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/*
* Copyright 2003-2018 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_BUFFERED_SOCKET_HXX
#define MPD_BUFFERED_SOCKET_HXX
#include "SocketMonitor.hxx"
#include "util/StaticFifoBuffer.hxx"
#include <exception>
#include <assert.h>
#include <stdint.h>
class EventLoop;
/**
* A #SocketMonitor specialization that adds an input buffer.
*/
class BufferedSocket : protected SocketMonitor {
StaticFifoBuffer<uint8_t, 8192> input;
public:
BufferedSocket(SocketDescriptor _fd, EventLoop &_loop) noexcept
:SocketMonitor(_fd, _loop) {
ScheduleRead();
}
using SocketMonitor::IsDefined;
using SocketMonitor::Close;
private:
/**
* @return the number of bytes read from the socket, 0 if the
* socket isn't ready for reading, -1 on error (the socket has
* been closed and probably destructed)
*/
ssize_t DirectRead(void *data, size_t length) noexcept;
/**
* Receive data from the socket to the input buffer.
*
* @return false if the socket has been closed
*/
bool ReadToBuffer() noexcept;
protected:
/**
* @return false if the socket has been closed
*/
bool ResumeInput() noexcept;
/**
* Mark a portion of the input buffer "consumed". Only
* allowed to be called from OnSocketInput(). This method
* does not invalidate the pointer passed to OnSocketInput()
* yet.
*/
void ConsumeInput(size_t nbytes) noexcept {
assert(IsDefined());
input.Consume(nbytes);
}
enum class InputResult {
/**
* The method was successful, and it is ready to
* read more data.
*/
MORE,
/**
* The method does not want to get more data for now.
* It will call ResumeInput() when it's ready for
* more.
*/
PAUSE,
/**
* The method wants to be called again immediately, if
* there's more data in the buffer.
*/
AGAIN,
/**
* The method has closed the socket.
*/
CLOSED,
};
/**
* Data has been received on the socket.
*
* @param data a pointer to the beginning of the buffer; the
* buffer may be modified by the method while it processes the
* data
*/
virtual InputResult OnSocketInput(void *data, size_t length) noexcept = 0;
virtual void OnSocketError(std::exception_ptr ep) noexcept = 0;
virtual void OnSocketClosed() noexcept = 0;
/* virtual methods from class SocketMonitor */
bool OnSocketReady(unsigned flags) noexcept override;
};
#endif
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