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/**
* @file lleventpoll.h
* @brief LLEvDescription of the LLEventPoll class.
*
* $LicenseInfo:firstyear=2006&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#ifndef LL_LLEVENTPOLL_H
#define LL_LLEVENTPOLL_H
class LLHost;
namespace LLEventPolling
{
namespace Details
{
class LLEventPollImpl;
}
}
class LLEventPoll
///< Implements the viewer side of server-to-viewer pushed events.
///
/// This class implements the sole consumer of the EventQueueGet capability
/// and delivers data, including llsd-encoded llmessage payloads, from
/// simulator to viewer.
///
/// https://wiki.secondlife.com/wiki/EventQueueGet
/// The wiki page is neither complete nor entirely correct. Request timeouts
/// became the de facto method of returning an empty event set to the viewer.
/// But the timeout behavior was never defined. It was simply whatever
/// behavior a given grid implementation implemented.
///
/// In SL's case, the path may include reverse proxies, http caches, http and
/// socks proxies, transparent hijacking, and other horrors. A pitfall for
/// implementors.
///
/// Current definition of a timeout is any of :
/// - libcurl easy 28 status code
/// - Linden 499 special http status code
/// - RFC - standard 502 - 504 http status codes
/// If requests are failing too quickly with the above errors, they are treated
/// as actual errors and not an empty payload. These will count towards a final
/// error declaration and can lead to disconnection from a simulator or the
/// entire grid.
{
public:
LLEventPoll(const std::string& pollURL, const LLHost& sender);
///< Start polling the URL.
virtual ~LLEventPoll();
///< will stop polling, canceling any poll in progress.
private:
std::shared_ptr<LLEventPolling::Details::LLEventPollImpl> mImpl;
};
#endif // LL_LLEVENTPOLL_H
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