1 5993a8f2 2003-11-23 devnull #include <u.h>
  2 5993a8f2 2003-11-23 devnull #include <libc.h>
  3 5993a8f2 2003-11-23 devnull #include <bio.h>
  4 5993a8f2 2003-11-23 devnull #include "diff.h"
  5 5993a8f2 2003-11-23 devnull 
  6 5993a8f2 2003-11-23 devnull /*	diff - differential file comparison
  7 5993a8f2 2003-11-23 devnull *
  8 5993a8f2 2003-11-23 devnull *	Uses an algorithm due to Harold Stone, which finds
  9 5993a8f2 2003-11-23 devnull *	a pair of longest identical subsequences in the two
 10 5993a8f2 2003-11-23 devnull *	files.
 11 5993a8f2 2003-11-23 devnull *
 12 5993a8f2 2003-11-23 devnull *	The major goal is to generate the match vector J.
 13 5993a8f2 2003-11-23 devnull *	J[i] is the index of the line in file1 corresponding
 14 5993a8f2 2003-11-23 devnull *	to line i file0. J[i] = 0 if there is no
 15 5993a8f2 2003-11-23 devnull *	such line in file1.
 16 5993a8f2 2003-11-23 devnull *
 17 5993a8f2 2003-11-23 devnull *	Lines are hashed so as to work in core. All potential
 18 5993a8f2 2003-11-23 devnull *	matches are located by sorting the lines of each file
 19 5993a8f2 2003-11-23 devnull *	on the hash (called value). In particular, this
 20 5993a8f2 2003-11-23 devnull *	collects the equivalence classes in file1 together.
 21 5993a8f2 2003-11-23 devnull *	Subroutine equiv replaces the value of each line in
 22 5993a8f2 2003-11-23 devnull *	file0 by the index of the first element of its 
 23 5993a8f2 2003-11-23 devnull *	matching equivalence in (the reordered) file1.
 24 5993a8f2 2003-11-23 devnull *	To save space equiv squeezes file1 into a single
 25 5993a8f2 2003-11-23 devnull *	array member in which the equivalence classes
 26 5993a8f2 2003-11-23 devnull *	are simply concatenated, except that their first
 27 5993a8f2 2003-11-23 devnull *	members are flagged by changing sign.
 28 5993a8f2 2003-11-23 devnull *
 29 5993a8f2 2003-11-23 devnull *	Next the indices that point into member are unsorted into
 30 5993a8f2 2003-11-23 devnull *	array class according to the original order of file0.
 31 5993a8f2 2003-11-23 devnull *
 32 5993a8f2 2003-11-23 devnull *	The cleverness lies in routine stone. This marches
 33 5993a8f2 2003-11-23 devnull *	through the lines of file0, developing a vector klist
 34 5993a8f2 2003-11-23 devnull *	of "k-candidates". At step i a k-candidate is a matched
 35 5993a8f2 2003-11-23 devnull *	pair of lines x,y (x in file0 y in file1) such that
 36 5993a8f2 2003-11-23 devnull *	there is a common subsequence of lenght k
 37 5993a8f2 2003-11-23 devnull *	between the first i lines of file0 and the first y 
 38 5993a8f2 2003-11-23 devnull *	lines of file1, but there is no such subsequence for
 39 5993a8f2 2003-11-23 devnull *	any smaller y. x is the earliest possible mate to y
 40 5993a8f2 2003-11-23 devnull *	that occurs in such a subsequence.
 41 5993a8f2 2003-11-23 devnull *
 42 5993a8f2 2003-11-23 devnull *	Whenever any of the members of the equivalence class of
 43 5993a8f2 2003-11-23 devnull *	lines in file1 matable to a line in file0 has serial number 
 44 5993a8f2 2003-11-23 devnull *	less than the y of some k-candidate, that k-candidate 
 45 5993a8f2 2003-11-23 devnull *	with the smallest such y is replaced. The new 
 46 5993a8f2 2003-11-23 devnull *	k-candidate is chained (via pred) to the current
 47 5993a8f2 2003-11-23 devnull *	k-1 candidate so that the actual subsequence can
 48 5993a8f2 2003-11-23 devnull *	be recovered. When a member has serial number greater
 49 5993a8f2 2003-11-23 devnull *	that the y of all k-candidates, the klist is extended.
