gecko-dev/netwerk/protocol/http/SpdySession.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla.
*
* The Initial Developer of the Original Code is
* Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2011
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Patrick McManus <mcmanus@ducksong.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef mozilla_net_SpdySession_h
#define mozilla_net_SpdySession_h
// SPDY as defined by
// http://www.chromium.org/spdy/spdy-protocol/spdy-protocol-draft2
#include "nsAHttpTransaction.h"
#include "nsAHttpConnection.h"
#include "nsClassHashtable.h"
#include "nsDataHashtable.h"
#include "nsDeque.h"
#include "nsHashKeys.h"
#include "zlib.h"
class nsHttpConnection;
class nsISocketTransport;
namespace mozilla { namespace net {
class SpdyStream;
class SpdySession : public nsAHttpTransaction
, public nsAHttpConnection
, public nsAHttpSegmentReader
, public nsAHttpSegmentWriter
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSAHTTPTRANSACTION
NS_DECL_NSAHTTPCONNECTION
NS_DECL_NSAHTTPSEGMENTREADER
NS_DECL_NSAHTTPSEGMENTWRITER
SpdySession(nsAHttpTransaction *, nsISocketTransport *, PRInt32);
~SpdySession();
bool AddStream(nsAHttpTransaction *, PRInt32);
bool CanReuse() { return !mShouldGoAway && !mClosed; }
bool RoomForMoreStreams();
// When the connection is active this is called every 15 seconds
void ReadTimeoutTick(PRIntervalTime now);
// Idle time represents time since "goodput".. e.g. a data or header frame
PRIntervalTime IdleTime();
PRUint32 RegisterStreamID(SpdyStream *);
const static PRUint8 kFlag_Control = 0x80;
const static PRUint8 kFlag_Data_FIN = 0x01;
const static PRUint8 kFlag_Data_UNI = 0x02;
const static PRUint8 kFlag_Data_ZLIB = 0x02;
const static PRUint8 kPri00 = 0x00;
const static PRUint8 kPri01 = 0x40;
const static PRUint8 kPri02 = 0x80;
const static PRUint8 kPri03 = 0xC0;
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,
CONTROL_TYPE_PING = 6,
CONTROL_TYPE_GOAWAY = 7,
CONTROL_TYPE_HEADERS = 8,
CONTROL_TYPE_WINDOW_UPDATE = 9, /* no longer in v2 */
CONTROL_TYPE_LAST = 10
};
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_BAD_ASSOC_STREAM = 8
};
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. Not used in v2.
};
// 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 requests to SPDY google services seem to be > 1000
// with all less than 2000.
const static PRUint32 kDefaultBufferSize = 2048;
// kDefaultQueueSize must be >= other queue size constants
const static PRUint32 kDefaultQueueSize = 16384;
const static PRUint32 kQueueMinimumCleanup = 8192;
const static PRUint32 kQueueTailRoom = 4096;
const static PRUint32 kQueueReserved = 1024;
const static PRUint32 kSendingChunkSize = 4096;
const static PRUint32 kDefaultMaxConcurrent = 100;
const static PRUint32 kMaxStreamID = 0x7800000;
static nsresult HandleSynStream(SpdySession *);
static nsresult HandleSynReply(SpdySession *);
static nsresult HandleRstStream(SpdySession *);
static nsresult HandleSettings(SpdySession *);
static nsresult HandleNoop(SpdySession *);
static nsresult HandlePing(SpdySession *);
static nsresult HandleGoAway(SpdySession *);
static nsresult HandleHeaders(SpdySession *);
static nsresult HandleWindowUpdate(SpdySession *);
static void EnsureBuffer(nsAutoArrayPtr<char> &,
PRUint32, PRUint32, PRUint32 &);
// For writing the SPDY data stream to LOG4
static void LogIO(SpdySession *, SpdyStream *, const char *,
const char *, PRUint32);
// an overload of nsAHttpConnection
void TransactionHasDataToWrite(nsAHttpTransaction *);
// a similar version for SpdyStream
void TransactionHasDataToWrite(SpdyStream *);
// an overload of nsAHttpSegementReader
virtual nsresult CommitToSegmentSize(PRUint32 size);
private:
enum stateType {
BUFFERING_FRAME_HEADER,
BUFFERING_CONTROL_FRAME,
PROCESSING_DATA_FRAME,
DISCARDING_DATA_FRAME,
PROCESSING_CONTROL_SYN_REPLY,
PROCESSING_CONTROL_RST_STREAM
};
void DeterminePingThreshold();
nsresult HandleSynReplyForValidStream();
PRUint32 GetWriteQueueSize();
void ChangeDownstreamState(enum stateType);
void ResetDownstreamState();
nsresult DownstreamUncompress(char *, PRUint32);
void zlibInit();
