yank.c revision 1.11 
1/*	$OpenBSD: yank.c,v 1.11 2014/03/20 07:47:29 lum Exp $	*/
2
3/* This file is in the public domain. */
4
5/*
6 *	kill ring functions
7 */
8
9#include "def.h"
10
11#include <string.h>
12
13#ifndef KBLOCK
14#define KBLOCK	256		/* Kill buffer block size.	 */
15#endif
16
17static char	*kbufp = NULL;	/* Kill buffer data.		 */
18static RSIZE	 kused = 0;	/* # of bytes used in KB.	 */
19static RSIZE	 ksize = 0;	/* # of bytes allocated in KB.	 */
20static RSIZE	 kstart = 0;	/* # of first used byte in KB.	 */
21
22static int	 kgrow(int);
23
24/*
25 * Delete all of the text saved in the kill buffer.  Called by commands when
26 * a new kill context is created. The kill buffer array is released, just in
27 * case the buffer has grown to an immense size.  No errors.
28 */
29void
30kdelete(void)
31{
32	if (kbufp != NULL) {
33		free(kbufp);
34		kbufp = NULL;
35		kstart = kused = ksize = 0;
36	}
37}
38
39/*
40 * Insert a character to the kill buffer, enlarging the buffer if there
41 * isn't any room. Always grow the buffer in chunks, on the assumption
42 * that if you put something in the kill buffer you are going to put more
43 * stuff there too later. Return TRUE if all is well, and FALSE on errors.
44 * Print a message on errors.  Dir says whether to put it at back or front.
45 * This call is ignored if  KNONE is set.
46 */
47int
48kinsert(int c, int dir)
49{
50	if (dir == KNONE)
51		return (TRUE);
52	if (kused == ksize && dir == KFORW && kgrow(dir) == FALSE)
53		return (FALSE);
54	if (kstart == 0 && dir == KBACK && kgrow(dir) == FALSE)
55		return (FALSE);
56	if (dir == KFORW)
57		kbufp[kused++] = c;
58	else if (dir == KBACK)
59		kbufp[--kstart] = c;
60	else
61		panic("broken kinsert call");	/* Oh shit! */
62	return (TRUE);
63}
64
65/*
66 * kgrow - just get more kill buffer for the callee. If dir = KBACK
67 * we are trying to get space at the beginning of the kill buffer.
68 */
69static int
70kgrow(int dir)
71{
72	int	 nstart;
73	char	*nbufp;
74
75	if ((unsigned)(ksize + KBLOCK) <= (unsigned)ksize) {
76		/* probably 16 bit unsigned */
77		dobeep();
78		ewprintf("Kill buffer size at maximum");
79		return (FALSE);
80	}
81	if ((nbufp = malloc((unsigned)(ksize + KBLOCK))) == NULL) {
82		dobeep();
83		ewprintf("Can't get %ld bytes", (long)(ksize + KBLOCK));
84		return (FALSE);
85	}
86	nstart = (dir == KBACK) ? (kstart + KBLOCK) : (KBLOCK / 4);
87	bcopy(&(kbufp[kstart]), &(nbufp[nstart]), (int)(kused - kstart));
88	if (kbufp != NULL)
89		free(kbufp);
90	kbufp = nbufp;
91	ksize += KBLOCK;
92	kused = kused - kstart + nstart;
93	kstart = nstart;
94	return (TRUE);
95}
96
97/*
98 * This function gets characters from the kill buffer. If the character
99 * index "n" is off the end, it returns "-1". This lets the caller just
100 * scan along until it gets a "-1" back.
101 */
102int
103kremove(int n)
104{
105	if (n < 0 || n + kstart >= kused)
106		return (-1);
107	return (CHARMASK(kbufp[n + kstart]));
108}
109
110/*
111 * Copy a string into the kill buffer. kflag gives direction.
112 * if KNONE, do nothing.
113 */
114int
115kchunk(char *cp1, RSIZE chunk, int kflag)
116{
117	/*
118	 * HACK - doesn't matter, and fixes back-over-nl bug for empty
119	 *	kill buffers.
