disk_io_task.h

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/*
 * Copyright (c) 2013-2014 ADTECH GmbH
 * Licensed under MIT (https://github.com/adtechlabs/libtasks/blob/master/COPYING)
 *
 * Author: Andreas Pohl
 */

#ifndef _TASKS_IO_TASK_H_
#define _TASKS_IO_TASK_H_

#include <tasks/event_task.h>
#include <tasks/ev_wrapper.h>
#include <tasks/tools/buffer.h>
#include <tasks/logging.h>
#include <future>

namespace tasks {

class worker;

class disk_io_task : public event_task {
  public:
    disk_io_task(int fd, int events, tools::buffer* buf);
    virtual ~disk_io_task();

    inline std::string get_string() const {
        std::ostringstream os;
        os << "disk_io_task(" << this << "," << m_fd << ":" << m_events << ")";
        return os.str();
    }

    inline std::streamsize bytes() const { return m_bytes; }

    virtual bool handle_event(worker* worker, int events);
    virtual void init_watcher() {}
    virtual void start_watcher(worker* /* worker */) {}
    virtual void stop_watcher(worker* /* worker */) {}

    virtual void dispose(worker* worker = nullptr);

    static std::shared_future<std::streamsize> add_task(disk_io_task* task) {
        assert(nullptr != task);
        return task->op();
    }

  private:
    int m_fd = -1;
    int m_events = EV_UNDEF;
    tools::buffer* m_buf = nullptr;
    std::streamsize m_bytes = -1;

    std::shared_future<std::streamsize> op();
};

}  // tasks

#endif  // _TASKS_IO_TASK_H_