/src/mozilla-central/toolkit/components/places/nsMaybeWeakPtr.h

Source (jump to first uncovered line)
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 nsMaybeWeakPtr_h_
#define nsMaybeWeakPtr_h_

#include "mozilla/Attributes.h"
#include "nsCOMPtr.h"
#include "nsWeakReference.h"
#include "nsTArray.h"
#include "nsCycleCollectionNoteChild.h"

// nsMaybeWeakPtr is a helper object to hold a strong-or-weak reference
// to the template class.  It's pretty minimal, but sufficient.

template<class T>
class nsMaybeWeakPtr
{
public:
  MOZ_IMPLICIT nsMaybeWeakPtr(nsISupports* aRef) : mPtr(aRef) {}
  MOZ_IMPLICIT nsMaybeWeakPtr(const nsCOMPtr<nsIWeakReference>& aRef) : mPtr(aRef) {}
  MOZ_IMPLICIT nsMaybeWeakPtr(const nsCOMPtr<T>& aRef) : mPtr(aRef) {}

  bool operator==(const nsMaybeWeakPtr<T> &other) const {
    return mPtr == other.mPtr;
  }

  nsISupports* GetRawValue() const { return mPtr.get(); }

  const nsCOMPtr<T> GetValue() const;

private:
  nsCOMPtr<nsISupports> mPtr;
};

// nsMaybeWeakPtrArray is an array of MaybeWeakPtr objects, that knows how to
// grab a weak reference to a given object if requested.  It only allows a
// given object to appear in the array once.

template<class T>
class nsMaybeWeakPtrArray : public nsTArray<nsMaybeWeakPtr<T>>
{
  typedef nsTArray<nsMaybeWeakPtr<T>> MaybeWeakArray;

public:
  nsresult AppendWeakElement(T* aElement, bool aOwnsWeak)
  {
    nsCOMPtr<nsISupports> ref;
    if (aOwnsWeak) {
      ref = do_GetWeakReference(aElement);
    } else {
      ref = aElement;
    }

    if (MaybeWeakArray::Contains(ref.get())) {
      return NS_ERROR_INVALID_ARG;
    }
    if (!MaybeWeakArray::AppendElement(ref)) {
      return NS_ERROR_OUT_OF_MEMORY;
    }
    return NS_OK;
  }

  nsresult RemoveWeakElement(T* aElement)
  {
    if (MaybeWeakArray::RemoveElement(aElement)) {
      return NS_OK;
    }

    // Don't use do_GetWeakReference; it should only be called if we know
    // the object supports weak references.
    nsCOMPtr<nsISupportsWeakReference> supWeakRef = do_QueryInterface(aElement);
    NS_ENSURE_TRUE(supWeakRef, NS_ERROR_INVALID_ARG);

    nsCOMPtr<nsIWeakReference> weakRef;
    nsresult rv = supWeakRef->GetWeakReference(getter_AddRefs(weakRef));
    NS_ENSURE_SUCCESS(rv, rv);

    if (MaybeWeakArray::RemoveElement(weakRef)) {
      return NS_OK;
    }

    return NS_ERROR_INVALID_ARG;
  }
};

template<class T>
const nsCOMPtr<T>
nsMaybeWeakPtr<T>::GetValue() const
{
  if (!mPtr) {
    return nullptr;
  }

  nsresult rv;
  nsCOMPtr<T> ref = do_QueryInterface(mPtr, &rv);
  if (NS_SUCCEEDED(rv)) {
    return ref;
  }

  nsCOMPtr<nsIWeakReference> weakRef = do_QueryInterface(mPtr);
  if (weakRef) {
    ref = do_QueryReferent(weakRef, &rv);
    if (NS_SUCCEEDED(rv)) {
      return ref;
    }
  }

  return nullptr;
}

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

template <typename E>
inline void
ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
                            nsMaybeWeakPtrArray<E>& aField,
                            const char* aName,
                            uint32_t aFlags = 0)
{
  aFlags |= CycleCollectionEdgeNameArrayFlag;
  size_t length = aField.Length();
  for (size_t i = 0; i < length; ++i) {
    CycleCollectionNoteChild(aCallback, aField[i].GetRawValue(), aName, aFlags);
  }
}

// Call a method on each element in the array, but only if the element is
// non-null.

