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cbe34bb5 | 1 | /* Copyright (C) 2008-2017 Free Software Foundation, Inc. |
7c1b4aba JB |
2 | Contributed by Janne Blomqvist |
3 | ||
4 | This file is part of the GNU Fortran runtime library (libgfortran). | |
5 | ||
6 | Libgfortran is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
748086b7 | 8 | the Free Software Foundation; either version 3, or (at your option) |
7c1b4aba JB |
9 | any later version. |
10 | ||
7c1b4aba JB |
11 | Libgfortran is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
748086b7 JJ |
16 | Under Section 7 of GPL version 3, you are granted additional |
17 | permissions described in the GCC Runtime Library Exception, version | |
18 | 3.1, as published by the Free Software Foundation. | |
19 | ||
20 | You should have received a copy of the GNU General Public License and | |
21 | a copy of the GCC Runtime Library Exception along with this program; | |
22 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
23 | <http://www.gnu.org/licenses/>. */ | |
7c1b4aba JB |
24 | |
25 | ||
26 | #include "io.h" | |
92cbdb68 JB |
27 | #include "fbuf.h" |
28 | #include "unix.h" | |
7c1b4aba | 29 | #include <string.h> |
7c1b4aba JB |
30 | |
31 | ||
7812c78c JD |
32 | //#define FBUF_DEBUG |
33 | ||
34 | ||
7c1b4aba | 35 | void |
f29876bb | 36 | fbuf_init (gfc_unit *u, int len) |
7c1b4aba JB |
37 | { |
38 | if (len == 0) | |
8947fd62 | 39 | len = 512; /* Default size. */ |
7c1b4aba | 40 | |
1a0fd3d3 JB |
41 | u->fbuf = xmalloc (sizeof (struct fbuf)); |
42 | u->fbuf->buf = xmalloc (len); | |
7c1b4aba | 43 | u->fbuf->len = len; |
7812c78c | 44 | u->fbuf->act = u->fbuf->pos = 0; |
7c1b4aba JB |
45 | } |
46 | ||
47 | ||
48 | void | |
f29876bb | 49 | fbuf_destroy (gfc_unit *u) |
7c1b4aba JB |
50 | { |
51 | if (u->fbuf == NULL) | |
52 | return; | |
04695783 | 53 | free (u->fbuf->buf); |
bb408e87 | 54 | free (u->fbuf); |
7812c78c JD |
55 | u->fbuf = NULL; |
56 | } | |
57 | ||
58 | ||
59 | static void | |
60 | #ifdef FBUF_DEBUG | |
f29876bb | 61 | fbuf_debug (gfc_unit *u, const char *format, ...) |
7812c78c JD |
62 | { |
63 | va_list args; | |
64 | va_start(args, format); | |
65 | vfprintf(stderr, format, args); | |
66 | va_end(args); | |
67 | fprintf (stderr, "fbuf_debug pos: %d, act: %d, buf: ''", | |
68 | u->fbuf->pos, u->fbuf->act); | |
69 | for (int ii = 0; ii < u->fbuf->act; ii++) | |
70 | { | |
71 | putc (u->fbuf->buf[ii], stderr); | |
72 | } | |
73 | fprintf (stderr, "''\n"); | |
74 | } | |
75 | #else | |
f29876bb JD |
76 | fbuf_debug (gfc_unit *u __attribute__ ((unused)), |
77 | const char *format __attribute__ ((unused)), | |
7812c78c JD |
78 | ...) {} |
79 | #endif | |
80 | ||
81 | ||
82 | ||
83 | /* You should probably call this before doing a physical seek on the | |
84 | underlying device. Returns how much the physical position was | |
85 | modified. */ | |
86 | ||
87 | int | |
f29876bb | 88 | fbuf_reset (gfc_unit *u) |
7812c78c JD |
89 | { |
90 | int seekval = 0; | |
91 | ||
92 | if (!u->fbuf) | |
93 | return 0; | |
94 | ||
95 | fbuf_debug (u, "fbuf_reset: "); | |
96 | fbuf_flush (u, u->mode); | |
97 | /* If we read past the current position, seek the underlying device | |
98 | back. */ | |
99 | if (u->mode == READING && u->fbuf->act > u->fbuf->pos) | |
100 | { | |
101 | seekval = - (u->fbuf->act - u->fbuf->pos); | |
102 | fbuf_debug (u, "fbuf_reset seekval %d, ", seekval); | |
103 | } | |
