guile/libguile/fports.h

#ifndef SCM_FPORTS_H
#define SCM_FPORTS_H

/* Copyright 1995-2001,2006,2008-2009,2011-2012,2017-2019
     Free Software Foundation, Inc.

   This file is part of Guile.

   Guile is free software: you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published
   by the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   Guile is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
   License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with Guile.  If not, see
   <https://www.gnu.org/licenses/>.  */



#include "libguile/gc.h"
#include "libguile/ports.h"



/* struct allocated for each buffered FPORT.  */
typedef struct scm_t_fport {
  /* The file descriptor.  */
  int fdes;
  /* Revealed count; 0 indicates not revealed, > 1 revealed.  */
  unsigned int revealed;
  /* Set of scm_fport_option flags.  */
  unsigned options;
} scm_t_fport;

SCM_API scm_t_port_type *scm_file_port_type;

#define SCM_FSTREAM(x) ((scm_t_fport *) SCM_STREAM (x))
#define SCM_FPORT_FDES(x) (SCM_FSTREAM (x)->fdes)

#define SCM_FPORTP(x) \
  (SCM_PORTP (x) && SCM_PORT_TYPE (x) == scm_file_port_type)
#define SCM_OPFPORTP(x) (SCM_FPORTP (x) && (SCM_CELL_WORD_0 (x) & SCM_OPN))
#define SCM_OPINFPORTP(x) (SCM_OPFPORTP (x) && (SCM_CELL_WORD_0 (x) & SCM_RDNG))
#define SCM_OPOUTFPORTP(x) (SCM_OPFPORTP (x) && (SCM_CELL_WORD_0 (x) & SCM_WRTNG))

#define SCM_VALIDATE_FPORT(pos, port) \
  SCM_MAKE_VALIDATE_MSG (pos, port, FPORTP, "file port")
#define SCM_VALIDATE_OPFPORT(pos, port) \
  SCM_MAKE_VALIDATE_MSG (pos, port, OPFPORTP, "open file port")


SCM_API void scm_evict_ports (int fd);
SCM_INTERNAL int scm_i_mode_to_open_flags (SCM mode, int *is_binary,
                                           const char *FUNC_NAME);
SCM_API SCM scm_open_file_with_encoding (SCM filename, SCM modes,
                                         SCM guess_encoding, SCM encoding);
SCM_API SCM scm_open_file (SCM filename, SCM modes);
SCM_API SCM scm_fdes_to_port (int fdes, char *mode, SCM name);
SCM_API SCM scm_file_port_p (SCM obj);


/* Revealed counts.  */
SCM_API int scm_revealed_count (SCM port);
SCM_API SCM scm_port_revealed (SCM port);
SCM_API SCM scm_set_port_revealed_x (SCM port, SCM rcount);
SCM_API SCM scm_adjust_port_revealed_x (SCM port, SCM addend);


SCM_INTERNAL void scm_init_fports_keywords (void);
SCM_INTERNAL void scm_init_fports (void);

/* internal functions */

#ifdef BUILDING_LIBGUILE
enum scm_fport_option
  {
    /* FD's that aren't created by Guile probably need to be checked for
       validity.  We also check that the open mode is valid.  */
    SCM_FPORT_OPTION_VERIFY = 1U<<0,
    /* We know some ports aren't seekable and can elide a syscall in
       that case.  */
    SCM_FPORT_OPTION_NOT_SEEKABLE = 1U<<1
  };
SCM_INTERNAL int scm_i_fdes_is_valid (int fdes, long mode_bits);
SCM_INTERNAL SCM scm_i_fdes_to_port (int fdes, long mode_bits, SCM name,
                                     unsigned options);

#endif /* BUILDING_LIBGUILE */

#endif  /* SCM_FPORTS_H */