DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (d80211b9dc59)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsClassHashtable_h__
#define nsClassHashtable_h__

#include "mozilla/Move.h"
#include "mozilla/UniquePtr.h"
#include "nsBaseHashtable.h"
#include "nsHashKeys.h"

/**
 * Helper class that provides methods to wrap and unwrap the UserDataType.
 */
template <class T>
class nsUniquePtrConverter {
 public:
  using UserDataType = T*;
  using DataType = mozilla::UniquePtr<T>;

  static UserDataType Unwrap(DataType& src) { return src.get(); }
  static DataType Wrap(UserDataType&& src) { return DataType(std::move(src)); }
  static DataType Wrap(const UserDataType& src) { return DataType(src); }
};

/**
 * templated hashtable class maps keys to C++ object pointers.
 * See nsBaseHashtable for complete declaration.
 * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
 *   for a complete specification.
 * @param Class the class-type being wrapped
 * @see nsInterfaceHashtable, nsClassHashtable
 */
template <class KeyClass, class T>
class nsClassHashtable : public nsBaseHashtable<KeyClass, mozilla::UniquePtr<T>,
                                                T*, nsUniquePtrConverter<T>> {
 public:
  typedef typename KeyClass::KeyType KeyType;
  typedef T* UserDataType;
  typedef nsBaseHashtable<KeyClass, mozilla::UniquePtr<T>, T*,
                          nsUniquePtrConverter<T>>
      base_type;

  using base_type::IsEmpty;
  using base_type::Remove;

  nsClassHashtable() {}
  explicit nsClassHashtable(uint32_t aInitLength)
      : nsBaseHashtable<KeyClass, mozilla::UniquePtr<T>, T*,
                        nsUniquePtrConverter<T>>(aInitLength) {}

  /**
   * Looks up aKey in the hash table. If it doesn't exist a new object of
   * KeyClass will be created (using the arguments provided) and then returned.
   */
  template <typename... Args>
  UserDataType LookupOrAdd(KeyType aKey, Args&&... aConstructionArgs);

  /**
   * @copydoc nsBaseHashtable::Get
   * @param aData if the key doesn't exist, pData will be set to nullptr.
   */
  bool Get(KeyType aKey, UserDataType* aData) const;

  /**
   * @copydoc nsBaseHashtable::Get
   * @returns nullptr if the key is not present.
   */
  UserDataType Get(KeyType aKey) const;
};

template <typename K, typename T>
inline void ImplCycleCollectionUnlink(nsClassHashtable<K, T>& aField) {
  aField.Clear();
}

template <typename K, typename T>
inline void ImplCycleCollectionTraverse(
    nsCycleCollectionTraversalCallback& aCallback,
    const nsClassHashtable<K, T>& aField, const char* aName,
    uint32_t aFlags = 0) {
  for (auto iter = aField.ConstIter(); !iter.Done(); iter.Next()) {
    ImplCycleCollectionTraverse(aCallback, *iter.UserData(), aName, aFlags);
  }
}

//
// nsClassHashtable definitions
//

template <class KeyClass, class T>
template <typename... Args>
T* nsClassHashtable<KeyClass, T>::LookupOrAdd(KeyType aKey,
                                              Args&&... aConstructionArgs) {
  auto count = this->Count();
  typename base_type::EntryType* ent = this->PutEntry(aKey);
  if (count != this->Count()) {
    ent->SetData(
        mozilla::MakeUnique<T>(std::forward<Args>(aConstructionArgs)...));
  }
  return ent->GetData().get();
}

template <class KeyClass, class T>
bool nsClassHashtable<KeyClass, T>::Get(KeyType aKey, T** aRetVal) const {
  typename base_type::EntryType* ent = this->GetEntry(aKey);

  if (ent) {
    if (aRetVal) {
      *aRetVal = ent->GetData().get();
    }

    return true;
  }

  if (aRetVal) {
    *aRetVal = nullptr;
  }

  return false;
}

template <class KeyClass, class T>
T* nsClassHashtable<KeyClass, T>::Get(KeyType aKey) const {
  typename base_type::EntryType* ent = this->GetEntry(aKey);
  if (!ent) {
    return nullptr;
  }

  return ent->GetData().get();
}

#endif  // nsClassHashtable_h__