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

/* 	Copyright (C) 2001 Free Software Foundation, Inc.
 * 
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

\f

/* This is the C part of the (ice-9 rw) module.  */

#if HAVE_CONFIG_H
#  include <config.h>
#endif

#include <errno.h>
#include <string.h>

#include "libguile/_scm.h"
#include "libguile/fports.h"
#include "libguile/ports.h"
#include "libguile/root.h"
#include "libguile/rw.h"
#include "libguile/strings.h"
#include "libguile/validate.h"
#include "libguile/modules.h"
#include "libguile/strports.h"

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_IO_H
#include <io.h>
#endif

\f

#if defined (EAGAIN)
#define SCM_MAYBE_EAGAIN || errno == EAGAIN
#else
#define SCM_MAYBE_EAGAIN
#endif

#if defined (EWOULDBLOCK)
#define SCM_MAYBE_EWOULDBLOCK || errno == EWOULDBLOCK
#else
#define SCM_MAYBE_EWOULDBLOCK
#endif

/* MAYBE there is EAGAIN way of defining this macro but now I EWOULDBLOCK.  */
#define SCM_EBLOCK(errno) \
   (0 SCM_MAYBE_EAGAIN SCM_MAYBE_EWOULDBLOCK)

SCM_DEFINE (scm_read_string_x_partial, "read-string!/partial", 1, 3, 0,
	    (SCM str, SCM port_or_fdes, SCM start, SCM end),
	    "Read characters from a port or file descriptor into a\n"
	    "string @var{str}.  A port must have an underlying file\n"
	    "descriptor --- a so-called fport.  This procedure is\n"
	    "scsh-compatible and can efficiently read large strings.\n"
	    "It will:\n\n"
	    "@itemize\n"
	    "@item\n"
	    "attempt to fill the entire string, unless the @var{start}\n"
	    "and/or @var{end} arguments are supplied.  i.e., @var{start}\n"
	    "defaults to 0 and @var{end} defaults to\n"
	    "@code{(string-length str)}\n"
	    "@item\n"
	    "use the current input port if @var{port_or_fdes} is not\n"
	    "supplied.\n" 
	    "@item\n"
	    "return fewer than the requested number of characters in some\n"
	    "cases, e.g., on end of file, if interrupted by a signal, or if\n"
	    "not all the characters are immediately available.\n"
	    "@item\n"
	    "wait indefinitely for some input if no characters are\n"
	    "currently available,\n"
	    "unless the port is in non-blocking mode.\n"
	    "@item\n"
	    "read characters from the port's input buffers if available,\n"
	    "instead from the underlying file descriptor.\n"
	    "@item\n"
	    "return @code{#f} if end-of-file is encountered before reading\n"
            "any characters, otherwise return the number of characters\n"
	    "read.\n"
	    "@item\n"
	    "return 0 if the port is in non-blocking mode and no characters\n"
	    "are immediately available.\n"
	    "@item\n"
	    "return 0 if the request is for 0 bytes, with no\n"
	    "end-of-file check.\n"
	    "@end itemize")
#define FUNC_NAME s_scm_read_string_x_partial
{
  char *dest;
  size_t offset;
  long read_len;
  long chars_read = 0;
  int fdes;

  {
    size_t last;

    SCM_VALIDATE_STRING (1, str);
    scm_i_get_substring_spec (scm_i_string_length (str),
			      start, &offset, end, &last);
    read_len = last - offset;
  }

  if (scm_is_integer (port_or_fdes))
    fdes = scm_to_int (port_or_fdes);
  else
    {
      SCM port = SCM_UNBNDP (port_or_fdes) ? scm_cur_inp : port_or_fdes;

      SCM_VALIDATE_OPFPORT (2, port);
      SCM_VALIDATE_INPUT_PORT (2, port);

