xpcom/ds/nsHashSets.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is Mozilla Communicator client code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either of the GNU General Public License Version 2 or later (the "GPL"),
  26  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  27  * in which case the provisions of the GPL or the LGPL are applicable instead
  28  * of those above. If you wish to allow use of your version of this file only
  29  * under the terms of either the GPL or the LGPL, and not to allow others to
  30  * use your version of this file under the terms of the MPL, indicate your
  31  * decision by deleting the provisions above and replace them with the notice
  32  * and other provisions required by the GPL or the LGPL. If you do not delete
  33  * the provisions above, a recipient may use your version of this file under
  34  * the terms of any one of the MPL, the GPL or the LGPL.
  35  *
  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #ifndef __nsHashSets_h__
  39 #define __nsHashSets_h__
  40
  41 #include "nsDoubleHashtable.h"
  42
  43 /*
  44  * HASH SETS
  45  *
  46  * These hash classes describe hashtables that contain keys without values.
  47  * This is useful when you want to store things and then just test for their
  48  * existence later.  We have defined standard ones for string, int and void.
  49  *
  50  * nsStringHashSet:  nsAString&
  51  * nsCStringHashSet: nsACString&
  52  * nsInt32HashSet:   PRInt32
  53  * nsVoidHashSet:    void*
  54  *
  55  * USAGE:
  56  * Put(): put a thing of the given type into the set
  57  * Contains(): whether it contains a thing of the given type
  58  * To use, you just do: (for example)
  59  *
  60  * #include "nsDoubleHashtable.h"
  61  * nsInt32HashSet mySet;
  62  * mySet.Init(1);
  63  * mySet.Put(5);
  64  * if (mySet.Contains(5)) {
  65  *   printf("yay\n");
  66  * }
  67  *
  68  * There is a nice convenient macro for declaring empty map classes:
  69  * DECL_DHASH_SET(CLASSNAME, ENTRY_CLASS, KEY_TYPE)
  70  * - CLASSNAME: the name of the class
  71  * - ENTRY_CLASS: the name of the entry class with the key in it
  72  * - KEY_TYPE: the type of key for Put() and Contains()
  73  *
  74  * DHASH_SET(CLASSNAME, ENTRY_CLASS, KEY_TYPE) is the companion macro
  75  * you must put in the .cpp (implementation) code.
  76  */
  77
  78 #define DECL_DHASH_SET(CLASSNAME,ENTRY_CLASS,KEY_TYPE)                        \
  79 DECL_DHASH_WRAPPER(CLASSNAME##Super,ENTRY_CLASS,KEY_TYPE)                     \
  80 class DHASH_EXPORT CLASSNAME : public CLASSNAME##Super {                      \
  81 public:                                                                       \
  82   CLASSNAME() : CLASSNAME##Super() { }                                        \
  83   ~CLASSNAME() { }                                                            \
  84   nsresult Put(const KEY_TYPE aKey) {                                         \
  85     return AddEntry(aKey) ? NS_OK : NS_ERROR_OUT_OF_MEMORY;                   \
  86   }                                                                           \
  87   PRBool Contains(const KEY_TYPE aKey) {                                      \
  88     return GetEntry(aKey) ? PR_TRUE : PR_FALSE;                               \
  89   }                                                                           \
  90 };
  91
  92 #define DHASH_SET(CLASSNAME,ENTRY_CLASS,KEY_TYPE)                              \
  93 DHASH_WRAPPER(CLASSNAME##Super,ENTRY_CLASS,KEY_TYPE)
  94
  95 #undef DHASH_EXPORT
  96 #define DHASH_EXPORT NS_COM
  97
  98 DECL_DHASH_SET(nsStringHashSet, PLDHashStringEntry, nsAString&)
  99 DECL_DHASH_SET(nsCStringHashSet,PLDHashCStringEntry,nsACString&)
 100 DECL_DHASH_SET(nsInt32HashSet,  PLDHashInt32Entry,  PRInt32)
 101 DECL_DHASH_SET(nsVoidHashSet,   PLDHashVoidEntry,   void*)
 102
 103 #undef DHASH_EXPORT
 104 #define DHASH_EXPORT
 105
 106
 107 #endif