gecko-dev/dom/base/EventSource.h

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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/. */
/*
* This implementation has support only for http requests. It is because the
* spec has defined event streams only for http. HTTP is required because
* this implementation uses some http headers: "Last-Event-ID", "Cache-Control"
* and "Accept".
*/
#ifndef mozilla_dom_EventSource_h
#define mozilla_dom_EventSource_h
#include "mozilla/Attributes.h"
#include "mozilla/DOMEventTargetHelper.h"
#include "nsIObserver.h"
#include "nsIStreamListener.h"
#include "nsIChannelEventSink.h"
#include "nsIInterfaceRequestor.h"
#include "nsITimer.h"
#include "nsIHttpChannel.h"
#include "nsWeakReference.h"
#include "nsDeque.h"
#include "nsIUnicodeDecoder.h"
class nsPIDOMWindow;
namespace mozilla {
class ErrorResult;
namespace dom {
class AsyncVerifyRedirectCallbackFwr;
struct EventSourceInit;
class EventSource final : public DOMEventTargetHelper
, public nsIObserver
, public nsIStreamListener
, public nsIChannelEventSink
, public nsIInterfaceRequestor
, public nsSupportsWeakReference
{
friend class AsyncVerifyRedirectCallbackFwr;
public:
explicit EventSource(nsPIDOMWindow* aOwnerWindow);
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS_INHERITED(
EventSource, DOMEventTargetHelper)
NS_DECL_NSIOBSERVER
NS_DECL_NSISTREAMLISTENER
NS_DECL_NSIREQUESTOBSERVER
NS_DECL_NSICHANNELEVENTSINK
NS_DECL_NSIINTERFACEREQUESTOR
// nsWrapperCache
virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
// WebIDL
nsPIDOMWindow*
GetParentObject() const
{
return GetOwner();
}
static already_AddRefed<EventSource>
Constructor(const GlobalObject& aGlobal, const nsAString& aURL,
const EventSourceInit& aEventSourceInitDict,
ErrorResult& aRv);
void GetUrl(nsAString& aURL) const
{
aURL = mOriginalURL;
}
bool WithCredentials() const
{
return mWithCredentials;
}
enum {
CONNECTING = 0U,
OPEN = 1U,
CLOSED = 2U
};
uint16_t ReadyState() const
{
return mReadyState;
}
IMPL_EVENT_HANDLER(open)
IMPL_EVENT_HANDLER(message)
IMPL_EVENT_HANDLER(error)
void Close();
// Determine if preferences allow EventSource
static bool PrefEnabled(JSContext* aCx = nullptr, JSObject* aGlobal = nullptr);
virtual void DisconnectFromOwner() override;
protected:
virtual ~EventSource();
nsresult Init(nsISupports* aOwner,
const nsAString& aURL,
bool aWithCredentials);
nsresult GetBaseURI(nsIURI **aBaseURI);
net::ReferrerPolicy GetReferrerPolicy();
nsresult SetupHttpChannel();
nsresult InitChannelAndRequestEventSource();
nsresult ResetConnection();
nsresult DispatchFailConnection();
nsresult SetReconnectionTimeout();
void AnnounceConnection();
void DispatchAllMessageEvents();
void ReestablishConnection();
void FailConnection();
nsresult Thaw();
nsresult Freeze();
static void TimerCallback(nsITimer *aTimer, void *aClosure);
nsresult PrintErrorOnConsole(const char *aBundleURI,
const char16_t *aError,
const char16_t **aFormatStrings,
uint32_t aFormatStringsLen);
nsresult ConsoleError();
static NS_METHOD StreamReaderFunc(nsIInputStream *aInputStream,
void *aClosure,
const char *aFromRawSegment,
uint32_t aToOffset,
uint32_t aCount,
uint32_t *aWriteCount);
nsresult SetFieldAndClear();
nsresult ClearFields();
nsresult ResetEvent();
nsresult DispatchCurrentMessageEvent();
