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

/* -*- Mode: C++; tab-width: 4; 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 nsHttpHandler_h__
#define nsHttpHandler_h__

#include <functional>

#include "nsHttp.h"
#include "nsHttpAuthCache.h"
#include "nsHttpConnectionMgr.h"
#include "ASpdySession.h"

#include "mozilla/Mutex.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/TimeStamp.h"
#include "nsString.h"
#include "nsCOMPtr.h"
#include "nsWeakReference.h"

#include "nsIHttpProtocolHandler.h"
#include "nsIObserver.h"
#include "nsISpeculativeConnect.h"

class nsIHttpChannel;
class nsIPrefBranch;
class nsICancelable;
class nsICookieService;
class nsIIOService;
class nsIRequestContextService;
class nsISiteSecurityService;
class nsIStreamConverterService;

namespace mozilla {
namespace net {

bool OnSocketThread();

class ATokenBucketEvent;
class EventTokenBucket;
class Tickler;
class nsHttpConnection;
class nsHttpConnectionInfo;
class nsHttpTransaction;
class AltSvcMapping;

enum FrameCheckLevel { FRAMECHECK_LAX, FRAMECHECK_BARELY, FRAMECHECK_STRICT };

//-----------------------------------------------------------------------------
// nsHttpHandler - protocol handler for HTTP and HTTPS
//-----------------------------------------------------------------------------

class nsHttpHandler final : public nsIHttpProtocolHandler,
                            public nsIObserver,
                            public nsSupportsWeakReference,
                            public nsISpeculativeConnect {
 public:
  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSIPROTOCOLHANDLER
  NS_DECL_NSIPROXIEDPROTOCOLHANDLER
  NS_DECL_NSIHTTPPROTOCOLHANDLER
  NS_DECL_NSIOBSERVER
  NS_DECL_NSISPECULATIVECONNECT

  static already_AddRefed<nsHttpHandler> GetInstance();

  MOZ_MUST_USE nsresult
  AddStandardRequestHeaders(nsHttpRequestHead *, bool isSecure,
                            nsContentPolicyType aContentPolicyType);
  MOZ_MUST_USE nsresult AddConnectionHeader(nsHttpRequestHead *,
                                            uint32_t capabilities);
  bool IsAcceptableEncoding(const char *encoding, bool isSecure);

  const nsCString &UserAgent();

  enum HttpVersion HttpVersion() { return mHttpVersion; }
  enum HttpVersion ProxyHttpVersion() { return mProxyHttpVersion; }
  uint8_t ReferrerLevel() { return mReferrerLevel; }
  bool SpoofReferrerSource() { return mSpoofReferrerSource; }
  bool HideOnionReferrerSource() { return mHideOnionReferrerSource; }
  uint8_t ReferrerTrimmingPolicy() { return mReferrerTrimmingPolicy; }
  uint8_t ReferrerXOriginTrimmingPolicy() {
    return mReferrerXOriginTrimmingPolicy;
  }
  uint8_t ReferrerXOriginPolicy() { return mReferrerXOriginPolicy; }
  uint8_t RedirectionLimit() { return mRedirectionLimit; }
  PRIntervalTime IdleTimeout() { return mIdleTimeout; }
  PRIntervalTime SpdyTimeout() { return mSpdyTimeout; }
  PRIntervalTime ResponseTimeout() {
    return mResponseTimeoutEnabled ? mResponseTimeout : 0;
  }
  PRIntervalTime ResponseTimeoutEnabled() { return mResponseTimeoutEnabled; }
  uint32_t NetworkChangedTimeout() { return mNetworkChangedTimeout; }
  uint16_t MaxRequestAttempts() { return mMaxRequestAttempts; }
  const char *DefaultSocketType() {
    return mDefaultSocketType.IsVoid() ? nullptr : mDefaultSocketType.get();
  }
  uint32_t PhishyUserPassLength() { return mPhishyUserPassLength; }
  uint8_t GetQoSBits() { return mQoSBits; }
  uint16_t GetIdleSynTimeout() { return mIdleSynTimeout; }
  uint16_t GetFallbackSynTimeout() { return mFallbackSynTimeout; }
  bool FastFallbackToIPv4() { return mFastFallbackToIPv4; }
  uint32_t MaxSocketCount();
  bool EnforceAssocReq() { return mEnforceAssocReq; }

