// vi:ft=cpp
/**
 * \file
 * \brief Common factory related definitions.
 * \ingroup l4_api
 */
/*
 * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
 *               Alexander Warg <warg@os.inf.tu-dresden.de>
 *     economic rights: Technische Universität Dresden (Germany)
 *
 * This file is part of TUD:OS and distributed under the terms of the
 * GNU General Public License 2.
 * Please see the COPYING-GPL-2 file for details.
 *
 * As a special exception, you may use this file as part of a free software
 * library without restriction.  Specifically, if other files instantiate
 * templates or use macros or inline functions from this file, or you compile
 * this file and link it with other files to produce an executable, this
 * file does not by itself cause the resulting executable to be covered by
 * the GNU General Public License.  This exception does not however
 * invalidate any other reasons why the executable file might be covered by
 * the GNU General Public License.
 */

#pragma once

#include <l4/sys/factory.h>
#include <l4/sys/capability>

namespace L4 {

/**
 * \brief C++ L4 Factory, to create all kinds of kernel objects.
 * \ingroup l4_factory_api
 *
 * <c>\#include <l4/sys/factory></c>
 *
 * \see \ref l4_factory_api for an overview and C bindings.
 */
class Factory : public Kobject_t<Factory, Kobject, L4_PROTO_FACTORY>
{
  L4_KOBJECT(Factory)

public:

  typedef l4_mword_t Proto;

  /**
   * \brief Special type to add a void argument into the factory create
   *        stream.
   */
  struct Nil {};

  /**
   * \brief Special type to add a pascal string into the factory create
   *        stream.
   *
   * This encapsulates a string that has an explicit length.
   */
  struct Lstr
  {
    /**
     * \brief The character buffer.
     */
    char const *s;

    /**
     * \brief The number of characters in the buffer.
     */
    int len;

    Lstr(char const *s, int len) : s(s), len(len) {}
  };

  /**
   * \brief Stream class for the create() argument stream.
   *
   * This stream allows a variable number of arguments to be
   * added to a create() call.
   */
  class S
  {
  private:
    l4_utcb_t *u;
    l4_msgtag_t t;
    l4_cap_idx_t f;

  public:
    /**
     * \brief create a copy.
     */
    S(S const &o)
    : u(o.u), t(o.t), f(o.f)
    { const_cast<S&>(o).t.raw = 0; }

    /**
     * \brief create a stream for a specific create() call.
     * \param f is the capability for the factory object (L4::Factory).
     * \param obj is the protocol ID to describe the type of the object that
     *            shall be created.
     * \param target is the capabilit selector for the new object.
     * \param utcb is the UTCB that shall be used for the operation.
     */
    S(l4_cap_idx_t f, long obj, L4::Cap<L4::Kobject> target,
      l4_utcb_t *utcb) throw()
    : u(utcb), t(l4_factory_create_start_u(obj, target.cap(), u)), f(f)
    {}

    /**
     * \brief Commit the operation in the destructor to have a cool syntax
     *        for create().
     */
    ~S()
    {
      if (t.raw)
	l4_factory_create_commit_u(f, t, u);
    }

    /**
     * \brief Explicitely commits the operation and returns the result.
     * \return The result of the create() operation.
     */
    operator l4_msgtag_t ()
    {
      l4_msgtag_t r = l4_factory_create_commit_u(f, t, u);
      t.raw = 0;
      return r;
    }

    /**
     * \brief Put a single l4_mword_t as next argument.
     * \param i is the value to add as next argument.
     */
    S &operator  << (l4_mword_t i)
    {
      l4_factory_create_add_int_u(i, &t, u);
      return *this;
    }

    /**
     * \brief Put a single l4_umword_t as next argument.
     * \param i is the value to add as next argument.
     */
    S &operator  << (l4_umword_t i)
    {
      l4_factory_create_add_uint_u(i, &t, u);
      return *this;
    }

    /**
     * \brief Add a zero-terminated string as next argument.
     * \param s is the string to add as next argument.
     */
    S &operator << (char const *s)
    {
      l4_factory_create_add_str_u(s, &t, u);
      return *this;
    }