nsresult ParseCharacter(char16_t aChr);
bool CheckCanRequestSrc(nsIURI* aSrc = nullptr); // if null, it tests mSrc
nsresult CheckHealthOfRequestCallback(nsIRequest *aRequestCallback);
nsresult OnRedirectVerifyCallback(nsresult result);
nsCOMPtr<nsIURI> mSrc;
nsString mLastEventID;
uint32_t mReconnectionTime; // in ms
struct Message {
nsString mEventName;
nsString mLastEventID;
nsString mData;
};
nsDeque mMessagesToDispatch;
Message mCurrentMessage;
/**
* A simple state machine used to manage the event-source's line buffer
*
* PARSE_STATE_OFF -> PARSE_STATE_BEGIN_OF_STREAM
*
* PARSE_STATE_BEGIN_OF_STREAM -> PARSE_STATE_BOM_WAS_READ |
* PARSE_STATE_CR_CHAR |
* PARSE_STATE_BEGIN_OF_LINE |
* PARSE_STATE_COMMENT |
* PARSE_STATE_FIELD_NAME
*
* PARSE_STATE_BOM_WAS_READ -> PARSE_STATE_CR_CHAR |
* PARSE_STATE_BEGIN_OF_LINE |
* PARSE_STATE_COMMENT |
* PARSE_STATE_FIELD_NAME
*
* PARSE_STATE_CR_CHAR -> PARSE_STATE_CR_CHAR |
* PARSE_STATE_COMMENT |
* PARSE_STATE_FIELD_NAME |
* PARSE_STATE_BEGIN_OF_LINE
*
* PARSE_STATE_COMMENT -> PARSE_STATE_CR_CHAR |
* PARSE_STATE_BEGIN_OF_LINE
*
* PARSE_STATE_FIELD_NAME -> PARSE_STATE_CR_CHAR |
* PARSE_STATE_BEGIN_OF_LINE |
* PARSE_STATE_FIRST_CHAR_OF_FIELD_VALUE
*
* PARSE_STATE_FIRST_CHAR_OF_FIELD_VALUE -> PARSE_STATE_FIELD_VALUE |
* PARSE_STATE_CR_CHAR |
* PARSE_STATE_BEGIN_OF_LINE
*
* PARSE_STATE_FIELD_VALUE -> PARSE_STATE_CR_CHAR |
* PARSE_STATE_BEGIN_OF_LINE
*
* PARSE_STATE_BEGIN_OF_LINE -> PARSE_STATE_CR_CHAR |
* PARSE_STATE_COMMENT |
* PARSE_STATE_FIELD_NAME |
* PARSE_STATE_BEGIN_OF_LINE
*
* Whenever the parser find an empty line or the end-of-file
* it dispatches the stacked event.
*
*/
enum ParserStatus {
PARSE_STATE_OFF,
PARSE_STATE_BEGIN_OF_STREAM,
PARSE_STATE_BOM_WAS_READ,
PARSE_STATE_CR_CHAR,
PARSE_STATE_COMMENT,
PARSE_STATE_FIELD_NAME,
PARSE_STATE_FIRST_CHAR_OF_FIELD_VALUE,
PARSE_STATE_FIELD_VALUE,
PARSE_STATE_BEGIN_OF_LINE
};
ParserStatus mStatus;
bool mFrozen;
bool mErrorLoadOnRedirect;
bool mGoingToDispatchAllMessages;
bool mWithCredentials;
bool mWaitingForOnStopRequest;
// used while reading the input streams
nsCOMPtr<nsIUnicodeDecoder> mUnicodeDecoder;
nsresult mLastConvertionResult;
nsString mLastFieldName;
nsString mLastFieldValue;
nsCOMPtr<nsILoadGroup> mLoadGroup;
/**
* The notification callbacks the channel had initially.
* We want to forward things here as needed.
*/
nsCOMPtr<nsIInterfaceRequestor> mNotificationCallbacks;
nsCOMPtr<nsIChannelEventSink> mChannelEventSink;
nsCOMPtr<nsIHttpChannel> mHttpChannel;
nsCOMPtr<nsITimer> mTimer;
uint16_t mReadyState;
nsString mOriginalURL;
nsCOMPtr<nsIPrincipal> mPrincipal;
nsString mOrigin;
uint32_t mRedirectFlags;
nsCOMPtr<nsIAsyncVerifyRedirectCallback> mRedirectCallback;
nsCOMPtr<nsIChannel> mNewRedirectChannel;
// Event Source owner information:
// - the script file name
// - source code line number where the Event Source object was constructed.
// - the ID of the inner window where the script lives. Note that this may not
// be the same as the Event Source owner window.
// These attributes are used for error reporting.
nsString mScriptFile;
uint32_t mScriptLine;
uint64_t mInnerWindowID;
private:
EventSource(const EventSource& x); // prevent bad usage
EventSource& operator=(const EventSource& x);
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_EventSource_h