xpcom/ds/nsArray.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   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 XPCOM Array implementation.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corp.
  19  * Portions created by the Initial Developer are Copyright (C) 2002
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   Alec Flett <alecf@netscape.com>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
  27  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
  29  * of those above. If you wish to allow use of your version of this file only
  30  * under the terms of either the GPL or the LGPL, and not to allow others to
  31  * use your version of this file under the terms of the MPL, indicate your
  32  * decision by deleting the provisions above and replace them with the notice
  33  * and other provisions required by the GPL or the LGPL. If you do not delete
  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #include "nsArray.h"
  40 #include "nsArrayEnumerator.h"
  41 #include "nsWeakReference.h"
  42 #include "nsThreadUtils.h"
  43
  44 // used by IndexOf()
  45 struct findIndexOfClosure
  46 {
  47     nsISupports *targetElement;
  48     PRUint32 startIndex;
  49     PRUint32 resultIndex;
  50 };
  51
  52 static PRBool FindElementCallback(void* aElement, void* aClosure);
  53
  54 NS_INTERFACE_MAP_BEGIN(nsArray)
  55   NS_INTERFACE_MAP_ENTRY(nsIArray)
  56   NS_INTERFACE_MAP_ENTRY(nsIMutableArray)
  57   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIMutableArray)
  58 NS_INTERFACE_MAP_END
  59
  60 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsArrayCC)
  61   NS_INTERFACE_MAP_ENTRY(nsIArray)
  62   NS_INTERFACE_MAP_ENTRY(nsIMutableArray)
  63   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIMutableArray)
  64 NS_INTERFACE_MAP_END
  65
  66 nsArray::~nsArray()
  67 {
  68     Clear();
  69 }
  70
  71
  72 NS_IMPL_ADDREF(nsArray)
  73 NS_IMPL_RELEASE(nsArray)
  74
  75 NS_IMPL_CYCLE_COLLECTING_ADDREF(nsArrayCC)
  76 NS_IMPL_CYCLE_COLLECTING_RELEASE(nsArrayCC)
  77
  78 NS_IMPL_CYCLE_COLLECTION_CLASS(nsArrayCC)
  79 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsArrayCC)
  80     tmp->Clear();
  81 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
  82 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsArrayCC)
  83     NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMARRAY(mArray)
  84 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
  85
  86 NS_IMETHODIMP
  87 nsArray::GetLength(PRUint32* aLength)
  88 {
  89     *aLength = mArray.Count();
  90     return NS_OK;
  91 }
  92
  93 NS_IMETHODIMP
  94 nsArray::QueryElementAt(PRUint32 aIndex,
  95                         const nsIID& aIID,
  96                         void ** aResult)
  97 {
  98     nsISupports * obj = mArray.SafeObjectAt(aIndex);
  99     if (!obj) return NS_ERROR_ILLEGAL_VALUE;
 100
 101     // no need to worry about a leak here, because SafeObjectAt()
 102     // doesn't addref its result
 103     return obj->QueryInterface(aIID, aResult);
 104 }
 105
 106 NS_IMETHODIMP
 107 nsArray::IndexOf(PRUint32 aStartIndex, nsISupports* aElement,
 108                  PRUint32* aResult)
 109 {
 110     // optimize for the common case by forwarding to mArray
 111     if (aStartIndex == 0) {
 112         PRUint32 idx = mArray.IndexOf(aElement);
 113         if (idx == PR_UINT32_MAX)
 114             return NS_ERROR_FAILURE;
 115
 116         *aResult = idx;
 117         return NS_OK;
 118     }
 119
 120     findIndexOfClosure closure = { aElement, aStartIndex, 0 };
 121     PRBool notFound = mArray.EnumerateForwards(FindElementCallback, &closure);
 122     if (notFound)
 123         return NS_ERROR_FAILURE;
 124
 125     *aResult = closure.resultIndex;
 126     return NS_OK;
