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 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #ifndef mozilla_net_SpdySession3_h

 #define mozilla_net_SpdySession3_h

 // SPDY as defined by

 // http://dev.chromium.org/spdy/spdy-protocol/spdy-protocol-draft3

 #include "ASpdySession.h"

 #include "mozilla/Attributes.h"

 #include "nsAHttpConnection.h"

 #include "nsClassHashtable.h"

 #include "nsDataHashtable.h"

 #include "nsDeque.h"

 #include "nsHashKeys.h"

 #include "zlib.h"

 class nsISocketTransport;

 namespace mozilla { namespace net {

 class SpdyPushedStream3;

 class SpdyStream3;

 class SpdySession3 MOZ_FINAL : public ASpdySession

                              , public nsAHttpConnection

                              , public nsAHttpSegmentReader

                              , public nsAHttpSegmentWriter

 {

 public:

   NS_DECL_THREADSAFE_ISUPPORTS

   NS_DECL_NSAHTTPTRANSACTION

   NS_DECL_NSAHTTPCONNECTION(mConnection)

   NS_DECL_NSAHTTPSEGMENTREADER

   NS_DECL_NSAHTTPSEGMENTWRITER

   SpdySession3(nsAHttpTransaction *, nsISocketTransport *, int32_t);

   ~SpdySession3();

   bool AddStream(nsAHttpTransaction *, int32_t);

   bool CanReuse() { return !mShouldGoAway && !mClosed; }

   bool RoomForMoreStreams();

   // When the connection is active this is called up to once every 1 second

   // return the interval (in seconds) that the connection next wants to

   // have this invoked. It might happen sooner depending on the needs of

   // other connections.

   uint32_t  ReadTimeoutTick(PRIntervalTime now);

   // Idle time represents time since "goodput".. e.g. a data or header frame

   PRIntervalTime IdleTime();

   // Registering with a newID of 0 means pick the next available odd ID

   uint32_t RegisterStreamID(SpdyStream3 *, uint32_t aNewID = 0);

   const static uint8_t kVersion        = 3;

   const static uint8_t kFlag_Control   = 0x80;

   const static uint8_t kFlag_Data_FIN  = 0x01;

   const static uint8_t kFlag_Data_UNI  = 0x02;

   enum

   {

     CONTROL_TYPE_FIRST = 0,

     CONTROL_TYPE_SYN_STREAM = 1,

     CONTROL_TYPE_SYN_REPLY = 2,

     CONTROL_TYPE_RST_STREAM = 3,

     CONTROL_TYPE_SETTINGS = 4,

     CONTROL_TYPE_NOOP = 5,                        /* deprecated */

     CONTROL_TYPE_PING = 6,

     CONTROL_TYPE_GOAWAY = 7,

     CONTROL_TYPE_HEADERS = 8,

     CONTROL_TYPE_WINDOW_UPDATE = 9,

     CONTROL_TYPE_CREDENTIAL = 10,

     CONTROL_TYPE_LAST = 11

   };

   enum rstReason

   {

     RST_PROTOCOL_ERROR = 1,

     RST_INVALID_STREAM = 2,

     RST_REFUSED_STREAM = 3,

     RST_UNSUPPORTED_VERSION = 4,

     RST_CANCEL = 5,

     RST_INTERNAL_ERROR = 6,

     RST_FLOW_CONTROL_ERROR = 7,

     RST_STREAM_IN_USE = 8,

     RST_STREAM_ALREADY_CLOSED = 9,

     RST_INVALID_CREDENTIALS = 10,

     RST_FRAME_TOO_LARGE = 11

   };

   enum goawayReason

   {

     OK = 0,

     PROTOCOL_ERROR = 1,

     INTERNAL_ERROR = 2,    // sometimes misdocumented as 11

     NUM_STATUS_CODES = 3   // reserved by chromium but undocumented

   };

   enum settingsFlags

   {

     PERSIST_VALUE = 1,

     PERSISTED_VALUE = 2

   };

   enum

   {

     SETTINGS_TYPE_UPLOAD_BW = 1, // kb/s

     SETTINGS_TYPE_DOWNLOAD_BW = 2, // kb/s

     SETTINGS_TYPE_RTT = 3, // ms

     SETTINGS_TYPE_MAX_CONCURRENT = 4, // streams

     SETTINGS_TYPE_CWND = 5, // packets

     SETTINGS_TYPE_DOWNLOAD_RETRANS_RATE = 6, // percentage

     SETTINGS_TYPE_INITIAL_WINDOW = 7,  // bytes for flow control

     SETTINGS_CLIENT_CERTIFICATE_VECTOR_SIZE = 8

   };

