xref: /freebsd/sys/dev/syscons/schistory.c (revision f35e5d0ef0a10ebda81a076bbd838d12b916dab5)
1 /*-
2  * Copyright (c) 1999 Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>
3  * Copyright (c) 1992-1998 S�ren Schmidt
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer,
11  *    without modification, immediately at the beginning of the file.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #include "sc.h"
33 #include "opt_syscons.h"
34 
35 #if NSC > 0
36 
37 #ifndef SC_NO_HISTORY
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/tty.h>
42 #include <sys/kernel.h>
43 #include <sys/malloc.h>
44 
45 #include <machine/console.h>
46 
47 #include <dev/syscons/syscons.h>
48 
49 #if !defined(SC_MAX_HISTORY_SIZE)
50 #define SC_MAX_HISTORY_SIZE	(1000 * MAXCONS * NSC)
51 #endif
52 
53 #if !defined(SC_HISTORY_SIZE)
54 #define SC_HISTORY_SIZE		(ROW * 4)
55 #endif
56 
57 #if (SC_HISTORY_SIZE * MAXCONS * NSC) > SC_MAX_HISTORY_SIZE
58 #undef SC_MAX_HISTORY_SIZE
59 #define SC_MAX_HISTORY_SIZE	(SC_HISTORY_SIZE * MAXCONS * NSC)
60 #endif
61 
62 /* local variables */
63 static int		extra_history_size
64 				= SC_MAX_HISTORY_SIZE - SC_HISTORY_SIZE*MAXCONS;
65 
66 /* local functions */
67 static void history_to_screen(scr_stat *scp);
68 
69 /* allocate a history buffer */
70 int
71 sc_alloc_history_buffer(scr_stat *scp, int lines, int prev_ysize, int wait)
72 {
73 	/*
74 	 * syscons unconditionally allocates buffers upto
75 	 * SC_HISTORY_SIZE lines or scp->ysize lines, whichever
76 	 * is larger. A value greater than that is allowed,
77 	 * subject to extra_history_size.
78 	 */
79 	sc_vtb_t *history;
80 	sc_vtb_t *prev_history;
81 	int cur_lines;				/* current buffer size */
82 	int min_lines;				/* guaranteed buffer size */
83 	int delta;				/* lines to put back */
84 
85 	if (lines <= 0)
86 		lines = SC_HISTORY_SIZE;	/* use the default value */
87 
88 	/* make it at least as large as the screen size */
89 	lines = imax(lines, scp->ysize);
90 
91 	/* remove the history buffer while we update it */
92 	history = prev_history = scp->history;
93 	scp->history = NULL;
94 
95 	/* calculate the amount of lines to put back to extra_history_size */
96 	delta = 0;
97 	if (prev_history) {
98 		cur_lines = sc_vtb_rows(history);
99 		min_lines = imax(SC_HISTORY_SIZE, prev_ysize);
100 		if (cur_lines > min_lines)
101 			delta = cur_lines - min_lines;
102 	}
103 
104 	/* lines upto min_lines are always allowed. */
105 	min_lines = imax(SC_HISTORY_SIZE, scp->ysize);
106 	if (lines > min_lines) {
107 		if (lines - min_lines > extra_history_size + delta) {
108 			/* too many lines are requested */
109 			scp->history = prev_history;
110 			return EINVAL;
111 		}
112 	}
113 
114 	/* destroy the previous buffer and allocate a new one */
115 	if (prev_history == NULL) {
116 		history = (sc_vtb_t *)malloc(sizeof(*history),
117 					     M_DEVBUF,
118 					     (wait) ? M_WAITOK : M_NOWAIT);
119 	} else {
120 		extra_history_size += delta;
121 		sc_vtb_destroy(prev_history);
122 	}
123 	if (history != NULL) {
124 		if (lines > min_lines)
125 			extra_history_size -= lines - min_lines;
126 		sc_vtb_init(history, VTB_RINGBUFFER, scp->xsize, lines,
127 			    NULL, wait);
128 	}
129 
130 	scp->history_pos = 0;
131 	scp->history = history;
132 
133 	return 0;
134 }
135 
136 void
137 sc_free_history_buffer(scr_stat *scp, int prev_ysize)
138 {
139 	sc_vtb_t *history;
140 	int cur_lines;				/* current buffer size */
