summaryrefslogtreecommitdiffstats
path: root/src/libs/xpcom18a4/xpcom/ds/nsInterfaceHashtable.h
blob: 68b06d66f7a2e94b71213e8b2006c3ce97c5893c (plain)
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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is C++ hashtable templates.
 *
 * The Initial Developer of the Original Code is
 * Benjamin Smedberg.
 * Portions created by the Initial Developer are Copyright (C) 2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef nsInterfaceHashtable_h__
#define nsInterfaceHashtable_h__

#include "nsBaseHashtable.h"
#include "nsHashKeys.h"
#include "nsCOMPtr.h"

/**
 * templated hashtable class maps keys to interface pointers.
 * See nsBaseHashtable for complete declaration.
 * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
 *   for a complete specification.
 * @param Interface the interface-type being wrapped
 * @see nsDataHashtable, nsClassHashtable
 */
template<class KeyClass,class Interface>
class nsInterfaceHashtable :
  public nsBaseHashtable< KeyClass, nsCOMPtr<Interface> , Interface* >
{
public:
  typedef typename KeyClass::KeyType KeyType;
  typedef Interface* UserDataType;

  /**
   * @copydoc nsBaseHashtable::Get
   * @param pData This is an XPCOM getter, so pData is already_addrefed.
   *   If the key doesn't exist, pData will be set to nsnull.
   */
  PRBool Get(KeyType aKey, UserDataType* pData) const;

  /**
   * Gets a weak reference to the hashtable entry.
   * @param aFound If not nsnull, will be set to PR_TRUE if the entry is found,
   *               to PR_FALSE otherwise.
   * @return The entry, or nsnull if not found. Do not release this pointer!
   */
  Interface* GetWeak(KeyType aKey, PRBool* aFound = nsnull) const;
};

/**
 * Thread-safe version of nsInterfaceHashtable
 * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
 *   for a complete specification.
 * @param Interface the interface-type being wrapped
 */
template<class KeyClass,class Interface>
class nsInterfaceHashtableMT :
  public nsBaseHashtableMT< KeyClass, nsCOMPtr<Interface> , Interface* >
{
public:
  typedef typename KeyClass::KeyType KeyType;
  typedef Interface* UserDataType;

  /**
   * @copydoc nsBaseHashtable::Get
   * @param pData This is an XPCOM getter, so pData is already_addrefed.
   *   If the key doesn't exist, pData will be set to nsnull.
   */
  PRBool Get(KeyType aKey, UserDataType* pData) const;

  // GetWeak does not make sense on a multi-threaded hashtable, where another
  // thread may remove the entry (and hence release it) as soon as GetWeak
  // returns
};


//
// nsInterfaceHashtable definitions
//

template<class KeyClass,class Interface>
PRBool
nsInterfaceHashtable<KeyClass,Interface>::Get
  (KeyType aKey, UserDataType* pInterface) const
{
  typename nsBaseHashtable<KeyClass, nsCOMPtr<Interface>, Interface*>::EntryType* ent =
    this->GetEntry(aKey);

  if (ent)
  {
    if (pInterface)
    {
      *pInterface = ent->mData;

      NS_IF_ADDREF(*pInterface);
    }

    return PR_TRUE;
  }

  // if the key doesn't exist, set *pInterface to null
  // so that it is a valid XPCOM getter
  if (pInterface)
    *pInterface = nsnull;

  return PR_FALSE;
}

template<class KeyClass,class Interface>
Interface*
nsInterfaceHashtable<KeyClass,Interface>::GetWeak
  (KeyType aKey, PRBool* aFound) const
{
  typename nsBaseHashtable<KeyClass, nsCOMPtr<Interface>, Interface*>::EntryType* ent =
    this->GetEntry(aKey);

  if (ent)
  {
    if (aFound)
      *aFound = PR_TRUE;

    return ent->mData;
  }

  // Key does not exist, return nsnull and set aFound to PR_FALSE
  if (aFound)
    *aFound = PR_FALSE;
  return nsnull;
}

//
// nsInterfaceHashtableMT definitions
//

template<class KeyClass,class Interface>
PRBool
nsInterfaceHashtableMT<KeyClass,Interface>::Get
  (KeyType aKey, UserDataType* pInterface) const
{
  PR_Lock(this->mLock);

  typename nsBaseHashtableMT<KeyClass, nsCOMPtr<Interface>, Interface*>::EntryType* ent =
    this->GetEntry(aKey);

  if (ent)
  {
    if (pInterface)
    {
      *pInterface = ent->mData;

      NS_IF_ADDREF(*pInterface);
    }

    PR_Unlock(this->mLock);

    return PR_TRUE;
  }

  // if the key doesn't exist, set *pInterface to null
  // so that it is a valid XPCOM getter
  if (pInterface)
    *pInterface = nsnull;

  PR_Unlock(this->mLock);

  return PR_FALSE;
}

#endif // nsInterfaceHashtable_h__