Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
14 pmbaty 1
//===- llvm/ADT/UniqueVector.h ----------------------------------*- C++ -*-===//
2
//
3
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4
// See https://llvm.org/LICENSE.txt for license information.
5
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6
//
7
//===----------------------------------------------------------------------===//
8
 
9
#ifndef LLVM_ADT_UNIQUEVECTOR_H
10
#define LLVM_ADT_UNIQUEVECTOR_H
11
 
12
#include <cassert>
13
#include <cstddef>
14
#include <map>
15
#include <vector>
16
 
17
namespace llvm {
18
 
19
//===----------------------------------------------------------------------===//
20
/// UniqueVector - This class produces a sequential ID number (base 1) for each
21
/// unique entry that is added.  T is the type of entries in the vector. This
22
/// class should have an implementation of operator== and of operator<.
23
/// Entries can be fetched using operator[] with the entry ID.
24
template<class T> class UniqueVector {
25
public:
26
  using VectorType = typename std::vector<T>;
27
  using iterator = typename VectorType::iterator;
28
  using const_iterator = typename VectorType::const_iterator;
29
 
30
private:
31
  // Map - Used to handle the correspondence of entry to ID.
32
  std::map<T, unsigned> Map;
33
 
34
  // Vector - ID ordered vector of entries. Entries can be indexed by ID - 1.
35
  VectorType Vector;
36
 
37
public:
38
  /// insert - Append entry to the vector if it doesn't already exist.  Returns
39
  /// the entry's index + 1 to be used as a unique ID.
40
  unsigned insert(const T &Entry) {
41
    // Check if the entry is already in the map.
42
    unsigned &Val = Map[Entry];
43
 
44
    // See if entry exists, if so return prior ID.
45
    if (Val) return Val;
46
 
47
    // Compute ID for entry.
48
    Val = static_cast<unsigned>(Vector.size()) + 1;
49
 
50
    // Insert in vector.
51
    Vector.push_back(Entry);
52
    return Val;
53
  }
54
 
55
  /// idFor - return the ID for an existing entry.  Returns 0 if the entry is
56
  /// not found.
57
  unsigned idFor(const T &Entry) const {
58
    // Search for entry in the map.
59
    typename std::map<T, unsigned>::const_iterator MI = Map.find(Entry);
60
 
61
    // See if entry exists, if so return ID.
62
    if (MI != Map.end()) return MI->second;
63
 
64
    // No luck.
65
    return 0;
66
  }
67
 
68
  /// operator[] - Returns a reference to the entry with the specified ID.
69
  const T &operator[](unsigned ID) const {
70
    assert(ID-1 < size() && "ID is 0 or out of range!");
71
    return Vector[ID - 1];
72
  }
73
 
74
  /// Return an iterator to the start of the vector.
75
  iterator begin() { return Vector.begin(); }
76
 
77
  /// Return an iterator to the start of the vector.
78
  const_iterator begin() const { return Vector.begin(); }
79
 
80
  /// Return an iterator to the end of the vector.
81
  iterator end() { return Vector.end(); }
82
 
83
  /// Return an iterator to the end of the vector.
84
  const_iterator end() const { return Vector.end(); }
85
 
86
  /// size - Returns the number of entries in the vector.
87
  size_t size() const { return Vector.size(); }
88
 
89
  /// empty - Returns true if the vector is empty.
90
  bool empty() const { return Vector.empty(); }
91
 
92
  /// reset - Clears all the entries.
93
  void reset() {
94
    Map.clear();
95
    Vector.resize(0, 0);
96
  }
97
};
98
 
99
} // end namespace llvm
100
 
101
#endif // LLVM_ADT_UNIQUEVECTOR_H