xref: /plan9/sys/src/cmd/sam/rasp.c (revision ec59a3ddbfceee0efe34584c2c9981a5e5ff1ec4)
1 #include "sam.h"
2 /*
3  * GROWDATASIZE must be big enough that all errors go out as Hgrowdata's,
4  * so they will be scrolled into visibility in the ~~sam~~ window (yuck!).
5  */
6 #define	GROWDATASIZE	50	/* if size is > this, send data with grow */
7 
8 void	rcut(List*, Posn, Posn);
9 int	rterm(List*, Posn);
10 void	rgrow(List*, Posn, Posn);
11 
12 static	Posn	growpos;
13 static	Posn	grown;
14 static	Posn	shrinkpos;
15 static	Posn	shrunk;
16 
17 /*
18  * rasp routines inform the terminal of changes to the file.
19  *
20  * a rasp is a list of spans within the file, and an indication
21  * of whether the terminal knows about the span.
22  *
23  * optimize by coalescing multiple updates to the same span
24  * if it is not known by the terminal.
25  *
26  * other possible optimizations: flush terminal's rasp by cut everything,
27  * insert everything if rasp gets too large.
28  */
29 
30 /*
31  * only called for initial load of file
32  */
33 void
34 raspload(File *f)
35 {
36 	if(f->rasp == nil)
37 		return;
38 	grown = f->nc;
39 	growpos = 0;
40 	if(f->nc)
41 		rgrow(f->rasp, 0, f->nc);
42 	raspdone(f, 1);
43 }
44 
45 void
46 raspstart(File *f)
47 {
48 	if(f->rasp == nil)
49 		return;
50 	grown = 0;
51 	shrunk = 0;
52 	noflush = 1;
53 }
54 
55 void
56 raspdone(File *f, int toterm)
57 {
58 	if(f->dot.r.p1 > f->nc)
59 		f->dot.r.p1 = f->nc;
60 	if(f->dot.r.p2 > f->nc)
61 		f->dot.r.p2 = f->nc;
62 	if(f->mark.p1 > f->nc)
63 		f->mark.p1 = f->nc;
64 	if(f->mark.p2 > f->nc)
65 		f->mark.p2 = f->nc;
66 	if(f->rasp == nil)
67 		return;
68 	if(grown)
69 		outTsll(Hgrow, f->tag, growpos, grown);
70 	else if(shrunk)
71 		outTsll(Hcut, f->tag, shrinkpos, shrunk);
72 	if(toterm)
73 		outTs(Hcheck0, f->tag);
74 	outflush();
75 	noflush = 0;
76 	if(f == cmd){
77 		cmdpt += cmdptadv;
78 		cmdptadv = 0;
79 	}
80 }
81 
82 void
83 raspdelete(File *f, uint p1, uint p2, int toterm)
84 {
85 	long n;
86 
87 	n = p2 - p1;
88 	if(n == 0)
89 		return;
90 
91 	if(p2 <= f->dot.r.p1){
92 		f->dot.r.p1 -= n;
93 		f->dot.r.p2 -= n;
94 	}
95 	if(p2 <= f->mark.p1){
96 		f->mark.p1 -= n;
97 		f->mark.p2 -= n;
98 	}
99 
100 	if(f->rasp == nil)
101 		return;
102 
103 	if(f==cmd && p1<cmdpt){
104 		if(p2 <= cmdpt)
105 			cmdpt -= n;
106 		else
107 			cmdpt = p1;
108 	}
109 	if(toterm){
110 		if(grown){
111 			outTsll(Hgrow, f->tag, growpos, grown);
112 			grown = 0;
113 		}else if(shrunk && shrinkpos!=p1 && shrinkpos!=p2){
114 			outTsll(Hcut, f->tag, shrinkpos, shrunk);
115 			shrunk = 0;
116 		}
117 		if(!shrunk || shrinkpos==p2)
118 			shrinkpos = p1;
119 		shrunk += n;
120 	}
121 	rcut(f->rasp, p1, p2);
122 }
123 
124 void
125 raspinsert(File *f, uint p1, Rune *buf, uint n, int toterm)
126 {
127 	Range r;
128 
129 	if(n == 0)
130 		return;
131 
132 	if(p1 < f->dot.r.p1){
133 		f->dot.r.p1 += n;
134 		f->dot.r.p2 += n;
135 	}
136 	if(p1 < f->mark.p1){
137 		f->mark.p1 += n;
138 		f->mark.p2 += n;
139 	}
140 
141 
142 	if(f->rasp == nil)
143 		return;
144 	if(f==cmd && p1<cmdpt)
145 		cmdpt += n;
146 	if(toterm){
147 		if(shrunk){
148 			outTsll(Hcut, f->tag, shrinkpos, shrunk);
149 			shrunk = 0;
150 		}
151 		if(n>GROWDATASIZE || !rterm(f->rasp, p1)){
152 			rgrow(f->rasp, p1, n);
153 			if(grown && growpos+grown!=p1 && growpos!=p1){
154 				outTsll(Hgrow, f->tag, growpos, grown);
155 				grown = 0;
156 			}
157 			if(!grown)