      /* if there's anything in the port buffers, use it, but then
	 don't touch the file descriptor.  otherwise the
	 "return immediately if something is available" rule may
	 be violated.  */
      dest = scm_i_string_writable_chars (str) + offset;
      chars_read = scm_take_from_input_buffers (port, dest, read_len);
      scm_i_string_stop_writing ();
      fdes = SCM_FPORT_FDES (port);
    }

  if (chars_read == 0 && read_len > 0) /* don't confuse read_len == 0 with
					  EOF.  */
    {
      dest = scm_i_string_writable_chars (str) + offset;
      SCM_SYSCALL (chars_read = read (fdes, dest, read_len));
      scm_i_string_stop_writing ();
      if (chars_read == -1)
	{
	  if (SCM_EBLOCK (errno))
	    chars_read = 0;
	  else
	    SCM_SYSERROR;
        }
      else if (chars_read == 0)
	{
	  scm_remember_upto_here_1 (str);
	  return SCM_BOOL_F;
	}
    }

  scm_remember_upto_here_1 (str);
  return scm_from_long (chars_read);
}
#undef FUNC_NAME

SCM_DEFINE (scm_write_string_partial, "write-string/partial", 1, 3, 0,
	    (SCM str, SCM port_or_fdes, SCM start, SCM end),
	    "Write characters from a string @var{str} to a port or file\n"
	    "descriptor.  A port must have an underlying file descriptor\n"
	    "--- a so-called fport.  This procedure is\n"
	    "scsh-compatible and can efficiently write large strings.\n"
	    "It will:\n\n"
	    "@itemize\n"
	    "@item\n"
	    "attempt to write the entire string, unless the @var{start}\n"
	    "and/or @var{end} arguments are supplied.  i.e., @var{start}\n"
	    "defaults to 0 and @var{end} defaults to\n"
	    "@code{(string-length str)}\n"
	    "@item\n"
	    "use the current output port if @var{port_of_fdes} is not\n"
	    "supplied.\n"
	    "@item\n"
	    "in the case of a buffered port, store the characters in the\n"
	    "port's output buffer, if all will fit.  If they will not fit\n"
	    "then any existing buffered characters will be flushed\n"
	    "before attempting\n"
	    "to write the new characters directly to the underlying file\n"
	    "descriptor.  If the port is in non-blocking mode and\n"
	    "buffered characters can not be flushed immediately, then an\n"
	    "@code{EAGAIN} system-error exception will be raised (Note:\n"
	    "scsh does not support the use of non-blocking buffered ports.)\n"
	    "@item\n"
	    "write fewer than the requested number of\n"
	    "characters in some cases, e.g., if interrupted by a signal or\n"
	    "if not all of the output can be accepted immediately.\n"
	    "@item\n"
	    "wait indefinitely for at least one character\n"
	    "from @var{str} to be accepted by the port, unless the port is\n"
	    "in non-blocking mode.\n"
	    "@item\n"
	    "return the number of characters accepted by the port.\n"
	    "@item\n"
	    "return 0 if the port is in non-blocking mode and can not accept\n"
	    "at least one character from @var{str} immediately\n"
	    "@item\n"
	    "return 0 immediately if the request size is 0 bytes.\n"
	    "@end itemize")
#define FUNC_NAME s_scm_write_string_partial
{
  const char *src;
  long write_len;
  int fdes;

  {
    size_t offset;
    size_t last;

    SCM_VALIDATE_STRING (1, str);
    src = scm_i_string_chars (str);
    scm_i_get_substring_spec (scm_i_string_length (str),
			      start, &offset, end, &last);
    src += offset;
    write_len = last - offset;
  }

  if (write_len == 0)
    return SCM_INUM0;

  if (scm_is_integer (port_or_fdes))
    fdes = scm_to_int (port_or_fdes);
  else
    {
      SCM port = SCM_UNBNDP (port_or_fdes) ? scm_cur_outp : port_or_fdes;
      scm_t_port *pt;
      off_t space;

      SCM_VALIDATE_OPFPORT (2, port);
      SCM_VALIDATE_OUTPUT_PORT (2, port);
      pt = SCM_PTAB_ENTRY (port);
      /* filling the last character in the buffer would require a flush.  */
      space = pt->write_end - pt->write_pos - 1;
      if (space >= write_len)
	{
	  memcpy (pt->write_pos, src, write_len);
	  pt->write_pos += write_len;
	  return scm_from_long (write_len);
	}
      if (pt->write_pos > pt->write_buf)
	scm_flush (port);
      fdes = SCM_FPORT_FDES (port);
    }
  {
    long rv;

    SCM_SYSCALL (rv = write (fdes, src, write_len));
    if (rv == -1)
      {
	if (SCM_EBLOCK (errno))
	  rv = 0;
	else
	  SCM_SYSERROR;
      }

    scm_remember_upto_here_1 (str);
    return scm_from_long (rv);
  }
}
#undef FUNC_NAME