 50 5993a8f2 2003-11-23 devnull *	At the end, the longest subsequence is pulled out
 51 5993a8f2 2003-11-23 devnull *	and placed in the array J by unravel.
 52 5993a8f2 2003-11-23 devnull *
 53 5993a8f2 2003-11-23 devnull *	With J in hand, the matches there recorded are
 54 5993a8f2 2003-11-23 devnull *	check'ed against reality to assure that no spurious
 55 5993a8f2 2003-11-23 devnull *	matches have crept in due to hashing. If they have,
 56 5993a8f2 2003-11-23 devnull *	they are broken, and "jackpot " is recorded--a harmless
 57 5993a8f2 2003-11-23 devnull *	matter except that a true match for a spuriously
 58 5993a8f2 2003-11-23 devnull *	mated line may now be unnecessarily reported as a change.
 59 5993a8f2 2003-11-23 devnull *
 60 5993a8f2 2003-11-23 devnull *	Much of the complexity of the program comes simply
 61 5993a8f2 2003-11-23 devnull *	from trying to minimize core utilization and
 62 5993a8f2 2003-11-23 devnull *	maximize the range of doable problems by dynamically
 63 5993a8f2 2003-11-23 devnull *	allocating what is needed and reusing what is not.
 64 5993a8f2 2003-11-23 devnull *	The core requirements for problems larger than somewhat
 65 5993a8f2 2003-11-23 devnull *	are (in words) 2*length(file0) + length(file1) +
 66 5993a8f2 2003-11-23 devnull *	3*(number of k-candidates installed),  typically about
 67 5993a8f2 2003-11-23 devnull *	6n words for files of length n. 
 68 5993a8f2 2003-11-23 devnull */
 69 5993a8f2 2003-11-23 devnull /* TIDY THIS UP */
 70 5993a8f2 2003-11-23 devnull struct cand {
 71 5993a8f2 2003-11-23 devnull 	int x;
 72 5993a8f2 2003-11-23 devnull 	int y;
 73 5993a8f2 2003-11-23 devnull 	int pred;
 74 5993a8f2 2003-11-23 devnull } cand;
 75 5993a8f2 2003-11-23 devnull struct line {
 76 5993a8f2 2003-11-23 devnull 	int serial;
 77 5993a8f2 2003-11-23 devnull 	int value;
 78 5993a8f2 2003-11-23 devnull } *file[2], line;
 79 5993a8f2 2003-11-23 devnull int len[2];
 80 5993a8f2 2003-11-23 devnull int binary;
 81 5993a8f2 2003-11-23 devnull struct line *sfile[2];	/*shortened by pruning common prefix and suffix*/
 82 5993a8f2 2003-11-23 devnull int slen[2];
 83 5993a8f2 2003-11-23 devnull int pref, suff;	/*length of prefix and suffix*/
 84 5993a8f2 2003-11-23 devnull int *class;	/*will be overlaid on file[0]*/
 85 5993a8f2 2003-11-23 devnull int *member;	/*will be overlaid on file[1]*/
 86 5993a8f2 2003-11-23 devnull int *klist;		/*will be overlaid on file[0] after class*/
 87 5993a8f2 2003-11-23 devnull struct cand *clist;	/* merely a free storage pot for candidates */
 88 5993a8f2 2003-11-23 devnull int clen;
 89 5993a8f2 2003-11-23 devnull int *J;		/*will be overlaid on class*/
 90 5993a8f2 2003-11-23 devnull long *ixold;	/*will be overlaid on klist*/
 91 5993a8f2 2003-11-23 devnull long *ixnew;	/*will be overlaid on file[1]*/
