_p, 1, 1, 0, /*
|
|
797 Return t if OBJECT is a hash table, else nil.
|
|
798 */
|
|
799 (object))
|
|
800 {
|
|
801 return HASH_TABLEP (object) ? Qt : Qnil;
|
|
802 }
|
|
803
|
|
804 DEFUN ("make-hash-table", Fmake_hash_table, 0, MANY, 0, /*
|
|
805 Return a new empty hash table object.
|
|
806 Use Common Lisp style keywords to specify hash table properties.
|
|
807 (make-hash-table &key test size rehash-size rehash-threshold weakness)
|
|
808
|
|
809 Keyword :test can be `eq', `eql' (default) or `equal'.
|
|
810 Comparison between keys is done using this function.
|
|
811 If speed is important, consider using `eq'.
|
|
812 When storing strings in the hash table, you will likely need to use `equal'.
|
|
813
|
|
814 Keyword :size specifies the number of keys likely to be inserted.
|
|
815 This number of entries can be inserted without enlarging the hash table.
|
|
816
|
|
817 Keyword :rehash-size must be a float greater than 1.0, and specifies
|
|
818 the factor by which to increase the size of the hash table when enlarging.
|
|
819
|
|
820 Keyword :rehash-threshold must be a float between 0.0 and 1.0,
|
|
821 and specifies the load factor of the hash table which triggers enlarging.
|
|
822
|
442
|
823 Non-standard keyword :weakness can be `nil' (default), `t', `key-and-value',
|
|
824 `key', `value' or `key-or-value'. `t' is an alias for `key-and-value'.
|
428
|
825
|
442
|
826 A key-and-value-weak hash table, also known as a fully-weak or simply
|
|
827 as a weak hash table, is one whose pointers do not count as GC
|
|
828 referents: for any key-value pair in the hash table, if the only
|
|
829 remaining pointer to either the key or the value is in a weak hash
|
|
830 table, then the pair will be removed from the hash table, and the key
|
|
831 and value collected. A non-weak hash table (or any other pointer)
|
|
832 would prevent the object from being collected.
|
428
|
833
|
|
834 A key-weak hash table is similar to a fully-weak hash table except that
|
|
835 a key-value pair will be removed only if the key remains unmarked
|
|
836 outside of weak hash tables. The pair will remain in the hash table if
|
|
837 the key is pointed to by something other than a weak hash table, even
|
|
838 if the value is not.
|
|
839
|
|
840 A value-weak hash table is similar to a fully-weak hash table except
|
|
841 that a key-value pair will be removed only if the value remains
|
|
842 unmarked outside of weak hash tables. The pair will remain in the
|
|
843 hash table if the value is pointed to by something other than a weak
|
|
844 hash table, even if the key is not.
|
442
|
845
|
|
846 A key-or-value-weak hash table is similar to a fully-weak hash table except
|
|
847 that a key-value pair will be removed only if the value and the key remain
|
|
848 unmarked outside of weak hash tables. The pair will remain in the
|
|
849 hash table if the value or key are pointed to by something other than a weak
|
|
850 hash table, even if the other is not.
|
428
|
851 */
|
|
852 (int nargs, Lisp_Object *args))
|
|
853 {
|
|
854 int i = 0;
|
|
855 Lisp_Object test = Qnil;
|
|
856 Lisp_Object size = Qnil;
|
|
857 Lisp_Object rehash_size = Qnil;
|
|
858 Lisp_Object rehash_threshold = Qnil;
|
|
859 Lisp_Object weakness = Qnil;
|
|
860
|
|
861 while (i + 1 < nargs)
|
|
862 {
|
|
863 Lisp_Object keyword = args[i++];
|
|
864 Lisp_Object value = args[i++];
|
|
865
|
|
866 if (EQ (keyword, Q_test)) test = value;
|
|
867 else if (EQ (keyword, Q_size)) size = value;
|
|
868 else if (EQ (keyword, Q_rehash_size)) rehash_size = value;
|
|
869 else if (EQ (keyword, Q_rehash_threshold)) rehash_threshold = value;
|
|
870 else if (EQ (keyword, Q_weakness)) weakness = value;
|
|
871 else if (EQ (keyword, Q_type))/*obsolete*/ weakness = value;
|
|
872 else signal_simple_error ("Invalid hash table property keyword", keyword);
|
|
873 }
|
|
874
|
|
875 if (i < nargs)
|
|
876 signal_simple_error ("Hash table property requires a value", args[i]);
|
|
877
|
|
878 #define VALIDATE_VAR(var) \
|
|
879 if (!NILP (var)) hash_table_##var##_validate (Q##var, var, ERROR_ME);
|
|
880
|
|
881 VALIDATE_VAR (test);
|
|
882 VALIDATE_VAR (size);
|
|
883 VALIDATE_VAR (rehash_size);
|
|
884 VALIDATE_VAR (rehash_threshold);
|
|
885 VALIDATE_VAR (weakness);
|
|
886
|
450
|
887 return make_standard_lisp_hash_table
|
428
|
888 (decode_hash_table_test (test),
|
|
889 decode_hash_table_size (size),
|
|
890 decode_hash_table_rehash_size (rehash_size),
|
|
891 decode_hash_table_rehash_threshold (rehash_threshold),
|
|
892 decode_hash_table_weakness (weakness));