SCM 
scm_init_rw_builtins ()
{
#include "libguile/rw.x"

  return SCM_UNSPECIFIED;
}

void
scm_init_rw ()
{
  scm_c_define_gsubr ("%init-rw-builtins", 0, 0, 0, scm_init_rw_builtins);
}

/*
  Local Variables:
  c-file-style: "gnu"
  End:
*/
Commit	Line	Data
b0e5fd8c GH	1	/* Copyright (C) 2001 Free Software Foundation, Inc.
b0e5fd8c GH	2	*
73be1d9e MV	3	* This library is free software; you can redistribute it and/or
	4	* modify it under the terms of the GNU Lesser General Public
	5	* License as published by the Free Software Foundation; either
	6	* version 2.1 of the License, or (at your option) any later version.
b0e5fd8c	7	*
73be1d9e MV	8	* This library is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* Lesser General Public License for more details.
b0e5fd8c	12	*
73be1d9e MV	13	* You should have received a copy of the GNU Lesser General Public
	14	* License along with this library; if not, write to the Free Software
	15	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	16	*/
b0e5fd8c GH	17
	18	\f
	19
	20	/* This is the C part of the (ice-9 rw) module. */
	21
7b5a83d3 RB	22	#if HAVE_CONFIG_H
	23	# include <config.h>
	24	#endif
	25
b0e5fd8c	26	#include <errno.h>
fbbdb121	27	#include <string.h>
b0e5fd8c GH	28
	29	#include "libguile/_scm.h"
	30	#include "libguile/fports.h"
	31	#include "libguile/ports.h"
	32	#include "libguile/root.h"
	33	#include "libguile/rw.h"
	34	#include "libguile/strings.h"
	35	#include "libguile/validate.h"
fee12d18 MV	36	#include "libguile/modules.h"
fee12d18 MV	37	#include "libguile/strports.h"
b0e5fd8c GH	38
	39	#ifdef HAVE_UNISTD_H
	40	#include <unistd.h>
	41	#endif
7beabedb MG	42	#ifdef HAVE_IO_H
	43	#include <io.h>
	44	#endif
b0e5fd8c GH	45
	46	\f
	47
	48	#if defined (EAGAIN)
	49	#define SCM_MAYBE_EAGAIN \|\| errno == EAGAIN
	50	#else
	51	#define SCM_MAYBE_EAGAIN
	52	#endif
	53
	54	#if defined (EWOULDBLOCK)
	55	#define SCM_MAYBE_EWOULDBLOCK \|\| errno == EWOULDBLOCK
	56	#else
	57	#define SCM_MAYBE_EWOULDBLOCK
	58	#endif
	59
	60	/* MAYBE there is EAGAIN way of defining this macro but now I EWOULDBLOCK. */
	61	#define SCM_EBLOCK(errno) \
	62	(0 SCM_MAYBE_EAGAIN SCM_MAYBE_EWOULDBLOCK)
	63
	64	SCM_DEFINE (scm_read_string_x_partial, "read-string!/partial", 1, 3, 0,
	65	(SCM str, SCM port_or_fdes, SCM start, SCM end),
99004a28 GH	66	"Read characters from a port or file descriptor into a\n"
	67	"string @var{str}. A port must have an underlying file\n"
	68	"descriptor --- a so-called fport. This procedure is\n"
	69	"scsh-compatible and can efficiently read large strings.\n"
	70	"It will:\n\n"
b0e5fd8c GH	71	"@itemize\n"
	72	"@item\n"
	73	"attempt to fill the entire string, unless the @var{start}\n"
	74	"and/or @var{end} arguments are supplied. i.e., @var{start}\n"
	75	"defaults to 0 and @var{end} defaults to\n"
	76	"@code{(string-length str)}\n"
	77	"@item\n"
	78	"use the current input port if @var{port_or_fdes} is not\n"
	79	"supplied.\n"
	80	"@item\n"
99004a28 GH	81	"return fewer than the requested number of characters in some\n"
	82	"cases, e.g., on end of file, if interrupted by a signal, or if\n"
	83	"not all the characters are immediately available.\n"
b0e5fd8c	84	"@item\n"
99004a28 GH	85	"wait indefinitely for some input if no characters are\n"
	86	"currently available,\n"
