usock_server.h

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/*
 * Copyright (c) 2016 Juniper Networks, Inc. All rights reserved.
 */
 
/*
 * Implement a UNIX domain socket interface using boost::asio.
 */
#ifndef SRC_IO_USOCK_SERVER_H_
#define SRC_IO_USOCK_SERVER_H_
 
#include <cstdio>
#include <iostream>
#include <list>
#include <string>
#include <boost/array.hpp>
#include <boost/bind/bind.hpp>
#include <boost/enable_shared_from_this.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/asio.hpp>
#include <boost/function.hpp>
 
using namespace boost::placeholders;
 
#if defined(BOOST_ASIO_HAS_LOCAL_SOCKETS)
 
class UnixDomainSocketSession :
public boost::enable_shared_from_this<UnixDomainSocketSession> {
public:
    static const int kPDULen = 4096;
    static const int kPDUHeaderLen = 4;
    static const int kPDUDataLen = 4092;
 
    enum Event {
        EVENT_NONE,
        READY,
        CLOSE
    };
 
    typedef boost::function <void (UnixDomainSocketSession *, Event)>
      EventObserver;
 
    explicit UnixDomainSocketSession(boost::asio::io_context *io_service)
        : socket_(*io_service), session_id_(0) {
    }
 
    ~UnixDomainSocketSession();
 
    boost::asio::local::stream_protocol::socket &socket() {
        return socket_;
    }
 
    void set_observer(EventObserver observer) { observer_ = observer; }
    uint64_t session_id() { return session_id_; }
    void set_session_id(uint64_t id) { session_id_ = id; }
    void Start();
    void Send(const uint8_t * data, int data_len);
 
private:
    typedef std::list <boost::asio::mutable_buffer> BufferQueue;
 
    void WriteToSocket();
    void AppendBuffer(const uint8_t * data, int len);
    void DeleteBuffer(boost::asio::mutable_buffer);
    void HandleRead(const boost::system::error_code & error, size_t bytes);
    void HandleWrite(const boost::system::error_code & error);
 
    boost::asio::local::stream_protocol::socket socket_;
    BufferQueue buffer_queue_;
    uint8_t data_[kPDULen];
    EventObserver observer_;
    uint64_t session_id_;
};
 
typedef boost::shared_ptr <UnixDomainSocketSession> SessionPtr;
 
class UnixDomainSocketServer {
public:
    enum Event {
        EVENT_NONE,
        NEW_SESSION,
        DELETE_SESSION
    };
 
    typedef boost::function <void (UnixDomainSocketServer *,
                                   UnixDomainSocketSession *, Event) >
      EventObserver;
 
    UnixDomainSocketServer(boost::asio::io_context *io_service,
                           const std::string &file);
 
    void HandleAccept(SessionPtr new_session,
                      const boost::system::error_code &error);
 
    void set_observer(EventObserver observer) { observer_ = observer; }
 
private:
    boost::asio::io_context *io_service_;
    EventObserver observer_;
    boost::asio::local::stream_protocol::acceptor acceptor_;
    uint64_t session_idspace_;
};
 
#else  // defined(BOOST_ASIO_HAS_LOCAL_SOCKETS)
#error Local sockets not available on this platform.
#endif  // defined(BOOST_ASIO_HAS_LOCAL_SOCKETS)
 
#endif  // SRC_IO_USOCK_SERVER_H_