[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;
  long read_len;
  long chars_read = 0;
  int fdes;

  {
    long offset;
    long last;

    SCM_VALIDATE_SUBSTRING_SPEC_COPY (1, str, dest, 3, start, offset,
				      4, end, last);
    dest += offset;
    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.  */
      chars_read = scm_take_from_input_buffers (port, dest, read_len);
      fdes = SCM_FPORT_FDES (port);
    }

  if (chars_read == 0 && read_len > 0) /* don't confuse read_len == 0 with
					  EOF.  */
    {
      SCM_SYSCALL (chars_read = read (fdes, dest, read_len));
      if (chars_read == -1)
	{
	  if (SCM_EBLOCK (errno))
	    chars_read = 0;
	  else
	    SCM_SYSERROR;
        }
      else if (chars_read == 0)
	return SCM_BOOL_F;
    }
  return scm_long2num (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
{
  char *src;
  long write_len;
  int fdes;

  {
    long offset;
    long last;

    SCM_VALIDATE_SUBSTRING_SPEC_COPY (1, str, src, 3, start, offset,
				      4, 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_long2num (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;
      }
    
    return scm_long2num (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;
c014a02e ML	105	long read_len;
c014a02e ML	106	long chars_read = 0;
b0e5fd8c GH	107	int fdes;
	108
	109	{
c014a02e ML	110	long offset;
c014a02e ML	111	long last;
b0e5fd8c GH	112
	113	SCM_VALIDATE_SUBSTRING_SPEC_COPY (1, str, dest, 3, start, offset,
	114	4, end, last);
	115	dest += offset;
	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. */
	132	chars_read = scm_take_from_input_buffers (port, dest, read_len);
	133	fdes = SCM_FPORT_FDES (port);
	134	}
	135
	136	if (chars_read == 0 && read_len > 0) /* don't confuse read_len == 0 with
	137	EOF. */
	138	{
	139	SCM_SYSCALL (chars_read = read (fdes, dest, read_len));
	140	if (chars_read == -1)
	141	{
	142	if (SCM_EBLOCK (errno))
	143	chars_read = 0;
	144	else
	145	SCM_SYSERROR;
	146	}
	147	else if (chars_read == 0)
	148	return SCM_BOOL_F;
	149	}
	150	return scm_long2num (chars_read);
	151	}
	152	#undef FUNC_NAME
	153
99004a28 GH	154	SCM_DEFINE (scm_write_string_partial, "write-string/partial", 1, 3, 0,
	155	(SCM str, SCM port_or_fdes, SCM start, SCM end),
	156	"Write characters from a string @var{str} to a port or file\n"
	157	"descriptor. A port must have an underlying file descriptor\n"
	158	"--- a so-called fport. This procedure is\n"
	159	"scsh-compatible and can efficiently write large strings.\n"
	160	"It will:\n\n"
	161	"@itemize\n"
	162	"@item\n"
	163	"attempt to write the entire string, unless the @var{start}\n"
	164	"and/or @var{end} arguments are supplied. i.e., @var{start}\n"
	165	"defaults to 0 and @var{end} defaults to\n"
	166	"@code{(string-length str)}\n"
	167	"@item\n"
	168	"use the current output port if @var{port_of_fdes} is not\n"
	169	"supplied.\n"
	170	"@item\n"
	171	"in the case of a buffered port, store the characters in the\n"
	172	"port's output buffer, if all will fit. If they will not fit\n"
	173	"then any existing buffered characters will be flushed\n"
	174	"before attempting\n"
	175	"to write the new characters directly to the underlying file\n"
	176	"descriptor. If the port is in non-blocking mode and\n"
	177	"buffered characters can not be flushed immediately, then an\n"
	178	"@code{EAGAIN} system-error exception will be raised (Note:\n"
	179	"scsh does not support the use of non-blocking buffered ports.)\n"
	180	"@item\n"
	181	"write fewer than the requested number of\n"
	182	"characters in some cases, e.g., if interrupted by a signal or\n"
	183	"if not all of the output can be accepted immediately.\n"
	184	"@item\n"
	185	"wait indefinitely for at least one character\n"
	186	"from @var{str} to be accepted by the port, unless the port is\n"
	187	"in non-blocking mode.\n"
	188	"@item\n"
	189	"return the number of characters accepted by the port.\n"
	190	"@item\n"
	191	"return 0 if the port is in non-blocking mode and can not accept\n"
	192	"at least one character from @var{str} immediately\n"
	193	"@item\n"
	194	"return 0 immediately if the request size is 0 bytes.\n"
	195	"@end itemize")
	196	#define FUNC_NAME s_scm_write_string_partial
	197	{
	198	char *src;
	199	long write_len;
	200	int fdes;
	201
	202	{
	203	long offset;
	204	long last;
	205
	206	SCM_VALIDATE_SUBSTRING_SPEC_COPY (1, str, src, 3, start, offset,
	207	4, end, last);
	208	src += offset;
	209	write_len = last - offset;
	210	}
	211
	212	if (write_len == 0)
	213	return SCM_INUM0;
	214
e11e83f3 MV	215	if (scm_is_integer (port_or_fdes))
e11e83f3 MV	216	fdes = scm_to_int (port_or_fdes);
99004a28 GH	217	else
	218	{
	219	SCM port = SCM_UNBNDP (port_or_fdes) ? scm_cur_outp : port_or_fdes;
92c2555f	220	scm_t_port *pt;
99004a28 GH	221	off_t space;
	222
	223	SCM_VALIDATE_OPFPORT (2, port);
	224	SCM_VALIDATE_OUTPUT_PORT (2, port);
	225	pt = SCM_PTAB_ENTRY (port);
	226	/* filling the last character in the buffer would require a flush. */
	227	space = pt->write_end - pt->write_pos - 1;
	228	if (space >= write_len)
	229	{
	230	memcpy (pt->write_pos, src, write_len);
	231	pt->write_pos += write_len;
	232	return scm_long2num (write_len);
	233	}
	234	if (pt->write_pos > pt->write_buf)
	235	scm_flush (port);
	236	fdes = SCM_FPORT_FDES (port);
	237	}
	238	{
	239	long rv;
	240
	241	SCM_SYSCALL (rv = write (fdes, src, write_len));
	242	if (rv == -1)
	243	{
	244	if (SCM_EBLOCK (errno))
	245	rv = 0;
	246	else
	247	SCM_SYSERROR;
	248	}
	249
	250	return scm_long2num (rv);
	251	}
	252	}
	253	#undef FUNC_NAME
	254
e615ee8d MV	255	SCM
e615ee8d MV	256	scm_init_rw_builtins ()
b0e5fd8c	257	{
b0e5fd8c	258	#include "libguile/rw.x"
b0e5fd8c	259
e615ee8d MV	260	return SCM_UNSPECIFIED;
	261	}
	262
	263	void
	264	scm_init_rw ()
	265	{
9a441ddb	266	scm_c_define_gsubr ("%init-rw-builtins", 0, 0, 0, scm_init_rw_builtins);
b0e5fd8c GH	267	}
	268
	269	/*
	270	Local Variables:
	271	c-file-style: "gnu"
	272	End:
	273	*/