	87	"unless the port is in non-blocking mode.\n"
	88	"@item\n"
	89	"read characters from the port's input buffers if available,\n"
	90	"instead from the underlying file descriptor.\n"
b0e5fd8c GH	91	"@item\n"
	92	"return @code{#f} if end-of-file is encountered before reading\n"
	93	"any characters, otherwise return the number of characters\n"
	94	"read.\n"
	95	"@item\n"
	96	"return 0 if the port is in non-blocking mode and no characters\n"
	97	"are immediately available.\n"
	98	"@item\n"
	99	"return 0 if the request is for 0 bytes, with no\n"
99004a28	100	"end-of-file check.\n"
b0e5fd8c GH	101	"@end itemize")
	102	#define FUNC_NAME s_scm_read_string_x_partial
	103	{
	104	char *dest;
a9d13d44	105	size_t offset;
c014a02e ML	106	long read_len;
c014a02e ML	107	long chars_read = 0;
b0e5fd8c GH	108	int fdes;
	109
	110	{
8824ac88	111	size_t last;
b0e5fd8c	112
8824ac88	113	SCM_VALIDATE_STRING (1, str);
cc95e00a	114	scm_i_get_substring_spec (scm_i_string_length (str),
8824ac88	115	start, &offset, end, &last);
b0e5fd8c GH	116	read_len = last - offset;
	117	}
	118
e11e83f3 MV	119	if (scm_is_integer (port_or_fdes))
e11e83f3 MV	120	fdes = scm_to_int (port_or_fdes);
b0e5fd8c GH	121	else
	122	{
	123	SCM port = SCM_UNBNDP (port_or_fdes) ? scm_cur_inp : port_or_fdes;
	124
	125	SCM_VALIDATE_OPFPORT (2, port);
	126	SCM_VALIDATE_INPUT_PORT (2, port);
	127
	128	/* if there's anything in the port buffers, use it, but then
	129	don't touch the file descriptor. otherwise the
	130	"return immediately if something is available" rule may
	131	be violated. */
a9d13d44	132	dest = scm_i_string_writable_chars (str) + offset;
b0e5fd8c	133	chars_read = scm_take_from_input_buffers (port, dest, read_len);
cc95e00a	134	scm_i_string_stop_writing ();
b0e5fd8c GH	135	fdes = SCM_FPORT_FDES (port);
	136	}
	137
	138	if (chars_read == 0 && read_len > 0) /* don't confuse read_len == 0 with
	139	EOF. */
	140	{
a9d13d44	141	dest = scm_i_string_writable_chars (str) + offset;
b0e5fd8c	142	SCM_SYSCALL (chars_read = read (fdes, dest, read_len));
cc95e00a	143	scm_i_string_stop_writing ();
b0e5fd8c GH	144	if (chars_read == -1)
	145	{
	146	if (SCM_EBLOCK (errno))
	147	chars_read = 0;
	148	else
	149	SCM_SYSERROR;
	150	}
	151	else if (chars_read == 0)
8824ac88 MV	152	{
	153	scm_remember_upto_here_1 (str);
	154	return SCM_BOOL_F;
	155	}
b0e5fd8c	156	}
8824ac88 MV	157
8824ac88 MV	158	scm_remember_upto_here_1 (str);
b9bd8526	159	return scm_from_long (chars_read);
b0e5fd8c GH	160	}
	161	#undef FUNC_NAME
	162
99004a28 GH	163	SCM_DEFINE (scm_write_string_partial, "write-string/partial", 1, 3, 0,
	164	(SCM str, SCM port_or_fdes, SCM start, SCM end),
	165	"Write characters from a string @var{str} to a port or file\n"
	166	"descriptor. A port must have an underlying file descriptor\n"
	167	"--- a so-called fport. This procedure is\n"
	168	"scsh-compatible and can efficiently write large strings.\n"
	169	"It will:\n\n"
	170	"@itemize\n"
	171	"@item\n"
	172	"attempt to write the entire string, unless the @var{start}\n"
	173	"and/or @var{end} arguments are supplied. i.e., @var{start}\n"
	174	"defaults to 0 and @var{end} defaults to\n"
	175	"@code{(string-length str)}\n"
	176	"@item\n"
	177	"use the current output port if @var{port_of_fdes} is not\n"
	178	"supplied.\n"
	179	"@item\n"
	180	"in the case of a buffered port, store the characters in the\n"
