yank.c revision 1.15 
1/*	$OpenBSD: yank.c,v 1.15 2021/03/01 10:51:14 lum Exp $	*/
2
3/* This file is in the public domain. */
4
5/*
6 *	kill ring functions
7 */
8
9#include <sys/queue.h>
10#include <signal.h>
11#include <stdio.h>
12#include <stdlib.h>
13#include <string.h>
14
15#include "def.h"
16
17#define KBLOCK	 8192		/* Kill grow.                    */
18
19static char	*kbufp = NULL;	/* Kill buffer data.		 */
20static RSIZE	 kused = 0;	/* # of bytes used in KB.	 */
21static RSIZE	 ksize = 0;	/* # of bytes allocated in KB.	 */
22static RSIZE	 kstart = 0;	/* # of first used byte in KB.	 */
23
24static int	 kgrow(int);
25
26/*
27 * Delete all of the text saved in the kill buffer.  Called by commands when
28 * a new kill context is created. The kill buffer array is released, just in
29 * case the buffer has grown to an immense size.  No errors.
30 */
31void
32kdelete(void)
33{
34	if (kbufp != NULL) {
35		free(kbufp);
36		kbufp = NULL;
37		kstart = kused = ksize = 0;
38	}
39}
40
41/*
42 * Insert a character to the kill buffer, enlarging the buffer if there
43 * isn't any room. Always grow the buffer in chunks, on the assumption
44 * that if you put something in the kill buffer you are going to put more
45 * stuff there too later. Return TRUE if all is well, and FALSE on errors.
46 * Print a message on errors.  Dir says whether to put it at back or front.
47 * This call is ignored if  KNONE is set.
48 */
49int
50kinsert(int c, int dir)
51{
52	if (dir == KNONE)
53		return (TRUE);
54	if (kused == ksize && dir == KFORW && kgrow(dir) == FALSE)
55		return (FALSE);
56	if (kstart == 0 && dir == KBACK && kgrow(dir) == FALSE)
57		return (FALSE);
58	if (dir == KFORW)
59		kbufp[kused++] = c;
60	else if (dir == KBACK)
61		kbufp[--kstart] = c;
62	else
63		panic("broken kinsert call");	/* Oh shit! */
64	return (TRUE);
65}
66
67/*
68 * kgrow - just get more kill buffer for the callee. If dir = KBACK
69 * we are trying to get space at the beginning of the kill buffer.
70 */
71static int
72kgrow(int dir)
73{
74	int	 nstart;
75	char	*nbufp;
76
77	if ((unsigned)(ksize + KBLOCK) <= (unsigned)ksize) {
78		/* probably 16 bit unsigned */
79		dobeep();
80		ewprintf("Kill buffer size at maximum");
81		return (FALSE);
82	}
83	if ((nbufp = malloc((unsigned)(ksize + KBLOCK))) == NULL) {
84		dobeep();
85		ewprintf("Can't get %ld bytes", (long)(ksize + KBLOCK));
86		return (FALSE);
87	}
88	nstart = (dir == KBACK) ? (kstart + KBLOCK) : (KBLOCK / 4);
89	bcopy(&(kbufp[kstart]), &(nbufp[nstart]), (int)(kused - kstart));
90	free(kbufp);
91	kbufp = nbufp;
92	ksize += KBLOCK;
93	kused = kused - kstart + nstart;
94	kstart = nstart;
95	return (TRUE);
96}
97
98/*
99 * This function gets characters from the kill buffer. If the character
100 * index "n" is off the end, it returns "-1". This lets the caller just
101 * scan along until it gets a "-1" back.
102 */
103int
104kremove(int n)
105{
106	if (n < 0 || n + kstart >= kused)
107		return (-1);
108	return (CHARMASK(kbufp[n + kstart]));
109}
110
111/*
112 * Copy a string into the kill buffer. kflag gives direction.
113 * if KNONE, do nothing.
114 */
115int
116kchunk(char *cp1, RSIZE chunk, int kflag)
117{
118	/*
119	 * HACK - doesn't matter, and fixes back-over-nl bug for empty
120	 *	kill buffers.
