netwerk/base/src/nsRequestObserverProxy.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/
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  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.org 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) 2001
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   Darin Fisher <darin@netscape.com> (original author)
  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
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  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #include "nscore.h"
  40 #include "nsRequestObserverProxy.h"
  41 #include "nsIRequest.h"
  42 #include "nsIServiceManager.h"
  43 #include "nsProxyRelease.h"
  44 #include "nsAutoPtr.h"
  45 #include "nsString.h"
  46 #include "prlog.h"
  47
  48 #if defined(PR_LOGGING)
  49 static PRLogModuleInfo *gRequestObserverProxyLog;
  50 #endif
  51
  52 #define LOG(args) PR_LOG(gRequestObserverProxyLog, PR_LOG_DEBUG, args)
  53
  54 //-----------------------------------------------------------------------------
  55 // nsARequestObserverEvent internal class...
  56 //-----------------------------------------------------------------------------
  57
  58 nsARequestObserverEvent::nsARequestObserverEvent(nsIRequest *request,
  59                                                  nsISupports *context)
  60     : mRequest(request)
  61     , mContext(context)
  62 {
  63     NS_PRECONDITION(mRequest, "null pointer");
  64 }
  65
  66 //-----------------------------------------------------------------------------
  67 // nsOnStartRequestEvent internal class...
  68 //-----------------------------------------------------------------------------
  69
  70 class nsOnStartRequestEvent : public nsARequestObserverEvent
  71 {
  72     nsRefPtr<nsRequestObserverProxy> mProxy;
  73 public:
  74     nsOnStartRequestEvent(nsRequestObserverProxy *proxy,
  75                           nsIRequest *request,
  76                           nsISupports *context)
  77         : nsARequestObserverEvent(request, context)
  78         , mProxy(proxy)
  79     {
  80         NS_PRECONDITION(mProxy, "null pointer");
  81     }
  82
  83     virtual ~nsOnStartRequestEvent() {}
  84
  85     NS_IMETHOD Run()
  86     {
  87         LOG(("nsOnStartRequestEvent::HandleEvent [req=%x]\n", mRequest.get()));
  88
  89         if (!mProxy->mObserver) {
  90             NS_NOTREACHED("already handled onStopRequest event (observer is null)");
  91             return NS_OK;
  92         }
  93
  94         LOG(("handle startevent=%8lX\n",(long)this));
  95         nsresult rv = mProxy->mObserver->OnStartRequest(mRequest, mContext);
  96         if (NS_FAILED(rv)) {
  97             LOG(("OnStartRequest failed [rv=%x] canceling request!\n", rv));
  98             rv = mRequest->Cancel(rv);
  99             NS_ASSERTION(NS_SUCCEEDED(rv), "Cancel failed for request!");
 100         }
 101
 102         return NS_OK;
 103     }
 104 };
 105
 106 //-----------------------------------------------------------------------------
 107 // nsOnStopRequestEvent internal class...
 108 //-----------------------------------------------------------------------------
 109
 110 class nsOnStopRequestEvent : public nsARequestObserverEvent
 111 {
 112     nsRefPtr<nsRequestObserverProxy> mProxy;
 113 public:
 114     nsOnStopRequestEvent(nsRequestObserverProxy *proxy,
 115                          nsIRequest *request, nsISupports *context)
 116         : nsARequestObserverEvent(request, context)
 117         , mProxy(proxy)
 118     {
 119         NS_PRECONDITION(mProxy, "null pointer");
 120     }
 121
 122     virtual ~nsOnStopRequestEvent() {}
 123
 124     NS_IMETHOD Run()
 125     {
 126         nsresult rv, status = NS_OK;
 127
 128         LOG(("nsOnStopRequestEvent::HandleEvent [req=%x]\n", mRequest.get()));
 129
 130         nsCOMPtr<nsIRequestObserver> observer = mProxy->mObserver;
 131         if (!observer) {
 132             NS_NOTREACHED("already handled onStopRequest event (observer is null)");
 133             return NS_OK;
 134         }
 135         // Do not allow any more events to be handled after OnStopRequest
 136         mProxy->mObserver = 0;
 137
 138         rv = mRequest->GetStatus(&status);
 139         NS_ASSERTION(NS_SUCCEEDED(rv), "GetStatus failed for request!");
 140
 141         LOG(("handle stopevent=%8lX\n",(long)this));
 142         (void) observer->OnStopRequest(mRequest, mContext, status);
 143
 144         return NS_OK;
 145     }
 146 };
 147
 148 //-----------------------------------------------------------------------------
 149 // nsRequestObserverProxy <public>
 150 //-----------------------------------------------------------------------------
 151
 152 nsRequestObserverProxy::~nsRequestObserverProxy()
 153 {
 154     if (mObserver) {
 155         // order is crucial here... we must be careful to clear mObserver
 156         // before posting the proxy release event.  otherwise, we'd risk
 157         // releasing the object on this thread.
