michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /**
michael@0:  * This class allows you to prefix an existing nsIAsyncInputStream
michael@0:  * with a preloaded block of data known at construction time by wrapping the
michael@0:  * two data sources into a new nsIAsyncInputStream. Readers of the new
michael@0:  * stream initially see the preloaded data and when that has been exhausted
michael@0:  * they automatically read from the wrapped stream.
michael@0:  *
michael@0:  * It is used by nsHttpConnection when it has over buffered while reading from
michael@0:  * the HTTP input socket and accidentally consumed data that belongs to
michael@0:  * a different protocol via the HTTP Upgrade mechanism. That over-buffered
michael@0:  * data is preloaded together with the input socket to form the new input socket
michael@0:  * given to the new protocol handler.
michael@0: */
michael@0: 
michael@0: #ifndef nsPreloadedStream_h__
michael@0: #define nsPreloadedStream_h__
michael@0: 
michael@0: #include "nsIAsyncInputStream.h"
michael@0: #include "nsCOMPtr.h"
michael@0: #include "mozilla/Attributes.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace net {
michael@0: 
michael@0: class nsPreloadedStream MOZ_FINAL : public nsIAsyncInputStream
michael@0: {
michael@0:  public:
michael@0:     NS_DECL_THREADSAFE_ISUPPORTS
michael@0:     NS_DECL_NSIINPUTSTREAM
michael@0:     NS_DECL_NSIASYNCINPUTSTREAM
michael@0: 
michael@0:     nsPreloadedStream(nsIAsyncInputStream *aStream, 
michael@0:                       const char *data, uint32_t datalen);
michael@0: private:
michael@0:     ~nsPreloadedStream();
michael@0: 
michael@0:     nsCOMPtr<nsIAsyncInputStream> mStream;
michael@0: 
michael@0:     char *mBuf;
michael@0:     uint32_t mOffset;
michael@0:     uint32_t mLen;
michael@0: };
michael@0:         
michael@0: } // namespace net
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif