directory.h

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/*
 * This file is part of the µOS++ distribution.
 *   (https://github.com/micro-os-plus)
 * Copyright (c) 2015 Liviu Ionescu.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
 
#ifndef CMSIS_PLUS_POSIX_IO_DIRECTORY_H_
#define CMSIS_PLUS_POSIX_IO_DIRECTORY_H_
 
// ----------------------------------------------------------------------------
 
#if defined(__cplusplus)
 
// ----------------------------------------------------------------------------
 
#if defined(OS_USE_OS_APP_CONFIG_H)
#include <cmsis-plus/os-app-config.h>
#endif
 
#include <cmsis-plus/utils/lists.h>
#include <cmsis-plus/posix/dirent.h>
 
#include <cmsis-plus/diag/trace.h>
 
#include <mutex>
 
// ----------------------------------------------------------------------------
 
#pragma GCC diagnostic push
 
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wc++98-compat"
#pragma clang diagnostic ignored "-Wdocumentation-unknown-command"
#endif
 
// ----------------------------------------------------------------------------
 
namespace os
{
  namespace posix
  {
    // ------------------------------------------------------------------------
 
    class directory;
    class directory_impl;
    class file_system;
 
    // ------------------------------------------------------------------------
 
    // ========================================================================
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpadded"
 
    class directory
    {
      // ----------------------------------------------------------------------
 
      friend class file_system;
 
      // ----------------------------------------------------------------------
    public:
 
      directory (directory_impl& impl);
 
      // The rule of five.
      directory (const directory&) = delete;
      directory (directory&&) = delete;
      directory&
      operator= (const directory&) = delete;
      directory&
      operator= (directory&&) = delete;
 
      virtual
      ~directory ();
 
      // ----------------------------------------------------------------------
    public:
 
      // http://pubs.opengroup.org/onlinepubs/9699919799/functions/readdir.html
      virtual struct dirent *
      read (void);
 
      // http://pubs.opengroup.org/onlinepubs/9699919799/functions/rewinddir.html
      virtual void
      rewind (void);
 
      // http://pubs.opengroup.org/onlinepubs/9699919799/functions/closedir.html
      virtual int
      close (void);
 
      // ----------------------------------------------------------------------
      // Support functions.
 
      struct dirent*
      dir_entry (void);
 
      class file_system&
      file_system (void) const;
 
      directory_impl&
      impl (void) const;
 
      // ----------------------------------------------------------------------
    public:
 
      // Intrusive node used to link this device to the deferred
      // deallocation list. Must be public.
      utils::double_list_links deferred_links_;
 
      // ----------------------------------------------------------------------
    protected:
 
      directory_impl& impl_;
 
    };
 
    // ========================================================================
 
    class directory_impl
    {
      // ----------------------------------------------------------------------
 
      friend class directory;
 
      // ----------------------------------------------------------------------
    public:
 
      directory_impl (class file_system& fs);
 
      // The rule of five.
      directory_impl (const directory_impl&) = delete;
      directory_impl (directory_impl&&) = delete;
      directory_impl&
      operator= (const directory_impl&) = delete;
      directory_impl&
      operator= (directory_impl&&) = delete;
 
      virtual
      ~directory_impl ();
 
      // ----------------------------------------------------------------------
    public:
 
      // Implementations
 
      virtual struct dirent*
      do_read (void) = 0;
 
      virtual void
      do_rewind (void) = 0;
 
      virtual int
      do_close (void) = 0;
 
      // ----------------------------------------------------------------------
      // Support functions.
 
      class file_system&
      file_system (void) const;
 
      // ----------------------------------------------------------------------
    protected:
 
      // This also solves the readdir() re-entrancy issue.
      struct dirent dir_entry_;
 
      class file_system& file_system_;
 
    };
 
    // ========================================================================
 
    template<typename T>
      class directory_implementable : public directory
      {
        // --------------------------------------------------------------------
 
      public:
 
        using value_type = T;
 
        // --------------------------------------------------------------------
      public:
 
        directory_implementable (class file_system& fs);
 
        // The rule of five.
        directory_implementable (const directory_implementable&) = delete;
        directory_implementable (directory_implementable&&) = delete;
        directory_implementable&
        operator= (const directory_implementable&) = delete;
        directory_implementable&
        operator= (directory_implementable&&) = delete;
 
        virtual
        ~directory_implementable () override;
 
        // --------------------------------------------------------------------
      public:
 
        // Support functions.
 
        value_type&
        impl (void) const;
 
        // --------------------------------------------------------------------
      protected:
 
        value_type impl_instance_;
 
      };
 
    // ========================================================================
 
    template<typename T, typename L>
      class directory_lockable : public directory
      {
        // --------------------------------------------------------------------
 
      public:
 
        using value_type = T;
        using lockable_type = L;
 
        // --------------------------------------------------------------------
 
      public:
 
        directory_lockable (class file_system& fs, lockable_type& locker);
 
        // The rule of five.
        directory_lockable (const directory_lockable&) = delete;
        directory_lockable (directory_lockable&&) = delete;
        directory_lockable&
        operator= (const directory_lockable&) = delete;
        directory_lockable&
        operator= (directory_lockable&&) = delete;
 
        virtual
        ~directory_lockable () override;
 
        // --------------------------------------------------------------------
      public:
 
        // opendir() uses the file system lock.
 