    /**
     * \brief Add a pascal string as next argument.
     * \param s is the string to add as next argument.
     */
    S &operator << (Lstr const &s)
    {
      l4_factory_create_add_lstr_u(s.s, s.len, &t, u);
      return *this;
    }

    /**
     * \brief Add an empty argument.
     */
    S &operator << (Nil)
    {
      l4_factory_create_add_nil_u(&t, u);
      return *this;
    }

    /**
     * \brief Add a flex page as next argument.
     * \param d is the flex page to add (there will be no map operation).
     */
    S &operator << (l4_fpage_t d)
    {
      l4_factory_create_add_fpage_u(d, &t, u);
      return *this;
    }
  };


public:

  /**
   * \brief Generic create call to the factory.
   * \param target is the target capability selector where the new
   *               object shall be received.
   * \param obj is the protocol ID that specifies which kind of object
   *            shall be created.
   * \param utcb is the UTCB to use for the operation.
   * \return a create stream that allows adding additional arguments to the
   *         create() call.
   *
   * This method does currently not directly invoke the factory. It returns a
   * stream that shall invoke the factory after adding all additional arguments.
   *
   * Usage:
   * \code
   * L4::Cap<L4Re::Namespace> ns = L4Re::Util::cap_alloc.alloc<L4Re::Namespace>();
   * factory->create(ns, L4Re::Namespace::Protocol) << "Argument text";
   * \endcode
   */
  S create(Cap<Kobject> target, long obj, l4_utcb_t *utcb = l4_utcb()) throw()
  {
    return S(cap(), obj, target, utcb);
  }

  /**
   * \copydoc l4_factory_create_task()
   * \note \a factory is the implicit \a this pointer.
   */
  l4_msgtag_t create_task(Cap<Task> const & target_cap,
                          l4_fpage_t const &utcb_area,
                          l4_utcb_t *utcb = l4_utcb()) throw()
  { return l4_factory_create_task_u(cap(), target_cap.cap(), utcb_area, utcb); }

  /**
   * \copydoc l4_factory_create_thread()
   * \note \a factory is the implicit \a this pointer.
   */
  l4_msgtag_t create_thread(Cap<Thread> const &target_cap,
                            l4_utcb_t *utcb = l4_utcb()) throw()
  { return l4_factory_create_thread_u(cap(), target_cap.cap(), utcb); }

  /**
   * \copydoc l4_factory_create_factory()
   * \note \a factory is the implicit \a this pointer.
   */
  l4_msgtag_t create_factory(Cap<Factory> const &target_cap,
                             unsigned long limit,
                             l4_utcb_t *utcb = l4_utcb()) throw()
  { return l4_factory_create_factory_u(cap(), target_cap.cap(), limit, utcb); }

  /**
   * \copydoc l4_factory_create_gate()
   * \note \a factory is the implicit \a this pointer.
   */
  l4_msgtag_t create_gate(Cap<Kobject> const &target_cap,
                          Cap<Thread> const &thread_cap, l4_umword_t label,
                          l4_utcb_t *utcb = l4_utcb()) throw()
  { return l4_factory_create_gate_u(cap(), target_cap.cap(), thread_cap.cap(), label, utcb); }

  /**
   * \copydoc l4_factory_create_semaphore()
   * \note \a factory is the implicit \a this pointer.
   */
  l4_msgtag_t create_semaphore(Cap<K_semaphore> const &target_cap,
                               l4_utcb_t *utcb = l4_utcb()) throw()
  { return l4_factory_create_semaphore_u(cap(), target_cap.cap(), utcb); }

  /**
   * \copydoc l4_factory_create_irq()
   * \note \a factory is the implicit \a this pointer.
   */
  l4_msgtag_t create_irq(Cap<Irq>const &target_cap,
                         l4_utcb_t *utcb = l4_utcb()) throw()
  { return l4_factory_create_irq_u(cap(), target_cap.cap(), utcb); }

  /**
   * \copydoc l4_factory_create_vm()
   * \note \a factory is the implicit \a this pointer.
   */
  l4_msgtag_t create_vm(Cap<Vm>const &target_cap,
                        l4_utcb_t *utcb = l4_utcb()) throw()
  { return l4_factory_create_vm_u(cap(), target_cap.cap(), utcb); }
};

}