gcc/hash-set.h

   1 /* A type-safe hash set.
   2    Copyright (C) 2014-2016 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 KeyId, typename Traits = default_hash_traits<KeyId> >
  25 class hash_set
  26 {
  27 public:
  28   typedef typename Traits::value_type Key;
  29   explicit hash_set (size_t n = 13, bool ggc = false CXX_MEM_STAT_INFO)
  30     : m_table (n, ggc, GATHER_STATISTICS, HASH_SET_ORIGIN PASS_MEM_STAT) {}
  31
  32   /* Create a hash_set in gc memory with space for at least n elements.  */
  33
  34   static hash_set *
  35     create_ggc (size_t n)
  36       {
  37         hash_set *set = ggc_alloc<hash_set> ();
  38         new (set) hash_set (n, true);
  39         return set;
  40       }
  41
  42   /* If key k isn't already in the map add it to the map, and
  43      return false.  Otherwise return true.  */
  44
  45   bool add (const Key &k)
  46     {
  47       Key *e = m_table.find_slot_with_hash (k, Traits::hash (k), INSERT);
  48       bool existed = !Traits::is_empty (*e);
  49       if (!existed)
  50         *e = k;
  51
  52       return existed;
  53     }
  54
  55   /* if the passed in key is in the map return its value otherwise NULL.  */
  56
  57   bool contains (const Key &k)
  58     {
  59       Key &e = m_table.find_with_hash (k, Traits::hash (k));
  60       return !Traits::is_empty (e);
  61     }
  62
  63   void remove (const Key &k)
  64     {
  65       m_table.remove_elt_with_hash (k, Traits::hash (k));
  66     }
  67
  68   /* Call the call back on each pair of key and value with the passed in
  69      arg.  */
  70
  71   template<typename Arg, bool (*f)(const typename Traits::value_type &, Arg)>
  72   void traverse (Arg a) const
  73     {
  74       for (typename hash_table<Traits>::iterator iter = m_table.begin ();
  75            iter != m_table.end (); ++iter)
  76         f (*iter, a);
  77     }
  78
  79   /* Return the number of elements in the set.  */
  80
  81   size_t elements () const { return m_table.elements (); }
  82
  83   class iterator
  84   {
  85   public:
  86     explicit iterator (const typename hash_table<Traits>::iterator &iter) :
  87       m_iter (iter) {}
  88
  89     iterator &operator++ ()
  90       {
  91         ++m_iter;
  92         return *this;
  93       }
  94
  95     Key
  96     operator* ()
  97       {
  98         return *m_iter;
  99       }
 100
 101     bool
 102     operator != (const iterator &other) const
 103       {
 104         return m_iter != other.m_iter;
 105       }
 106
 107   private:
 108     typename hash_table<Traits>::iterator m_iter;
 109   };
 110
 111   /* Standard iterator retrieval methods.  */
 112
 113   iterator begin () const { return iterator (m_table.begin ()); }
 114   iterator end () const { return iterator (m_table.end ()); }
 115
 116
 117 private:
 118
 119   template<typename T, typename U> friend void gt_ggc_mx (hash_set<T, U> *);
 120   template<typename T, typename U> friend void gt_pch_nx (hash_set<T, U> *);
 121       template<typename T, typename U> friend void gt_pch_nx (hash_set<T, U> *, gt_pointer_operator, void *);
 122
 123   hash_table<Traits> m_table;
 124 };
 125
 126 /* ggc marking routines.  */
 127
 128 template<typename K, typename H>
 129 static inline void
 130 gt_ggc_mx (hash_set<K, H> *h)
 131 {
 132   gt_ggc_mx (&h->m_table);
 133 }
 134
 135 template<typename K, typename H>
 136 static inline void
 137 gt_pch_nx (hash_set<K, H> *h)
 138 {
 139   gt_pch_nx (&h->m_table);
 140 }
 141
 142 template<typename K, typename H>
 143 static inline void
 144 gt_pch_nx (hash_set<K, H> *h, gt_pointer_operator op, void *cookie)
 145 {
 146   op (&h->m_table.m_entries, cookie);
 147 }
 148
 149 #endif