 92 5993a8f2 2003-11-23 devnull /* END OF SOME TIDYING */
 93 5993a8f2 2003-11-23 devnull 
 94 5993a8f2 2003-11-23 devnull static void	
 95 5993a8f2 2003-11-23 devnull sort(struct line *a, int n)	/*shellsort CACM #201*/
 96 5993a8f2 2003-11-23 devnull {
 97 5993a8f2 2003-11-23 devnull 	int m;
 98 5993a8f2 2003-11-23 devnull 	struct line *ai, *aim, *j, *k;
 99 5993a8f2 2003-11-23 devnull 	struct line w;
100 5993a8f2 2003-11-23 devnull 	int i;
101 5993a8f2 2003-11-23 devnull 
102 5993a8f2 2003-11-23 devnull 	m = 0;
103 5993a8f2 2003-11-23 devnull 	for (i = 1; i <= n; i *= 2)
104 5993a8f2 2003-11-23 devnull 		m = 2*i - 1;
105 5993a8f2 2003-11-23 devnull 	for (m /= 2; m != 0; m /= 2) {
106 5993a8f2 2003-11-23 devnull 		k = a+(n-m);
107 5993a8f2 2003-11-23 devnull 		for (j = a+1; j <= k; j++) {
108 5993a8f2 2003-11-23 devnull 			ai = j;
109 5993a8f2 2003-11-23 devnull 			aim = ai+m;
110 5993a8f2 2003-11-23 devnull 			do {
111 5993a8f2 2003-11-23 devnull 				if (aim->value > ai->value ||
112 5993a8f2 2003-11-23 devnull 				   aim->value == ai->value &&
113 5993a8f2 2003-11-23 devnull 				   aim->serial > ai->serial)
114 5993a8f2 2003-11-23 devnull 					break;
115 5993a8f2 2003-11-23 devnull 				w = *ai;
116 5993a8f2 2003-11-23 devnull 				*ai = *aim;
117 5993a8f2 2003-11-23 devnull 				*aim = w;
118 5993a8f2 2003-11-23 devnull 
119 5993a8f2 2003-11-23 devnull 				aim = ai;
120 5993a8f2 2003-11-23 devnull 				ai -= m;
121 5993a8f2 2003-11-23 devnull 			} while (ai > a && aim >= ai);
122 5993a8f2 2003-11-23 devnull 		}
123 5993a8f2 2003-11-23 devnull 	}
124 5993a8f2 2003-11-23 devnull }
125 5993a8f2 2003-11-23 devnull 
126 5993a8f2 2003-11-23 devnull static void
127 5993a8f2 2003-11-23 devnull unsort(struct line *f, int l, int *b)
128 5993a8f2 2003-11-23 devnull {
129 5993a8f2 2003-11-23 devnull 	int *a;
130 5993a8f2 2003-11-23 devnull 	int i;
131 5993a8f2 2003-11-23 devnull 
132 5993a8f2 2003-11-23 devnull 	a = MALLOC(int, (l+1));
133 5993a8f2 2003-11-23 devnull 	for(i=1;i<=l;i++)
134 5993a8f2 2003-11-23 devnull 		a[f[i].serial] = f[i].value;
135 5993a8f2 2003-11-23 devnull 	for(i=1;i<=l;i++)
136 5993a8f2 2003-11-23 devnull 		b[i] = a[i];
137 5993a8f2 2003-11-23 devnull 	FREE(a);
138 5993a8f2 2003-11-23 devnull }
139 5993a8f2 2003-11-23 devnull 
140 5993a8f2 2003-11-23 devnull static void
141 5993a8f2 2003-11-23 devnull prune(void)
142 5993a8f2 2003-11-23 devnull {
143 5993a8f2 2003-11-23 devnull 	int i,j;
144 5993a8f2 2003-11-23 devnull 
145 5993a8f2 2003-11-23 devnull 	for(pref=0;pref<len[0]&&pref<len[1]&&
146 5993a8f2 2003-11-23 devnull 		file[0][pref+1].value==file[1][pref+1].value;
147 5993a8f2 2003-11-23 devnull 		pref++ ) ;
148 5993a8f2 2003-11-23 devnull 	for(suff=0;suff<len[0]-pref&&suff<len[1]-pref&&