104 | u->fbuf->act = u->fbuf->pos = 0; | |
105 | return seekval; | |
7c1b4aba JB |
106 | } |
107 | ||
108 | ||
109 | /* Return a pointer to the current position in the buffer, and increase | |
110 | the pointer by len. Makes sure that the buffer is big enough, | |
7812c78c | 111 | reallocating if necessary. */ |
7c1b4aba JB |
112 | |
113 | char * | |
f29876bb | 114 | fbuf_alloc (gfc_unit *u, int len) |
7c1b4aba | 115 | { |
7812c78c | 116 | int newlen; |
7c1b4aba | 117 | char *dest; |
7812c78c | 118 | fbuf_debug (u, "fbuf_alloc len %d, ", len); |
8947fd62 | 119 | if (u->fbuf->pos + len > u->fbuf->len) |
7c1b4aba | 120 | { |
7812c78c | 121 | /* Round up to nearest multiple of the current buffer length. */ |
f29876bb | 122 | newlen = ((u->fbuf->pos + len) / u->fbuf->len + 1) *u->fbuf->len; |
d74fd3c7 | 123 | u->fbuf->buf = xrealloc (u->fbuf->buf, newlen); |
7812c78c | 124 | u->fbuf->len = newlen; |
7c1b4aba | 125 | } |
8947fd62 JB |
126 | |
127 | dest = u->fbuf->buf + u->fbuf->pos; | |
128 | u->fbuf->pos += len; | |
129 | if (u->fbuf->pos > u->fbuf->act) | |
130 | u->fbuf->act = u->fbuf->pos; | |
7c1b4aba JB |
131 | return dest; |
132 | } | |
133 | ||
134 | ||
7812c78c JD |
135 | /* mode argument is WRITING for write mode and READING for read |
136 | mode. Return value is 0 for success, -1 on failure. */ | |
8947fd62 | 137 | |
7c1b4aba | 138 | int |
f29876bb | 139 | fbuf_flush (gfc_unit *u, unit_mode mode) |
7c1b4aba | 140 | { |
7812c78c | 141 | int nwritten; |
7c1b4aba JB |
142 | |
143 | if (!u->fbuf) | |
144 | return 0; | |
7812c78c JD |
145 | |
146 | fbuf_debug (u, "fbuf_flush with mode %d: ", mode); | |
147 | ||
148 | if (mode == WRITING) | |
7c1b4aba | 149 | { |
7812c78c JD |
150 | if (u->fbuf->pos > 0) |
151 | { | |
152 | nwritten = swrite (u->s, u->fbuf->buf, u->fbuf->pos); | |
153 | if (nwritten < 0) | |
154 | return -1; | |
155 | } | |
7c1b4aba | 156 | } |
7812c78c JD |
157 | /* Salvage remaining bytes for both reading and writing. This |
158 | happens with the combination of advance='no' and T edit | |
159 | descriptors leaving the final position somewhere not at the end | |
160 | of the record. For reading, this also happens if we sread() past | |
161 | the record boundary. */ | |
162 | if (u->fbuf->act > u->fbuf->pos && u->fbuf->pos > 0) | |
163 | memmove (u->fbuf->buf, u->fbuf->buf + u->fbuf->pos, | |
164 | u->fbuf->act - u->fbuf->pos); | |
165 | ||
166 | u->fbuf->act -= u->fbuf->pos; | |
167 | u->fbuf->pos = 0; | |
168 | ||
169 | return 0; | |
7c1b4aba JB |
170 | } |
171 | ||
172 | ||
1060d940 JD |
173 | /* The mode argument is LIST_WRITING for write mode and LIST_READING for |
174 | read. This should only be used for list directed I/O. | |
175 | Return value is 0 for success, -1 on failure. */ | |
176 | ||
177 | int | |
f29876bb | 178 | fbuf_flush_list (gfc_unit *u, unit_mode mode) |
1060d940 JD |
179 | { |
180 | int nwritten; | |
181 | ||
182 | if (!u->fbuf) | |
183 | return 0; | |
184 | ||
185 | if (u->fbuf->pos < 524288) /* Upper limit for list writing. */ | |
186 | return 0; | |
187 | ||
188 | fbuf_debug (u, "fbuf_flush_list with mode %d: ", mode); | |
189 | ||
190 | if (mode == LIST_WRITING) | |
191 | { | |
192 | nwritten = swrite (u->s, u->fbuf->buf, u->fbuf->pos); | |
193 | if (nwritten < 0) | |
194 | return -1; | |
195 | } | |
196 | ||
197 | /* Salvage remaining bytes for both reading and writing. */ | |
198 | if (u->fbuf->act > u->fbuf->pos) | |