121	 */
122	if (kused == kstart)
123		kflag = KFORW;
124
125	if (kflag & KFORW) {
126		while (ksize - kused < chunk)
127			if (kgrow(kflag) == FALSE)
128				return (FALSE);
129		bcopy(cp1, &(kbufp[kused]), (int)chunk);
130		kused += chunk;
131	} else if (kflag & KBACK) {
132		while (kstart < chunk)
133			if (kgrow(kflag) == FALSE)
134				return (FALSE);
135		bcopy(cp1, &(kbufp[kstart - chunk]), (int)chunk);
136		kstart -= chunk;
137	}
138
139	return (TRUE);
140}
141
142/*
143 * Kill line.  If called without an argument, it kills from dot to the end
144 * of the line, unless it is at the end of the line, when it kills the
145 * newline.  If called with an argument of 0, it kills from the start of the
146 * line to dot.  If called with a positive argument, it kills from dot
147 * forward over that number of newlines.  If called with a negative argument
148 * it kills any text before dot on the current line, then it kills back
149 * abs(arg) lines.
150 */
151/* ARGSUSED */
152int
153killline(int f, int n)
154{
155	struct line	*nextp;
156	RSIZE	 chunk;
157	int	 i, c;
158
159	/* clear kill buffer if last wasn't a kill */
160	if ((lastflag & CFKILL) == 0)
161		kdelete();
162	thisflag |= CFKILL;
163	if (!(f & FFARG)) {
164		for (i = curwp->w_doto; i < llength(curwp->w_dotp); ++i)
165			if ((c = lgetc(curwp->w_dotp, i)) != ' ' && c != '\t')
166				break;
167		if (i == llength(curwp->w_dotp))
168			chunk = llength(curwp->w_dotp) - curwp->w_doto + 1;
169		else {
170			chunk = llength(curwp->w_dotp) - curwp->w_doto;
171			if (chunk == 0)
172				chunk = 1;
173		}
174	} else if (n > 0) {
175		chunk = llength(curwp->w_dotp) - curwp->w_doto;
176		nextp = lforw(curwp->w_dotp);
177		if (nextp != curbp->b_headp)
178			chunk++;		/* newline */
179		if (nextp == curbp->b_headp)
180			goto done;		/* EOL */
181		i = n;
182		while (--i) {
183			chunk += llength(nextp);
184			nextp = lforw(nextp);
185			if (nextp != curbp->b_headp)
186				chunk++;	/* newline */
187			if (nextp == curbp->b_headp)
188				break;		/* EOL */
189		}
190	} else {
191		/* n <= 0 */
192		chunk = curwp->w_doto;
193		curwp->w_doto = 0;
194		i = n;
195		while (i++) {
196			if (lforw(curwp->w_dotp))
197				chunk++;
198			curwp->w_dotp = lback(curwp->w_dotp);
199			curwp->w_rflag |= WFMOVE;
200			chunk += llength(curwp->w_dotp);
201		}
202	}
203	/*
204	 * KFORW here is a bug.  Should be KBACK/KFORW, but we need to
205	 * rewrite the ldelete code (later)?
206	 */
207done:
208	if (chunk)
209		return (ldelete(chunk, KFORW));
210	return (TRUE);
211}
212
213/*
214 * Yank text back from the kill buffer.  This is really easy.  All of the work
215 * is done by the standard insert routines.  All you do is run the loop, and
216 * check for errors.  The blank lines are inserted with a call to "newline"
217 * instead of a call to "lnewline" so that the magic stuff that happens when
218 * you type a carriage return also happens when a carriage return is yanked
219 * back from the kill buffer.  An attempt has been made to fix the cosmetic
220 * bug associated with a yank when dot is on the top line of the window
221 * (nothing moves, because all of the new text landed off screen).
222 */
223/* ARGSUSED */
224int
225yank(int f, int n)
226{
227	struct line	*lp;
228	int	 c, i, nline;
229
230	if (n < 0)
231		return (FALSE);
232
233	/* newline counting */
234	nline = 0;
235
236	undo_boundary_enable(FFRAND, 0);
237	while (n--) {
238		/* mark around last yank */
239		isetmark();
240		i = 0;
241		while ((c = kremove(i)) >= 0) {
242			if (c == *curbp->b_nlchr) {
243				if (enewline(FFRAND, 1) == FALSE)
244					return (FALSE);
245				++nline;
246			} else {
247				if (linsert(1, c) == FALSE)
248					return (FALSE);
249			}
250			++i;
251		}
252	}
253	/* cosmetic adjustment */
254	lp = curwp->w_linep;
255
256	/* if offscreen insert */
257	if (curwp->w_dotp == lp) {
258		while (nline-- && lback(lp) != curbp->b_headp)
259			lp = lback(lp);
260		/* adjust framing */
261		curwp->w_linep = lp;
262		curwp->w_rflag |= WFFULL;
263	}
264	undo_boundary_enable(FFRAND, 1);
265	return (TRUE);
266}
267
268