  bool IsPersistentHttpsCachingEnabled() {
    return mEnablePersistentHttpsCaching;
  }

  bool IsSpdyEnabled() { return mEnableSpdy; }
  bool IsHttp2Enabled() { return mHttp2Enabled; }
  bool EnforceHttp2TlsProfile() { return mEnforceHttp2TlsProfile; }
  bool CoalesceSpdy() { return mCoalesceSpdy; }
  bool UseSpdyPersistentSettings() { return mSpdyPersistentSettings; }
  uint32_t SpdySendingChunkSize() { return mSpdySendingChunkSize; }
  uint32_t SpdySendBufferSize() { return mSpdySendBufferSize; }
  uint32_t SpdyPushAllowance() { return mSpdyPushAllowance; }
  uint32_t SpdyPullAllowance() { return mSpdyPullAllowance; }
  uint32_t DefaultSpdyConcurrent() { return mDefaultSpdyConcurrent; }
  PRIntervalTime SpdyPingThreshold() { return mSpdyPingThreshold; }
  PRIntervalTime SpdyPingTimeout() { return mSpdyPingTimeout; }
  bool AllowPush() { return mAllowPush; }
  bool AllowAltSvc() { return mEnableAltSvc; }
  bool AllowAltSvcOE() { return mEnableAltSvcOE; }
  bool AllowOriginExtension() { return mEnableOriginExtension; }
  uint32_t ConnectTimeout() { return mConnectTimeout; }
  uint32_t TLSHandshakeTimeout() { return mTLSHandshakeTimeout; }
  uint32_t ParallelSpeculativeConnectLimit() {
    return mParallelSpeculativeConnectLimit;
  }
  bool CriticalRequestPrioritization() {
    return mCriticalRequestPrioritization;
  }
  bool UseH2Deps() { return mUseH2Deps; }
  bool IsH2WebsocketsEnabled() { return mEnableH2Websockets; }

  uint32_t MaxConnectionsPerOrigin() {
    return mMaxPersistentConnectionsPerServer;
  }
  bool UseRequestTokenBucket() { return mRequestTokenBucketEnabled; }
  uint16_t RequestTokenBucketMinParallelism() {
    return mRequestTokenBucketMinParallelism;
  }
  uint32_t RequestTokenBucketHz() { return mRequestTokenBucketHz; }
  uint32_t RequestTokenBucketBurst() { return mRequestTokenBucketBurst; }

  bool PromptTempRedirect() { return mPromptTempRedirect; }
  bool IsUrgentStartEnabled() { return mUrgentStartEnabled; }
  bool IsTailBlockingEnabled() { return mTailBlockingEnabled; }
  uint32_t TailBlockingDelayQuantum(bool aAfterDOMContentLoaded) {
    return aAfterDOMContentLoaded ? mTailDelayQuantumAfterDCL
                                  : mTailDelayQuantum;
  }
  uint32_t TailBlockingDelayMax() { return mTailDelayMax; }
  uint32_t TailBlockingTotalMax() { return mTailTotalMax; }

  uint32_t ThrottlingReadLimit() {
    return mThrottleVersion == 1 ? 0 : mThrottleReadLimit;
  }
  int32_t SendWindowSize() { return mSendWindowSize * 1024; }

  // TCP Keepalive configuration values.

