gcc/hash-set.h

   1 /* A type-safe hash set.
   2    Copyright (C) 2014-2015 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along 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 template<typename Key, typename Traits = default_hash_traits<Key> >
  25 class hash_set
  26 {
  27 public:
  28   explicit hash_set (size_t n = 13, bool ggc = false CXX_MEM_STAT_INFO)
  29     : m_table (n, ggc, true, HASH_SET_ORIGIN PASS_MEM_STAT) {}
  30
  31   /* Create a hash_set in gc memory with space for at least n elements.  */
  32
  33   static hash_set *
  34     create_ggc (size_t n)
  35       {
  36         hash_set *set = ggc_alloc<hash_set> ();
  37         new (set) hash_set (n, true);
  38         return set;
  39       }
  40
  41   /* If key k isn't already in the map add it to the map, and
  42      return false.  Otherwise return true.  */
  43
  44   bool add (const Key &k)
  45     {
  46       Key *e = m_table.find_slot_with_hash (k, Traits::hash (k), INSERT);
  47       bool existed = !Traits::is_empty (*e);
  48       if (!existed)
  49         *e = k;
  50
  51       return existed;
  52     }
  53
  54   /* if the passed in key is in the map return its value otherwise NULL.  */
  55
  56   bool contains (const Key &k)
  57     {
  58       Key &e = m_table.find_with_hash (k, Traits::hash (k));
  59       return !Traits::is_empty (e);
  60     }
  61
  62   void remove (const Key &k)
  63     {
  64       m_table.remove_elt_with_hash (k, Traits::hash (k));
  65     }
  66
  67   /* Call the call back on each pair of key and value with the passed in
  68      arg.  */
  69
  70   template<typename Arg, bool (*f)(const Key &, Arg)>
  71   void traverse (Arg a) const
  72     {
  73       for (typename hash_table<Traits>::iterator iter = m_table.begin ();
  74            iter != m_table.end (); ++iter)
  75         f (*iter, a);
  76     }
  77
  78   /* Return the number of elements in the set.  */
  79
  80   size_t elements () const { return m_table.elements (); }
  81
  82   class iterator
  83   {
  84   public:
  85     explicit iterator (const typename hash_table<Traits>::iterator &iter) :
  86       m_iter (iter) {}
  87
  88     iterator &operator++ ()
  89       {
  90         ++m_iter;
  91         return *this;
  92       }
  93
  94     Key
  95     operator* ()
  96       {
  97         return *m_iter;
  98       }
  99
 100     bool
 101     operator != (const iterator &other) const
 102       {
 103         return m_iter != other.m_iter;
 104       }
 105
 106   private:
 107     typename hash_table<Traits>::iterator m_iter;
 108   };
 109
 110   /* Standard iterator retrieval methods.  */
 111
 112   iterator begin () const { return iterator (m_table.begin ()); }
 113   iterator end () const { return iterator (m_table.end ()); }
 114
 115
 116 private:
 117
 118   template<typename T, typename U> friend void gt_ggc_mx (hash_set<T, U> *);
 119   template<typename T, typename U> friend void gt_pch_nx (hash_set<T, U> *);
 120       template<typename T, typename U> friend void gt_pch_nx (hash_set<T, U> *, gt_pointer_operator, void *);
 121
 122   hash_table<Traits> m_table;
 123 };
 124
 125 /* ggc marking routines.  */
 126
 127 template<typename K, typename H>
 128 static inline void
 129 gt_ggc_mx (hash_set<K, H> *h)
 130 {
 131   gt_ggc_mx (&h->m_table);
 132 }
 133
 134 template<typename K, typename H>
 135 static inline void
 136 gt_pch_nx (hash_set<K, H> *h)
 137 {
 138   gt_pch_nx (&h->m_table);
 139 }
 140
 141 template<typename K, typename H>
 142 static inline void
 143 gt_pch_nx (hash_set<K, H> *h, gt_pointer_operator op, void *cookie)
 144 {
 145   op (&h->m_table.m_entries, cookie);
 146 }
 147
 148 #endif