|
|
893 }
|
|
894
|
|
895 DEFUN ("copy-hash-table", Fcopy_hash_table, 1, 1, 0, /*
|
|
896 Return a new hash table containing the same keys and values as HASH-TABLE.
|
|
897 The keys and values will not themselves be copied.
|
|
898 */
|
|
899 (hash_table))
|
|
900 {
|
442
|
901 const Lisp_Hash_Table *ht_old = xhash_table (hash_table);
|
428
|
902 Lisp_Hash_Table *ht = alloc_lcrecord_type (Lisp_Hash_Table, &lrecord_hash_table);
|
|
903
|
|
904 copy_lcrecord (ht, ht_old);
|
|
905
|
|
906 ht->hentries = xnew_array (hentry, ht_old->size + 1);
|
|
907 memcpy (ht->hentries, ht_old->hentries, (ht_old->size + 1) * sizeof (hentry));
|
|
908
|
|
909 XSETHASH_TABLE (hash_table, ht);
|
|
910
|
|
911 if (! EQ (ht->next_weak, Qunbound))
|
|
912 {
|
|
913 ht->next_weak = Vall_weak_hash_tables;
|
|
914 Vall_weak_hash_tables = hash_table;
|
|
915 }
|
|
916
|
|
917 return hash_table;
|
|
918 }
|
|
919
|
|
920 static void
|
|
921 resize_hash_table (Lisp_Hash_Table *ht, size_t new_size)
|
|
922 {
|
440
|
923 hentry *old_entries, *new_entries, *sentinel, *e;
|
428
|
924 size_t old_size;
|
|
925
|
|
926 old_size = ht->size;
|
|
927 ht->size = new_size;
|
|
928
|
|
929 old_entries = ht->hentries;
|
|
930
|
440
|
931 ht->hentries = xnew_array_and_zero (hentry, new_size + 1);
|
428
|
932 new_entries = ht->hentries;
|
|
933
|
|
934 compute_hash_table_derived_values (ht);
|
|
935
|
440
|
936 for (e = old_entries, sentinel = e + old_size; e < sentinel; e++)
|
428
|
937 if (!HENTRY_CLEAR_P (e))
|
|
938 {
|
|
939 hentry *probe = new_entries + HASH_CODE (e->key, ht);
|
|
940 LINEAR_PROBING_LOOP (probe, new_entries, new_size)
|
|
941 ;
|
|
942 *probe = *e;
|
|
943 }
|
|
944
|
|
945 if (!DUMPEDP (old_entries))
|
|
946 xfree (old_entries);
|
|
947 }
|
|
948
|
440
|
949 /* After a hash table has been saved to disk and later restored by the
|
|
950 portable dumper, it contains the same objects, but their addresses
|
|
951 and thus their HASH_CODEs have changed. */
|
428
|
952 void
|
440
|
953 pdump_reorganize_hash_table (Lisp_Object hash_table)
|
428
|
954 {
|
442
|
955 const Lisp_Hash_Table *ht = xhash_table (hash_table);
|
440
|
956 hentry *new_entries = xnew_array_and_zero (hentry, ht->size + 1);
|
|
957 hentry *e, *sentinel;
|
|
958
|
|
959 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
|
|
960 if (!HENTRY_CLEAR_P (e))
|
|
961 {
|
|
962 hentry *probe = new_entries + HASH_CODE (e->key, ht);
|
|
963 LINEAR_PROBING_LOOP (probe, new_entries, ht->size)
|
|
964 ;
|
|
965 *probe = *e;
|
|
966 }
|
|
967
|
|
968 memcpy (ht->hentries, new_entries, ht->size * sizeof (hentry));
|
|
969
|
|
970 xfree (new_entries);
|
428
|
971 }
|
|
972
|
|
973 static void
|
|
974 enlarge_hash_table (Lisp_Hash_Table *ht)
|
|
975 {
|
432
|
976 size_t new_size =
|
428
|
977 hash_table_size ((size_t) ((double) ht->size * ht->rehash_size));
|
|
978 resize_hash_table (ht, new_size);
|
|
979 }
|
|
980
|
|
981 static hentry *
|
442
|
982 find_hentry (Lisp_Object key, const Lisp_Hash_Table *ht)
|
428
|
983 {
|
|
984 hash_table_test_function_t test_function = ht->test_function;
|
|
985 hentry *entries = ht->hentries;
|
|
986 hentry *probe = entries + HASH_CODE (key, ht);
|
|
987
|
|
988 LINEAR_PROBING_LOOP (probe, entries, ht->size)
|
|
989 if (KEYS_EQUAL_P (probe->key, key, test_function))
|
|
990 break;
|
|
991
|
|
992 return probe;