nsresult FindHeader(nsCString, nsDependentCSubstring &);
nsresult ConvertHeaders(nsDependentCSubstring &,
nsDependentCSubstring &);
void GeneratePing(PRUint32);
void ClearPing(bool);
void GenerateRstStream(PRUint32, PRUint32);
void GenerateGoAway();
void CleanupStream(SpdyStream *, nsresult, rstReason);
void SetWriteCallbacks();
void FlushOutputQueue();
bool RoomForMoreConcurrent();
void ActivateStream(SpdyStream *);
void ProcessPending();
// a wrapper for all calls to the nshttpconnection level segment writer. Used
// to track network I/O for timeout purposes
nsresult NetworkRead(nsAHttpSegmentWriter *, char *, PRUint32, PRUint32 *);
static PLDHashOperator ShutdownEnumerator(nsAHttpTransaction *,
nsAutoPtr<SpdyStream> &,
void *);
// This is intended to be nsHttpConnectionMgr:nsHttpConnectionHandle 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;
PRUint32 mSendingChunkSize; /* the transmission chunk size */
PRUint32 mNextStreamID; /* 24 bits */
PRUint32 mConcurrentHighWater; /* max parallelism on session */
stateType mDownstreamState; /* in frame, between frames, etc.. */
// Maintain 5 indexes - one by stream ID, one by transaction ptr,
// one list of streams ready to write, one list of streams that are queued
// due to max parallelism settings, and one list of streams
// that must be given priority to write for window updates. The objects
// are not ref counted - they get destroyed
// by the nsClassHashtable implementation when they are removed from
// there.
nsDataHashtable<nsUint32HashKey, SpdyStream *> mStreamIDHash;
nsClassHashtable<nsPtrHashKey<nsAHttpTransaction>,
SpdyStream> mStreamTransactionHash;
nsDeque mReadyForWrite;
nsDeque mQueuedStreams;
// UrgentForWrite is meant to carry window updates. They were defined in
// the v2 spec but apparently never implemented so are now scheduled to
// be removed. But they will be reintroduced for v3, so we will leave
// this queue in place to ease that transition.
nsDeque mUrgentForWrite;
// Compression contexts for header transport using deflate.
// SPDY compresses only HTTP headers and does not reset zlib in between
// frames.
z_stream mDownstreamZlib;
z_stream mUpstreamZlib;
// mInputFrameBuffer is used to store received control packets and the 8 bytes
// of header on data packets
PRUint32 mInputFrameBufferSize;
PRUint32 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
PRUint32 mInputFrameDataSize;
PRUint32 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.
SpdyStream *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.
SpdyStream *mNeedsCleanup;
// The CONTROL_TYPE value for a control frame
PRUint32 mFrameControlType;
// This reason code in the last processed RESET frame
PRUint32 mDownstreamRstReason;
// These are used for decompressing downstream spdy response headers
// This is done at the session level because sometimes the stream
// has already been canceled but the decompression still must happen
// to keep the zlib state correct for the next state of headers.
PRUint32 mDecompressBufferSize;
PRUint32 mDecompressBufferUsed;
nsAutoArrayPtr<char> mDecompressBuffer;
// for the conversion of downstream http headers into spdy formatted headers
nsCString mFlatHTTPResponseHeaders;
PRUint32 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;
// If a GoAway message was received this is the ID of the last valid
// stream. 0 otherwise. (0 is never a valid stream id.)
PRUint32 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.
PRUint32 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
PRUint32 mConcurrent;
// The number of server initiated SYN-STREAMS, tracked for telemetry
PRUint32 mServerPushedResources;
// 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.
PRUint32 mOutputQueueSize;
PRUint32 mOutputQueueUsed;
PRUint32 mOutputQueueSent;
nsAutoArrayPtr<char> mOutputQueueBuffer;
PRIntervalTime mPingThreshold;
PRIntervalTime mLastReadEpoch; // used for ping timeouts
PRIntervalTime mLastDataReadEpoch; // used for IdleTime()
PRIntervalTime mPingSentEpoch;
PRUint32 mNextPingID;
bool mPingThresholdExperiment;
};
}} // namespace mozilla::net
#endif // mozilla_net_SpdySession_h