1/* A type-safe hash set. 2 Copyright (C) 2014-2015 Free Software Foundation, Inc. 3 4This file is part of GCC. 5 6GCC is free software; you can redistribute it and/or modify it under 7the terms of the GNU General Public License as published by the Free 8Software Foundation; either version 3, or (at your option) any later 9version. 10 11GCC is distributed in the hope that it will be useful, but WITHOUT ANY 12WARRANTY; without even the implied warranty of MERCHANTABILITY or 13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14for more details. 15 16You should have received a copy of the GNU General Public License 17along with GCC; see the file COPYING3. If not see 18<http://www.gnu.org/licenses/>. */ 19 20 21#ifndef hash_set_h 22#define hash_set_h 23 24#include "hash-table.h" 25 26/* implement default behavior for traits when types allow it. */ 27 28struct default_hashset_traits 29{ 30 /* Hashes the passed in key. */ 31 32 template<typename T> 33 static hashval_t 34 hash (T *p) 35 { 36 return uintptr_t(p) >> 3; 37 } 38 39 template<typename T> static hashval_t hash(const T &v) { return v; } 40 41 /* Return true if the two keys passed as arguments are equal. */ 42 43 template<typename T> 44 static bool 45 equal (const T &a, const T &b) 46 { 47 return a == b; 48 } 49 50 /* Called to dispose of the key before marking the entry as deleted. */ 51 52 template<typename T> static void remove (T &v) { v.~T (); } 53 54 /* Mark the passed in entry as being deleted. */ 55 56 template<typename T> 57 static void 58 mark_deleted (T *&e) 59 { 60 e = reinterpret_cast<void *> (1); 61 } 62 63 /* Mark the passed in entry as being empty. */ 64 65 template<typename T> 66 static void 67 mark_empty (T *&e) 68 { 69 e = NULL; 70 } 71 72 /* Return true if the passed in entry is marked as deleted. */ 73 74 template<typename T> 75 static bool 76 is_deleted (T *e) 77 { 78 return e == reinterpret_cast<void *> (1); 79 } 80 81 /* Return true if the passed in entry is marked as empty. */ 82 83 template<typename T> static bool is_empty (T *e) { return e == NULL; } 84 85 /* ggc walking routine, mark all objects refered to by this one. */ 86 87 template<typename T> 88 static void 89 ggc_mx (T &x) 90 { 91 extern void gt_ggc_mx (T &); 92 gt_ggc_mx (x); 93 } 94 95 /* pch walking routine, note all objects refered to by this element. */ 96 97 template<typename T> 98 static void 99 pch_nx (T &x) 100 { 101 extern void gt_pch_nx (T &); 102 gt_pch_nx (x); 103 } 104}; 105 106template<typename Key, typename Traits = default_hashset_traits> 107class hash_set 108{ 109 struct hash_entry 110 { 111 Key m_key; 112 113 typedef hash_entry value_type; 114 typedef Key compare_type; 115 typedef int store_values_directly; 116 117 static hashval_t hash (const hash_entry &e) 118 { 119 return Traits::hash (e.m_key); 120 } 121 122 static bool equal (const hash_entry &a, const Key &b) 123 { 124 return Traits::equal (a.m_key, b); 125 } 126 127 static void remove (hash_entry &e) { Traits::remove (e.m_key); } 128 129 static void 130 mark_deleted (hash_entry &e) 131 { 132 Traits::mark_deleted (e.m_key); 133 } 134 135 static bool is_deleted (const hash_entry &e) 136 { 137 return Traits::is_deleted (e.m_key); 138 } 139 140 static void 141 mark_empty (hash_entry &e) 142 { 143 Traits::mark_empty (e.m_key); 144 } 145 146 static bool 147 is_empty (const hash_entry &e) 148 { 149 return Traits::is_empty (e.m_key); 150 } 151 152 static void ggc_mx (hash_entry &e) 153 { 154 Traits::ggc_mx (e.m_key); 155 } 156 157 static void pch_nx (hash_entry &e) 158 { 159 Traits::pch_nx (e.m_key); 160 } 161 162 static void pch_nx (hash_entry &e, gt_pointer_operator op, void *c) 163 { 164 pch_nx_helper (e.m_key, op, c); 165 } 166 167 private: 168 template<typename T> 169 static void 170 pch_nx_helper (T &x, gt_pointer_operator op, void *cookie) 171 { 172 gt_pch_nx (&x, op, cookie); 173 } 174 175 template<typename T> 176 static void 177 pch_nx_helper (T *&x, gt_pointer_operator op, void *cookie) 178 { 179 op (&x, cookie); 180 } 181 }; 182 183public: 184 explicit hash_set (size_t n = 13, bool ggc = false) : m_table (n, ggc) {} 185 186 /* Create a hash_set in gc memory with space for at least n elements. */ 187 188 static hash_set * 189 create_ggc (size_t n) 190 { 191 hash_set *set = ggc_alloc<hash_set> (); 192 new (set) hash_set (n, true); 193 return set; 194 } 195 196 /* If key k isn't already in the map add it to the map, and 197 return false. Otherwise return true. */ 198 199 bool add (const Key &k) 200 { 201 hash_entry *e = m_table.find_slot_with_hash (k, Traits::hash (k), 202 INSERT); 203 bool existed = !hash_entry::is_empty (*e); 204 if (!existed) 205 e->m_key = k; 206 207 return existed; 208 } 209 210 /* if the passed in key is in the map return its value otherwise NULL. */ 211 212 bool contains (const Key &k) 213 { 214 hash_entry &e = m_table.find_with_hash (k, Traits::hash (k)); 215 return !Traits::is_empty (e.m_key); 216 } 217 218 /* Call the call back on each pair of key and value with the passed in 219 arg. */ 220 221 template<typename Arg, bool (*f)(const Key &, Arg)> 222 void traverse (Arg a) const 223 { 224 for (typename hash_table<hash_entry>::iterator iter = m_table.begin (); 225 iter != m_table.end (); ++iter) 226 f ((*iter).m_key, a); 227 } 228 229 /* Return the number of elements in the set. */ 230 231 size_t elements () const { return m_table.elements (); } 232 233private: 234 235 template<typename T, typename U> friend void gt_ggc_mx (hash_set<T, U> *); 236 template<typename T, typename U> friend void gt_pch_nx (hash_set<T, U> *); 237 template<typename T, typename U> friend void gt_pch_nx (hash_set<T, U> *, gt_pointer_operator, void *); 238 239 hash_table<hash_entry> m_table; 240}; 241 242/* ggc marking routines. */ 243 244template<typename K, typename H> 245static inline void 246gt_ggc_mx (hash_set<K, H> *h) 247{ 248 gt_ggc_mx (&h->m_table); 249} 250 251template<typename K, typename H> 252static inline void 253gt_pch_nx (hash_set<K, H> *h) 254{ 255 gt_pch_nx (&h->m_table); 256} 257 258template<typename K, typename H> 259static inline void 260gt_pch_nx (hash_set<K, H> *h, gt_pointer_operator op, void *cookie) 261{ 262 op (&h->m_table.m_entries, cookie); 263} 264 265#endif 266