|
|
993 }
|
|
994
|
|
995 DEFUN ("gethash", Fgethash, 2, 3, 0, /*
|
|
996 Find hash value for KEY in HASH-TABLE.
|
|
997 If there is no corresponding value, return DEFAULT (which defaults to nil).
|
|
998 */
|
|
999 (key, hash_table, default_))
|
|
1000 {
|
442
|
1001 const Lisp_Hash_Table *ht = xhash_table (hash_table);
|
428
|
1002 hentry *e = find_hentry (key, ht);
|
|
1003
|
|
1004 return HENTRY_CLEAR_P (e) ? default_ : e->value;
|
|
1005 }
|
|
1006
|
|
1007 DEFUN ("puthash", Fputhash, 3, 3, 0, /*
|
|
1008 Hash KEY to VALUE in HASH-TABLE.
|
|
1009 */
|
|
1010 (key, value, hash_table))
|
|
1011 {
|
|
1012 Lisp_Hash_Table *ht = xhash_table (hash_table);
|
|
1013 hentry *e = find_hentry (key, ht);
|
|
1014
|
|
1015 if (!HENTRY_CLEAR_P (e))
|
|
1016 return e->value = value;
|
|
1017
|
|
1018 e->key = key;
|
|
1019 e->value = value;
|
|
1020
|
|
1021 if (++ht->count >= ht->rehash_count)
|
|
1022 enlarge_hash_table (ht);
|
|
1023
|
|
1024 return value;
|
|
1025 }
|
|
1026
|
|
1027 /* Remove hentry pointed at by PROBE.
|
|
1028 Subsequent entries are removed and reinserted.
|
|
1029 We don't use tombstones - too wasteful. */
|
|
1030 static void
|
|
1031 remhash_1 (Lisp_Hash_Table *ht, hentry *entries, hentry *probe)
|
|
1032 {
|
|
1033 size_t size = ht->size;
|
|
1034 CLEAR_HENTRY (probe);
|
|
1035 probe++;
|
|
1036 ht->count--;
|
|
1037
|
|
1038 LINEAR_PROBING_LOOP (probe, entries, size)
|
|
1039 {
|
|
1040 Lisp_Object key = probe->key;
|
|
1041 hentry *probe2 = entries + HASH_CODE (key, ht);
|
|
1042 LINEAR_PROBING_LOOP (probe2, entries, size)
|
|
1043 if (EQ (probe2->key, key))
|
|
1044 /* hentry at probe doesn't need to move. */
|
|
1045 goto continue_outer_loop;
|
|
1046 /* Move hentry from probe to new home at probe2. */
|
|
1047 *probe2 = *probe;
|
|
1048 CLEAR_HENTRY (probe);
|
|
1049 continue_outer_loop: continue;
|
|
1050 }
|
|
1051 }
|
|
1052
|
|
1053 DEFUN ("remhash", Fremhash, 2, 2, 0, /*
|
|
1054 Remove the entry for KEY from HASH-TABLE.
|
|
1055 Do nothing if there is no entry for KEY in HASH-TABLE.
|
|
1056 */
|
|
1057 (key, hash_table))
|
|
1058 {
|
|
1059 Lisp_Hash_Table *ht = xhash_table (hash_table);
|
|
1060 hentry *e = find_hentry (key, ht);
|
|
1061
|
|
1062 if (HENTRY_CLEAR_P (e))
|
|
1063 return Qnil;
|
|
1064
|
|
1065 remhash_1 (ht, ht->hentries, e);
|
|
1066 return Qt;
|
|
1067 }
|
|
1068
|
|
1069 DEFUN ("clrhash", Fclrhash, 1, 1, 0, /*
|
|
1070 Remove all entries from HASH-TABLE, leaving it empty.
|
|
1071 */
|
|
1072 (hash_table))
|
|
1073 {
|
|
1074 Lisp_Hash_Table *ht = xhash_table (hash_table);
|
|
1075 hentry *e, *sentinel;
|
|
1076
|
|
1077 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
|
|
1078 CLEAR_HENTRY (e);
|
|
1079 ht->count = 0;
|
|
1080
|
|
1081 return hash_table;
