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 * Version: NPL 1.1/GPL 2.0/LGPL 2.1
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 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
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 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is 
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 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
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 *
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 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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#include "nsDownloader.h"
#include "nsIInputStream.h"
#include "nsIURL.h"
#include "nsNetUtil.h"
#include "nsIChannel.h"
#include "nsIFileChannel.h"
#include "nsICachingChannel.h"
#include "nsProxiedService.h"
#include "nsIFile.h"
#include "nsXPIDLString.h"

static NS_DEFINE_CID(kProxyObjectManagerCID, NS_PROXYEVENT_MANAGER_CID);

NS_IMETHODIMP
nsDownloader::Init(nsIURI* aURL,
                   nsIDownloadObserver* aObserver,
                   nsISupports* aContext,
                   PRBool aIsSynchronous,
                   nsILoadGroup* aGroup,
                   nsIInterfaceRequestor* aNotificationCallbacks,
                   nsLoadFlags aLoadAttributes)
{
  nsresult rv;
  mObserver = aObserver;
  mContext  = aContext;
  nsCOMPtr<nsIFile> localFile;
  nsCOMPtr<nsIChannel> channel;

  rv = NS_OpenURI(getter_AddRefs(channel), aURL, nsnull, aGroup, aNotificationCallbacks,
                  aLoadAttributes);
  if (NS_SUCCEEDED(rv) && channel)
  {
    nsCOMPtr<nsIFileChannel> fc = do_QueryInterface(channel);
    if (fc)
        rv = fc->GetFile(getter_AddRefs(localFile));
  }
  if (mObserver && (NS_FAILED(rv) || localFile)) 
  {
     if (aIsSynchronous)
       return mObserver->OnDownloadComplete(this, mContext, rv, localFile);
     else
     {
       // If the open failed or the file is local, call the observer.
       // don't callback synchronously as it puts the caller
       // in a recursive situation and breaks the asynchronous
       // semantics of nsIDownloader
       nsresult rv2 = NS_OK;
       nsCOMPtr<nsIProxyObjectManager> pIProxyObjectManager = 
                do_GetService(kProxyObjectManagerCID, &rv);
       if (NS_FAILED(rv2)) return rv2;
           nsCOMPtr<nsIDownloadObserver> pObserver;
           rv2 = pIProxyObjectManager->GetProxyForObject(NS_CURRENT_EVENTQ, 
                     NS_GET_IID(nsIDownloadObserver), mObserver, 
                     PROXY_ASYNC | PROXY_ALWAYS, getter_AddRefs(pObserver));
           if (NS_FAILED(rv2)) return rv2;
           return pObserver->OnDownloadComplete(this, mContext, rv, localFile);
     }
  }
  return channel->AsyncOpen(this, aContext);
}

NS_METHOD
nsDownloader::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
{
  if (aOuter) return NS_ERROR_NO_AGGREGATION;

  nsDownloader* it = new nsDownloader();
  if (it == nsnull)
    return NS_ERROR_OUT_OF_MEMORY;
  NS_ADDREF(it);
  nsresult rv = it->QueryInterface(aIID, aResult);
  NS_RELEASE(it);
  return rv;
}

NS_IMPL_ISUPPORTS3(nsDownloader, nsIDownloader,
                   nsIRequestObserver, nsIStreamListener)

NS_IMETHODIMP 
nsDownloader::OnStartRequest(nsIRequest *request, nsISupports *ctxt)
{
  nsresult rv;
  nsCOMPtr<nsICachingChannel> caching = do_QueryInterface(request, &rv);
  if (caching)
    rv = caching->SetCacheAsFile(PR_TRUE);
  // Returning failure from here will cancel the load
  return rv;
}

NS_IMETHODIMP 
nsDownloader::OnStopRequest(nsIRequest *request, nsISupports *ctxt,
                              nsresult aStatus)
{
  nsCOMPtr<nsIFile> file;
  if (NS_SUCCEEDED(aStatus))
  {
    nsCOMPtr<nsICachingChannel> caching = do_QueryInterface(request, &aStatus);
    if (caching)
      aStatus = caching->GetCacheFile(getter_AddRefs(file));
  }

  return mObserver->OnDownloadComplete(this, mContext, aStatus, file);
}

NS_METHOD
nsDownloader::ConsumeData(nsIInputStream* in,
                          void* closure,
                          const char* fromRawSegment,
                          PRUint32 toOffset,
                          PRUint32 count,
                          PRUint32 *writeCount)
{
  *writeCount = count;
  return NS_OK;
}

NS_IMETHODIMP 
nsDownloader::OnDataAvailable(nsIRequest *request, nsISupports *ctxt, 
                                nsIInputStream *inStr, 
                                PRUint32 sourceOffset, PRUint32 count)
{
  // This function simply disposes of the data as it's read in. 
  // We assume it's already been cached and that's what we're interested in.
  PRUint32 lenRead;  
  return inStr->ReadSegments(nsDownloader::ConsumeData, nsnull, count, &lenRead);
}