Simplify smob and port marking; set the mark bit in the generic

[bpt/guile.git] / libguile / fports.c

/*	Copyright (C) 1995,1996,1997 Free Software Foundation, Inc.
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this software; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307 USA
 *
 * As a special exception, the Free Software Foundation gives permission
 * for additional uses of the text contained in its release of GUILE.
 *
 * The exception is that, if you link the GUILE library with other files
 * to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the GUILE library code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public License.
 *
 * This exception applies only to the code released by the
 * Free Software Foundation under the name GUILE.  If you copy
 * code from other Free Software Foundation releases into a copy of
 * GUILE, as the General Public License permits, the exception does
 * not apply to the code that you add in this way.  To avoid misleading
 * anyone as to the status of such modified files, you must delete
 * this exception notice from them.
 *
 * If you write modifications of your own for GUILE, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.  */
\f

#include <stdio.h>
#include "_scm.h"
#include "markers.h"

#include "fports.h"

#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#else
scm_sizet fwrite ();
#endif

/* {Ports - file ports}
 * 
 */

/* should be called with SCM_DEFER_INTS active */

SCM 
scm_setbuf0 (port)
     SCM port;
{
  /* NOSETBUF was provided by scm to allow unbuffered ports to be
     avoided on systems where ungetc didn't work correctly.  See
     comment in unif.c, which seems to be the only place where it
     could still be a problem.  */
#ifndef NOSETBUF
  /*  SCM_SYSCALL (setbuf ((FILE *)SCM_STREAM (port), 0);); */
  SCM_SYSCALL (setvbuf ((FILE *)SCM_STREAM (port), 0, _IONBF, 0););
#endif
  return SCM_UNSPECIFIED;
}

SCM_PROC (s_setvbuf, "setvbuf", 2, 1, 0, scm_setvbuf);
SCM
scm_setvbuf (SCM port, SCM mode, SCM size)
{
  int rv;
  int cmode, csize;

  port = SCM_COERCE_OUTPORT (port);

  SCM_ASSERT (SCM_NIMP (port) && SCM_FPORTP (port), port, SCM_ARG1, s_setvbuf);
  SCM_ASSERT (SCM_INUMP (mode), mode, SCM_ARG2, s_setvbuf);
  if (SCM_UNBNDP (size))
    csize = 0;
  else
    {
      SCM_ASSERT (SCM_INUMP (size), size, SCM_ARG3, s_setvbuf);
      csize = SCM_INUM (size);
    }
  cmode = SCM_INUM (mode);
  if (csize == 0 && cmode == _IOFBF)
    cmode = _IONBF;
  SCM_DEFER_INTS;
  SCM_SYSCALL (rv = setvbuf ((FILE *)SCM_STREAM (port), 0, cmode, csize));
  if (rv < 0)
    scm_syserror (s_setvbuf);
  if (cmode == _IONBF)
    SCM_SETCAR (port, SCM_CAR (port) | SCM_BUF0);
  else
    SCM_SETCAR (port, (SCM_CAR (port) & ~SCM_BUF0));
  SCM_ALLOW_INTS;
  return SCM_UNSPECIFIED;
}

#ifdef FD_SETTER
#define SET_FILE_FD_FIELD(F,D) ((F)->FD_SETTER = (D))
#endif

void
scm_setfileno (fs, fd)
     FILE *fs;
     int fd;
{
#ifdef SET_FILE_FD_FIELD
  SET_FILE_FD_FIELD(fs, fd);
#else
  scm_misc_error ("scm_setfileno", "Not fully implemented on this platform",
		  SCM_EOL);
#endif
}

/* Move ports with the specified file descriptor to new descriptors,
 * reseting the revealed count to 0.
 * Should be called with SCM_DEFER_INTS active.
 */

void
scm_evict_ports (fd)
     int fd;
{
  int i;

  for (i = 0; i < scm_port_table_size; i++)
    {
      if (SCM_FPORTP (scm_port_table[i]->port)
	  && fileno ((FILE *)SCM_STREAM (scm_port_table[i]->port)) == fd)
	{
	  scm_setfileno ((FILE *)SCM_STREAM (scm_port_table[i]->port), dup (fd));
	  scm_set_port_revealed_x (scm_port_table[i]->port, SCM_MAKINUM (0));
	}
    }
}

/* scm_open_file
 * Return a new port open on a given file.
 *
 * The mode string must match the pattern: [rwa+]** which
 * is interpreted in the usual unix way.
 *
 * Return the new port.
 */
SCM_PROC(s_open_file, "open-file", 2, 0, 0, scm_open_file);

SCM
scm_open_file (filename, modes)
     SCM filename;
     SCM modes;
{
  SCM port;
  FILE *f;
  char *file;
  char *mode;