	181	"port's output buffer, if all will fit. If they will not fit\n"
	182	"then any existing buffered characters will be flushed\n"
	183	"before attempting\n"
	184	"to write the new characters directly to the underlying file\n"
	185	"descriptor. If the port is in non-blocking mode and\n"
	186	"buffered characters can not be flushed immediately, then an\n"
	187	"@code{EAGAIN} system-error exception will be raised (Note:\n"
	188	"scsh does not support the use of non-blocking buffered ports.)\n"
	189	"@item\n"
	190	"write fewer than the requested number of\n"
	191	"characters in some cases, e.g., if interrupted by a signal or\n"
	192	"if not all of the output can be accepted immediately.\n"
	193	"@item\n"
	194	"wait indefinitely for at least one character\n"
	195	"from @var{str} to be accepted by the port, unless the port is\n"
	196	"in non-blocking mode.\n"
	197	"@item\n"
	198	"return the number of characters accepted by the port.\n"
	199	"@item\n"
	200	"return 0 if the port is in non-blocking mode and can not accept\n"
	201	"at least one character from @var{str} immediately\n"
	202	"@item\n"
	203	"return 0 immediately if the request size is 0 bytes.\n"
	204	"@end itemize")
	205	#define FUNC_NAME s_scm_write_string_partial
	206	{
cc95e00a	207	const char *src;
99004a28 GH	208	long write_len;
	209	int fdes;
	210
	211	{
8824ac88 MV	212	size_t offset;
8824ac88 MV	213	size_t last;
99004a28	214
8824ac88	215	SCM_VALIDATE_STRING (1, str);
cc95e00a MV	216	src = scm_i_string_chars (str);
cc95e00a MV	217	scm_i_get_substring_spec (scm_i_string_length (str),
8824ac88	218	start, &offset, end, &last);
99004a28 GH	219	src += offset;
	220	write_len = last - offset;
	221	}
	222
	223	if (write_len == 0)
	224	return SCM_INUM0;
	225
e11e83f3 MV	226	if (scm_is_integer (port_or_fdes))
e11e83f3 MV	227	fdes = scm_to_int (port_or_fdes);
99004a28 GH	228	else
	229	{
	230	SCM port = SCM_UNBNDP (port_or_fdes) ? scm_cur_outp : port_or_fdes;
92c2555f	231	scm_t_port *pt;
99004a28 GH	232	off_t space;
	233
	234	SCM_VALIDATE_OPFPORT (2, port);
	235	SCM_VALIDATE_OUTPUT_PORT (2, port);
	236	pt = SCM_PTAB_ENTRY (port);
	237	/* filling the last character in the buffer would require a flush. */
	238	space = pt->write_end - pt->write_pos - 1;
	239	if (space >= write_len)
	240	{
	241	memcpy (pt->write_pos, src, write_len);
	242	pt->write_pos += write_len;
b9bd8526	243	return scm_from_long (write_len);
99004a28 GH	244	}
	245	if (pt->write_pos > pt->write_buf)
	246	scm_flush (port);
	247	fdes = SCM_FPORT_FDES (port);
	248	}
	249	{
	250	long rv;
	251
	252	SCM_SYSCALL (rv = write (fdes, src, write_len));
	253	if (rv == -1)
	254	{
	255	if (SCM_EBLOCK (errno))
	256	rv = 0;
	257	else
	258	SCM_SYSERROR;
	259	}
8824ac88 MV	260
8824ac88 MV	261	scm_remember_upto_here_1 (str);
b9bd8526	262	return scm_from_long (rv);
99004a28 GH	263	}
	264	}
	265	#undef FUNC_NAME
	266
e615ee8d MV	267	SCM
e615ee8d MV	268	scm_init_rw_builtins ()
b0e5fd8c	269	{
b0e5fd8c	270	#include "libguile/rw.x"
b0e5fd8c	271
e615ee8d MV	272	return SCM_UNSPECIFIED;
	273	}
	274
	275	void
	276	scm_init_rw ()
	277	{
9a441ddb	278	scm_c_define_gsubr ("%init-rw-builtins", 0, 0, 0, scm_init_rw_builtins);
b0e5fd8c GH	279	}
	280
	281	/*
	282	Local Variables:
	283	c-file-style: "gnu"
	284	End:
	285	*/