 158         nsIRequestObserver *obs = nsnull;
 159         mObserver.swap(obs);
 160         NS_ProxyRelease(mTarget, obs);
 161     }
 162 }
 163
 164 //-----------------------------------------------------------------------------
 165 // nsRequestObserverProxy::nsISupports implementation...
 166 //-----------------------------------------------------------------------------
 167
 168 NS_IMPL_THREADSAFE_ISUPPORTS2(nsRequestObserverProxy,
 169                               nsIRequestObserver,
 170                               nsIRequestObserverProxy)
 171
 172 //-----------------------------------------------------------------------------
 173 // nsRequestObserverProxy::nsIRequestObserver implementation...
 174 //-----------------------------------------------------------------------------
 175
 176 NS_IMETHODIMP
 177 nsRequestObserverProxy::OnStartRequest(nsIRequest *request,
 178                                        nsISupports *context)
 179 {
 180     LOG(("nsRequestObserverProxy::OnStartRequest [this=%x req=%x]\n", this, request));
 181
 182     nsOnStartRequestEvent *ev =
 183         new nsOnStartRequestEvent(this, request, context);
 184     if (!ev)
 185         return NS_ERROR_OUT_OF_MEMORY;
 186
 187     LOG(("post startevent=%p queue=%p\n", ev, mTarget.get()));
 188     nsresult rv = FireEvent(ev);
 189     if (NS_FAILED(rv))
 190         delete ev;
 191     return rv;
 192 }
 193
 194 NS_IMETHODIMP
 195 nsRequestObserverProxy::OnStopRequest(nsIRequest *request,
 196                                       nsISupports *context,
 197                                       nsresult status)
 198 {
 199     LOG(("nsRequestObserverProxy: OnStopRequest [this=%x req=%x status=%x]\n",
 200         this, request, status));
 201
 202     // The status argument is ignored because, by the time the OnStopRequestEvent
 203     // is actually processed, the status of the request may have changed :-(
 204     // To make sure that an accurate status code is always used, GetStatus() is
 205     // called when the OnStopRequestEvent is actually processed (see above).
 206
 207     nsOnStopRequestEvent *ev =
 208         new nsOnStopRequestEvent(this, request, context);
 209     if (!ev)
 210         return NS_ERROR_OUT_OF_MEMORY;
 211
 212     LOG(("post stopevent=%p queue=%p\n", ev, mTarget.get()));
 213     nsresult rv = FireEvent(ev);
 214     if (NS_FAILED(rv))
 215         delete ev;
 216     return rv;
 217 }
 218
 219 //-----------------------------------------------------------------------------
 220 // nsRequestObserverProxy::nsIRequestObserverProxy implementation...
 221 //-----------------------------------------------------------------------------
 222
 223 NS_IMETHODIMP
 224 nsRequestObserverProxy::Init(nsIRequestObserver *observer,
 225                              nsIEventTarget *target)
 226 {
 227     NS_ENSURE_ARG_POINTER(observer);
 228
 229 #if defined(PR_LOGGING)
 230     if (!gRequestObserverProxyLog)
 231         gRequestObserverProxyLog = PR_NewLogModule("nsRequestObserverProxy");
 232 #endif
 233
 234     mObserver = observer;
 235
 236     SetTarget(target ? target : NS_GetCurrentThread());
 237     NS_ENSURE_STATE(mTarget);
 238
 239     return NS_OK;
 240 }
 241
 242 //-----------------------------------------------------------------------------
 243 // nsRequestObserverProxy implementation...
 244 //-----------------------------------------------------------------------------
 245
 246 nsresult
 247 nsRequestObserverProxy::FireEvent(nsARequestObserverEvent *event)
 248 {
 249     NS_ENSURE_TRUE(mTarget, NS_ERROR_NOT_INITIALIZED);
 250     return mTarget->Dispatch(event, NS_DISPATCH_NORMAL);
 251 }