  SCM_ASSERT (SCM_NIMP (filename) && SCM_ROSTRINGP (filename), filename, SCM_ARG1, s_open_file);
  SCM_ASSERT (SCM_NIMP (modes) && SCM_ROSTRINGP (modes), modes, SCM_ARG2, s_open_file);
  if (SCM_SUBSTRP (filename))
    filename = scm_makfromstr (SCM_ROCHARS (filename), SCM_ROLENGTH (filename), 0);
  if (SCM_SUBSTRP (modes))
    modes = scm_makfromstr (SCM_ROCHARS (modes), SCM_ROLENGTH (modes), 0);

  file = SCM_ROCHARS (filename);
  mode = SCM_ROCHARS (modes);

  SCM_NEWCELL (port);
  SCM_DEFER_INTS;
  SCM_SYSCALL (f = fopen (file, mode));
  if (!f)
    {
      int en = errno;

      scm_syserror_msg (s_open_file, "%s: %S",
			scm_listify (scm_makfrom0str (strerror (errno)),
				     filename,
				     SCM_UNDEFINED),
			en);
    }
  else
    {
      struct scm_port_table * pt;

      pt = scm_add_to_port_table (port);
      SCM_SETPTAB_ENTRY (port, pt);
      SCM_SETCAR (port, scm_tc16_fport | scm_mode_bits (mode));
      SCM_SETSTREAM (port, (SCM) f);
      if (SCM_BUF0 & SCM_CAR (port))
	scm_setbuf0 (port);
      SCM_PTAB_ENTRY (port)->file_name = filename;
    }
  SCM_ALLOW_INTS;
  return port;
}


/* Build a Scheme port from an open stdio port, FILE.
   MODE indicates whether FILE is open for reading or writing; it uses
      the same notation as open-file's second argument.
   If NAME is non-zero, use it as the port's filename.

   scm_stdio_to_port sets the revealed count for FILE's file
   descriptor to 1, so that FILE won't be closed when the port object
   is GC'd.  */
SCM
scm_stdio_to_port (file, mode, name)
     FILE *file;
     char *mode;
     char *name;
{
  long mode_bits = scm_mode_bits (mode);
  SCM port;
  struct scm_port_table * pt;

  SCM_NEWCELL (port);
  SCM_DEFER_INTS;
  {
    pt = scm_add_to_port_table (port);
    SCM_SETPTAB_ENTRY (port, pt);
    SCM_SETCAR (port, (scm_tc16_fport | mode_bits));
    SCM_SETSTREAM (port, (SCM) file);
    if (SCM_BUF0 & SCM_CAR (port))
      scm_setbuf0 (port);
    SCM_PTAB_ENTRY (port)->file_name = scm_makfrom0str (name);
  }
  SCM_ALLOW_INTS;
  scm_set_port_revealed_x (port, SCM_MAKINUM (1));
  return port;
}



static int prinfport SCM_P ((SCM exp, SCM port, scm_print_state *pstate));

static int 
prinfport (exp, port, pstate)
     SCM exp;
     SCM port;
     scm_print_state *pstate;
{
  SCM name;
  char * c;
  if (SCM_CLOSEDP (exp))
    {
      c = "file";
    }
  else
    {
      name = SCM_PTAB_ENTRY (exp)->file_name;
      if (SCM_NIMP (name) && SCM_ROSTRINGP (name))
	c = SCM_ROCHARS (name);
      else
	c = "file";
    }
    
  scm_prinport (exp, port, c);
  return !0;
}



static int scm_fgetc SCM_P ((FILE * s));

static int
scm_fgetc (s)
     FILE * s;
{
  if (feof (s))
    return EOF;
  else
    return fgetc (s);
}

/*
 * The fgets method must take a port as its argument, rather than
 * the underlying file handle.  The reason is that we also provide
 * a generic fgets method for ports which can't use fgets(3) (e.g.
 * string ports).  This generic method calls the port's own
 * fgetc method.  In order for it to know how to get that method,
 * we must pass the original Scheme port object.
 */

static char * scm_fgets SCM_P ((SCM port, int *len));

static char *
scm_fgets (port, len)
     SCM port;
     int *len;
{
  FILE *f;

  char *buf   = NULL;
  char *p;		/* pointer to current buffer position */
  int   limit = 80;	/* current size of buffer */

  f = (FILE *) SCM_STREAM (port);
  if (feof (f))
    return NULL;

  buf = (char *) malloc (limit * sizeof(char));
  *len = 0;