  // Returns true if TCP keepalive should be enabled for short-lived conns.
  bool TCPKeepaliveEnabledForShortLivedConns() {
    return mTCPKeepaliveShortLivedEnabled;
  }
  // Return time (secs) that a connection is consider short lived (for TCP
  // keepalive purposes). After this time, the connection is long-lived.
  int32_t GetTCPKeepaliveShortLivedTime() {
    return mTCPKeepaliveShortLivedTimeS;
  }
  // Returns time (secs) before first TCP keepalive probes should be sent;
  // same time used between successful keepalive probes.
  int32_t GetTCPKeepaliveShortLivedIdleTime() {
    return mTCPKeepaliveShortLivedIdleTimeS;
  }

  // Returns true if TCP keepalive should be enabled for long-lived conns.
  bool TCPKeepaliveEnabledForLongLivedConns() {
    return mTCPKeepaliveLongLivedEnabled;
  }
  // Returns time (secs) before first TCP keepalive probes should be sent;
  // same time used between successful keepalive probes.
  int32_t GetTCPKeepaliveLongLivedIdleTime() {
    return mTCPKeepaliveLongLivedIdleTimeS;
  }

  bool UseFastOpen() {
    return mUseFastOpen && mFastOpenSupported &&
           (mFastOpenStallsCounter < mFastOpenStallsLimit) &&
           (mFastOpenConsecutiveFailureCounter <
            mFastOpenConsecutiveFailureLimit);
  }
  // If one of tcp connections return PR_NOT_TCP_SOCKET_ERROR while trying
  // fast open, it means that Fast Open is turned off so we will not try again
  // until a restart. This is only on Linux.
  void SetFastOpenNotSupported() { mFastOpenSupported = false; }

  void IncrementFastOpenConsecutiveFailureCounter();

  void ResetFastOpenConsecutiveFailureCounter() {
    mFastOpenConsecutiveFailureCounter = 0;
  }

  void IncrementFastOpenStallsCounter();
  uint32_t CheckIfConnectionIsStalledOnlyIfIdleForThisAmountOfSeconds() {
    return mFastOpenStallsIdleTime;
  }
  uint32_t FastOpenStallsTimeout() { return mFastOpenStallsTimeout; }

  // returns the HTTP framing check level preference, as controlled with
  // network.http.enforce-framing.http1 and network.http.enforce-framing.soft
  FrameCheckLevel GetEnforceH1Framing() { return mEnforceH1Framing; }

  nsHttpAuthCache *AuthCache(bool aPrivate) {
    return aPrivate ? &mPrivateAuthCache : &mAuthCache;
  }
  nsHttpConnectionMgr *ConnMgr() { return mConnMgr; }

  // cache support
  uint32_t GenerateUniqueID() { return ++mLastUniqueID; }
  uint32_t SessionStartTime() { return mSessionStartTime; }

  //
  // Connection management methods:
  //
  // - the handler only owns idle connections; it does not own active
  //   connections.
  //
  // - the handler keeps a count of active connections to enforce the
  //   steady-state max-connections pref.
  //

  // Called to kick-off a new transaction, by default the transaction
  // will be put on the pending transaction queue if it cannot be
  // initiated at this time.  Callable from any thread.
  MOZ_MUST_USE nsresult InitiateTransaction(nsHttpTransaction *trans,
                                            int32_t priority) {
    return mConnMgr->AddTransaction(trans, priority);
  }

  // This function is also called to kick-off a new transaction. But the new
  // transaction will take a sticky connection from |transWithStickyConn|
  // and reuse it.
  MOZ_MUST_USE nsresult
  InitiateTransactionWithStickyConn(nsHttpTransaction *trans, int32_t priority,
                                    nsHttpTransaction *transWithStickyConn) {
    return mConnMgr->AddTransactionWithStickyConn(trans, priority,
                                                  transWithStickyConn);
  }

  // Called to change the priority of an existing transaction that has
  // already been initiated.
  MOZ_MUST_USE nsresult RescheduleTransaction(nsHttpTransaction *trans,
                                              int32_t priority) {
    return mConnMgr->RescheduleTransaction(trans, priority);
  }

  void UpdateClassOfServiceOnTransaction(nsHttpTransaction *trans,
                                         uint32_t classOfService) {
    mConnMgr->UpdateClassOfServiceOnTransaction(trans, classOfService);
  }