   // This should be big enough to hold all of your control packets,

   // but if it needs to grow for huge headers it can do so dynamically.

   // About 1% of responses from SPDY google services seem to be > 1000

   // with all less than 2000 when compression is enabled.

   const static uint32_t kDefaultBufferSize = 2048;

   // kDefaultQueueSize must be >= other queue size constants

   const static uint32_t kDefaultQueueSize =  32768;

   const static uint32_t kQueueMinimumCleanup = 24576;

   const static uint32_t kQueueTailRoom    =  4096;

   const static uint32_t kQueueReserved    =  1024;

   const static uint32_t kDefaultMaxConcurrent = 100;

   const static uint32_t kMaxStreamID = 0x7800000;

   // This is a sentinel for a deleted stream. It is not a valid

   // 31 bit stream ID.

   const static uint32_t kDeadStreamID = 0xffffdead;

   // below the emergency threshold of local window we ack every received

   // byte. Above that we coalesce bytes into the MinimumToAck size.

   const static int32_t  kEmergencyWindowThreshold = 1024 * 1024;

   const static uint32_t kMinimumToAck = 64 * 1024;

   // The default peer rwin is 64KB unless updated by a settings frame

   const static uint32_t kDefaultServerRwin = 64 * 1024;

   static nsresult HandleSynStream(SpdySession3 *);

   static nsresult HandleSynReply(SpdySession3 *);

   static nsresult HandleRstStream(SpdySession3 *);

   static nsresult HandleSettings(SpdySession3 *);

   static nsresult HandleNoop(SpdySession3 *);

   static nsresult HandlePing(SpdySession3 *);

   static nsresult HandleGoAway(SpdySession3 *);

   static nsresult HandleHeaders(SpdySession3 *);

   static nsresult HandleWindowUpdate(SpdySession3 *);

   static nsresult HandleCredential(SpdySession3 *);

   template<typename T>

   static void EnsureBuffer(nsAutoArrayPtr<T> &,

                            uint32_t, uint32_t, uint32_t &);

   // For writing the SPDY data stream to LOG4

   static void LogIO(SpdySession3 *, SpdyStream3 *, const char *,

                     const char *, uint32_t);

   // an overload of nsAHttpConnection

   void TransactionHasDataToWrite(nsAHttpTransaction *);

   // a similar version for SpdyStream3

   void TransactionHasDataToWrite(SpdyStream3 *);

   // an overload of nsAHttpSegementReader

   virtual nsresult CommitToSegmentSize(uint32_t size, bool forceCommitment);

   uint32_t GetServerInitialWindow() { return mServerInitialWindow; }

   void ConnectPushedStream(SpdyStream3 *stream);

   void DecrementConcurrent(SpdyStream3 *stream);

   uint64_t Serial() { return mSerial; }

   void     PrintDiagnostics (nsCString &log);

   // Streams need access to these

   uint32_t SendingChunkSize() { return mSendingChunkSize; }

   uint32_t PushAllowance() { return mPushAllowance; }

   z_stream *UpstreamZlib() { return &mUpstreamZlib; }

   nsISocketTransport *SocketTransport() { return mSocketTransport; }

 private:

   enum stateType {

     BUFFERING_FRAME_HEADER,

     BUFFERING_CONTROL_FRAME,

     PROCESSING_DATA_FRAME,

     DISCARDING_DATA_FRAME,

     PROCESSING_COMPLETE_HEADERS,

     PROCESSING_CONTROL_RST_STREAM

   };

   nsresult    ResponseHeadersComplete();

   uint32_t    GetWriteQueueSize();

