Revising nsIChannel to allow for overlapped i/o. This consists of three parts:

1. Factoring nsIChannel into a protocol specific part, the nsIChannel, and a socket specific, the nsITransport.
2. Derive the nsIChannel from a nsIRequest.
2. Changes the notification system from necko and the URILoader to pass the nsIRequest interface instead of nsIChannel interface.

This goal stems from wanting to be able to have active AsyncRead and AsyncWrite operations on nsSocketTransport.
This is desired because it would greatly simplify the task of maintaining persistent/reusable socket connections
for FTP, HTTP, and Imap (and potentially other protocols).  The problem with the existing nsIChannel interface is
that it does not allow one to selectively suspend just one of the read or write operations while keeping the other active.

The full details of the change on written up in the netlib newsgroup.

r=darin@netscape.com
sr=rpotts@netscape.com

content/base/src/nsDOMParser.cpp

@@ -82,7 +82,9 @@ nsDOMParserChannel::~nsDOMParserChannel()
 {
 }
 
-NS_IMPL_ISUPPORTS2(nsDOMParserChannel, nsIRequest, nsIChannel)
+NS_IMPL_ISUPPORTS2(nsDOMParserChannel, 
+                   nsIChannel,
+                   nsIRequest)
 
 /* boolean isPending (); */
 NS_IMETHODIMP nsDOMParserChannel::GetName(PRUnichar* *result)
@@ -159,38 +161,6 @@ NS_IMETHODIMP nsDOMParserChannel::SetURI(nsIURI * aURI)
   return NS_OK;
 }
 
-/* attribute unsigned long transferOffset; */
-NS_IMETHODIMP nsDOMParserChannel::GetTransferOffset(PRUint32 *aTransferOffset)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-NS_IMETHODIMP nsDOMParserChannel::SetTransferOffset(PRUint32 aTransferOffset)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-/* attribute long transferCount; */
-NS_IMETHODIMP nsDOMParserChannel::GetTransferCount(PRInt32 *aTransferCount)
-{
-  NS_ENSURE_ARG(aTransferCount);
-  *aTransferCount = -1;
-  return NS_OK;
-}
-NS_IMETHODIMP nsDOMParserChannel::SetTransferCount(PRInt32 aTransferCount)
-{
-    return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-/* attribute nsLoadFlags loadAttributes; */
-NS_IMETHODIMP nsDOMParserChannel::GetLoadAttributes(nsLoadFlags *aLoadAttributes)
-{
-    return NS_ERROR_NOT_IMPLEMENTED;
-}
-NS_IMETHODIMP nsDOMParserChannel::SetLoadAttributes(nsLoadFlags aLoadAttributes)
-{
-    return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 /* attribute string contentType; */
 NS_IMETHODIMP nsDOMParserChannel::GetContentType(char * *aContentType)
 {
@@ -232,6 +202,16 @@ NS_IMETHODIMP nsDOMParserChannel::SetOwner(nsISupports * aOwner)
   return NS_OK;
 }
 
