text: /* Copyright  (C) 2010-2020 The RetroArch team
   *
   * ---------------------------------------------------------------------------------------
   * The following license statement only applies to this file (nbio.h).
   * ---------------------------------------------------------------------------------------
   *
   * 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 __LIBRETRO_SDK_NBIO_H
  #define __LIBRETRO_SDK_NBIO_H
  
  #include <stddef.h>
  #include <boolean.h>
  
  #include <retro_common_api.h>
  
  RETRO_BEGIN_DECLS
  
  #ifndef NBIO_READ
  #define NBIO_READ   0
  #endif
  
  #ifndef NBIO_WRITE
  #define NBIO_WRITE  1
  #endif
  
  #ifndef NBIO_UPDATE
  #define NBIO_UPDATE 2
  #endif
  
  /* these two are blocking; nbio_iterate always returns true, but that operation (or something earlier) may take arbitrarily long */
  #ifndef BIO_READ
  #define BIO_READ    3
  #endif
  
  #ifndef BIO_WRITE
  #define BIO_WRITE   4
  #endif
  
  typedef struct nbio_intf
  {
     void *(*open)(const char * filename, unsigned mode);
  
     void (*begin_read)(void *data);
  
     void (*begin_write)(void *data);
  
     bool (*iterate)(void *data);
  
     void (*resize)(void *data, size_t len);
  
     void *(*get_ptr)(void *data, size_t* len);
  
     void (*cancel)(void *data);
  
     void (*free)(void *data);
  
     /* Human readable string. */
     const char *ident;
  } nbio_intf_t;
  
  /*
   * Creates an nbio structure for performing the
   * given operation on the given file.
   */
  void *nbio_open(const char * filename, unsigned mode);
  
  /*
   * Starts reading the given file. When done, it will be available in nbio_get_ptr.
   * Can not be done if the structure was created with {N,}BIO_WRITE.
   */
  void nbio_begin_read(void *data);
  
  /*
   * Starts writing to the given file. Before this, you should've copied the data to nbio_get_ptr.
   * Can not be done if the structure was created with {N,}BIO_READ.
   */
  void nbio_begin_write(void *data);
  
  /*
   * Performs part of the requested operation, or checks how it's going.
   * When it returns true, it's done.
   */
  bool nbio_iterate(void *data);
  
  /*
   * Resizes the file up to the given size; cannot shrink.
   * Can not be done if the structure was created with {N,}BIO_READ.
   */
  void nbio_resize(void *data, size_t len);
  
  /*
   * Returns a pointer to the file data. Writable only if structure was not created with {N,}BIO_READ.
   * If any operation is in progress, the pointer will be NULL, but len will still be correct.
   */
  void* nbio_get_ptr(void *data, size_t* len);
  
  /*
   * Stops any pending operation, allowing the object to be freed.
   */
  void nbio_cancel(void *data);
  
  /*
   * Deletes the nbio structure and its associated pointer.
   */
  void nbio_free(void *data);
  
  RETRO_END_DECLS
  
  #endif
  