        // http://pubs.opengroup.org/onlinepubs/9699919799/functions/readdir.html
        virtual struct dirent *
        read (void) override;
 
        // http://pubs.opengroup.org/onlinepubs/9699919799/functions/rewinddir.html
        virtual void
        rewind (void) override;
 
        // http://pubs.opengroup.org/onlinepubs/9699919799/functions/closedir.html
        virtual int
        close (void) override;
 
        // --------------------------------------------------------------------
        // Support functions.
 
        value_type&
        impl (void) const;
 
        // --------------------------------------------------------------------
      protected:
 
        value_type impl_instance_;
 
        lockable_type& locker_;
 
      };
 
#pragma GCC diagnostic pop
 
  // ==========================================================================
  } /* namespace posix */
} /* namespace os */
 
// ===== Inline & template implementations ====================================
 
namespace os
{
  namespace posix
  {
    // ========================================================================
 
    inline file_system&
    directory::file_system (void) const
    {
      return impl ().file_system ();
    }
 
    inline struct dirent*
    directory::dir_entry (void)
    {
      return &(impl ().dir_entry_);
    }
 
    inline directory_impl&
    directory::impl (void) const
    {
      return static_cast<directory_impl&> (impl_);
    }
 
    // ========================================================================
 
    inline file_system&
    directory_impl::file_system (void) const
    {
      return file_system_;
    }
 
    // ========================================================================
 
    template<typename T>
      directory_implementable<T>::directory_implementable (
          class file_system& fs) :
          directory
            { impl_instance_ }, //
          impl_instance_
            { fs }
      {
#if defined(OS_TRACE_POSIX_IO_DIRECTORY)
        trace::printf ("directory_implementable::%s()=@%p\n", __func__, this);
#endif
      }
 
    template<typename T>
      directory_implementable<T>::~directory_implementable ()
      {
#if defined(OS_TRACE_POSIX_IO_DIRECTORY)
        trace::printf ("directory_implementable::%s() @%p\n", __func__, this);
#endif
      }
 
    template<typename T>
      typename directory_implementable<T>::value_type&
      directory_implementable<T>::impl (void) const
      {
        return static_cast<value_type&> (impl_);
      }
 
    // ========================================================================
 
    template<typename T, typename L>
      directory_lockable<T, L>::directory_lockable (class file_system& fs,
                                                    lockable_type& locker) :
          directory
            { impl_instance_ }, //
          impl_instance_
            { fs }, //
          locker_ (locker)
      {
#if defined(OS_TRACE_POSIX_IO_DIRECTORY)
        trace::printf ("directory_lockable::%s()=@%p\n", __func__, this);
#endif
      }
 
    template<typename T, typename L>
      directory_lockable<T, L>::~directory_lockable ()
      {
#if defined(OS_TRACE_POSIX_IO_DIRECTORY)
        trace::printf ("directory_lockable::%s() @%p\n", __func__, this);
#endif
      }
 
    // ------------------------------------------------------------------------
 
    template<typename T, typename L>
      struct dirent *
      directory_lockable<T, L>::read (void)
      {
#if defined(OS_TRACE_POSIX_IO_DIRECTORY)
        trace::printf ("directory_lockable::%s() @%p\n", __func__, this);
#endif
 
        std::lock_guard<L> lock
          { locker_ };
 
        return directory::read ();
      }
 
    template<typename T, typename L>
      void
      directory_lockable<T, L>::rewind (void)
      {
#if defined(OS_TRACE_POSIX_IO_DIRECTORY)
        trace::printf ("directory_lockable::%s() @%p\n", __func__, this);
#endif
 
        std::lock_guard<L> lock
          { locker_ };
 
        return directory::rewind ();
      }
 
    template<typename T, typename L>
      int
      directory_lockable<T, L>::close (void)
      {
#if defined(OS_TRACE_POSIX_IO_DIRECTORY)
        trace::printf ("directory_lockable::%s() @%p\n", __func__, this);
#endif
 
        std::lock_guard<L> lock
          { locker_ };
 
        return directory::close ();
      }
 
    template<typename T, typename L>
      typename directory_lockable<T, L>::value_type&
      directory_lockable<T, L>::impl (void) const
      {
        return static_cast<value_type&> (impl_);
      }
 
  // ==========================================================================
  } /* namespace posix */
} /* namespace os */
 
#pragma GCC diagnostic pop
 
// ----------------------------------------------------------------------------
 
#endif /* __cplusplus */
 
// ----------------------------------------------------------------------------
 
#endif /* CMSIS_PLUS_POSIX_IO_DIRECTORY_H_ */