 127 }
 128
 129 NS_IMETHODIMP
 130 nsArray::Enumerate(nsISimpleEnumerator **aResult)
 131 {
 132     return NS_NewArrayEnumerator(aResult, static_cast<nsIArray*>(this));
 133 }
 134
 135 // nsIMutableArray implementation
 136
 137 NS_IMETHODIMP
 138 nsArray::AppendElement(nsISupports* aElement, PRBool aWeak)
 139 {
 140     PRBool result;
 141     if (aWeak) {
 142         nsCOMPtr<nsISupports> elementRef =
 143             getter_AddRefs(static_cast<nsISupports*>
 144                                       (NS_GetWeakReference(aElement)));
 145         NS_ASSERTION(elementRef, "AppendElement: Trying to use weak references on an object that doesn't support it");
 146         if (!elementRef)
 147             return NS_ERROR_FAILURE;
 148         result = mArray.AppendObject(elementRef);
 149     }
 150
 151     else {
 152         // add the object directly
 153         result = mArray.AppendObject(aElement);
 154     }
 155     return result ? NS_OK : NS_ERROR_FAILURE;
 156 }
 157
 158 NS_IMETHODIMP
 159 nsArray::RemoveElementAt(PRUint32 aIndex)
 160 {
 161     PRBool result = mArray.RemoveObjectAt(aIndex);
 162     return result ? NS_OK : NS_ERROR_FAILURE;
 163 }
 164
 165 NS_IMETHODIMP
 166 nsArray::InsertElementAt(nsISupports* aElement, PRUint32 aIndex, PRBool aWeak)
 167 {
 168     nsCOMPtr<nsISupports> elementRef;
 169     if (aWeak) {
 170         elementRef =
 171             getter_AddRefs(static_cast<nsISupports*>
 172                                       (NS_GetWeakReference(aElement)));
 173         NS_ASSERTION(elementRef, "InsertElementAt: Trying to use weak references on an object that doesn't support it");
 174         if (!elementRef)
 175             return NS_ERROR_FAILURE;
 176     } else {
 177         elementRef = aElement;
 178     }
 179     PRBool result = mArray.InsertObjectAt(elementRef, aIndex);
 180     return result ? NS_OK : NS_ERROR_FAILURE;
 181 }
 182
 183 NS_IMETHODIMP
 184 nsArray::ReplaceElementAt(nsISupports* aElement, PRUint32 aIndex, PRBool aWeak)
 185 {
 186     nsCOMPtr<nsISupports> elementRef;
 187     if (aWeak) {
 188         elementRef =
 189             getter_AddRefs(static_cast<nsISupports*>
 190                                       (NS_GetWeakReference(aElement)));
 191         NS_ASSERTION(elementRef, "ReplaceElementAt: Trying to use weak references on an object that doesn't support it");
 192         if (!elementRef)
 193             return NS_ERROR_FAILURE;
 194     } else {
 195         elementRef = aElement;
 196     }
 197     PRBool result = mArray.ReplaceObjectAt(elementRef, aIndex);
 198     return result ? NS_OK : NS_ERROR_FAILURE;
 199 }
 200
 201 NS_IMETHODIMP
 202 nsArray::Clear()
 203 {
 204     mArray.Clear();
 205     return NS_OK;
 206 }
 207
 208 //
 209 // static helper routines
 210 //
 211 PRBool
 212 FindElementCallback(void *aElement, void* aClosure)
 213 {
 214     findIndexOfClosure* closure =
 215         static_cast<findIndexOfClosure*>(aClosure);
 216
 217     nsISupports* element =
 218         static_cast<nsISupports*>(aElement);
 219
 220     // don't start searching until we're past the startIndex
 221     if (closure->resultIndex >= closure->startIndex &&
 222         element == closure->targetElement) {
 223         return PR_FALSE;    // stop! We found it
 224     }
 225     closure->resultIndex++;
 226
 227     return PR_TRUE;
 228 }
 229
 230 nsresult
 231 nsArrayConstructor(nsISupports *aOuter, const nsIID& aIID, void **aResult)
 232 {
 233     if (aOuter)
 234         return NS_ERROR_NO_AGGREGATION;
 235
 236     nsCOMPtr<nsIArray> inst = NS_IsMainThread() ? new nsArrayCC : new nsArray;
 237     if (!inst)
 238         return NS_ERROR_OUT_OF_MEMORY;
 239
 240     return inst->QueryInterface(aIID, aResult);
 241 }