#define ENUMERATE_WEAKARRAY(array, type, method)                           \
  for (uint32_t array_idx = 0; array_idx < array.Length(); ++array_idx) {  \
    const nsCOMPtr<type> &e = array.ElementAt(array_idx).GetValue();       \
    if (e)                                                                 \
      e->method;                                                           \
  }

#endif

Line	Count	Source (jump to first uncovered line)
1		/* -- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -- */
2		/* This Source Code Form is subject to the terms of the Mozilla Public
3		* License, v. 2.0. If a copy of the MPL was not distributed with this
4		* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6		#ifndef nsMaybeWeakPtr_h_
7		#define nsMaybeWeakPtr_h_
8
9		#include "mozilla/Attributes.h"
10		#include "nsCOMPtr.h"
11		#include "nsWeakReference.h"
12		#include "nsTArray.h"
13		#include "nsCycleCollectionNoteChild.h"
14
15		// nsMaybeWeakPtr is a helper object to hold a strong-or-weak reference
16		// to the template class. It's pretty minimal, but sufficient.
17
18		template<class T>
19		class nsMaybeWeakPtr
20		{
21		public:
22	0	MOZ_IMPLICIT nsMaybeWeakPtr(nsISupports* aRef) : mPtr(aRef) {} Unexecuted instantiation: nsMaybeWeakPtr<nsINavBookmarkObserver>::nsMaybeWeakPtr(nsISupports) Unexecuted instantiation: nsMaybeWeakPtr<nsINavHistoryObserver>::nsMaybeWeakPtr(nsISupports) Unexecuted instantiation: nsMaybeWeakPtr<nsINavHistoryResultObserver>::nsMaybeWeakPtr(nsISupports*)
23	0	MOZ_IMPLICIT nsMaybeWeakPtr(const nsCOMPtr<nsIWeakReference>& aRef) : mPtr(aRef) {} Unexecuted instantiation: nsMaybeWeakPtr<nsINavBookmarkObserver>::nsMaybeWeakPtr(nsCOMPtr<nsIWeakReference> const&) Unexecuted instantiation: nsMaybeWeakPtr<nsINavHistoryObserver>::nsMaybeWeakPtr(nsCOMPtr<nsIWeakReference> const&) Unexecuted instantiation: nsMaybeWeakPtr<nsINavHistoryResultObserver>::nsMaybeWeakPtr(nsCOMPtr<nsIWeakReference> const&)
24		MOZ_IMPLICIT nsMaybeWeakPtr(const nsCOMPtr<T>& aRef) : mPtr(aRef) {}
25
26	0	bool operator==(const nsMaybeWeakPtr<T> &other) const {
27	0	return mPtr == other.mPtr;
28	0	} Unexecuted instantiation: nsMaybeWeakPtr<nsINavBookmarkObserver>::operator==(nsMaybeWeakPtr<nsINavBookmarkObserver> const&) const Unexecuted instantiation: nsMaybeWeakPtr<nsINavHistoryObserver>::operator==(nsMaybeWeakPtr<nsINavHistoryObserver> const&) const Unexecuted instantiation: nsMaybeWeakPtr<nsINavHistoryResultObserver>::operator==(nsMaybeWeakPtr<nsINavHistoryResultObserver> const&) const
29
30	0	nsISupports* GetRawValue() const { return mPtr.get(); }
31
32		const nsCOMPtr<T> GetValue() const;
33
34		private:
35		nsCOMPtr<nsISupports> mPtr;
36		};
37
38		// nsMaybeWeakPtrArray is an array of MaybeWeakPtr objects, that knows how to
39		// grab a weak reference to a given object if requested. It only allows a
40		// given object to appear in the array once.
41
42		template<class T>
43		class nsMaybeWeakPtrArray : public nsTArray<nsMaybeWeakPtr<T>>
44		{
45		typedef nsTArray<nsMaybeWeakPtr<T>> MaybeWeakArray;
46
47		public:
48		nsresult AppendWeakElement(T* aElement, bool aOwnsWeak)
49	0	{
50	0	nsCOMPtr<nsISupports> ref;
51	0	if (aOwnsWeak) {
52	0	ref = do_GetWeakReference(aElement);
53	0	} else {
54	0	ref = aElement;
55	0	}
56	0
57	0	if (MaybeWeakArray::Contains(ref.get())) {
