/* -*- 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/. */
//----------------------------------------------------------------------------- // nsBaseChannel is designed to be subclassed. The subclass is responsible for // implementing the OpenContentStream method, which will be called by the // nsIChannel::AsyncOpen and nsIChannel::Open implementations. // // nsBaseChannel implements nsIInterfaceRequestor to provide a convenient way // for subclasses to query both the nsIChannel::notificationCallbacks and // nsILoadGroup::notificationCallbacks for supported interfaces. // // nsBaseChannel implements nsITransportEventSink to support progress & status // notifications generated by the transport layer.
class nsBaseChannel
: public nsHashPropertyBag, public nsIBaseChannel, public nsIChannel, public nsIThreadRetargetableRequest, public nsIInterfaceRequestor, public nsITransportEventSink, public nsIAsyncVerifyRedirectCallback, public mozilla::net::PrivateBrowsingChannel<nsBaseChannel>, public mozilla::net::NeckoTargetHolder, protected nsIThreadRetargetableStreamListener { public:
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_NSIREQUEST
NS_DECL_NSICHANNEL
NS_DECL_NSIBASECHANNEL
NS_DECL_NSIINTERFACEREQUESTOR
NS_DECL_NSITRANSPORTEVENTSINK
NS_DECL_NSIASYNCVERIFYREDIRECTCALLBACK
NS_DECL_NSITHREADRETARGETABLEREQUEST
NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
nsBaseChannel();
protected: // ----------------------------------------------- // Methods to be implemented by the derived class:
virtual ~nsBaseChannel();
using BlockingPromise = mozilla::MozPromise<nsresult, nsresult, true>;
private: // Implemented by subclass to supply data stream. The parameter, async, is // true when called from nsIChannel::AsyncOpen and false otherwise. When // async is true, the resulting stream will be used with a nsIInputStreamPump // instance. This means that if it is a non-blocking stream that supports // nsIAsyncInputStream that it will be read entirely on the main application // thread, and its AsyncWait method will be called whenever ReadSegments // returns NS_BASE_STREAM_WOULD_BLOCK. Otherwise, if the stream is blocking, // then it will be read on one of the background I/O threads, and it does not // need to implement ReadSegments. If async is false, this method may return // NS_ERROR_NOT_IMPLEMENTED to cause the basechannel to implement Open in // terms of AsyncOpen (see NS_ImplementChannelOpen). // A callee is allowed to return an nsIChannel instead of an nsIInputStream. // That case will be treated as a redirect to the new channel. By default // *channel will be set to null by the caller, so callees who don't want to // return one an just not touch it. virtual nsresult OpenContentStream(bool async, nsIInputStream** stream,
nsIChannel** channel) = 0;
// Implemented by subclass to begin pumping data for an async channel, in // lieu of returning a stream. If implemented, OpenContentStream will never // be called for async channels. If not implemented, AsyncOpen will fall // back to OpenContentStream. // // On success, the callee must begin pumping data to the stream listener, // and at some point call OnStartRequest followed by OnStopRequest. // // Additionally, when a successful nsresult is returned, then the subclass // should be setting through its two out params either: // - a request object, which may be used to suspend, resume, and cancel // the underlying request. // - or a cancelable object (e.g. when a request can't be returned right away // due to some async work needed to retrieve it). which may be used to // cancel the underlying request (e.g. because the channel has been // canceled) // // Not returning a request or cancelable leads to potentially leaking the // an underling stream pump (which would keep to be pumping data even after // the channel has been canceled and nothing is going to handle the data // available, e.g. see Bug 1706594). virtual nsresult BeginAsyncRead(nsIStreamListener* listener,
nsIRequest** request,
nsICancelable** cancelableRequest) { return NS_ERROR_NOT_IMPLEMENTED;
}
// This method may return a promise that will keep the input stream pump // suspended until the promise is resolved or rejected. On resolution the // pump is resumed. On rejection the channel is canceled with the resulting // error and then the pump is also resumed to propagate the error to the // channel listener. Use it to do any asynchronous/background tasks you need // to finish prior calling OnStartRequest of the listener. This method is // called right after OpenContentStream() with async == true, after the input // stream pump has already been called asyncRead(). virtual nsresult ListenerBlockingPromise(BlockingPromise** aPromise) {
NS_ENSURE_ARG(aPromise);
*aPromise = nullptr; return NS_OK;
}
// The basechannel calls this method from its OnTransportStatus method to // determine whether to call nsIProgressEventSink::OnStatus in addition to // nsIProgressEventSink::OnProgress. This method may be overriden by the // subclass to enable nsIProgressEventSink::OnStatus events. If this method // returns true, then the statusArg out param specifies the "statusArg" value // to pass to the OnStatus method. By default, OnStatus messages are // suppressed. The status parameter passed to this method is the status value // from the OnTransportStatus method. virtualbool GetStatusArg(nsresult status, nsString& statusArg) { returnfalse;
}
// Called when the callbacks available to this channel may have changed. virtualvoid OnCallbacksChanged() {}
// Called when our channel is done, to allow subclasses to drop resources. virtualvoid OnChannelDone() {}
public: // ---------------------------------------------- // Methods provided for use by the derived class:
// Redirect to another channel. This method takes care of notifying // observers of this redirect as well as of opening the new channel, if asked // to do so. It also cancels |this| with the status code // NS_BINDING_REDIRECTED. A failure return from this method means that the // redirect could not be performed (no channel was opened; this channel // wasn't canceled.) The redirectFlags parameter consists of the flag values // defined on nsIChannelEventSink.
