communication_handler.hpp

#pragma once

#include <tuple>
#include <variant>

#include "communication_error.hpp"
#include "object/data_header.hpp"
#include "object/data_object.hpp"
#include "object/binary_data.hpp"
#include "object/java_symbol.hpp"
#include "object/ping.hpp"

namespace ipc {

/// Variant for all data types
using DataObject = std::variant<Ping, JavaSymbol, BinaryData>;

/**
 * Interface for all inter-process communication handlers.
 */
class ICommunicationHandler {
public:
    /// Size of the buffer and limit of header and body combined.
    static constexpr short BUFFER_SIZE = 512 + sizeof(DataHeader);

    /// Time to wait for each poll in milliseconds.
    static constexpr short WAIT_TIME = 5000;

    virtual ~ICommunicationHandler() = default;

    /**
     * Open handler.
     *
     * @return True, if handler was successfully opened.
     */
    virtual bool open() = 0;

    /**
     * Close the handler.
     *
     * @return True, if handler was successfully closed.
     */
    virtual bool close() = 0;

    /**
     * Check if the handler is opened.
     *
     * @return True, if handler is open.
     */
    virtual bool is_open() const = 0;

    /**
     * Poll new data from the handler.
     *
     * @return True, if poll was successful.
     * @remark Method will block until an event or timeout occurred.
     */
    virtual bool await_data() = 0;

    /**
     * Check if new data is available.
     *
     * @return True, if data is available.
     */
    virtual bool has_data() const = 0;

    /**
     * Write a data object into the inter-process communication handler.
     *
     * @param obj Object to write into the handler.
     *
     * @return True, if write was successful.
     */
    virtual bool write(const IDataObject &obj) = 0;

    /**
     * Read a data objects from the inter-process communication handler.
     *
     * @return Objects received from the handler or an error.
     */
    virtual std::variant<std::tuple<DataHeader, DataObject>, CommunicationError> read() = 0;
};

}