netwerk/base/src/nsBaseContentStream.cpp

   1 /* -*- Mode: C++; tab-width: 2; 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 Google Inc.
  18  * Portions created by the Initial Developer are Copyright (C) 2005
  19  * the Initial Developer. All Rights Reserved.
  20  *
  21  * Contributor(s):
  22  *  Darin Fisher <darin@meer.net>
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either the GNU General Public License Version 2 or later (the "GPL"), or
  26  * 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
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  33  * the provisions above, a recipient may use your version of this file under
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  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #include "nsBaseContentStream.h"
  39 #include "nsStreamUtils.h"
  40
  41 //-----------------------------------------------------------------------------
  42
  43 void
  44 nsBaseContentStream::DispatchCallback(PRBool async)
  45 {
  46   if (!mCallback)
  47     return;
  48
  49   // It's important to clear mCallback and mCallbackTarget up-front because the
  50   // OnInputStreamReady implementation may call our AsyncWait method.
  51
  52   nsCOMPtr<nsIInputStreamCallback> callback;
  53   if (async) {
  54     NS_NewInputStreamReadyEvent(getter_AddRefs(callback), mCallback,
  55                                 mCallbackTarget);
  56     if (!callback)
  57       return;  // out of memory!
  58     mCallback = nsnull;
  59   } else {
  60     callback.swap(mCallback);
  61   }
  62   mCallbackTarget = nsnull;
  63
  64   callback->OnInputStreamReady(this);
  65 }
  66
  67 //-----------------------------------------------------------------------------
  68 // nsBaseContentStream::nsISupports
  69
  70 NS_IMPL_THREADSAFE_ADDREF(nsBaseContentStream)
  71 NS_IMPL_THREADSAFE_RELEASE(nsBaseContentStream)
  72
  73 // We only support nsIAsyncInputStream when we are in non-blocking mode.
  74 NS_INTERFACE_MAP_BEGIN(nsBaseContentStream)
  75   NS_INTERFACE_MAP_ENTRY(nsIInputStream)
  76   NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStream, mNonBlocking)
  77   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIInputStream)
  78 NS_INTERFACE_MAP_END_THREADSAFE
  79
  80 //-----------------------------------------------------------------------------
  81 // nsBaseContentStream::nsIInputStream
  82
  83 NS_IMETHODIMP
  84 nsBaseContentStream::Close()
  85 {
  86   return IsClosed() ? NS_OK : CloseWithStatus(NS_BASE_STREAM_CLOSED);
  87 }
  88
  89 NS_IMETHODIMP
  90 nsBaseContentStream::Available(PRUint32 *result)
  91 {
  92   *result = 0;
  93   return mStatus;
  94 }
  95
  96 NS_IMETHODIMP
  97 nsBaseContentStream::Read(char *buf, PRUint32 count, PRUint32 *result)
  98 {
  99   return ReadSegments(NS_CopySegmentToBuffer, buf, count, result);
 100 }
 101
 102 NS_IMETHODIMP
 103 nsBaseContentStream::ReadSegments(nsWriteSegmentFun fun, void *closure,
 104                                   PRUint32 count, PRUint32 *result)
 105 {
 106   *result = 0;
 107
 108   if (mStatus == NS_BASE_STREAM_CLOSED)
 109     return NS_OK;
 110
 111   // No data yet
 112   if (!IsClosed() && IsNonBlocking())
 113     return NS_BASE_STREAM_WOULD_BLOCK;
 114
 115   return mStatus;
 116 }
 117
 118 NS_IMETHODIMP
 119 nsBaseContentStream::IsNonBlocking(PRBool *result)
 120 {
 121   *result = mNonBlocking;
 122   return NS_OK;
 123 }
 124
 125 //-----------------------------------------------------------------------------
 126 // nsBaseContentStream::nsIAsyncInputStream
 127
 128 NS_IMETHODIMP
 129 nsBaseContentStream::CloseWithStatus(nsresult status)
 130 {
 131   if (IsClosed())
 132     return NS_OK;
 133
 134   NS_ENSURE_ARG(NS_FAILED(status));
 135   mStatus = status;
 136
 137   DispatchCallback();
 138   return NS_OK;
 139 }
 140
 141 NS_IMETHODIMP
 142 nsBaseContentStream::AsyncWait(nsIInputStreamCallback *callback,
 143                                PRUint32 flags, PRUint32 requestedCount,
 144                                nsIEventTarget *target)
 145 {
 146   // Our _only_ consumer is nsInputStreamPump, so we simplify things here by
 147   // making assumptions about how we will be called.
 148   NS_ASSERTION(target, "unexpected parameter");
 149   NS_ASSERTION(flags == 0, "unexpected parameter");
 150   NS_ASSERTION(requestedCount == 0, "unexpected parameter");
 151
 152 #ifdef DEBUG
 153   PRBool correctThread;
 154   target->IsOnCurrentThread(&correctThread);
 155   NS_ASSERTION(correctThread, "event target must be on the current thread");
 156 #endif
 157
 158   mCallback = callback;
 159   mCallbackTarget = target;
 160
 161   if (!mCallback)
 162     return NS_OK;
 163
 164   // If we're already closed, then dispatch this callback immediately.
 165   if (IsClosed()) {
 166     DispatchCallback();
 167     return NS_OK;
 168   }
 169
 170   OnCallbackPending();
 171   return NS_OK;
 172 }