  // Called to cancel a transaction, which may or may not be assigned to
  // a connection.  Callable from any thread.
  MOZ_MUST_USE nsresult CancelTransaction(nsHttpTransaction *trans,
                                          nsresult reason) {
    return mConnMgr->CancelTransaction(trans, reason);
  }

  // Called when a connection is done processing a transaction.  Callable
  // from any thread.
  MOZ_MUST_USE nsresult ReclaimConnection(nsHttpConnection *conn) {
    return mConnMgr->ReclaimConnection(conn);
  }

  MOZ_MUST_USE nsresult ProcessPendingQ(nsHttpConnectionInfo *cinfo) {
    return mConnMgr->ProcessPendingQ(cinfo);
  }

  MOZ_MUST_USE nsresult ProcessPendingQ() {
    return mConnMgr->ProcessPendingQ();
  }

  MOZ_MUST_USE nsresult GetSocketThreadTarget(nsIEventTarget **target) {
    return mConnMgr->GetSocketThreadTarget(target);
  }

  MOZ_MUST_USE nsresult SpeculativeConnect(nsHttpConnectionInfo *ci,
                                           nsIInterfaceRequestor *callbacks,
                                           uint32_t caps = 0) {
    TickleWifi(callbacks);
    return mConnMgr->SpeculativeConnect(ci, callbacks, caps);
  }

  // Alternate Services Maps are main thread only
  void UpdateAltServiceMapping(AltSvcMapping *map, nsProxyInfo *proxyInfo,
                               nsIInterfaceRequestor *callbacks, uint32_t caps,
                               const OriginAttributes &originAttributes) {
    mConnMgr->UpdateAltServiceMapping(map, proxyInfo, callbacks, caps,
                                      originAttributes);
  }

  already_AddRefed<AltSvcMapping> GetAltServiceMapping(
      const nsACString &scheme, const nsACString &host, int32_t port, bool pb,
      const OriginAttributes &originAttributes) {
    return mConnMgr->GetAltServiceMapping(scheme, host, port, pb,
                                          originAttributes);
  }

  //
  // The HTTP handler caches pointers to specific XPCOM services, and
  // provides the following helper routines for accessing those services:
  //
  MOZ_MUST_USE nsresult GetStreamConverterService(nsIStreamConverterService **);
  MOZ_MUST_USE nsresult GetIOService(nsIIOService **service);
  nsICookieService *GetCookieService();  // not addrefed
  nsISiteSecurityService *GetSSService();

  // callable from socket thread only
  uint32_t Get32BitsOfPseudoRandom();

  // Called by the channel synchronously during asyncOpen
  void OnOpeningRequest(nsIHttpChannel *chan) {
    NotifyObservers(chan, NS_HTTP_ON_OPENING_REQUEST_TOPIC);
  }

  // Called by the channel before writing a request
  void OnModifyRequest(nsIHttpChannel *chan) {
    NotifyObservers(chan, NS_HTTP_ON_MODIFY_REQUEST_TOPIC);
  }

  // Called by the channel before writing a request
  void OnStopRequest(nsIHttpChannel *chan) {
    NotifyObservers(chan, NS_HTTP_ON_STOP_REQUEST_TOPIC);
  }

  // Called by the channel and cached in the loadGroup
  void OnUserAgentRequest(nsIHttpChannel *chan) {
    NotifyObservers(chan, NS_HTTP_ON_USERAGENT_REQUEST_TOPIC);
  }

  // Called by the channel before setting up the transaction
  void OnBeforeConnect(nsIHttpChannel *chan) {
    NotifyObservers(chan, NS_HTTP_ON_BEFORE_CONNECT_TOPIC);
  }

  // Called by the channel once headers are available
  void OnExamineResponse(nsIHttpChannel *chan) {
    NotifyObservers(chan, NS_HTTP_ON_EXAMINE_RESPONSE_TOPIC);
  }

  // Called by the channel once headers have been merged with cached headers
  void OnExamineMergedResponse(nsIHttpChannel *chan) {
    NotifyObservers(chan, NS_HTTP_ON_EXAMINE_MERGED_RESPONSE_TOPIC);
  }