199 | memmove (u->fbuf->buf, u->fbuf->buf + u->fbuf->pos, | |
200 | u->fbuf->act - u->fbuf->pos); | |
201 | ||
202 | u->fbuf->act -= u->fbuf->pos; | |
203 | u->fbuf->pos = 0; | |
204 | ||
205 | return 0; | |
206 | } | |
207 | ||
208 | ||
7c1b4aba | 209 | int |
f29876bb | 210 | fbuf_seek (gfc_unit *u, int off, int whence) |
7c1b4aba | 211 | { |
7812c78c | 212 | if (!u->fbuf) |
7c1b4aba | 213 | return -1; |
7812c78c JD |
214 | |
215 | switch (whence) | |
216 | { | |
217 | case SEEK_SET: | |
218 | break; | |
219 | case SEEK_CUR: | |
220 | off += u->fbuf->pos; | |
221 | break; | |
222 | case SEEK_END: | |
223 | off += u->fbuf->act; | |
224 | break; | |
225 | default: | |
226 | return -1; | |
227 | } | |
228 | ||
229 | fbuf_debug (u, "fbuf_seek, off %d ", off); | |
230 | /* The start of the buffer is always equal to the left tab | |
231 | limit. Moving to the left past the buffer is illegal in C and | |
232 | would also imply moving past the left tab limit, which is never | |
233 | allowed in Fortran. Similarly, seeking past the end of the buffer | |
234 | is not possible, in that case the user must make sure to allocate | |
235 | space with fbuf_alloc(). So return error if that is | |
236 | attempted. */ | |
237 | if (off < 0 || off > u->fbuf->act) | |
238 | return -1; | |
239 | u->fbuf->pos = off; | |
240 | return off; | |
241 | } | |
242 | ||
243 | ||
244 | /* Fill the buffer with bytes for reading. Returns a pointer to start | |
245 | reading from. If we hit EOF, returns a short read count. If any | |
246 | other error occurs, return NULL. After reading, the caller is | |
247 | expected to call fbuf_seek to update the position with the number | |
248 | of bytes actually processed. */ | |
249 | ||
250 | char * | |
f29876bb | 251 | fbuf_read (gfc_unit *u, int *len) |
7812c78c JD |
252 | { |
253 | char *ptr; | |
254 | int oldact, oldpos; | |
255 | int readlen = 0; | |
256 | ||
257 | fbuf_debug (u, "fbuf_read, len %d: ", *len); | |
258 | oldact = u->fbuf->act; | |
259 | oldpos = u->fbuf->pos; | |
260 | ptr = fbuf_alloc (u, *len); | |
261 | u->fbuf->pos = oldpos; | |
262 | if (oldpos + *len > oldact) | |
263 | { | |
264 | fbuf_debug (u, "reading %d bytes starting at %d ", | |
265 | oldpos + *len - oldact, oldact); | |
266 | readlen = sread (u->s, u->fbuf->buf + oldact, oldpos + *len - oldact); | |
267 | if (readlen < 0) | |
268 | return NULL; | |
269 | *len = oldact - oldpos + readlen; | |
270 | } | |
271 | u->fbuf->act = oldact + readlen; | |
272 | fbuf_debug (u, "fbuf_read done: "); | |
273 | return ptr; | |
274 | } | |
275 | ||
276 | ||
277 | /* When the fbuf_getc() inline function runs out of buffer space, it | |
278 | calls this function to fill the buffer with bytes for | |
279 | reading. Never call this function directly. */ | |
280 | ||
281 | int | |
f29876bb | 282 | fbuf_getc_refill (gfc_unit *u) |
7812c78c JD |
283 | { |
284 | int nread; | |
285 | char *p; | |
286 | ||
287 | fbuf_debug (u, "fbuf_getc_refill "); | |
288 | ||
289 | /* Read 80 bytes (average line length?). This is a compromise | |
290 | between not needing to call the read() syscall all the time and | |
291 | not having to memmove unnecessary stuff when switching to the | |
292 | next record. */ | |
293 | nread = 80; | |
294 | ||
295 | p = fbuf_read (u, &nread); | |
296 | ||
297 | if (p && nread > 0) | |
298 | return (unsigned char) u->fbuf->buf[u->fbuf->pos++]; | |
299 | else | |
300 | return EOF; | |
7c1b4aba | 301 | } |