  /* If a char has been pushed onto the port with scm_ungetc,
     read that first. */
  if (SCM_CRDYP (port))
    {
      buf[*len] = SCM_CGETUN (port);
      SCM_CLRDY (port);
      if (buf[(*len)++] == '\n')
	{
	  buf[*len] = '\0';
	  return buf;
	}
    }

  while (1)
    {
      int chunk_size = limit - *len;
      long int numread, pos;

      p = buf + *len;

      /* We must use ftell to figure out how many characters were read.
	 If there are null characters near the end of file, and no
	 terminating newline, there is no other way to tell the difference
	 between an embedded null and the string-terminating null. */

      pos = ftell (f);
      if (fgets (p, chunk_size, f) == NULL) {
	if (*len)
	  return buf;
	free (buf);
	return NULL;
      }
      numread = ftell (f) - pos;
      *len += numread;

      if (numread < chunk_size - 1 || buf[limit-2] == '\n')
	return buf;

      buf = (char *) realloc (buf, sizeof(char) * limit * 2);
      limit *= 2;
    }
}

#ifdef vms

static scm_sizet pwrite SCM_P ((char *ptr, scm_sizet size, nitems, FILE *port));

static scm_sizet 
pwrite (ptr, size, nitems, port)
     char *ptr;
     scm_sizet size, nitems;
     FILE *port;
{
  scm_sizet len = size * nitems;
  scm_sizet i = 0;
  for (; i < len; i++)
    putc (ptr[i], port);
  return len;
}

#define ffwrite pwrite
#else
#define ffwrite fwrite
#endif

\f
/* This otherwise pointless code helps some poor 
 * crippled C compilers cope with life. 
 */

static int local_fclose SCM_P ((FILE *fp));

static int
local_fclose (fp)
     FILE * fp;
{
  return fclose (fp);
}

static int local_fflush SCM_P ((FILE *fp));

static int
local_fflush (fp)
     FILE * fp;
{
  return fflush (fp);
}

static int local_fputc SCM_P ((int c, FILE *fp));

static int
local_fputc (c, fp)
     int c;
     FILE * fp;
{
  return fputc (c, fp);
}

static int local_fputs SCM_P ((char *s, FILE *fp));

static int
local_fputs (s, fp)
     char * s;
     FILE * fp;
{
  return fputs (s, fp);
}

static scm_sizet local_ffwrite SCM_P ((void *ptr, int size, int nitems, FILE *fp));

static scm_sizet
local_ffwrite (ptr, size, nitems, fp)
     void * ptr;
     int size;
     int nitems;
     FILE * fp;
{
  return ffwrite (ptr, size, nitems, fp);
}

static int
print_pipe_port (SCM exp, SCM port, scm_print_state *pstate)
{
  scm_prinport (exp, port, "pipe");
  return 1;
}



/* On SunOS, there's no declaration for pclose in the headers, so
   putting it directly in the initializer for scm_pipob doesn't really
   fly.  We could add an extern declaration for it, but then it'll
   mismatch on some systems that do have a declaration.  So we just
   wrap it up this way.  */
static int
local_pclose (fp)
     FILE * fp;
{
  return pclose (fp);
}

\f
scm_ptobfuns scm_fptob =
{
  0,
  (int (*) SCM_P ((SCM))) local_fclose,
  prinfport,
  0,
  (int (*) SCM_P ((int, SCM))) local_fputc,
  (int (*) SCM_P ((char *, SCM))) local_fputs,
  (scm_sizet (*) SCM_P ((char *, scm_sizet, scm_sizet, SCM))) local_ffwrite,
  (int (*) SCM_P ((SCM))) local_fflush,
  (int (*) SCM_P ((SCM))) scm_fgetc,
  (char * (*) SCM_P ((SCM, int *))) scm_fgets,
  (int (*) SCM_P ((SCM))) local_fclose
};

/* {Pipe ports} */
scm_ptobfuns scm_pipob =
{
  0,
  (int (*) SCM_P ((SCM))) local_pclose,  
  print_pipe_port,
  0,
  (int (*) SCM_P ((int, SCM))) local_fputc,
  (int (*) SCM_P ((char *, SCM))) local_fputs,
  (scm_sizet (*) SCM_P ((char *, scm_sizet, scm_sizet, SCM))) local_ffwrite,
  (int (*) SCM_P ((SCM))) local_fflush,
  (int (*) SCM_P ((SCM))) scm_fgetc,
  (char * (*) SCM_P ((SCM, int *))) scm_generic_fgets,
  (int (*) SCM_P ((SCM))) local_pclose
};

void
scm_init_fports ()
{
#include "fports.x"
  scm_sysintern ("_IOFBF", SCM_MAKINUM (_IOFBF));
  scm_sysintern ("_IOLBF", SCM_MAKINUM (_IOLBF));
  scm_sysintern ("_IONBF", SCM_MAKINUM (_IONBF));
}