  // Called by channels before a redirect happens. This notifies both the
  // channel's and the global redirect observers.
  MOZ_MUST_USE nsresult AsyncOnChannelRedirect(
      nsIChannel *oldChan, nsIChannel *newChan, uint32_t flags,
      nsIEventTarget *mainThreadEventTarget = nullptr);

  // Called by the channel when the response is read from the cache without
  // communicating with the server.
  void OnExamineCachedResponse(nsIHttpChannel *chan) {
    NotifyObservers(chan, NS_HTTP_ON_EXAMINE_CACHED_RESPONSE_TOPIC);
  }

  void OnMayChangeProcess(nsIHttpChannel *chan) {
    NotifyObservers(chan, NS_HTTP_ON_MAY_CHANGE_PROCESS_TOPIC);
  }

  // Generates the host:port string for use in the Host: header as well as the
  // CONNECT line for proxies. This handles IPv6 literals correctly.
  static MOZ_MUST_USE nsresult GenerateHostPort(const nsCString &host,
                                                int32_t port,
                                                nsACString &hostLine);

  SpdyInformation *SpdyInfo() { return &mSpdyInfo; }
  bool IsH2MandatorySuiteEnabled() { return mH2MandatorySuiteEnabled; }

  // returns true in between Init and Shutdown states
  bool Active() { return mHandlerActive; }

  nsIRequestContextService *GetRequestContextService() {
    return mRequestContextService.get();
  }

  void ShutdownConnectionManager();

  uint32_t DefaultHpackBuffer() const { return mDefaultHpackBuffer; }

  uint32_t MaxHttpResponseHeaderSize() const {
    return mMaxHttpResponseHeaderSize;
  }

  float FocusedWindowTransactionRatio() const {
    return mFocusedWindowTransactionRatio;
  }

  bool ActiveTabPriority() const { return mActiveTabPriority; }

  // Called when an optimization feature affecting active vs background tab load
  // took place.  Called only on the parent process and only updates
  // mLastActiveTabLoadOptimizationHit timestamp to now.
  void NotifyActiveTabLoadOptimization();
  TimeStamp const GetLastActiveTabLoadOptimizationHit();
  void SetLastActiveTabLoadOptimizationHit(TimeStamp const &when);
  bool IsBeforeLastActiveTabLoadOptimization(TimeStamp const &when);

  bool DumpHpackTables() { return mDumpHpackTables; }

 private:
  nsHttpHandler();

  virtual ~nsHttpHandler();

  MOZ_MUST_USE nsresult Init();

  //
  // Useragent/prefs helper methods
  //
  void BuildUserAgent();
  void InitUserAgentComponents();
  void PrefsChanged(const char *pref);

  MOZ_MUST_USE nsresult SetAcceptLanguages();
  MOZ_MUST_USE nsresult SetAcceptEncodings(const char *, bool mIsSecure);

  MOZ_MUST_USE nsresult InitConnectionMgr();

  void NotifyObservers(nsIHttpChannel *chan, const char *event);

  void SetFastOpenOSSupport();

  void EnsureUAOverridesInit();

  // Checks if there are any user certs or active smart cards on a different
  // thread. Updates mSpeculativeConnectEnabled when done.
  void MaybeEnableSpeculativeConnect();

 private:
  // cached services
  nsMainThreadPtrHandle<nsIIOService> mIOService;
  nsMainThreadPtrHandle<nsIStreamConverterService> mStreamConvSvc;
  nsMainThreadPtrHandle<nsICookieService> mCookieService;
  nsMainThreadPtrHandle<nsISiteSecurityService> mSSService;

  // the authentication credentials cache
  nsHttpAuthCache mAuthCache;
  nsHttpAuthCache mPrivateAuthCache;

  // the connection manager
  RefPtr<nsHttpConnectionMgr> mConnMgr;

  // This thread is used for performing operations that should not block
  // the main thread.
  nsCOMPtr<nsIThread> mBackgroundThread;