|
|
1082 }
|
|
1083
|
|
1084 /************************************************************************/
|
|
1085 /* Accessor Functions */
|
|
1086 /************************************************************************/
|
|
1087
|
|
1088 DEFUN ("hash-table-count", Fhash_table_count, 1, 1, 0, /*
|
|
1089 Return the number of entries in HASH-TABLE.
|
|
1090 */
|
|
1091 (hash_table))
|
|
1092 {
|
|
1093 return make_int (xhash_table (hash_table)->count);
|
|
1094 }
|
|
1095
|
|
1096 DEFUN ("hash-table-test", Fhash_table_test, 1, 1, 0, /*
|
|
1097 Return the test function of HASH-TABLE.
|
|
1098 This can be one of `eq', `eql' or `equal'.
|
|
1099 */
|
|
1100 (hash_table))
|
|
1101 {
|
|
1102 hash_table_test_function_t fun = xhash_table (hash_table)->test_function;
|
|
1103
|
|
1104 return (fun == lisp_object_eql_equal ? Qeql :
|
|
1105 fun == lisp_object_equal_equal ? Qequal :
|
|
1106 Qeq);
|
|
1107 }
|
|
1108
|
|
1109 DEFUN ("hash-table-size", Fhash_table_size, 1, 1, 0, /*
|
|
1110 Return the size of HASH-TABLE.
|
|
1111 This is the current number of slots in HASH-TABLE, whether occupied or not.
|
|
1112 */
|
|
1113 (hash_table))
|
|
1114 {
|
|
1115 return make_int (xhash_table (hash_table)->size);
|
|
1116 }
|
|
1117
|
|
1118 DEFUN ("hash-table-rehash-size", Fhash_table_rehash_size, 1, 1, 0, /*
|
|
1119 Return the current rehash size of HASH-TABLE.
|
|
1120 This is a float greater than 1.0; the factor by which HASH-TABLE
|
|
1121 is enlarged when the rehash threshold is exceeded.
|
|
1122 */
|
|
1123 (hash_table))
|
|
1124 {
|
|
1125 return make_float (xhash_table (hash_table)->rehash_size);
|
|
1126 }
|
|
1127
|
|
1128 DEFUN ("hash-table-rehash-threshold", Fhash_table_rehash_threshold, 1, 1, 0, /*
|
|
1129 Return the current rehash threshold of HASH-TABLE.
|
|
1130 This is a float between 0.0 and 1.0; the maximum `load factor' of HASH-TABLE,
|
|
1131 beyond which the HASH-TABLE is enlarged by rehashing.
|
|
1132 */
|
|
1133 (hash_table))
|
|
1134 {
|
438
|
1135 return make_float (xhash_table (hash_table)->rehash_threshold);
|
428
|
1136 }
|
|
1137
|
|
1138 DEFUN ("hash-table-weakness", Fhash_table_weakness, 1, 1, 0, /*
|
|
1139 Return the weakness of HASH-TABLE.
|
442
|
1140 This can be one of `nil', `key-and-value', `key-or-value', `key' or `value'.
|
428
|
1141 */
|
|
1142 (hash_table))
|
|
1143 {
|
|
1144 switch (xhash_table (hash_table)->weakness)
|
|
1145 {
|
442
|
1146 case HASH_TABLE_WEAK: return Qkey_and_value;
|
|
1147 case HASH_TABLE_KEY_WEAK: return Qkey;
|
|
1148 case HASH_TABLE_KEY_VALUE_WEAK: return Qkey_or_value;
|
|
1149 case HASH_TABLE_VALUE_WEAK: return Qvalue;
|
|
1150 default: return Qnil;
|
428
|
1151 }
|
|
1152 }
|
|
1153
|
|
1154 /* obsolete as of 19990901 in xemacs-21.2 */
|
|
1155 DEFUN ("hash-table-type", Fhash_table_type, 1, 1, 0, /*
|
|
1156 Return the type of HASH-TABLE.
|
|
1157 This can be one of `non-weak', `weak', `key-weak' or `value-weak'.
|
|
1158 */
|
|
1159 (hash_table))
|
|
1160 {
|
|
1161 switch (xhash_table (hash_table)->weakness)
|
|
1162 {
|
442
|
1163 case HASH_TABLE_WEAK: return Qweak;
|
|
1164 case HASH_TABLE_KEY_WEAK: return Qkey_weak;
|
|
1165 case HASH_TABLE_KEY_VALUE_WEAK: return Qkey_or_value_weak;
|
|
1166 case HASH_TABLE_VALUE_WEAK: return Qvalue_weak;
|
|
1167 default: return Qnon_weak;
|
428
|
1168 }
|
|
1169 }
|
|
1170
|
|
1171 /************************************************************************/
|
|
1172 /* Mapping Functions */
|
|
1173 /************************************************************************/
|
|
1174 DEFUN ("maphash", Fmaphash, 2, 2, 0, /*
|
|
1175 Map FUNCTION over entries in HASH-TABLE, calling it with two args,
|
|
1176 each key and value in HASH-TABLE.
