libreoffice-online/wsd/LOOLWebSocket.hpp
Ashod Nakashian 875d11f88b loolwsd: simplify checking for closed socket
Change-Id: I1f41c40bdd42ad6ab9224a2b13af97f84175492c
Reviewed-on: https://gerrit.libreoffice.org/31983
Reviewed-by: Ashod Nakashian <ashnakash@gmail.com>
Tested-by: Ashod Nakashian <ashnakash@gmail.com>
2016-12-14 04:14:57 +00:00

186 lines
6.2 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
/*
* This file is part of the LibreOffice project.
*
* 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 INCLUDED_LOOLWEBSOCKET_HPP
#define INCLUDED_LOOLWEBSOCKET_HPP
#include <cstdlib>
#include <mutex>
#include <thread>
#include <Poco/Net/WebSocket.h>
#include <Common.hpp>
#include <Protocol.hpp>
#include <Log.hpp>
/// WebSocket that is thread safe, and handles large frames transparently.
/// Careful - sendFrame and receiveFrame are _not_ virtual,
/// we need to make sure that we use LOOLWebSocket all over the place.
/// It would be a kind of more natural to encapsulate Poco::Net::WebSocket
/// instead of inheriting (from that reason,) but that would requite much
/// larger code changes.
class LOOLWebSocket : public Poco::Net::WebSocket
{
private:
std::mutex _mutex;
#if ENABLE_DEBUG
static std::chrono::milliseconds getWebSocketDelay()
{
unsigned long baseDelay = 0;
unsigned long jitter = 0;
if (std::getenv("LOOL_WS_DELAY"))
{
baseDelay = std::stoul(std::getenv("LOOL_WS_DELAY"));
}
if (std::getenv("LOOL_WS_JITTER"))
{
jitter = std::stoul(std::getenv("LOOL_WS_JITTER"));
}
return std::chrono::milliseconds(baseDelay + (jitter > 0 ? (std::rand() % jitter) : 0));
}
#endif
public:
LOOLWebSocket(const Socket& socket) :
Poco::Net::WebSocket(socket)
{
}
LOOLWebSocket(Poco::Net::HTTPServerRequest& request,
Poco::Net::HTTPServerResponse& response) :
Poco::Net::WebSocket(request, response)
{
}
LOOLWebSocket(Poco::Net::HTTPClientSession& cs,
Poco::Net::HTTPRequest& request,
Poco::Net::HTTPResponse& response) :
Poco::Net::WebSocket(cs, request, response)
{
}
LOOLWebSocket(Poco::Net::HTTPClientSession& cs,
Poco::Net::HTTPRequest& request,
Poco::Net::HTTPResponse& response,
Poco::Net::HTTPCredentials& credentials) :
Poco::Net::WebSocket(cs, request, response, credentials)
{
}
/// Wrapper for Poco::Net::WebSocket::receiveFrame() that handles PING frames
/// (by replying with a PONG frame) and PONG frames. PONG frames are ignored.
/// Returns number of bytes received, or 0 if the Poco receiveFrame() returned 0,
/// or -1 if no "interesting" (not PING or PONG) frame was actually received).
/// Should we also factor out the handling of non-final and continuation frames into this?
int receiveFrame(char* buffer, const int length, int& flags)
{
#if ENABLE_DEBUG
// Delay receiving the frame
std::this_thread::sleep_for(getWebSocketDelay());
#endif
// Timeout is in microseconds. We don't need this, except to yield the cpu.
static const Poco::Timespan waitTime(POLL_TIMEOUT_MS * 1000 / 10);
static const Poco::Timespan waitZero(0);
std::unique_lock<std::mutex> lock(_mutex);
while (poll(waitTime, Poco::Net::Socket::SELECT_READ))
{
const int n = Poco::Net::WebSocket::receiveFrame(buffer, length, flags);
LOG_TRC("Got frame: " << LOOLProtocol::getAbbreviatedFrameDump(buffer, n, flags));
if ((flags & WebSocket::FRAME_OP_BITMASK) == WebSocket::FRAME_OP_CLOSE)
{
// Nothing to do.
return n;
}
if ((flags & WebSocket::FRAME_OP_BITMASK) == WebSocket::FRAME_OP_PING)
{
// Echo back the ping message.
if (poll(waitZero, Socket::SelectMode::SELECT_ERROR) ||
!poll(waitZero, Socket::SelectMode::SELECT_WRITE) ||
Poco::Net::WebSocket::sendFrame(buffer, n, WebSocket::FRAME_FLAG_FIN | WebSocket::FRAME_OP_PONG) != n)
{
LOG_WRN("Sending Pong failed.");
return -1;
}
}
else if ((flags & WebSocket::FRAME_OP_BITMASK) == WebSocket::FRAME_OP_PONG)
{
// In case we do send pings in the future.
}
else
{
return n;
}
}
// Not ready for read.
return -1;
}
/// Wrapper for Poco::Net::WebSocket::sendFrame() that handles large frames.
int sendFrame(const char* buffer, const int length, const int flags = FRAME_TEXT)
{
#if ENABLE_DEBUG
// Delay sending the frame
std::this_thread::sleep_for(getWebSocketDelay());
#endif
static const Poco::Timespan waitZero(0);
std::unique_lock<std::mutex> lock(_mutex);
if (length >= LARGE_MESSAGE_SIZE)
{
const std::string nextmessage = "nextmessage: size=" + std::to_string(length);
const int size = nextmessage.size();
if (!poll(waitZero, Socket::SelectMode::SELECT_ERROR) &&
poll(waitZero, Socket::SelectMode::SELECT_WRITE) &&
Poco::Net::WebSocket::sendFrame(nextmessage.data(), size) == size)
{
LOG_TRC("Sent long message preample: " + nextmessage);
}
else
{
LOG_WRN("Failed to send long message preample.");
return -1;
}
}
int result = -1;
if (!poll(waitZero, Socket::SelectMode::SELECT_ERROR) &&
poll(waitZero, Socket::SelectMode::SELECT_WRITE))
{
result = Poco::Net::WebSocket::sendFrame(buffer, length, flags);
}
lock.unlock();
if (result != length)
{
LOG_ERR("Sent incomplete message, expected " << length << " bytes but sent " << result <<
" for: " << LOOLProtocol::getAbbreviatedFrameDump(buffer, length, flags));
}
else
{
LOG_TRC("Sent frame: " << LOOLProtocol::getAbbreviatedFrameDump(buffer, length, flags));
}
return result;
}
};
#endif
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