149 5993a8f2 2003-11-23 devnull 		file[0][len[0]-suff].value==file[1][len[1]-suff].value;
150 5993a8f2 2003-11-23 devnull 		suff++) ;
151 5993a8f2 2003-11-23 devnull 	for(j=0;j<2;j++) {
152 5993a8f2 2003-11-23 devnull 		sfile[j] = file[j]+pref;
153 5993a8f2 2003-11-23 devnull 		slen[j] = len[j]-pref-suff;
154 5993a8f2 2003-11-23 devnull 		for(i=0;i<=slen[j];i++)
155 5993a8f2 2003-11-23 devnull 			sfile[j][i].serial = i;
156 5993a8f2 2003-11-23 devnull 	}
157 5993a8f2 2003-11-23 devnull }
158 5993a8f2 2003-11-23 devnull 
159 5993a8f2 2003-11-23 devnull static void
160 5993a8f2 2003-11-23 devnull equiv(struct line *a, int n, struct line *b, int m, int *c)
161 5993a8f2 2003-11-23 devnull {
162 5993a8f2 2003-11-23 devnull 	int i, j;
163 5993a8f2 2003-11-23 devnull 
164 5993a8f2 2003-11-23 devnull 	i = j = 1;
165 5993a8f2 2003-11-23 devnull 	while(i<=n && j<=m) {
166 5993a8f2 2003-11-23 devnull 		if(a[i].value < b[j].value)
167 5993a8f2 2003-11-23 devnull 			a[i++].value = 0;
168 5993a8f2 2003-11-23 devnull 		else if(a[i].value == b[j].value)
169 5993a8f2 2003-11-23 devnull 			a[i++].value = j;
170 5993a8f2 2003-11-23 devnull 		else
171 5993a8f2 2003-11-23 devnull 			j++;
172 5993a8f2 2003-11-23 devnull 	}
173 5993a8f2 2003-11-23 devnull 	while(i <= n)
174 5993a8f2 2003-11-23 devnull 		a[i++].value = 0;
175 5993a8f2 2003-11-23 devnull 	b[m+1].value = 0;
176 5993a8f2 2003-11-23 devnull 	j = 0;
177 5993a8f2 2003-11-23 devnull 	while(++j <= m) {
178 5993a8f2 2003-11-23 devnull 		c[j] = -b[j].serial;
179 5993a8f2 2003-11-23 devnull 		while(b[j+1].value == b[j].value) {
180 5993a8f2 2003-11-23 devnull 			j++;
181 5993a8f2 2003-11-23 devnull 			c[j] = b[j].serial;
182 5993a8f2 2003-11-23 devnull 		}
183 5993a8f2 2003-11-23 devnull 	}
184 5993a8f2 2003-11-23 devnull 	c[j] = -1;
185 5993a8f2 2003-11-23 devnull }
186 5993a8f2 2003-11-23 devnull 
187 5993a8f2 2003-11-23 devnull static int
188 5993a8f2 2003-11-23 devnull newcand(int x, int  y, int pred)
189 5993a8f2 2003-11-23 devnull {
190 5993a8f2 2003-11-23 devnull 	struct cand *q;
191 5993a8f2 2003-11-23 devnull 
192 5993a8f2 2003-11-23 devnull 	clist = REALLOC(clist, struct cand, (clen+1));
193 5993a8f2 2003-11-23 devnull 	q = clist + clen;
194 5993a8f2 2003-11-23 devnull 	q->x = x;
195 5993a8f2 2003-11-23 devnull 	q->y = y;
196 5993a8f2 2003-11-23 devnull 	q->pred = pred;
197 5993a8f2 2003-11-23 devnull 	return clen++;
198 5993a8f2 2003-11-23 devnull }
199 5993a8f2 2003-11-23 devnull 
200 5993a8f2 2003-11-23 devnull static int
201 5993a8f2 2003-11-23 devnull search(int *c, int k, int y)
202 5993a8f2 2003-11-23 devnull {
203 5993a8f2 2003-11-23 devnull 	int i, j, l;
204 5993a8f2 2003-11-23 devnull 	int t;
205 5993a8f2 2003-11-23 devnull 
206 5993a8f2 2003-11-23 devnull 	if(clist[c[k]].y < y)	/*quick look for typical case*/