|
|
1177
|
|
1178 FUNCTION may not modify HASH-TABLE, with the one exception that FUNCTION
|
|
1179 may remhash or puthash the entry currently being processed by FUNCTION.
|
|
1180 */
|
|
1181 (function, hash_table))
|
|
1182 {
|
442
|
1183 const Lisp_Hash_Table *ht = xhash_table (hash_table);
|
|
1184 const hentry *e, *sentinel;
|
428
|
1185
|
|
1186 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
|
|
1187 if (!HENTRY_CLEAR_P (e))
|
|
1188 {
|
|
1189 Lisp_Object args[3], key;
|
|
1190 again:
|
|
1191 key = e->key;
|
|
1192 args[0] = function;
|
|
1193 args[1] = key;
|
|
1194 args[2] = e->value;
|
|
1195 Ffuncall (countof (args), args);
|
|
1196 /* Has FUNCTION done a remhash? */
|
|
1197 if (!EQ (key, e->key) && !HENTRY_CLEAR_P (e))
|
|
1198 goto again;
|
|
1199 }
|
|
1200
|
|
1201 return Qnil;
|
|
1202 }
|
|
1203
|
464
|
1204 /* #### If the Lisp function being called does a puthash and this
|
|
1205 #### causes the hash table to be resized, the results will be quite
|
|
1206 #### random and we will likely crash. To fix this, either set a
|
|
1207 #### flag in the hash table while we're mapping and signal an error
|
|
1208 #### when new entries are added, or fix things to make this
|
|
1209 #### operation work properly, like this: Store two hash tables in
|
|
1210 #### each hash table object -- the second one is written to when
|
|
1211 #### you do a puthash inside of a mapping operation, and the
|
|
1212 #### various operations need to check both hash tables for entries.
|
|
1213 #### As soon as the last maphash over a particular hash table
|
|
1214 #### object terminates, the entries in the second table are added
|
|
1215 #### to the first (using an unwind-protect). --ben */
|
|
1216
|
428
|
1217 /* Map *C* function FUNCTION over the elements of a lisp hash table. */
|
|
1218 void
|
|
1219 elisp_maphash (maphash_function_t function,
|
|
1220 Lisp_Object hash_table, void *extra_arg)
|
|
1221 {
|
442
|
1222 const Lisp_Hash_Table *ht = XHASH_TABLE (hash_table);
|
|
1223 const hentry *e, *sentinel;
|
428
|
1224
|
|
1225 for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
|
|
1226 if (!HENTRY_CLEAR_P (e))
|
|
1227 {
|
|
1228 Lisp_Object key;
|
|
1229 again:
|
|
1230 key = e->key;
|
|
1231 if (function (key, e->value, extra_arg))
|
|
1232 return;
|
|
1233 /* Has FUNCTION done a remhash? */
|
|
1234 if (!EQ (key, e->key) && !HENTRY_CLEAR_P (e))
|
|
1235 goto again;
|
|
1236 }
|
|
1237 }
|
|
1238
|
|
1239 /* Remove all elements of a lisp hash table satisfying *C* predicate PREDICATE. */
|
|
1240 void
|
|
1241 elisp_map_remhash (maphash_function_t predicate,
|
|
1242 Lisp_Object hash_table, void *extra_arg)
|
|
1243 {
|
|
1244 Lisp_Hash_Table *ht = XHASH_TABLE (hash_table);
|
|
1245 hentry *e, *entries, *sentinel;
|
|
1246
|
|
1247 for (e = entries = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
|
|
1248 if (!HENTRY_CLEAR_P (e))
|
|
1249 {
|
|
1250 again:
|
|
1251 if (predicate (e->key, e->value, extra_arg))
|
|
1252 {
|
|
1253 remhash_1 (ht, entries, e);
|
|
1254 if (!HENTRY_CLEAR_P (e))
|
|
1255 goto again;
|
|
1256 }
|
|
1257 }
|
|
1258 }
|
|
1259
|
|
1260
|
|
1261 /************************************************************************/
|
|
1262 /* garbage collecting weak hash tables */
|
|
1263 /************************************************************************/
|
442
|
1264 #define MARK_OBJ(obj) do { \
|
|
1265 Lisp_Object mo_obj = (obj); \
