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

/* 	Copyright (C) 2001, 2006 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 3 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., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

\f

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

#ifdef 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_current_input_port () : 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_current_output_port () : 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
2b829bbb	1	/* Copyright (C) 2001, 2006 Free Software Foundation, Inc.
b0e5fd8c	2	*
73be1d9e	3	* This library is free software; you can redistribute it and/or
53befeb7 NJ	4	* modify it under the terms of the GNU Lesser General Public License
	5	* as published by the Free Software Foundation; either version 3 of
	6	* the License, or (at your option) any later version.
b0e5fd8c	7	*
53befeb7 NJ	8	* This library is distributed in the hope that it will be useful, but
53befeb7 NJ	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
73be1d9e MV	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
73be1d9e MV	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
73be1d9e MV	14	* License along with this library; if not, write to the Free Software
53befeb7 NJ	15	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
53befeb7 NJ	16	* 02110-1301 USA
73be1d9e	17	*/
b0e5fd8c GH	18
	19	\f
	20
	21	/* This is the C part of the (ice-9 rw) module. */
	22
dbb605f5	23	#ifdef HAVE_CONFIG_H
7b5a83d3 RB	24	# include <config.h>
	25	#endif
	26
b0e5fd8c	27	#include <errno.h>
fbbdb121	28	#include <string.h>
b0e5fd8c GH	29
	30	#include "libguile/_scm.h"
	31	#include "libguile/fports.h"
	32	#include "libguile/ports.h"
	33	#include "libguile/root.h"
	34	#include "libguile/rw.h"
	35	#include "libguile/strings.h"
	36	#include "libguile/validate.h"
fee12d18 MV	37	#include "libguile/modules.h"
fee12d18 MV	38	#include "libguile/strports.h"
b0e5fd8c GH	39
	40	#ifdef HAVE_UNISTD_H
	41	#include <unistd.h>
	42	#endif
7beabedb MG	43	#ifdef HAVE_IO_H
	44	#include <io.h>
	45	#endif
b0e5fd8c GH	46
	47	\f
	48
	49	#if defined (EAGAIN)
	50	#define SCM_MAYBE_EAGAIN \|\| errno == EAGAIN
	51	#else
	52	#define SCM_MAYBE_EAGAIN
	53	#endif
	54
	55	#if defined (EWOULDBLOCK)
	56	#define SCM_MAYBE_EWOULDBLOCK \|\| errno == EWOULDBLOCK
	57	#else
	58	#define SCM_MAYBE_EWOULDBLOCK
	59	#endif
	60
	61	/* MAYBE there is EAGAIN way of defining this macro but now I EWOULDBLOCK. */
	62	#define SCM_EBLOCK(errno) \
	63	(0 SCM_MAYBE_EAGAIN SCM_MAYBE_EWOULDBLOCK)
	64
	65	SCM_DEFINE (scm_read_string_x_partial, "read-string!/partial", 1, 3, 0,
	66	(SCM str, SCM port_or_fdes, SCM start, SCM end),
99004a28 GH	67	"Read characters from a port or file descriptor into a\n"
	68	"string @var{str}. A port must have an underlying file\n"
	69	"descriptor --- a so-called fport. This procedure is\n"
	70	"scsh-compatible and can efficiently read large strings.\n"
	71	"It will:\n\n"
b0e5fd8c GH	72	"@itemize\n"
	73	"@item\n"
	74	"attempt to fill the entire string, unless the @var{start}\n"
	75	"and/or @var{end} arguments are supplied. i.e., @var{start}\n"
	76	"defaults to 0 and @var{end} defaults to\n"
	77	"@code{(string-length str)}\n"
	78	"@item\n"
	79	"use the current input port if @var{port_or_fdes} is not\n"
	80	"supplied.\n"
	81	"@item\n"
99004a28 GH	82	"return fewer than the requested number of characters in some\n"
	83	"cases, e.g., on end of file, if interrupted by a signal, or if\n"