nsresult Redirect(nsIChannel* newChannel, uint32_t redirectFlags, bool openNewChannel);
// Tests whether a type hint was set. Subclasses can use this to decide // whether to call SetContentType. // NOTE: This is only reliable if the subclass didn't itself call // SetContentType, and should also not be called after OpenContentStream. bool HasContentTypeHint() const;
// The URI member should be initialized before the channel is used, and then // it should never be changed again until the channel is destroyed.
nsIURI* URI() { return mURI; } void SetURI(nsIURI* uri) {
NS_ASSERTION(uri, "must specify a non-null URI");
NS_ASSERTION(!mURI, "must not modify URI");
NS_ASSERTION(!mOriginalURI, "how did that get set so early?");
mURI = uri;
mOriginalURI = uri;
}
nsIURI* OriginalURI() { return mOriginalURI; }
// The security info is a property of the transport-layer, which should be // assigned by the subclass.
nsITransportSecurityInfo* SecurityInfo() { return mSecurityInfo; } void SetSecurityInfo(nsITransportSecurityInfo* info) { mSecurityInfo = info; }
// Test the load flags bool HasLoadFlag(uint32_t flag) { return (mLoadFlags & flag) != 0; }
// This is a short-cut to calling nsIRequest::IsPending() virtualbool Pending() const { return mPumpingData || mWaitingOnAsyncRedirect;
}
// Helper function for querying the channel's notification callbacks. template <class T> void GetCallback(nsCOMPtr<T>& result) {
GetInterface(NS_GET_TEMPLATE_IID(T), getter_AddRefs(result));
}
// If a subclass does not want to feed transport-layer progress events to the // base channel via nsITransportEventSink, then it may set this flag to cause // the base channel to synthesize progress events when it receives data from // the content stream. By default, progress events are not synthesized. void EnableSynthesizedProgressEvents(bool enable) {
mSynthProgressEvents = enable;
}
// Some subclasses may wish to manually insert a stream listener between this // and the channel's listener. The following methods make that possible. void SetStreamListener(nsIStreamListener* listener) { mListener = listener; }
nsIStreamListener* StreamListener() { return mListener; }
// Called to setup mPump and call AsyncRead on it.
nsresult BeginPumpingData();
// Called when the callbacks available to this channel may have changed. void CallbacksChanged() {
mProgressSink = nullptr;
mQueriedProgressSink = false;
OnCallbacksChanged();
}
// Called when our channel is done. This should drop no-longer-needed // pointers. void ChannelDone() {
mListener = nullptr;
OnChannelDone();
}
// Handle an async redirect callback. This will only be called if we // returned success from AsyncOpen while posting a redirect runnable. void HandleAsyncRedirect(nsIChannel* newChannel); void ContinueHandleAsyncRedirect(nsresult result);
nsresult ContinueRedirect();
// start URI classifier if requested void ClassifyURI();
class RedirectRunnable : public mozilla::Runnable { public:
RedirectRunnable(nsBaseChannel* chan, nsIChannel* newChannel)
: mozilla::Runnable("nsBaseChannel::RedirectRunnable"),
mChannel(chan),
mNewChannel(newChannel) {
MOZ_ASSERT(newChannel, "Must have channel to redirect to");
}
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