|
|
1266 if (!marked_p (mo_obj)) \
|
|
1267 { \
|
|
1268 mark_object (mo_obj); \
|
|
1269 did_mark = 1; \
|
|
1270 } \
|
|
1271 } while (0)
|
|
1272
|
428
|
1273
|
|
1274 /* Complete the marking for semi-weak hash tables. */
|
|
1275 int
|
|
1276 finish_marking_weak_hash_tables (void)
|
|
1277 {
|
|
1278 Lisp_Object hash_table;
|
|
1279 int did_mark = 0;
|
|
1280
|
|
1281 for (hash_table = Vall_weak_hash_tables;
|
|
1282 !NILP (hash_table);
|
|
1283 hash_table = XHASH_TABLE (hash_table)->next_weak)
|
|
1284 {
|
442
|
1285 const Lisp_Hash_Table *ht = XHASH_TABLE (hash_table);
|
|
1286 const hentry *e = ht->hentries;
|
|
1287 const hentry *sentinel = e + ht->size;
|
428
|
1288
|
|
1289 if (! marked_p (hash_table))
|
|
1290 /* The hash table is probably garbage. Ignore it. */
|
|
1291 continue;
|
|
1292
|
|
1293 /* Now, scan over all the pairs. For all pairs that are
|
|
1294 half-marked, we may need to mark the other half if we're
|
|
1295 keeping this pair. */
|
|
1296 switch (ht->weakness)
|
|
1297 {
|
|
1298 case HASH_TABLE_KEY_WEAK:
|
|
1299 for (; e < sentinel; e++)
|
|
1300 if (!HENTRY_CLEAR_P (e))
|
|
1301 if (marked_p (e->key))
|
|
1302 MARK_OBJ (e->value);
|
|
1303 break;
|
|
1304
|
|
1305 case HASH_TABLE_VALUE_WEAK:
|
|
1306 for (; e < sentinel; e++)
|
|
1307 if (!HENTRY_CLEAR_P (e))
|
|
1308 if (marked_p (e->value))
|
|
1309 MARK_OBJ (e->key);
|
|
1310 break;
|
|
1311
|
442
|
1312 case HASH_TABLE_KEY_VALUE_WEAK:
|
|
1313 for (; e < sentinel; e++)
|
|
1314 if (!HENTRY_CLEAR_P (e))
|
|
1315 {
|
|
1316 if (marked_p (e->value))
|
|
1317 MARK_OBJ (e->key);
|
|
1318 else if (marked_p (e->key))
|
|
1319 MARK_OBJ (e->value);
|
|
1320 }
|
|
1321 break;
|
|
1322
|
428
|
1323 case HASH_TABLE_KEY_CAR_WEAK:
|
|
1324 for (; e < sentinel; e++)
|
|
1325 if (!HENTRY_CLEAR_P (e))
|
|
1326 if (!CONSP (e->key) || marked_p (XCAR (e->key)))
|
|
1327 {
|
|
1328 MARK_OBJ (e->key);
|
|
1329 MARK_OBJ (e->value);
|
|
1330 }
|
|
1331 break;
|
|
1332
|
450
|
1333 /* We seem to be sprouting new weakness types at an alarming
|
|
1334 rate. At least this is not externally visible - and in
|
|
1335 fact all of these KEY_CAR_* types are only used by the
|
|
1336 glyph code. */
|
|
1337 case HASH_TABLE_KEY_CAR_VALUE_WEAK:
|
|
1338 for (; e < sentinel; e++)
|
|
1339 if (!HENTRY_CLEAR_P (e))
|
|
1340 {
|
|
1341 if (!CONSP (e->key) || marked_p (XCAR (e->key)))
|
|
1342 {
|
|
1343 MARK_OBJ (e->key);
|
|
1344 MARK_OBJ (e->value);
|
|
1345 }
|
|
1346 else if (marked_p (e->value))
|
|
1347 MARK_OBJ (e->key);
|
|
1348 }
|
|
1349 break;
|
|
1350
|
428
|
1351 case HASH_TABLE_VALUE_CAR_WEAK:
|
|
1352 for (; e < sentinel; e++)
|
|
1353 if (!HENTRY_CLEAR_P (e))
|
|
1354 if (!CONSP (e->value) || marked_p (XCAR (e->value)))
|
|
1355 {
|
|
1356 MARK_OBJ (e->key);
|
|
1357 MARK_OBJ (e->value);
|
|
1358 }
|
|
1359 break;
|
|
1360
|
|
1361 default:
|
|
1362 break;
|
|
1363 }
|
|
1364 }
|
|
1365
|
|
1366 return did_mark;
|
|
1367 }
|
|
1368
|
|
1369 void
|
|
1370 prune_weak_hash_tables (void)
|
|
1371 {
|
|
1372 Lisp_Object hash_table, prev = Qnil;
|
|
1373 for (hash_table = Vall_weak_hash_tables;
|
|
1374 !NILP (hash_table);
|
|
1375 hash_table = XHASH_TABLE (hash_table)->next_weak)
|
|
1376 {
|
|
1377 if (! marked_p (hash_table))
|
|
1378 {
|
|
1379 /* This hash table itself is garbage. Remove it from the list. */
|
|
1380 if (NILP (prev))
|
|
1381 Vall_weak_hash_tables = XHASH_TABLE (hash_table)->next_weak;