207 5993a8f2 2003-11-23 devnull 		return k+1;
208 5993a8f2 2003-11-23 devnull 	i = 0;
209 5993a8f2 2003-11-23 devnull 	j = k+1;
210 5993a8f2 2003-11-23 devnull 	while((l=(i+j)/2) > i) {
211 5993a8f2 2003-11-23 devnull 		t = clist[c[l]].y;
212 5993a8f2 2003-11-23 devnull 		if(t > y)
213 5993a8f2 2003-11-23 devnull 			j = l;
214 5993a8f2 2003-11-23 devnull 		else if(t < y)
215 5993a8f2 2003-11-23 devnull 			i = l;
216 5993a8f2 2003-11-23 devnull 		else
217 5993a8f2 2003-11-23 devnull 			return l;
218 5993a8f2 2003-11-23 devnull 	}
219 5993a8f2 2003-11-23 devnull 	return l+1;
220 5993a8f2 2003-11-23 devnull }
221 5993a8f2 2003-11-23 devnull 
222 5993a8f2 2003-11-23 devnull static int
223 5993a8f2 2003-11-23 devnull stone(int *a, int n, int *b, int *c)
224 5993a8f2 2003-11-23 devnull {
225 5993a8f2 2003-11-23 devnull 	int i, k,y;
226 5993a8f2 2003-11-23 devnull 	int j, l;
227 5993a8f2 2003-11-23 devnull 	int oldc, tc;
228 5993a8f2 2003-11-23 devnull 	int oldl;
229 5993a8f2 2003-11-23 devnull 
230 5993a8f2 2003-11-23 devnull 	k = 0;
231 5993a8f2 2003-11-23 devnull 	c[0] = newcand(0,0,0);
232 5993a8f2 2003-11-23 devnull 	for(i=1; i<=n; i++) {
233 5993a8f2 2003-11-23 devnull 		j = a[i];
234 5993a8f2 2003-11-23 devnull 		if(j==0)
235 5993a8f2 2003-11-23 devnull 			continue;
236 5993a8f2 2003-11-23 devnull 		y = -b[j];
237 5993a8f2 2003-11-23 devnull 		oldl = 0;
238 5993a8f2 2003-11-23 devnull 		oldc = c[0];
239 5993a8f2 2003-11-23 devnull 		do {
240 5993a8f2 2003-11-23 devnull 			if(y <= clist[oldc].y)
241 5993a8f2 2003-11-23 devnull 				continue;
242 5993a8f2 2003-11-23 devnull 			l = search(c, k, y);
243 5993a8f2 2003-11-23 devnull 			if(l!=oldl+1)
244 5993a8f2 2003-11-23 devnull 				oldc = c[l-1];
245 5993a8f2 2003-11-23 devnull 			if(l<=k) {
246 5993a8f2 2003-11-23 devnull 				if(clist[c[l]].y <= y)
247 5993a8f2 2003-11-23 devnull 					continue;
248 5993a8f2 2003-11-23 devnull 				tc = c[l];
249 5993a8f2 2003-11-23 devnull 				c[l] = newcand(i,y,oldc);
250 5993a8f2 2003-11-23 devnull 				oldc = tc;
251 5993a8f2 2003-11-23 devnull 				oldl = l;
252 5993a8f2 2003-11-23 devnull 			} else {
253 5993a8f2 2003-11-23 devnull 				c[l] = newcand(i,y,oldc);
254 5993a8f2 2003-11-23 devnull 				k++;
255 5993a8f2 2003-11-23 devnull 				break;
256 5993a8f2 2003-11-23 devnull 			}
257 5993a8f2 2003-11-23 devnull 		} while((y=b[++j]) > 0);
258 5993a8f2 2003-11-23 devnull 	}
259 5993a8f2 2003-11-23 devnull 	return k;
260 5993a8f2 2003-11-23 devnull }
261 5993a8f2 2003-11-23 devnull 
262 5993a8f2 2003-11-23 devnull static void
263 5993a8f2 2003-11-23 devnull unravel(int p)
264 5993a8f2 2003-11-23 devnull {
265 5993a8f2 2003-11-23 devnull 	int i;
266 5993a8f2 2003-11-23 devnull 	struct cand *q;
267 5993a8f2 2003-11-23 devnull 
