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      1 //===- llvm/ADT/DenseSet.h - Dense probed hash table ------------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file defines the DenseSet class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_ADT_DENSESET_H
     15 #define LLVM_ADT_DENSESET_H
     16 
     17 #include "llvm/ADT/DenseMap.h"
     18 
     19 namespace llvm {
     20 
     21 /// DenseSet - This implements a dense probed hash-table based set.
     22 ///
     23 /// FIXME: This is currently implemented directly in terms of DenseMap, this
     24 /// should be optimized later if there is a need.
     25 template<typename ValueT, typename ValueInfoT = DenseMapInfo<ValueT> >
     26 class DenseSet {
     27   typedef DenseMap<ValueT, char, ValueInfoT> MapTy;
     28   MapTy TheMap;
     29 public:
     30   typedef ValueT key_type;
     31   typedef ValueT value_type;
     32   typedef unsigned size_type;
     33 
     34   explicit DenseSet(unsigned NumInitBuckets = 0) : TheMap(NumInitBuckets) {}
     35 
     36   bool empty() const { return TheMap.empty(); }
     37   size_type size() const { return TheMap.size(); }
     38   size_t getMemorySize() const { return TheMap.getMemorySize(); }
     39 
     40   /// Grow the DenseSet so that it has at least Size buckets. Will not shrink
     41   /// the Size of the set.
     42   void resize(size_t Size) { TheMap.resize(Size); }
     43 
     44   void clear() {
     45     TheMap.clear();
     46   }
     47 
     48   /// Return 1 if the specified key is in the set, 0 otherwise.
     49   size_type count(const ValueT &V) const {
     50     return TheMap.count(V);
     51   }
     52 
     53   bool erase(const ValueT &V) {
     54     return TheMap.erase(V);
     55   }
     56 
     57   void swap(DenseSet& RHS) {
     58     TheMap.swap(RHS.TheMap);
     59   }
     60 
     61   // Iterators.
     62 
     63   class Iterator {
     64     typename MapTy::iterator I;
     65     friend class DenseSet;
     66   public:
     67     typedef typename MapTy::iterator::difference_type difference_type;
     68     typedef ValueT value_type;
     69     typedef value_type *pointer;
     70     typedef value_type &reference;
     71     typedef std::forward_iterator_tag iterator_category;
     72 
     73     Iterator(const typename MapTy::iterator &i) : I(i) {}
     74 
     75     ValueT& operator*() { return I->first; }
     76     ValueT* operator->() { return &I->first; }
     77 
     78     Iterator& operator++() { ++I; return *this; }
     79     bool operator==(const Iterator& X) const { return I == X.I; }
     80     bool operator!=(const Iterator& X) const { return I != X.I; }
     81   };
     82 
     83   class ConstIterator {
     84     typename MapTy::const_iterator I;
     85     friend class DenseSet;
     86   public:
     87     typedef typename MapTy::const_iterator::difference_type difference_type;
     88     typedef ValueT value_type;
     89     typedef value_type *pointer;
     90     typedef value_type &reference;
     91     typedef std::forward_iterator_tag iterator_category;
     92 
     93     ConstIterator(const typename MapTy::const_iterator &i) : I(i) {}
     94 
     95     const ValueT& operator*() { return I->first; }
     96     const ValueT* operator->() { return &I->first; }
     97 
     98     ConstIterator& operator++() { ++I; return *this; }
     99     bool operator==(const ConstIterator& X) const { return I == X.I; }
    100     bool operator!=(const ConstIterator& X) const { return I != X.I; }
    101   };
    102 
    103   typedef Iterator      iterator;
    104   typedef ConstIterator const_iterator;
    105 
    106   iterator begin() { return Iterator(TheMap.begin()); }
    107   iterator end() { return Iterator(TheMap.end()); }
    108 
    109   const_iterator begin() const { return ConstIterator(TheMap.begin()); }
    110   const_iterator end() const { return ConstIterator(TheMap.end()); }
    111 
    112   iterator find(const ValueT &V) { return Iterator(TheMap.find(V)); }
    113   void erase(Iterator I) { return TheMap.erase(I.I); }
    114   void erase(ConstIterator CI) { return TheMap.erase(CI.I); }
    115 
    116   std::pair<iterator, bool> insert(const ValueT &V) {
    117     return TheMap.insert(std::make_pair(V, 0));
    118   }
    119 
    120   // Range insertion of values.
    121   template<typename InputIt>
    122   void insert(InputIt I, InputIt E) {
    123     for (; I != E; ++I)
    124       insert(*I);
    125   }
    126 };
    127 
    128 } // end namespace llvm
    129 
    130 #endif
    131