1 /* Copyright (C) 1995,1996,1998,1999,2000,2001, 2002, 2003, 2006 Free Software Foundation, Inc.
2 *
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.
7 *
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.
12 *
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16 */
17
18
19
20 #ifdef HAVE_CONFIG_H
21 # include <config.h>
22 #endif
23
24 #include <stdio.h>
25 #include <errno.h>
26
27 #include "libguile/_scm.h"
28 #include "libguile/eval.h"
29 #include "libguile/chars.h"
30 #include "libguile/fports.h"
31 #include "libguile/root.h"
32 #include "libguile/strings.h"
33 #include "libguile/vectors.h"
34
35 #include "libguile/validate.h"
36 #include "libguile/vports.h"
37
38 #ifdef HAVE_STRING_H
39 #include <string.h>
40 #endif
41
42
43
44 /* {Ports - soft ports}
45 *
46 */
47
48
49 static scm_t_bits scm_tc16_sfport;
50
51
52 static void
sf_flush(SCM port)53 sf_flush (SCM port)
54 {
55 scm_t_port *pt = SCM_PTAB_ENTRY (port);
56 SCM stream = SCM_PACK (pt->stream);
57
58 if (pt->write_pos > pt->write_buf)
59 {
60 /* write the byte. */
61 scm_call_1 (SCM_SIMPLE_VECTOR_REF (stream, 0),
62 SCM_MAKE_CHAR (*pt->write_buf));
63 pt->write_pos = pt->write_buf;
64
65 /* flush the output. */
66 {
67 SCM f = SCM_SIMPLE_VECTOR_REF (stream, 2);
68
69 if (scm_is_true (f))
70 scm_call_0 (f);
71 }
72 }
73 }
74
75 static void
sf_write(SCM port,const void * data,size_t size)76 sf_write (SCM port, const void *data, size_t size)
77 {
78 SCM p = SCM_PACK (SCM_STREAM (port));
79
80 scm_call_1 (SCM_SIMPLE_VECTOR_REF (p, 1),
81 scm_from_locale_stringn ((char *) data, size));
82 }
83
84 /* calling the flush proc (element 2) is in case old code needs it,
85 but perhaps softports could the use port buffer in the same way as
86 fports. */
87
88 /* places a single char in the input buffer. */
89 static int
sf_fill_input(SCM port)90 sf_fill_input (SCM port)
91 {
92 SCM p = SCM_PACK (SCM_STREAM (port));
93 SCM ans;
94
95 ans = scm_call_0 (SCM_SIMPLE_VECTOR_REF (p, 3)); /* get char. */
96 if (scm_is_false (ans) || SCM_EOF_OBJECT_P (ans))
97 return EOF;
98 SCM_ASSERT (SCM_CHARP (ans), ans, SCM_ARG1, "sf_fill_input");
99 {
100 scm_t_port *pt = SCM_PTAB_ENTRY (port);
101
102 *pt->read_buf = SCM_CHAR (ans);
103 pt->read_pos = pt->read_buf;
104 pt->read_end = pt->read_buf + 1;
105 return *pt->read_buf;
106 }
107 }
108
109
110 static int
sf_close(SCM port)111 sf_close (SCM port)
112 {
113 SCM p = SCM_PACK (SCM_STREAM (port));
114 SCM f = SCM_SIMPLE_VECTOR_REF (p, 4);
115 if (scm_is_false (f))
116 return 0;
117 f = scm_call_0 (f);
118 errno = 0;
119 return scm_is_false (f) ? EOF : 0;
120 }
121
122
123 static int
sf_input_waiting(SCM port)124 sf_input_waiting (SCM port)
125 {
126 SCM p = SCM_PACK (SCM_STREAM (port));
127 if (SCM_SIMPLE_VECTOR_LENGTH (p) >= 6)
128 {
129 SCM f = SCM_SIMPLE_VECTOR_REF (p, 5);
130 if (scm_is_true (f))
131 return scm_to_int (scm_call_0 (f));
132 }
133 /* Default is such that char-ready? for soft ports returns #t, as it
134 did before this extension was implemented. */
135 return 1;