	84	"not all the characters are immediately available.\n"
b0e5fd8c	85	"@item\n"
99004a28 GH	86	"wait indefinitely for some input if no characters are\n"
	87	"currently available,\n"
	88	"unless the port is in non-blocking mode.\n"
	89	"@item\n"
	90	"read characters from the port's input buffers if available,\n"
	91	"instead from the underlying file descriptor.\n"
b0e5fd8c GH	92	"@item\n"
	93	"return @code{#f} if end-of-file is encountered before reading\n"
	94	"any characters, otherwise return the number of characters\n"
	95	"read.\n"
	96	"@item\n"
	97	"return 0 if the port is in non-blocking mode and no characters\n"
	98	"are immediately available.\n"
	99	"@item\n"
	100	"return 0 if the request is for 0 bytes, with no\n"
99004a28	101	"end-of-file check.\n"
b0e5fd8c GH	102	"@end itemize")
	103	#define FUNC_NAME s_scm_read_string_x_partial
	104	{
	105	char *dest;
a9d13d44	106	size_t offset;
c014a02e ML	107	long read_len;
c014a02e ML	108	long chars_read = 0;
b0e5fd8c GH	109	int fdes;
	110
	111	{
8824ac88	112	size_t last;
b0e5fd8c	113
8824ac88	114	SCM_VALIDATE_STRING (1, str);
cc95e00a	115	scm_i_get_substring_spec (scm_i_string_length (str),
8824ac88	116	start, &offset, end, &last);
b0e5fd8c GH	117	read_len = last - offset;
	118	}
	119
e11e83f3 MV	120	if (scm_is_integer (port_or_fdes))
e11e83f3 MV	121	fdes = scm_to_int (port_or_fdes);
b0e5fd8c GH	122	else
b0e5fd8c GH	123	{
9de87eea MV	124	SCM port = (SCM_UNBNDP (port_or_fdes)?
9de87eea MV	125	scm_current_input_port () : port_or_fdes);
b0e5fd8c GH	126
	127	SCM_VALIDATE_OPFPORT (2, port);
	128	SCM_VALIDATE_INPUT_PORT (2, port);
	129
	130	/* if there's anything in the port buffers, use it, but then
	131	don't touch the file descriptor. otherwise the
	132	"return immediately if something is available" rule may
	133	be violated. */
a9d13d44	134	dest = scm_i_string_writable_chars (str) + offset;
b0e5fd8c	135	chars_read = scm_take_from_input_buffers (port, dest, read_len);
cc95e00a	136	scm_i_string_stop_writing ();
b0e5fd8c GH	137	fdes = SCM_FPORT_FDES (port);
	138	}
	139
	140	if (chars_read == 0 && read_len > 0) /* don't confuse read_len == 0 with
	141	EOF. */
	142	{
a9d13d44	143	dest = scm_i_string_writable_chars (str) + offset;
b0e5fd8c	144	SCM_SYSCALL (chars_read = read (fdes, dest, read_len));
cc95e00a	145	scm_i_string_stop_writing ();
b0e5fd8c GH	146	if (chars_read == -1)
	147	{
	148	if (SCM_EBLOCK (errno))
	149	chars_read = 0;
	150	else
	151	SCM_SYSERROR;
	152	}
	153	else if (chars_read == 0)
8824ac88 MV	154	{
	155	scm_remember_upto_here_1 (str);
	156	return SCM_BOOL_F;
	157	}
b0e5fd8c	158	}
8824ac88 MV	159
8824ac88 MV	160	scm_remember_upto_here_1 (str);
b9bd8526	161	return scm_from_long (chars_read);
b0e5fd8c GH	162	}
	163	#undef FUNC_NAME
	164
99004a28 GH	165	SCM_DEFINE (scm_write_string_partial, "write-string/partial", 1, 3, 0,
	166	(SCM str, SCM port_or_fdes, SCM start, SCM end),
	167	"Write characters from a string @var{str} to a port or file\n"
	168	"descriptor. A port must have an underlying file descriptor\n"
	169	"--- a so-called fport. This procedure is\n"
	170	"scsh-compatible and can efficiently write large strings.\n"
	171	"It will:\n\n"
	172	"@itemize\n"
	173	"@item\n"
	174	"attempt to write the entire string, unless the @var{start}\n"
	175	"and/or @var{end} arguments are supplied. i.e., @var{start}\n"
	176	"defaults to 0 and @var{end} defaults to\n"
	177	"@code{(string-length str)}\n"
	178	"@item\n"
