1//===- llvm/ADT/MapVector.h - Map with deterministic value order *- 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 implements a map that provides insertion order iteration. The 11// interface is purposefully minimal. The key is assumed to be cheap to copy 12// and 2 copies are kept, one for indexing in a DenseMap, one for iteration in 13// a std::vector. 14// 15//===----------------------------------------------------------------------===// 16 17#ifndef LLVM_ADT_MAPVECTOR_H 18#define LLVM_ADT_MAPVECTOR_H 19 20#include "llvm/ADT/ArrayRef.h" 21#include "llvm/ADT/DenseMap.h" 22#include "llvm/ADT/STLExtras.h" 23#include <vector> 24 25namespace llvm { 26 27/// This class implements a map that also provides access to all stored values 28/// in a deterministic order. The values are kept in a std::vector and the 29/// mapping is done with DenseMap from Keys to indexes in that vector. 30template<typename KeyT, typename ValueT, 31 typename MapType = llvm::DenseMap<KeyT, unsigned>, 32 typename VectorType = std::vector<std::pair<KeyT, ValueT> > > 33class MapVector { 34 typedef typename VectorType::size_type SizeType; 35 36 MapType Map; 37 VectorType Vector; 38 39public: 40 typedef typename VectorType::iterator iterator; 41 typedef typename VectorType::const_iterator const_iterator; 42 43 SizeType size() const { 44 return Vector.size(); 45 } 46 47 iterator begin() { 48 return Vector.begin(); 49 } 50 51 const_iterator begin() const { 52 return Vector.begin(); 53 } 54 55 iterator end() { 56 return Vector.end(); 57 } 58 59 const_iterator end() const { 60 return Vector.end(); 61 } 62 63 bool empty() const { 64 return Vector.empty(); 65 } 66 67 std::pair<KeyT, ValueT> &front() { return Vector.front(); } 68 const std::pair<KeyT, ValueT> &front() const { return Vector.front(); } 69 std::pair<KeyT, ValueT> &back() { return Vector.back(); } 70 const std::pair<KeyT, ValueT> &back() const { return Vector.back(); } 71 72 void clear() { 73 Map.clear(); 74 Vector.clear(); 75 } 76 77 ValueT &operator[](const KeyT &Key) { 78 std::pair<KeyT, unsigned> Pair = std::make_pair(Key, 0); 79 std::pair<typename MapType::iterator, bool> Result = Map.insert(Pair); 80 unsigned &I = Result.first->second; 81 if (Result.second) { 82 Vector.push_back(std::make_pair(Key, ValueT())); 83 I = Vector.size() - 1; 84 } 85 return Vector[I].second; 86 } 87 88 ValueT lookup(const KeyT &Key) const { 89 typename MapType::const_iterator Pos = Map.find(Key); 90 return Pos == Map.end()? ValueT() : Vector[Pos->second].second; 91 } 92 93 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) { 94 std::pair<KeyT, unsigned> Pair = std::make_pair(KV.first, 0); 95 std::pair<typename MapType::iterator, bool> Result = Map.insert(Pair); 96 unsigned &I = Result.first->second; 97 if (Result.second) { 98 Vector.push_back(std::make_pair(KV.first, KV.second)); 99 I = Vector.size() - 1; 100 return std::make_pair(llvm::prior(end()), true); 101 } 102 return std::make_pair(begin() + I, false); 103 } 104 105 unsigned count(const KeyT &Key) const { 106 typename MapType::const_iterator Pos = Map.find(Key); 107 return Pos == Map.end()? 0 : 1; 108 } 109 110 iterator find(const KeyT &Key) { 111 typename MapType::const_iterator Pos = Map.find(Key); 112 return Pos == Map.end()? Vector.end() : 113 (Vector.begin() + Pos->second); 114 } 115 116 const_iterator find(const KeyT &Key) const { 117 typename MapType::const_iterator Pos = Map.find(Key); 118 return Pos == Map.end()? Vector.end() : 119 (Vector.begin() + Pos->second); 120 } 121 122 /// \brief Remove the last element from the vector. 123 void pop_back() { 124 typename MapType::iterator Pos = Map.find(Vector.back().first); 125 Map.erase(Pos); 126 Vector.pop_back(); 127 } 128}; 129 130} 131 132#endif 133