136 }
137
138
139
140 SCM_DEFINE (scm_make_soft_port, "make-soft-port", 2, 0, 0,
141 (SCM pv, SCM modes),
142 "Return a port capable of receiving or delivering characters as\n"
143 "specified by the @var{modes} string (@pxref{File Ports,\n"
144 "open-file}). @var{pv} must be a vector of length 5 or 6. Its\n"
145 "components are as follows:\n"
146 "\n"
147 "@enumerate 0\n"
148 "@item\n"
149 "procedure accepting one character for output\n"
150 "@item\n"
151 "procedure accepting a string for output\n"
152 "@item\n"
153 "thunk for flushing output\n"
154 "@item\n"
155 "thunk for getting one character\n"
156 "@item\n"
157 "thunk for closing port (not by garbage collection)\n"
158 "@item\n"
159 "(if present and not @code{#f}) thunk for computing the number of\n"
160 "characters that can be read from the port without blocking.\n"
161 "@end enumerate\n"
162 "\n"
163 "For an output-only port only elements 0, 1, 2, and 4 need be\n"
164 "procedures. For an input-only port only elements 3 and 4 need\n"
165 "be procedures. Thunks 2 and 4 can instead be @code{#f} if\n"
166 "there is no useful operation for them to perform.\n"
167 "\n"
168 "If thunk 3 returns @code{#f} or an @code{eof-object}\n"
169 "(@pxref{Input, eof-object?, ,r5rs, The Revised^5 Report on\n"
170 "Scheme}) it indicates that the port has reached end-of-file.\n"
171 "For example:\n"
172 "\n"
173 "@lisp\n"
174 "(define stdout (current-output-port))\n"
175 "(define p (make-soft-port\n"
176 " (vector\n"
177 " (lambda (c) (write c stdout))\n"
178 " (lambda (s) (display s stdout))\n"
179 " (lambda () (display \".\" stdout))\n"
180 " (lambda () (char-upcase (read-char)))\n"
181 " (lambda () (display \"@@\" stdout)))\n"
182 " \"rw\"))\n"
183 "\n"
184 "(write p p) @result{} #<input-output: soft 8081e20>\n"
185 "@end lisp")
186 #define FUNC_NAME s_scm_make_soft_port
187 {
188 int vlen;
189 scm_t_port *pt;
190 SCM z;
191
192 SCM_VALIDATE_VECTOR (1, pv);
193 vlen = SCM_SIMPLE_VECTOR_LENGTH (pv);
194 SCM_ASSERT ((vlen == 5) || (vlen == 6), pv, 1, FUNC_NAME);
195 SCM_VALIDATE_STRING (2, modes);
196
197 scm_i_scm_pthread_mutex_lock (&scm_i_port_table_mutex);
198 z = scm_new_port_table_entry (scm_tc16_sfport);
199 pt = SCM_PTAB_ENTRY (z);
200 scm_port_non_buffer (pt);
201 SCM_SET_CELL_TYPE (z, scm_tc16_sfport | scm_i_mode_bits (modes));
202
203 SCM_SETSTREAM (z, SCM_UNPACK (pv));
204 scm_i_pthread_mutex_unlock (&scm_i_port_table_mutex);
205 return z;
206 }
207 #undef FUNC_NAME
208
209
210 static scm_t_bits
scm_make_sfptob()211 scm_make_sfptob ()
212 {
213 scm_t_bits tc = scm_make_port_type ("soft", sf_fill_input, sf_write);
214
215 scm_set_port_mark (tc, scm_markstream);
216 scm_set_port_flush (tc, sf_flush);
217 scm_set_port_close (tc, sf_close);
218 scm_set_port_input_waiting (tc, sf_input_waiting);
219
220 return tc;
221 }
222
223 void
scm_init_vports()224 scm_init_vports ()
225 {
226 scm_tc16_sfport = scm_make_sfptob ();
227
228 #include "libguile/vports.x"
229 }
230
231 /*
232 Local Variables:
233 c-file-style: "gnu"
234 End:
235 */
236