	179	"use the current output port if @var{port_of_fdes} is not\n"
	180	"supplied.\n"
	181	"@item\n"
	182	"in the case of a buffered port, store the characters in the\n"
	183	"port's output buffer, if all will fit. If they will not fit\n"
	184	"then any existing buffered characters will be flushed\n"
	185	"before attempting\n"
	186	"to write the new characters directly to the underlying file\n"
	187	"descriptor. If the port is in non-blocking mode and\n"
	188	"buffered characters can not be flushed immediately, then an\n"
	189	"@code{EAGAIN} system-error exception will be raised (Note:\n"
	190	"scsh does not support the use of non-blocking buffered ports.)\n"
	191	"@item\n"
	192	"write fewer than the requested number of\n"
	193	"characters in some cases, e.g., if interrupted by a signal or\n"
	194	"if not all of the output can be accepted immediately.\n"
	195	"@item\n"
	196	"wait indefinitely for at least one character\n"
	197	"from @var{str} to be accepted by the port, unless the port is\n"
	198	"in non-blocking mode.\n"
	199	"@item\n"
	200	"return the number of characters accepted by the port.\n"
	201	"@item\n"
	202	"return 0 if the port is in non-blocking mode and can not accept\n"
	203	"at least one character from @var{str} immediately\n"
	204	"@item\n"
	205	"return 0 immediately if the request size is 0 bytes.\n"
	206	"@end itemize")
	207	#define FUNC_NAME s_scm_write_string_partial
	208	{
cc95e00a	209	const char *src;
99004a28 GH	210	long write_len;
	211	int fdes;
	212
	213	{
8824ac88 MV	214	size_t offset;
8824ac88 MV	215	size_t last;
99004a28	216
8824ac88	217	SCM_VALIDATE_STRING (1, str);
cc95e00a MV	218	src = scm_i_string_chars (str);
cc95e00a MV	219	scm_i_get_substring_spec (scm_i_string_length (str),
8824ac88	220	start, &offset, end, &last);
99004a28 GH	221	src += offset;
	222	write_len = last - offset;
	223	}
	224
	225	if (write_len == 0)
	226	return SCM_INUM0;
	227
e11e83f3 MV	228	if (scm_is_integer (port_or_fdes))
e11e83f3 MV	229	fdes = scm_to_int (port_or_fdes);
99004a28 GH	230	else
99004a28 GH	231	{
9de87eea MV	232	SCM port = (SCM_UNBNDP (port_or_fdes)?
9de87eea MV	233	scm_current_output_port () : port_or_fdes);
92c2555f	234	scm_t_port *pt;
99004a28 GH	235	off_t space;
	236
	237	SCM_VALIDATE_OPFPORT (2, port);
	238	SCM_VALIDATE_OUTPUT_PORT (2, port);
	239	pt = SCM_PTAB_ENTRY (port);
	240	/* filling the last character in the buffer would require a flush. */
	241	space = pt->write_end - pt->write_pos - 1;
	242	if (space >= write_len)
	243	{
	244	memcpy (pt->write_pos, src, write_len);
	245	pt->write_pos += write_len;
b9bd8526	246	return scm_from_long (write_len);
99004a28 GH	247	}
	248	if (pt->write_pos > pt->write_buf)
	249	scm_flush (port);
	250	fdes = SCM_FPORT_FDES (port);
	251	}
	252	{
	253	long rv;
	254
	255	SCM_SYSCALL (rv = write (fdes, src, write_len));
	256	if (rv == -1)
	257	{
	258	if (SCM_EBLOCK (errno))
	259	rv = 0;
	260	else
	261	SCM_SYSERROR;
	262	}
8824ac88 MV	263
8824ac88 MV	264	scm_remember_upto_here_1 (str);
b9bd8526	265	return scm_from_long (rv);
99004a28 GH	266	}
	267	}
	268	#undef FUNC_NAME
	269
e615ee8d MV	270	SCM
e615ee8d MV	271	scm_init_rw_builtins ()
b0e5fd8c	272	{
b0e5fd8c	273	#include "libguile/rw.x"
b0e5fd8c	274
e615ee8d MV	275	return SCM_UNSPECIFIED;
	276	}
	277
	278	void
	279	scm_init_rw ()
	280	{
9a441ddb	281	scm_c_define_gsubr ("%init-rw-builtins", 0, 0, 0, scm_init_rw_builtins);
b0e5fd8c GH	282	}
	283
	284	/*
	285	Local Variables:
	286	c-file-style: "gnu"
	287	End:
	288	*/