+/* attribute nsLoadFlags loadAttributes; */
+NS_IMETHODIMP nsDOMParserChannel::GetLoadAttributes(nsLoadFlags *aLoadAttributes)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+NS_IMETHODIMP nsDOMParserChannel::SetLoadAttributes(nsLoadFlags aLoadAttributes)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
 /* attribute nsILoadGroup loadGroup; */
 NS_IMETHODIMP nsDOMParserChannel::GetLoadGroup(nsILoadGroup * *aLoadGroup)
 {
@@ -262,62 +242,12 @@ NS_IMETHODIMP nsDOMParserChannel::GetSecurityInfo(nsISupports * *aSecurityInfo)
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
-/* attribute unsigned long bufferSegmentSize; */
-NS_IMETHODIMP nsDOMParserChannel::GetBufferSegmentSize(PRUint32 *aBufferSegmentSize)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-NS_IMETHODIMP nsDOMParserChannel::SetBufferSegmentSize(PRUint32 aBufferSegmentSize)
+NS_IMETHODIMP nsDOMParserChannel::Open(nsIInputStream **_retval)
 {
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
-/* attribute unsigned long bufferMaxSize; */
-NS_IMETHODIMP nsDOMParserChannel::GetBufferMaxSize(PRUint32 *aBufferMaxSize)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-NS_IMETHODIMP nsDOMParserChannel::SetBufferMaxSize(PRUint32 aBufferMaxSize)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-/* readonly attribute nsIFile localFile; */
-NS_IMETHODIMP nsDOMParserChannel::GetLocalFile(nsIFile * *aLocalFile)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-/* attribute boolean pipeliningAllowed; */
-NS_IMETHODIMP nsDOMParserChannel::GetPipeliningAllowed(PRBool *aPipeliningAllowed)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-NS_IMETHODIMP nsDOMParserChannel::SetPipeliningAllowed(PRBool aPipeliningAllowed)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-/* nsIInputStream openInputStream (); */
-NS_IMETHODIMP nsDOMParserChannel::OpenInputStream(nsIInputStream **_retval)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-/* nsIOutputStream openOutputStream (); */
-NS_IMETHODIMP nsDOMParserChannel::OpenOutputStream(nsIOutputStream **_retval)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-/* void asyncRead (in nsIStreamListener listener, in nsISupports ctxt); */
-NS_IMETHODIMP nsDOMParserChannel::AsyncRead(nsIStreamListener *listener, nsISupports *ctxt)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-/* void asyncWrite (in nsIStreamProvider provider, in nsISupports ctxt); */
-NS_IMETHODIMP nsDOMParserChannel::AsyncWrite(nsIStreamProvider *provider, nsISupports *ctxt)
+NS_IMETHODIMP nsDOMParserChannel::AsyncOpen(nsIStreamListener *listener, nsISupports *ctxt)
 {
   return NS_ERROR_NOT_IMPLEMENTED;
 }
@@ -509,6 +439,7 @@ nsDOMParser::ParseFromStream(nsIInputStream *stream,
   if (principal) {
     channel->SetOwner(principal);
   }
+  nsCOMPtr<nsIRequest> request = NS_STATIC_CAST(nsIRequest*, parserChannel);
 
   // Tell the document to start loading
   nsCOMPtr<nsIStreamListener> listener;
@@ -525,15 +456,15 @@ nsDOMParser::ParseFromStream(nsIInputStream *stream,
   // Now start pumping data to the listener
   nsresult status;
 
-  rv = listener->OnStartRequest(channel, nsnull);
-  channel->GetStatus(&status);
+  rv = listener->OnStartRequest(request, nsnull);
+  request->GetStatus(&status);
 
   if (NS_SUCCEEDED(rv) && NS_SUCCEEDED(status)) {
-    rv = listener->OnDataAvailable(channel, nsnull, stream, 0, contentLength);
-    channel->GetStatus(&status);
+    rv = listener->OnDataAvailable(request, nsnull, stream, 0, contentLength);
+    request->GetStatus(&status);
   }
 
-  rv = listener->OnStopRequest(channel, nsnull, status, nsnull);
+  rv = listener->OnStopRequest(request, nsnull, status, nsnull);
   if (NS_FAILED(rv)) return NS_ERROR_FAILURE;
 
   *_retval = domDocument;

content/base/src/nsXMLHttpRequest.cpp

@@ -603,8 +603,8 @@ nsXMLHttpRequest::GetStatusText(char * *aStatusText)
 NS_IMETHODIMP 
 nsXMLHttpRequest::Abort()
 {
-  if (mChannel) {
-    return mChannel->Cancel(NS_BINDING_ABORTED);
+  if (mReadRequest) {
+    return mReadRequest->Cancel(NS_BINDING_ABORTED);
   }
   
   return NS_OK;
@@ -1038,7 +1038,7 @@ nsXMLHttpRequest::Send(nsISupports *body)
 
   // Start reading from the channel
   mStatus = XML_HTTP_REQUEST_SENT;
-  rv = mChannel->AsyncRead(listener, nsnull);
+  rv = mChannel->AsyncOpen(listener, nsnull);
 
 #ifdef IMPLEMENT_SYNC_LOAD
   if (NS_FAILED(rv)) {

content/base/src/nsXMLHttpRequest.h

@@ -89,6 +89,7 @@ protected:
                                nsIInputStream** aStream);
 
   nsCOMPtr<nsIHTTPChannel> mChannel;
+  nsCOMPtr<nsIRequest> mReadRequest;
   nsCOMPtr<nsIDOMDocument> mDocument;
   nsCOMPtr<nsIURI> mBaseURI;
   nsCOMPtr<nsIDocument> mBaseDocument;