   void        ChangeDownstreamState(enum stateType);

   void        ResetDownstreamState();

   nsresult    UncompressAndDiscard(uint32_t, uint32_t);

   void        zlibInit();

   void        GeneratePing(uint32_t);

   void        GenerateRstStream(uint32_t, uint32_t);

   void        GenerateGoAway(uint32_t);

   void        CleanupStream(SpdyStream3 *, nsresult, rstReason);

   void        CloseStream(SpdyStream3 *, nsresult);

   void        GenerateSettings();

   void        RemoveStreamFromQueues(SpdyStream3 *);

   void        SetWriteCallbacks();

   void        FlushOutputQueue();

   void        RealignOutputQueue();

   bool        RoomForMoreConcurrent();

   void        ActivateStream(SpdyStream3 *);

   void        ProcessPending();

   nsresult    SetInputFrameDataStream(uint32_t);

   bool        VerifyStream(SpdyStream3 *, uint32_t);

   void        SetNeedsCleanup();

   void        UpdateLocalRwin(SpdyStream3 *stream, uint32_t bytes);

   // a wrapper for all calls to the nshttpconnection level segment writer. Used

   // to track network I/O for timeout purposes

   nsresult   NetworkRead(nsAHttpSegmentWriter *, char *, uint32_t, uint32_t *);

   static PLDHashOperator ShutdownEnumerator(nsAHttpTransaction *,

                                             nsAutoPtr<SpdyStream3> &,

                                             void *);

   static PLDHashOperator GoAwayEnumerator(nsAHttpTransaction *,

                                           nsAutoPtr<SpdyStream3> &,

                                           void *);

   static PLDHashOperator UpdateServerRwinEnumerator(nsAHttpTransaction *,

                                                     nsAutoPtr<SpdyStream3> &,

                                                     void *);

   // This is intended to be nsHttpConnectionMgr:nsConnectionHandle taken

   // from the first transaction on this session. That object contains the

   // pointer to the real network-level nsHttpConnection object.

   nsRefPtr<nsAHttpConnection> mConnection;

   // The underlying socket transport object is needed to propogate some events

   nsISocketTransport         *mSocketTransport;

   // These are temporary state variables to hold the argument to

   // Read/WriteSegments so it can be accessed by On(read/write)segment

   // further up the stack.

   nsAHttpSegmentReader       *mSegmentReader;

   nsAHttpSegmentWriter       *mSegmentWriter;

   uint32_t          mSendingChunkSize;        /* the transmission chunk size */

   uint32_t          mNextStreamID;            /* 24 bits */

   uint32_t          mConcurrentHighWater;     /* max parallelism on session */

   uint32_t          mPushAllowance;           /* rwin for unmatched pushes */

   stateType         mDownstreamState; /* in frame, between frames, etc..  */

   // Maintain 2 indexes - one by stream ID, one by transaction pointer.

   // There are also several lists of streams: ready to write, queued due to

   // max parallelism, streams that need to force a read for push, and the full

   // set of pushed streams.

   // The objects are not ref counted - they get destroyed

   // by the nsClassHashtable implementation when they are removed from

   // the transaction hash.

   nsDataHashtable<nsUint32HashKey, SpdyStream3 *>     mStreamIDHash;

   nsClassHashtable<nsPtrHashKey<nsAHttpTransaction>,

                    SpdyStream3>                       mStreamTransactionHash;

   nsDeque                                             mReadyForWrite;

   nsDeque                                             mQueuedStreams;

   nsDeque                                             mReadyForRead;

   nsTArray<SpdyPushedStream3 *>                       mPushedStreams;

   // Compression contexts for header transport using deflate.