|
|
1382 else
|
|
1383 XHASH_TABLE (prev)->next_weak = XHASH_TABLE (hash_table)->next_weak;
|
|
1384 }
|
|
1385 else
|
|
1386 {
|
|
1387 /* Now, scan over all the pairs. Remove all of the pairs
|
|
1388 in which the key or value, or both, is unmarked
|
|
1389 (depending on the weakness of the hash table). */
|
|
1390 Lisp_Hash_Table *ht = XHASH_TABLE (hash_table);
|
|
1391 hentry *entries = ht->hentries;
|
|
1392 hentry *sentinel = entries + ht->size;
|
|
1393 hentry *e;
|
|
1394
|
|
1395 for (e = entries; e < sentinel; e++)
|
|
1396 if (!HENTRY_CLEAR_P (e))
|
|
1397 {
|
|
1398 again:
|
|
1399 if (!marked_p (e->key) || !marked_p (e->value))
|
|
1400 {
|
|
1401 remhash_1 (ht, entries, e);
|
|
1402 if (!HENTRY_CLEAR_P (e))
|
|
1403 goto again;
|
|
1404 }
|
|
1405 }
|
|
1406
|
|
1407 prev = hash_table;
|
|
1408 }
|
|
1409 }
|
|
1410 }
|
|
1411
|
|
1412 /* Return a hash value for an array of Lisp_Objects of size SIZE. */
|
|
1413
|
|
1414 hashcode_t
|
|
1415 internal_array_hash (Lisp_Object *arr, int size, int depth)
|
|
1416 {
|
|
1417 int i;
|
442
|
1418 hashcode_t hash = 0;
|
|
1419 depth++;
|
428
|
1420
|
|
1421 if (size <= 5)
|
|
1422 {
|
|
1423 for (i = 0; i < size; i++)
|
442
|
1424 hash = HASH2 (hash, internal_hash (arr[i], depth));
|
428
|
1425 return hash;
|
|
1426 }
|
|
1427
|
|
1428 /* just pick five elements scattered throughout the array.
|
|
1429 A slightly better approach would be to offset by some
|
|
1430 noise factor from the points chosen below. */
|
|
1431 for (i = 0; i < 5; i++)
|
442
|
1432 hash = HASH2 (hash, internal_hash (arr[i*size/5], depth));
|
428
|
1433
|
|
1434 return hash;
|
|
1435 }
|
|
1436
|
|
1437 /* Return a hash value for a Lisp_Object. This is for use when hashing
|
|
1438 objects with the comparison being `equal' (for `eq', you can just
|
|
1439 use the Lisp_Object itself as the hash value). You need to make a
|
|
1440 tradeoff between the speed of the hash function and how good the
|
|
1441 hashing is. In particular, the hash function needs to be FAST,
|
|
1442 so you can't just traipse down the whole tree hashing everything
|
|
1443 together. Most of the time, objects will differ in the first
|
|
1444 few elements you hash. Thus, we only go to a short depth (5)
|
|
1445 and only hash at most 5 elements out of a vector. Theoretically
|
|
1446 we could still take 5^5 time (a big big number) to compute a
|
|
1447 hash, but practically this won't ever happen. */
|
|
1448
|
|
1449 hashcode_t
|
|
1450 internal_hash (Lisp_Object obj, int depth)
|
|
1451 {
|
|
1452 if (depth > 5)
|
|
1453 return 0;
|
|
1454 if (CONSP (obj))
|
|
1455 {
|
|
1456 /* no point in worrying about tail recursion, since we're not
|
|
1457 going very deep */
|
|
1458 return HASH2 (internal_hash (XCAR (obj), depth + 1),
|
|
1459 internal_hash (XCDR (obj), depth + 1));
|
|
1460 }
|
|
1461 if (STRINGP (obj))
|
|
1462 {
|
|
1463 return hash_string (XSTRING_DATA (obj), XSTRING_LENGTH (obj));
|
|
1464 }
|
|
1465 if (LRECORDP (obj))
|
|
1466 {
|
442
|
1467 const struct lrecord_implementation
|
428
|
1468 *imp = XRECORD_LHEADER_IMPLEMENTATION (obj);
|
|
1469 if (imp->hash)
|
|
1470 return imp->hash (obj, depth);
|
|
1471 }
|
|
1472
|
|
1473 return LISP_HASH (obj);
|
|
1474 }
|
|
1475
|
|
1476 DEFUN ("sxhash", Fsxhash, 1, 1, 0, /*
|
|
1477 Return a hash value for OBJECT.
|
444
|
1478 \(equal obj1 obj2) implies (= (sxhash obj1) (sxhash obj2)).
