icinga2/lib/base/stream.hpp

147 lines
4.0 KiB
C++

/******************************************************************************
* Icinga 2 *
* Copyright (C) 2012-2018 Icinga Development Team (https://www.icinga.com/) *
* *
* 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 St, Fifth Floor, Boston, MA 02110-1301, USA. *
******************************************************************************/
#ifndef STREAM_H
#define STREAM_H
#include "base/i2-base.hpp"
#include "base/object.hpp"
#include <boost/signals2.hpp>
namespace icinga
{
class String;
class Stream;
enum ConnectionRole
{
RoleClient,
RoleServer
};
struct StreamReadContext
{
~StreamReadContext()
{
free(Buffer);
}
bool FillFromStream(const intrusive_ptr<Stream>& stream, bool may_wait);
void DropData(size_t count);
char *Buffer{nullptr};
size_t Size{0};
bool MustRead{true};
bool Eof{false};
};
enum StreamReadStatus
{
StatusNewItem,
StatusNeedData,
StatusEof
};
/**
* A stream.
*
* @ingroup base
*/
class Stream : public Object
{
public:
DECLARE_PTR_TYPEDEFS(Stream);
/**
* Reads data from the stream without removing it from the stream buffer.
*
* @param buffer The buffer where data should be stored. May be nullptr if you're
* not actually interested in the data.
* @param count The number of bytes to read from the queue.
* @param allow_partial Whether to allow partial reads.
* @returns The number of bytes actually read.
*/
virtual size_t Peek(void *buffer, size_t count, bool allow_partial = false);
/**
* Reads data from the stream.
*
* @param buffer The buffer where data should be stored. May be nullptr if you're
* not actually interested in the data.
* @param count The number of bytes to read from the queue.
* @param allow_partial Whether to allow partial reads.
* @returns The number of bytes actually read.
*/
virtual size_t Read(void *buffer, size_t count, bool allow_partial = false) = 0;
/**
* Writes data to the stream.
*
* @param buffer The data that is to be written.
* @param count The number of bytes to write.
* @returns The number of bytes written
*/
virtual void Write(const void *buffer, size_t count) = 0;
/**
* Causes the stream to be closed (via Close()) once all pending data has been
* written.
*/
virtual void Shutdown();
/**
* Closes the stream and releases resources.
*/
virtual void Close();
/**
* Checks whether we've reached the end-of-file condition.
*
* @returns true if EOF.
*/
virtual bool IsEof() const = 0;
/**
* Waits until data can be read from the stream.
*/
bool WaitForData(int timeout = -1);
virtual bool SupportsWaiting() const;
virtual bool IsDataAvailable() const;
void RegisterDataHandler(const std::function<void(const Stream::Ptr&)>& handler);
StreamReadStatus ReadLine(String *line, StreamReadContext& context, bool may_wait = false);
protected:
void SignalDataAvailable();
private:
boost::signals2::signal<void(const Stream::Ptr&)> OnDataAvailable;
boost::mutex m_Mutex;
boost::condition_variable m_CV;
};
}
#endif /* STREAM_H */