120	 */
121	if (kused == kstart)
122		kflag = KFORW;
123
124	if (kflag & KFORW) {
125		while (ksize - kused < chunk)
126			if (kgrow(kflag) == FALSE)
127				return (FALSE);
128		bcopy(cp1, &(kbufp[kused]), (int)chunk);
129		kused += chunk;
130	} else if (kflag & KBACK) {
131		while (kstart < chunk)
132			if (kgrow(kflag) == FALSE)
133				return (FALSE);
134		bcopy(cp1, &(kbufp[kstart - chunk]), (int)chunk);
135		kstart -= chunk;
136	}
137
138	return (TRUE);
139}
140
141/*
142 * Kill line.  If called without an argument, it kills from dot to the end
143 * of the line, unless it is at the end of the line, when it kills the
144 * newline.  If called with an argument of 0, it kills from the start of the
145 * line to dot.  If called with a positive argument, it kills from dot
146 * forward over that number of newlines.  If called with a negative argument
147 * it kills any text before dot on the current line, then it kills back
148 * abs(arg) lines.
149 */
150/* ARGSUSED */
151int
152killline(int f, int n)
153{
154	struct line	*nextp;
155	RSIZE	 chunk;
156	int	 i, c;
157
158	/* clear kill buffer if last wasn't a kill */
159	if ((lastflag & CFKILL) == 0)
160		kdelete();
161	thisflag |= CFKILL;
162	if (!(f & FFARG)) {
163		for (i = curwp->w_doto; i < llength(curwp->w_dotp); ++i)
164			if ((c = lgetc(curwp->w_dotp, i)) != ' ' && c != '\t')
165				break;
166		if (i == llength(curwp->w_dotp))
167			chunk = llength(curwp->w_dotp) - curwp->w_doto + 1;
168		else {
169			chunk = llength(curwp->w_dotp) - curwp->w_doto;
170			if (chunk == 0)
171				chunk = 1;
172		}
173	} else if (n > 0) {
174		chunk = llength(curwp->w_dotp) - curwp->w_doto;
175		nextp = lforw(curwp->w_dotp);
176		if (nextp != curbp->b_headp)
177			chunk++;		/* newline */
178		if (nextp == curbp->b_headp)
179			goto done;		/* EOL */
180		i = n;
181		while (--i) {
182			chunk += llength(nextp);
183			nextp = lforw(nextp);
184			if (nextp != curbp->b_headp)
185				chunk++;	/* newline */
186			if (nextp == curbp->b_headp)
187				break;		/* EOL */
188		}
189	} else {
190		/* n <= 0 */
191		chunk = curwp->w_doto;
192		curwp->w_doto = 0;
193		i = n;
194		while (i++) {
195			if (lforw(curwp->w_dotp))
196				chunk++;
197			curwp->w_dotp = lback(curwp->w_dotp);
198			curwp->w_rflag |= WFMOVE;
199			chunk += llength(curwp->w_dotp);
200		}
201	}
202	/*
203	 * KFORW here is a bug.  Should be KBACK/KFORW, but we need to
204	 * rewrite the ldelete code (later)?
205	 */
206done:
207	if (chunk)
208		return (ldelete(chunk, KFORW));
209	return (TRUE);
210}
211
212/*
213 * Yank text back from the kill buffer.  This is really easy.  All of the work
214 * is done by the standard insert routines.  All you do is run the loop, and
215 * check for errors.  The blank lines are inserted with a call to "newline"
216 * instead of a call to "lnewline" so that the magic stuff that happens when
217 * you type a carriage return also happens when a carriage return is yanked
218 * back from the kill buffer.  An attempt has been made to fix the cosmetic
219 * bug associated with a yank when dot is on the top line of the window
220 * (nothing moves, because all of the new text landed off screen).
221 */
222/* ARGSUSED */
223int
224yank(int f, int n)
225{
226	struct line	*lp;
227	int	 c, i, nline;
228
229	if (n < 0)
230		return (FALSE);
231
232	/* newline counting */
233	nline = 0;
234
235	undo_boundary_enable(FFRAND, 0);
236	while (n--) {
237		/* mark around last yank */
238		isetmark();
239		i = 0;
240		while ((c = kremove(i)) >= 0) {
241			if (c == '\n') {
242				if (newline(FFRAND, 1) == FALSE)
243					return (FALSE);
244				++nline;
245			} else {
246				if (linsert(1, c) == FALSE)
247					return (FALSE);
248			}
249			++i;
250		}
251	}
252	/* cosmetic adjustment */
253	lp = curwp->w_linep;
254
255	/* if offscreen insert */
256	if (curwp->w_dotp == lp) {
257		while (nline-- && lback(lp) != curbp->b_headp)
258			lp = lback(lp);
259		/* adjust framing */
260		curwp->w_linep = lp;
261		curwp->w_rflag |= WFFULL;
262	}
263	undo_boundary_enable(FFRAND, 1);
264	return (TRUE);
265}
266
267