  //
  // prefs
  //

  enum HttpVersion mHttpVersion;
  enum HttpVersion mProxyHttpVersion;
  uint32_t mCapabilities;
  uint8_t mReferrerLevel;
  uint8_t mSpoofReferrerSource;
  uint8_t mHideOnionReferrerSource;
  uint8_t mReferrerTrimmingPolicy;
  uint8_t mReferrerXOriginTrimmingPolicy;
  uint8_t mReferrerXOriginPolicy;

  bool mFastFallbackToIPv4;
  PRIntervalTime mIdleTimeout;
  PRIntervalTime mSpdyTimeout;
  PRIntervalTime mResponseTimeout;
  bool mResponseTimeoutEnabled;
  uint32_t mNetworkChangedTimeout;  // milliseconds
  uint16_t mMaxRequestAttempts;
  uint16_t mMaxRequestDelay;
  uint16_t mIdleSynTimeout;
  uint16_t mFallbackSynTimeout;  // seconds

  bool mH2MandatorySuiteEnabled;
  uint16_t mMaxUrgentExcessiveConns;
  uint16_t mMaxConnections;
  uint8_t mMaxPersistentConnectionsPerServer;
  uint8_t mMaxPersistentConnectionsPerProxy;

  bool mThrottleEnabled;
  uint32_t mThrottleVersion;
  uint32_t mThrottleSuspendFor;
  uint32_t mThrottleResumeFor;
  uint32_t mThrottleReadLimit;
  uint32_t mThrottleReadInterval;
  uint32_t mThrottleHoldTime;
  uint32_t mThrottleMaxTime;

  int32_t mSendWindowSize;

  bool mUrgentStartEnabled;
  bool mTailBlockingEnabled;
  uint32_t mTailDelayQuantum;
  uint32_t mTailDelayQuantumAfterDCL;
  uint32_t mTailDelayMax;
  uint32_t mTailTotalMax;

  uint8_t mRedirectionLimit;

  // we'll warn the user if we load an URL containing a userpass field
  // unless its length is less than this threshold.  this warning is
  // intended to protect the user against spoofing attempts that use
  // the userpass field of the URL to obscure the actual origin server.
  uint8_t mPhishyUserPassLength;

  uint8_t mQoSBits;

  bool mEnforceAssocReq;

  nsCString mAcceptLanguages;
  nsCString mHttpAcceptEncodings;
  nsCString mHttpsAcceptEncodings;

  nsCString mDefaultSocketType;

  // cache support
  uint32_t mLastUniqueID;
  uint32_t mSessionStartTime;

  // useragent components
  nsCString mLegacyAppName;
  nsCString mLegacyAppVersion;
  nsCString mPlatform;
  nsCString mOscpu;
  nsCString mMisc;
  nsCString mProduct;
  nsCString mProductSub;
  nsCString mAppName;
  nsCString mAppVersion;
  nsCString mCompatFirefox;
  bool mCompatFirefoxEnabled;
  nsCString mCompatDevice;
  nsCString mDeviceModelId;

  nsCString mUserAgent;
  nsCString mSpoofedUserAgent;
  nsCString mUserAgentOverride;
  bool mUserAgentIsDirty;  // true if mUserAgent should be rebuilt
  bool mAcceptLanguagesIsDirty;

  bool mPromptTempRedirect;

  // Persistent HTTPS caching flag
  bool mEnablePersistentHttpsCaching;

  // For broadcasting tracking preference
  bool mDoNotTrackEnabled;

  // for broadcasting safe hint;
  bool mSafeHintEnabled;
  bool mParentalControlEnabled;

  // true in between init and shutdown states
  Atomic<bool, Relaxed> mHandlerActive;

  // The value of 'hidden' network.http.debug-observations : 1;
  uint32_t mDebugObservations : 1;

  uint32_t mEnableSpdy : 1;
  uint32_t mHttp2Enabled : 1;
  uint32_t mUseH2Deps : 1;
  uint32_t mEnforceHttp2TlsProfile : 1;
  uint32_t mCoalesceSpdy : 1;
  uint32_t mSpdyPersistentSettings : 1;
  uint32_t mAllowPush : 1;
  uint32_t mEnableAltSvc : 1;
  uint32_t mEnableAltSvcOE : 1;
  uint32_t mEnableOriginExtension : 1;
  uint32_t mEnableH2Websockets : 1;
  uint32_t mDumpHpackTables : 1;