268 5993a8f2 2003-11-23 devnull 	for(i=0; i<=len[0]; i++) {
269 5993a8f2 2003-11-23 devnull 		if (i <= pref)
270 5993a8f2 2003-11-23 devnull 			J[i] = i;
271 5993a8f2 2003-11-23 devnull 		else if (i > len[0]-suff)
272 5993a8f2 2003-11-23 devnull 			J[i] = i+len[1]-len[0];
273 5993a8f2 2003-11-23 devnull 		else
274 5993a8f2 2003-11-23 devnull 			J[i] = 0;
275 5993a8f2 2003-11-23 devnull 	}
276 5993a8f2 2003-11-23 devnull 	for(q=clist+p;q->y!=0;q=clist+q->pred)
277 5993a8f2 2003-11-23 devnull 		J[q->x+pref] = q->y+pref;
278 5993a8f2 2003-11-23 devnull }
279 5993a8f2 2003-11-23 devnull 
280 5993a8f2 2003-11-23 devnull static void
281 5993a8f2 2003-11-23 devnull output(void)
282 5993a8f2 2003-11-23 devnull {
283 5993a8f2 2003-11-23 devnull 	int m, i0, i1, j0, j1;
284 5993a8f2 2003-11-23 devnull 
285 5993a8f2 2003-11-23 devnull 	m = len[0];
286 5993a8f2 2003-11-23 devnull 	J[0] = 0;
287 5993a8f2 2003-11-23 devnull 	J[m+1] = len[1]+1;
288 5993a8f2 2003-11-23 devnull 	if (mode != 'e') {
289 5993a8f2 2003-11-23 devnull 		for (i0 = 1; i0 <= m; i0 = i1+1) {
290 5993a8f2 2003-11-23 devnull 			while (i0 <= m && J[i0] == J[i0-1]+1)
291 5993a8f2 2003-11-23 devnull 				i0++;
292 5993a8f2 2003-11-23 devnull 			j0 = J[i0-1]+1;
293 5993a8f2 2003-11-23 devnull 			i1 = i0-1;
294 5993a8f2 2003-11-23 devnull 			while (i1 < m && J[i1+1] == 0)
295 5993a8f2 2003-11-23 devnull 				i1++;
296 5993a8f2 2003-11-23 devnull 			j1 = J[i1+1]-1;
297 5993a8f2 2003-11-23 devnull 			J[i1] = j1;
298 5993a8f2 2003-11-23 devnull 			change(i0, i1, j0, j1);
299 5993a8f2 2003-11-23 devnull 		}
300 5993a8f2 2003-11-23 devnull 	}
301 5993a8f2 2003-11-23 devnull 	else {
302 5993a8f2 2003-11-23 devnull 		for (i0 = m; i0 >= 1; i0 = i1-1) {
303 5993a8f2 2003-11-23 devnull 			while (i0 >= 1 && J[i0] == J[i0+1]-1 && J[i0])
304 5993a8f2 2003-11-23 devnull 				i0--;
305 5993a8f2 2003-11-23 devnull 			j0 = J[i0+1]-1;
306 5993a8f2 2003-11-23 devnull 			i1 = i0+1;
307 5993a8f2 2003-11-23 devnull 			while (i1 > 1 && J[i1-1] == 0)
308 5993a8f2 2003-11-23 devnull 				i1--;
309 5993a8f2 2003-11-23 devnull 			j1 = J[i1-1]+1;
310 5993a8f2 2003-11-23 devnull 			J[i1] = j1;
311 5993a8f2 2003-11-23 devnull 			change(i1 , i0, j1, j0);
312 5993a8f2 2003-11-23 devnull 		}
313 5993a8f2 2003-11-23 devnull 	}
314 5993a8f2 2003-11-23 devnull 	if (m == 0)
315 5993a8f2 2003-11-23 devnull 		change(1, 0, 1, len[1]);
316 4ac5f249 2005-01-26 devnull 	flushchanges();
317 5993a8f2 2003-11-23 devnull }
318 5993a8f2 2003-11-23 devnull 
319 5993a8f2 2003-11-23 devnull #define BUF 4096
320 5993a8f2 2003-11-23 devnull static int
321 5993a8f2 2003-11-23 devnull cmp(Biobuf* b1, Biobuf* b2)
322 5993a8f2 2003-11-23 devnull {
323 5993a8f2 2003-11-23 devnull 	int n;
324 5993a8f2 2003-11-23 devnull 	uchar buf1[BUF], buf2[BUF];
