MapVector.h revision 6bbf4ff9c545c881422da37494b1ccb9c18d9c6a
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 void clear() { 68 Map.clear(); 69 Vector.clear(); 70 } 71 72 ValueT &operator[](const KeyT &Key) { 73 std::pair<KeyT, unsigned> Pair = std::make_pair(Key, 0); 74 std::pair<typename MapType::iterator, bool> Result = Map.insert(Pair); 75 unsigned &I = Result.first->second; 76 if (Result.second) { 77 Vector.push_back(std::make_pair(Key, ValueT())); 78 I = Vector.size() - 1; 79 } 80 return Vector[I].second; 81 } 82 83 ValueT lookup(const KeyT &Key) const { 84 typename MapType::const_iterator Pos = Map.find(Key); 85 return Pos == Map.end()? ValueT() : Vector[Pos->second].second; 86 } 87 88 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) { 89 std::pair<KeyT, unsigned> Pair = std::make_pair(KV.first, 0); 90 std::pair<typename MapType::iterator, bool> Result = Map.insert(Pair); 91 unsigned &I = Result.first->second; 92 if (Result.second) { 93 Vector.push_back(std::make_pair(KV.first, KV.second)); 94 I = Vector.size() - 1; 95 return std::make_pair(llvm::prior(end()), true); 96 } 97 return std::make_pair(begin() + I, false); 98 } 99 100 unsigned count(const KeyT &Key) const { 101 typename MapType::const_iterator Pos = Map.find(Key); 102 return Pos == Map.end()? 0 : 1; 103 } 104 105 iterator find(const KeyT &Key) { 106 typename MapType::const_iterator Pos = Map.find(Key); 107 return Pos == Map.end()? Vector.end() : 108 (Vector.begin() + Pos->second); 109 } 110 111 const_iterator find(const KeyT &Key) const { 112 typename MapType::const_iterator Pos = Map.find(Key); 113 return Pos == Map.end()? Vector.end() : 114 (Vector.begin() + Pos->second); 115 } 116}; 117 118} 119 120#endif 121