   // SPDY compresses only HTTP headers and does not reset zlib in between

   // frames. Even data that is not associated with a stream (e.g invalid

   // stream ID) is passed through these contexts to keep the compression

   // context correct.

   z_stream            mDownstreamZlib;

   z_stream            mUpstreamZlib;

   // mInputFrameBuffer is used to store received control packets and the 8 bytes

   // of header on data packets

   uint32_t             mInputFrameBufferSize;

   uint32_t             mInputFrameBufferUsed;

   nsAutoArrayPtr<char> mInputFrameBuffer;

   // mInputFrameDataSize/Read are used for tracking the amount of data consumed

   // in a data frame. the data itself is not buffered in spdy

   // The frame size is mInputFrameDataSize + the constant 8 byte header

   uint32_t             mInputFrameDataSize;

   uint32_t             mInputFrameDataRead;

   bool                 mInputFrameDataLast; // This frame was marked FIN

   // When a frame has been received that is addressed to a particular stream

   // (e.g. a data frame after the stream-id has been decoded), this points

   // to the stream.

   SpdyStream3          *mInputFrameDataStream;

   // mNeedsCleanup is a state variable to defer cleanup of a closed stream

   // If needed, It is set in session::OnWriteSegments() and acted on and

   // cleared when the stack returns to session::WriteSegments(). The stream

   // cannot be destroyed directly out of OnWriteSegments because

   // stream::writeSegments() is on the stack at that time.

   SpdyStream3          *mNeedsCleanup;

   // The CONTROL_TYPE value for a control frame

   uint32_t             mFrameControlType;

   // This reason code in the last processed RESET frame

   uint32_t             mDownstreamRstReason;

   // for the conversion of downstream http headers into spdy formatted headers

   // The data here does not persist between frames

   nsCString            mFlatHTTPResponseHeaders;

   uint32_t             mFlatHTTPResponseHeadersOut;

   // when set, the session will go away when it reaches 0 streams. This flag

   // is set when: the stream IDs are running out (at either the client or the

   // server), when DontReuse() is called, a RST that is not specific to a

   // particular stream is received, a GOAWAY frame has been received from

   // the server.

   bool                 mShouldGoAway;

   // the session has received a nsAHttpTransaction::Close()  call

   bool                 mClosed;

   // the session received a GoAway frame with a valid GoAwayID

   bool                 mCleanShutdown;

   // indicates PROCESSING_COMPLETE_HEADERS state was pushed onto the stack

   // over an active PROCESSING_DATA_FRAME, which should be restored when

   // the processed headers are written to the stream

   bool                 mDataPending;

   // If a GoAway message was received this is the ID of the last valid

   // stream. 0 otherwise. (0 is never a valid stream id.)

   uint32_t             mGoAwayID;

   // The limit on number of concurrent streams for this session. Normally it

   // is basically unlimited, but the SETTINGS control message from the

   // server might bring it down.

   uint32_t             mMaxConcurrent;

   // The actual number of concurrent streams at this moment. Generally below

   // mMaxConcurrent, but the max can be lowered in real time to a value

   // below the current value

   uint32_t             mConcurrent;

   // The number of server initiated SYN-STREAMS, tracked for telemetry

   uint32_t             mServerPushedResources;

   // The server rwin for new streams as determined from a SETTINGS frame

   uint32_t             mServerInitialWindow;

   // This is a output queue of bytes ready to be written to the SSL stream.

   // When that streams returns WOULD_BLOCK on direct write the bytes get

   // coalesced together here. This results in larger writes to the SSL layer.

   // The buffer is not dynamically grown to accomodate stream writes, but

   // does expand to accept infallible session wide frames like GoAway and RST.

   uint32_t             mOutputQueueSize;

   uint32_t             mOutputQueueUsed;

   uint32_t             mOutputQueueSent;

   nsAutoArrayPtr<char> mOutputQueueBuffer;

   PRIntervalTime       mPingThreshold;

   PRIntervalTime       mLastReadEpoch;     // used for ping timeouts

   PRIntervalTime       mLastDataReadEpoch; // used for IdleTime()

   PRIntervalTime       mPingSentEpoch;

   uint32_t             mNextPingID;

   // used as a temporary buffer while enumerating the stream hash during GoAway

   nsDeque  mGoAwayStreamsToRestart;

   // Each session gets a unique serial number because the push cache is correlated

   // by the load group and the serial number can be used as part of the cache key

   // to make sure streams aren't shared across sessions.

   uint64_t        mSerial;

 };

 }} // namespace mozilla::net

 #endif // mozilla_net_SpdySession3_h