  // Try to use SPDY features instead of HTTP/1.1 over SSL
  SpdyInformation mSpdyInfo;

  uint32_t mSpdySendingChunkSize;
  uint32_t mSpdySendBufferSize;
  uint32_t mSpdyPushAllowance;
  uint32_t mSpdyPullAllowance;
  uint32_t mDefaultSpdyConcurrent;
  PRIntervalTime mSpdyPingThreshold;
  PRIntervalTime mSpdyPingTimeout;

  // The maximum amount of time to wait for socket transport to be
  // established. In milliseconds.
  uint32_t mConnectTimeout;

  // The maximum amount of time to wait for a tls handshake to be
  // established. In milliseconds.
  uint32_t mTLSHandshakeTimeout;

  // The maximum number of current global half open sockets allowable
  // when starting a new speculative connection.
  uint32_t mParallelSpeculativeConnectLimit;

  // For Rate Pacing of HTTP/1 requests through a netwerk/base/EventTokenBucket
  // Active requests <= *MinParallelism are not subject to the rate pacing
  bool mRequestTokenBucketEnabled;
  uint16_t mRequestTokenBucketMinParallelism;
  uint32_t mRequestTokenBucketHz;     // EventTokenBucket HZ
  uint32_t mRequestTokenBucketBurst;  // EventTokenBucket Burst

  // Whether or not to block requests for non head js/css items (e.g. media)
  // while those elements load.
  bool mCriticalRequestPrioritization;

  // TCP Keepalive configuration values.

  // True if TCP keepalive is enabled for short-lived conns.
  bool mTCPKeepaliveShortLivedEnabled;
  // Time (secs) indicating how long a conn is considered short-lived.
  int32_t mTCPKeepaliveShortLivedTimeS;
  // Time (secs) before first keepalive probe; between successful probes.
  int32_t mTCPKeepaliveShortLivedIdleTimeS;

  // True if TCP keepalive is enabled for long-lived conns.
  bool mTCPKeepaliveLongLivedEnabled;
  // Time (secs) before first keepalive probe; between successful probes.
  int32_t mTCPKeepaliveLongLivedIdleTimeS;

  // if true, generate NS_ERROR_PARTIAL_TRANSFER for h1 responses with
  // incorrect content lengths or malformed chunked encodings
  FrameCheckLevel mEnforceH1Framing;

  nsCOMPtr<nsIRequestContextService> mRequestContextService;

  // The default size (in bytes) of the HPACK decompressor table.
  uint32_t mDefaultHpackBuffer;

  // The max size (in bytes) for received Http response header.
  uint32_t mMaxHttpResponseHeaderSize;

  // The ratio for dispatching transactions from the focused window.
  float mFocusedWindowTransactionRatio;

  // We may disable speculative connect if the browser has user certificates
  // installed as that might randomly popup the certificate choosing window.
  Atomic<bool, Relaxed> mSpeculativeConnectEnabled;

  Atomic<bool, Relaxed> mUseFastOpen;
  Atomic<bool, Relaxed> mFastOpenSupported;
  uint32_t mFastOpenConsecutiveFailureLimit;
  uint32_t mFastOpenConsecutiveFailureCounter;
  uint32_t mFastOpenStallsLimit;
  uint32_t mFastOpenStallsCounter;
  uint32_t mFastOpenStallsIdleTime;
  uint32_t mFastOpenStallsTimeout;

  // If true, the transactions from active tab will be dispatched first.
  bool mActiveTabPriority;

 private:
  // For Rate Pacing Certain Network Events. Only assign this pointer on
  // socket thread.
  void MakeNewRequestTokenBucket();
  RefPtr<EventTokenBucket> mRequestTokenBucket;

 public:
  // Socket thread only
  MOZ_MUST_USE nsresult SubmitPacedRequest(ATokenBucketEvent *event,
                                           nsICancelable **cancel) {
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    if (!mRequestTokenBucket) {
      return NS_ERROR_NOT_AVAILABLE;
    }
    return mRequestTokenBucket->SubmitEvent(event, cancel);
  }