158 				growpos = p1;
159 			grown += n;
160 		}else{
161 			if(grown){
162 				outTsll(Hgrow, f->tag, growpos, grown);
163 				grown = 0;
164 			}
165 			rgrow(f->rasp, p1, n);
166 			r = rdata(f->rasp, p1, n);
167 			if(r.p1!=p1 || r.p2!=p1+n)
168 				panic("rdata in toterminal");
169 			outTsllS(Hgrowdata, f->tag, p1, n, tmprstr(buf, n));
170 		}
171 	}else{
172 		rgrow(f->rasp, p1, n);
173 		r = rdata(f->rasp, p1, n);
174 		if(r.p1!=p1 || r.p2!=p1+n)
175 			panic("rdata in toterminal");
176 	}
177 }
178 
179 #define	M	0x80000000L
180 #define	P(i)	r->posnptr[i]
181 #define	T(i)	(P(i)&M)	/* in terminal */
182 #define	L(i)	(P(i)&~M)	/* length of this piece */
183 
184 void
185 rcut(List *r, Posn p1, Posn p2)
186 {
187 	Posn p, x;
188 	int i;
189 
190 	if(p1 == p2)
191 		panic("rcut 0");
192 	for(p=0,i=0; i<r->nused && p+L(i)<=p1; p+=L(i++))
193 		;
194 	if(i == r->nused)
195 		panic("rcut 1");
196 	if(p < p1){	/* chop this piece */
197 		if(p+L(i) < p2){
198 			x = p1-p;
199 			p += L(i);
200 		}else{
201 			x = L(i)-(p2-p1);
202 			p = p2;
203 		}
204 		if(T(i))
205 			P(i) = x|M;
206 		else
207 			P(i) = x;
208 		i++;
209 	}
210 	while(i<r->nused && p+L(i)<=p2){
211 		p += L(i);
212 		dellist(r, i);
213 	}
214 	if(p < p2){
215 		if(i == r->nused)
216 			panic("rcut 2");
217 		x = L(i)-(p2-p);
218 		if(T(i))
219 			P(i) = x|M;
220 		else
221 			P(i) = x;
222 	}
223 	/* can we merge i and i-1 ? */
224 	if(i>0 && i<r->nused && T(i-1)==T(i)){
225 		x = L(i-1)+L(i);
226 		dellist(r, i--);
227 		if(T(i))
228 			P(i)=x|M;
229 		else
230 			P(i)=x;
231 	}
232 }
233 
234 void
235 rgrow(List *r, Posn p1, Posn n)
236 {
237 	Posn p;
238 	int i;
239 
240 	if(n == 0)
241 		panic("rgrow 0");
242 	for(p=0,i=0; i<r->nused && p+L(i)<=p1; p+=L(i++))
243 		;
244 	if(i == r->nused){	/* stick on end of file */
245 		if(p!=p1)
246 			panic("rgrow 1");
247 		if(i>0 && !T(i-1))
248 			P(i-1)+=n;
249 		else
250 			inslist(r, i, n);
251 	}else if(!T(i))		/* goes in this empty piece */
252 		P(i)+=n;
253 	else if(p==p1 && i>0 && !T(i-1))	/* special case; simplifies life */
254 		P(i-1)+=n;
255 	else if(p==p1)
256 		inslist(r, i, n);
257 	else{			/* must break piece in terminal */
258 		inslist(r, i+1, (L(i)-(p1-p))|M);
259 		inslist(r, i+1, n);
260 		P(i) = (p1-p)|M;
261 	}
262 }
263 
264 int
265 rterm(List *r, Posn p1)
266 {
267 	Posn p;
268 	int i;
269 
270 	for(p = 0,i = 0; i<r->nused && p+L(i)<=p1; p+=L(i++))
271 		;
272 	if(i==r->nused && (i==0 || !T(i-1)))
273 		return 0;
274 	return T(i);
275 }
276 
277 Range
278 rdata(List *r, Posn p1, Posn n)
279 {
280 	Posn p;
281 	int i;
282 	Range rg;
283 
284 	if(n==0)
285 		panic("rdata 0");
286 	for(p = 0,i = 0; i<r->nused && p+L(i)<=p1; p+=L(i++))
287 		;
288 	if(i==r->nused)
289 		panic("rdata 1");
290 	if(T(i)){
291 		n-=L(i)-(p1-p);
292 		if(n<=0){
293 			rg.p1 = rg.p2 = p1;
294 			return rg;
295 		}
296 		p+=L(i++);
297 		p1 = p;
298 	}
299 	if(T(i) || i==r->nused)
300 		panic("rdata 2");
301 	if(p+L(i)<p1+n)
302 		n = L(i)-(p1-p);
303 	rg.p1 = p1;
304 	rg.p2 = p1+n;
305 	if(p!=p1){
306 		inslist(r, i+1, L(i)-(p1-p));
307 		P(i)=p1-p;
308 		i++;
309 	}
310 	if(L(i)!=n){
311 		inslist(r, i+1, L(i)-n);
312 		P(i)=n;
313 	}
314 	P(i)|=M;
315 	/* now i is set; can we merge? */
316 	if(i<r->nused-1 && T(i+1)){
317 		P(i)=(n+=L(i+1))|M;
318 		dellist(r, i+1);
319 	}
320 	if(i>0 && T(i-1)){
321 		P(i)=(n+L(i-1))|M;
322 		dellist(r, i-1);
323 	}
324 	return rg;
325 }
326