325 5993a8f2 2003-11-23 devnull 	int f1, f2;
326 5993a8f2 2003-11-23 devnull 	vlong nc = 1;
327 5993a8f2 2003-11-23 devnull 	uchar *b1s, *b1e, *b2s, *b2e;
328 5993a8f2 2003-11-23 devnull 
329 5993a8f2 2003-11-23 devnull 	f1 = Bfildes(b1);
330 5993a8f2 2003-11-23 devnull 	f2 = Bfildes(b2);
331 5993a8f2 2003-11-23 devnull 	seek(f1, 0, 0);
332 5993a8f2 2003-11-23 devnull 	seek(f2, 0, 0);
333 5993a8f2 2003-11-23 devnull 	b1s = b1e = buf1;
334 5993a8f2 2003-11-23 devnull 	b2s = b2e = buf2;
335 5993a8f2 2003-11-23 devnull 	for(;;){
336 5993a8f2 2003-11-23 devnull 		if(b1s >= b1e){
337 5993a8f2 2003-11-23 devnull 			if(b1s >= &buf1[BUF])
338 5993a8f2 2003-11-23 devnull 				b1s = buf1;
339 5993a8f2 2003-11-23 devnull 			n = read(f1, b1s,  &buf1[BUF] - b1s);
340 5993a8f2 2003-11-23 devnull 			b1e = b1s + n;
341 5993a8f2 2003-11-23 devnull 		}
342 5993a8f2 2003-11-23 devnull 		if(b2s >= b2e){
343 5993a8f2 2003-11-23 devnull 			if(b2s >= &buf2[BUF])
344 5993a8f2 2003-11-23 devnull 				b2s = buf2;
345 5993a8f2 2003-11-23 devnull 			n = read(f2, b2s,  &buf2[BUF] - b2s);
346 5993a8f2 2003-11-23 devnull 			b2e = b2s + n;
347 5993a8f2 2003-11-23 devnull 		}
348 5993a8f2 2003-11-23 devnull 		n = b2e - b2s;
349 5993a8f2 2003-11-23 devnull 		if(n > b1e - b1s)
350 5993a8f2 2003-11-23 devnull 			n = b1e - b1s;
351 5993a8f2 2003-11-23 devnull 		if(n <= 0)
352 5993a8f2 2003-11-23 devnull 			break;
353 5993a8f2 2003-11-23 devnull 		if(memcmp((void *)b1s, (void *)b2s, n) != 0){
354 5993a8f2 2003-11-23 devnull 			return 1;
355 5993a8f2 2003-11-23 devnull 		}		
356 5993a8f2 2003-11-23 devnull 		nc += n;
357 5993a8f2 2003-11-23 devnull 		b1s += n;
358 5993a8f2 2003-11-23 devnull 		b2s += n;
359 5993a8f2 2003-11-23 devnull 	}
360 5993a8f2 2003-11-23 devnull 	if(b1e - b1s == b2e - b2s)
361 5993a8f2 2003-11-23 devnull 		return 0;
362 5993a8f2 2003-11-23 devnull 	return 1;	
363 5993a8f2 2003-11-23 devnull }
364 5993a8f2 2003-11-23 devnull 
365 5993a8f2 2003-11-23 devnull void
366 5993a8f2 2003-11-23 devnull diffreg(char *f, char *t)
367 5993a8f2 2003-11-23 devnull {
368 5993a8f2 2003-11-23 devnull 	Biobuf *b0, *b1;
369 5993a8f2 2003-11-23 devnull 	int k;
370 5993a8f2 2003-11-23 devnull 
371 5993a8f2 2003-11-23 devnull 	binary = 0;
372 5993a8f2 2003-11-23 devnull 	b0 = prepare(0, f);
373 5993a8f2 2003-11-23 devnull 	if (!b0)
374 5993a8f2 2003-11-23 devnull 		return;
375 5993a8f2 2003-11-23 devnull 	b1 = prepare(1, t);
376 5993a8f2 2003-11-23 devnull 	if (!b1) {
377 5993a8f2 2003-11-23 devnull 		FREE(file[0]);
378 5993a8f2 2003-11-23 devnull 		Bterm(b0);
379 5993a8f2 2003-11-23 devnull 		return;
380 5993a8f2 2003-11-23 devnull 	}
381 5993a8f2 2003-11-23 devnull 	if (binary){
382 5993a8f2 2003-11-23 devnull 		// could use b0 and b1 but this is simpler.