  // Socket thread only
  void SetRequestTokenBucket(EventTokenBucket *aTokenBucket) {
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    mRequestTokenBucket = aTokenBucket;
  }

  void StopRequestTokenBucket() {
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    if (mRequestTokenBucket) {
      mRequestTokenBucket->Stop();
      mRequestTokenBucket = nullptr;
    }
  }

 private:
  RefPtr<Tickler> mWifiTickler;
  void TickleWifi(nsIInterfaceRequestor *cb);

 private:
  MOZ_MUST_USE nsresult
  SpeculativeConnectInternal(nsIURI *aURI, nsIPrincipal *aPrincipal,
                             nsIInterfaceRequestor *aCallbacks, bool anonymous);

  // State for generating channelIds
  uint32_t mProcessId;
  uint32_t mNextChannelId;

  // The last time any of the active tab page load optimization took place.
  // This is accessed on multiple threads, hence a lock is needed.
  // On the parent process this is updated to now every time a scheduling
  // or rate optimization related to the active/background tab is hit.
  // We carry this value through each http channel's onstoprequest notification
  // to the parent process.  On the content process then we just update this
  // value from ipc onstoprequest arguments.  This is a sufficent way of passing
  // it down to the content process, since the value will be used only after
  // onstoprequest notification coming from an http channel.
  Mutex mLastActiveTabLoadOptimizationLock;
  TimeStamp mLastActiveTabLoadOptimizationHit;

 public:
  MOZ_MUST_USE nsresult NewChannelId(uint64_t &channelId);

  void BlacklistSpdy(const nsHttpConnectionInfo *ci);
  MOZ_MUST_USE bool IsSpdyBlacklisted(const nsHttpConnectionInfo *ci);

 private:
  nsTHashtable<nsCStringHashKey> mBlacklistedSpdyOrigins;
};

extern StaticRefPtr<nsHttpHandler> gHttpHandler;

//-----------------------------------------------------------------------------
// nsHttpsHandler - thin wrapper to distinguish the HTTP handler from the
//                  HTTPS handler (even though they share the same impl).
//-----------------------------------------------------------------------------

class nsHttpsHandler : public nsIHttpProtocolHandler,
                       public nsSupportsWeakReference,
                       public nsISpeculativeConnect {
  virtual ~nsHttpsHandler() = default;

 public:
  // we basically just want to override GetScheme and GetDefaultPort...
  // all other methods should be forwarded to the nsHttpHandler instance.

  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSIPROTOCOLHANDLER
  NS_FORWARD_NSIPROXIEDPROTOCOLHANDLER(gHttpHandler->)
  NS_FORWARD_NSIHTTPPROTOCOLHANDLER(gHttpHandler->)
  NS_FORWARD_NSISPECULATIVECONNECT(gHttpHandler->)

  nsHttpsHandler() = default;

  MOZ_MUST_USE nsresult Init();
};

//-----------------------------------------------------------------------------
// HSTSDataCallbackWrapper - A threadsafe helper class to wrap the callback.
//
// We need this because dom::promise and EnsureHSTSDataResolver are not
// threadsafe.
//-----------------------------------------------------------------------------
class HSTSDataCallbackWrapper final {
 public:
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(HSTSDataCallbackWrapper)

  explicit HSTSDataCallbackWrapper(std::function<void(bool)> &&aCallback)
      : mCallback(std::move(aCallback)) {
    MOZ_ASSERT(NS_IsMainThread());
  }

  void DoCallback(bool aResult) {
    MOZ_ASSERT(NS_IsMainThread());
    mCallback(aResult);
  }

 private:
  ~HSTSDataCallbackWrapper() = default;

  std::function<void(bool)> mCallback;
};

}  // namespace net
}  // namespace mozilla

#endif  // nsHttpHandler_h__