58	0	return NS_ERROR_INVALID_ARG;
59	0	}
60	0	if (!MaybeWeakArray::AppendElement(ref)) {
61	0	return NS_ERROR_OUT_OF_MEMORY;
62	0	}
63	0	return NS_OK;
64	0	} Unexecuted instantiation: nsMaybeWeakPtrArray<nsINavBookmarkObserver>::AppendWeakElement(nsINavBookmarkObserver, bool) Unexecuted instantiation: nsMaybeWeakPtrArray<nsINavHistoryObserver>::AppendWeakElement(nsINavHistoryObserver, bool) Unexecuted instantiation: nsMaybeWeakPtrArray<nsINavHistoryResultObserver>::AppendWeakElement(nsINavHistoryResultObserver*, bool)
65
66		nsresult RemoveWeakElement(T* aElement)
67	0	{
68	0	if (MaybeWeakArray::RemoveElement(aElement)) {
69	0	return NS_OK;
70	0	}
71	0
72	0	// Don't use do_GetWeakReference; it should only be called if we know
73	0	// the object supports weak references.
74	0	nsCOMPtr<nsISupportsWeakReference> supWeakRef = do_QueryInterface(aElement);
75	0	NS_ENSURE_TRUE(supWeakRef, NS_ERROR_INVALID_ARG);
76	0
77	0	nsCOMPtr<nsIWeakReference> weakRef;
78	0	nsresult rv = supWeakRef->GetWeakReference(getter_AddRefs(weakRef));
79	0	NS_ENSURE_SUCCESS(rv, rv);
80	0
81	0	if (MaybeWeakArray::RemoveElement(weakRef)) {
82	0	return NS_OK;
83	0	}
84	0
85	0	return NS_ERROR_INVALID_ARG;
86	0	} Unexecuted instantiation: nsMaybeWeakPtrArray<nsINavBookmarkObserver>::RemoveWeakElement(nsINavBookmarkObserver) Unexecuted instantiation: nsMaybeWeakPtrArray<nsINavHistoryObserver>::RemoveWeakElement(nsINavHistoryObserver) Unexecuted instantiation: nsMaybeWeakPtrArray<nsINavHistoryResultObserver>::RemoveWeakElement(nsINavHistoryResultObserver*)
87		};
88
89		template<class T>
90		const nsCOMPtr<T>
91		nsMaybeWeakPtr<T>::GetValue() const
92	0	{
93	0	if (!mPtr) {
94	0	return nullptr;
95	0	}
96	0
97	0	nsresult rv;
98	0	nsCOMPtr<T> ref = do_QueryInterface(mPtr, &rv);
99	0	if (NS_SUCCEEDED(rv)) {
100	0	return ref;
101	0	}
102	0
103	0	nsCOMPtr<nsIWeakReference> weakRef = do_QueryInterface(mPtr);
104	0	if (weakRef) {
105	0	ref = do_QueryReferent(weakRef, &rv);
106	0	if (NS_SUCCEEDED(rv)) {
107	0	return ref;
108	0	}
109	0	}
110	0
111	0	return nullptr;
112	0	} Unexecuted instantiation: nsMaybeWeakPtr<nsINavBookmarkObserver>::GetValue() const Unexecuted instantiation: nsMaybeWeakPtr<nsINavHistoryObserver>::GetValue() const Unexecuted instantiation: nsMaybeWeakPtr<nsINavHistoryResultObserver>::GetValue() const
113
114		template <typename T>
115		inline void
116		ImplCycleCollectionUnlink(nsMaybeWeakPtrArray<T>& aField)
117	0	{
118	0	aField.Clear();
119	0	}
120
121		template <typename E>
122		inline void
123		ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
124		nsMaybeWeakPtrArray<E>& aField,
125		const char* aName,
126		uint32_t aFlags = 0)
127	0	{
128	0	aFlags \|= CycleCollectionEdgeNameArrayFlag;
129	0	size_t length = aField.Length();
130	0	for (size_t i = 0; i < length; ++i) {
131	0	CycleCollectionNoteChild(aCallback, aField[i].GetRawValue(), aName, aFlags);
132	0	}
133	0	}
134
135		// Call a method on each element in the array, but only if the element is
136		// non-null.
137
138		#define ENUMERATE_WEAKARRAY(array, type, method) \
139	0	for (uint32_t array_idx = 0; array_idx < array.Length(); ++array_idx) { \
140	0	const nsCOMPtr<type> &e = array.ElementAt(array_idx).GetValue(); \
141	0	if (e) \
142	0	e->method; \
143	0	}
144
145		#endif

Coverage Report

Created: 2018-09-25 14:53