141 	int min_lines;				/* guaranteed buffer size */
142 
143 	history = scp->history;
144 	scp->history = NULL;
145 	if (history == NULL)
146 		return;
147 
148 	cur_lines = sc_vtb_rows(history);
149 	min_lines = imax(SC_HISTORY_SIZE, prev_ysize);
150 	extra_history_size += (cur_lines > min_lines) ? cur_lines - min_lines : 0;
151 
152 	sc_vtb_destroy(history);
153 	free(history, M_DEVBUF);
154 }
155 
156 /* copy entire screen into the top of the history buffer */
157 void
158 sc_hist_save(scr_stat *scp)
159 {
160 	sc_vtb_append(&scp->vtb, 0, scp->history, scp->xsize*scp->ysize);
161 	scp->history_pos = sc_vtb_tail(scp->history);
162 }
163 
164 /* restore the screen by copying from the history buffer */
165 int
166 sc_hist_restore(scr_stat *scp)
167 {
168 	int ret;
169 
170 	if (scp->history_pos != sc_vtb_tail(scp->history)) {
171 		scp->history_pos = sc_vtb_tail(scp->history);
172 		history_to_screen(scp);
173 		ret =  0;
174 	} else {
175 		ret = 1;
176 	}
177 	sc_vtb_seek(scp->history, sc_vtb_pos(scp->history,
178 					     sc_vtb_tail(scp->history),
179 					     -scp->xsize*scp->ysize));
180 	return ret;
181 }
182 
183 /* copy screen-full of saved lines */
184 static void
185 history_to_screen(scr_stat *scp)
186 {
187 	int pos;
188 	int i;
189 
190 	pos = scp->history_pos;
191 	for (i = 1; i <= scp->ysize; ++i) {
192 		pos = sc_vtb_pos(scp->history, pos, -scp->xsize);
193 		sc_vtb_copy(scp->history, pos,
194 			    &scp->vtb, scp->xsize*(scp->ysize - i),
195 			    scp->xsize);
196 	}
197 	mark_all(scp);
198 }
199 
200 /* go to the tail of the history buffer */
201 void
202 sc_hist_home(scr_stat *scp)
203 {
204 	scp->history_pos = sc_vtb_tail(scp->history);
205 	history_to_screen(scp);
206 }
207 
208 /* go to the top of the history buffer */
209 void
210 sc_hist_end(scr_stat *scp)
211 {
212 	scp->history_pos = sc_vtb_pos(scp->history, sc_vtb_tail(scp->history),
213 				      scp->xsize*scp->ysize);
214 	history_to_screen(scp);
215 }
216 
217 /* move one line up */
218 int
219 sc_hist_up_line(scr_stat *scp)
220 {
221 	if (sc_vtb_pos(scp->history, scp->history_pos, -(scp->xsize*scp->ysize))
222 	    == sc_vtb_tail(scp->history))
223 		return -1;
224 	scp->history_pos = sc_vtb_pos(scp->history, scp->history_pos,
225 				      -scp->xsize);
226 	history_to_screen(scp);
227 	return 0;
228 }
229 
230 /* move one line down */
231 int
232 sc_hist_down_line(scr_stat *scp)
233 {
234 	if (scp->history_pos == sc_vtb_tail(scp->history))
235 		return -1;
236 	scp->history_pos = sc_vtb_pos(scp->history, scp->history_pos,
237 				      scp->xsize);
238 	history_to_screen(scp);
239 	return 0;
240 }
241 
242 int
243 sc_hist_ioctl(struct tty *tp, u_long cmd, caddr_t data, int flag,
244 	      struct proc *p)
245 {
246 	scr_stat *scp;
247 	int error;
248 
249 	switch (cmd) {
250 
251 	case CONS_HISTORY:  	/* set history size */
252 		scp = sc_get_scr_stat(tp->t_dev);
253 		if (*(int *)data <= 0)
254 			return EINVAL;
255 		if (scp->status & BUFFER_SAVED)
256 			return EBUSY;
257 		DPRINTF(5, ("lines:%d, ysize:%d, pool:%d\n",
258 			    *(int *)data, scp->ysize, extra_history_size));
259 		error = sc_alloc_history_buffer(scp,
260 					       imax(*(int *)data, scp->ysize),
261 					       scp->ysize, TRUE);
262 		DPRINTF(5, ("error:%d, rows:%d, pool:%d\n", error,
263 			    sc_vtb_rows(scp->history), extra_history_size));
264 		return error;
265 	}
266 
267 	return ENOIOCTL;
268 }
269 
270 #endif /* SC_NO_HISTORY */
271 
272 #endif /* NSC */
273