|
428
|
1479 */
|
|
1480 (object))
|
|
1481 {
|
|
1482 return make_int (internal_hash (object, 0));
|
|
1483 }
|
|
1484
|
|
1485 #if 0
|
|
1486 xxDEFUN ("internal-hash-value", Finternal_hash_value, 1, 1, 0, /*
|
|
1487 Hash value of OBJECT. For debugging.
|
|
1488 The value is returned as (HIGH . LOW).
|
|
1489 */
|
|
1490 (object))
|
|
1491 {
|
|
1492 /* This function is pretty 32bit-centric. */
|
442
|
1493 hashcode_t hash = internal_hash (object, 0);
|
428
|
1494 return Fcons (hash >> 16, hash & 0xffff);
|
|
1495 }
|
|
1496 #endif
|
|
1497
|
|
1498
|
|
1499 /************************************************************************/
|
|
1500 /* initialization */
|
|
1501 /************************************************************************/
|
|
1502
|
|
1503 void
|
|
1504 syms_of_elhash (void)
|
|
1505 {
|
442
|
1506 INIT_LRECORD_IMPLEMENTATION (hash_table);
|
|
1507
|
428
|
1508 DEFSUBR (Fhash_table_p);
|
|
1509 DEFSUBR (Fmake_hash_table);
|
|
1510 DEFSUBR (Fcopy_hash_table);
|
|
1511 DEFSUBR (Fgethash);
|
|
1512 DEFSUBR (Fremhash);
|
|
1513 DEFSUBR (Fputhash);
|
|
1514 DEFSUBR (Fclrhash);
|
|
1515 DEFSUBR (Fmaphash);
|
|
1516 DEFSUBR (Fhash_table_count);
|
|
1517 DEFSUBR (Fhash_table_test);
|
|
1518 DEFSUBR (Fhash_table_size);
|
|
1519 DEFSUBR (Fhash_table_rehash_size);
|
|
1520 DEFSUBR (Fhash_table_rehash_threshold);
|
|
1521 DEFSUBR (Fhash_table_weakness);
|
|
1522 DEFSUBR (Fhash_table_type); /* obsolete */
|
|
1523 DEFSUBR (Fsxhash);
|
|
1524 #if 0
|
|
1525 DEFSUBR (Finternal_hash_value);
|
|
1526 #endif
|
|
1527
|
|
1528 defsymbol (&Qhash_tablep, "hash-table-p");
|
|
1529 defsymbol (&Qhash_table, "hash-table");
|
|
1530 defsymbol (&Qhashtable, "hashtable");
|
|
1531 defsymbol (&Qweakness, "weakness");
|
|
1532 defsymbol (&Qvalue, "value");
|
442
|
1533 defsymbol (&Qkey_or_value, "key-or-value");
|
|
1534 defsymbol (&Qkey_and_value, "key-and-value");
|
428
|
1535 defsymbol (&Qrehash_size, "rehash-size");
|
|
1536 defsymbol (&Qrehash_threshold, "rehash-threshold");
|
|
1537
|
|
1538 defsymbol (&Qweak, "weak"); /* obsolete */
|
|
1539 defsymbol (&Qkey_weak, "key-weak"); /* obsolete */
|
442
|
1540 defsymbol (&Qkey_or_value_weak, "key-or-value-weak"); /* obsolete */
|
428
|
1541 defsymbol (&Qvalue_weak, "value-weak"); /* obsolete */
|
|
1542 defsymbol (&Qnon_weak, "non-weak"); /* obsolete */
|
|
1543
|
|
1544 defkeyword (&Q_test, ":test");
|
|
1545 defkeyword (&Q_size, ":size");
|
|
1546 defkeyword (&Q_rehash_size, ":rehash-size");
|
|
1547 defkeyword (&Q_rehash_threshold, ":rehash-threshold");
|
|
1548 defkeyword (&Q_weakness, ":weakness");
|
|
1549 defkeyword (&Q_type, ":type"); /* obsolete */
|
|
1550 }
|
|
1551
|
|
1552 void
|
|
1553 vars_of_elhash (void)
|
|
1554 {
|
|
1555 /* This must NOT be staticpro'd */
|
|
1556 Vall_weak_hash_tables = Qnil;
|
452
|
1557 dump_add_weak_object_chain (&Vall_weak_hash_tables);
|
428
|
1558 }
|