383 5993a8f2 2003-11-23 devnull 		if (cmp(b0, b1))
384 5993a8f2 2003-11-23 devnull 			print("binary files %s %s differ\n", f, t);
385 5993a8f2 2003-11-23 devnull 		Bterm(b0);
386 5993a8f2 2003-11-23 devnull 		Bterm(b1);
387 5993a8f2 2003-11-23 devnull 		return;
388 5993a8f2 2003-11-23 devnull 	}
389 5993a8f2 2003-11-23 devnull 	clen = 0;
390 5993a8f2 2003-11-23 devnull 	prune();
391 5993a8f2 2003-11-23 devnull 	sort(sfile[0], slen[0]);
392 5993a8f2 2003-11-23 devnull 	sort(sfile[1], slen[1]);
393 5993a8f2 2003-11-23 devnull 
394 5993a8f2 2003-11-23 devnull 	member = (int *)file[1];
395 5993a8f2 2003-11-23 devnull 	equiv(sfile[0], slen[0], sfile[1], slen[1], member);
396 5993a8f2 2003-11-23 devnull 	member = REALLOC(member, int, slen[1]+2);
397 5993a8f2 2003-11-23 devnull 
398 5993a8f2 2003-11-23 devnull 	class = (int *)file[0];
399 5993a8f2 2003-11-23 devnull 	unsort(sfile[0], slen[0], class);
400 5993a8f2 2003-11-23 devnull 	class = REALLOC(class, int, slen[0]+2);
401 5993a8f2 2003-11-23 devnull 
402 5993a8f2 2003-11-23 devnull 	klist = MALLOC(int, slen[0]+2);
403 5993a8f2 2003-11-23 devnull 	clist = MALLOC(struct cand, 1);
404 5993a8f2 2003-11-23 devnull 	k = stone(class, slen[0], member, klist);
405 5993a8f2 2003-11-23 devnull 	FREE(member);
406 5993a8f2 2003-11-23 devnull 	FREE(class);
407 5993a8f2 2003-11-23 devnull 
408 5993a8f2 2003-11-23 devnull 	J = MALLOC(int, len[0]+2);
409 5993a8f2 2003-11-23 devnull 	unravel(klist[k]);
410 5993a8f2 2003-11-23 devnull 	FREE(clist);
411 5993a8f2 2003-11-23 devnull 	FREE(klist);
412 5993a8f2 2003-11-23 devnull 
413 5993a8f2 2003-11-23 devnull 	ixold = MALLOC(long, len[0]+2);
414 5993a8f2 2003-11-23 devnull 	ixnew = MALLOC(long, len[1]+2);
415 5993a8f2 2003-11-23 devnull 	Bseek(b0, 0, 0); Bseek(b1, 0, 0);
416 5993a8f2 2003-11-23 devnull 	check(b0, b1);
417 5993a8f2 2003-11-23 devnull 	output();
418 5993a8f2 2003-11-23 devnull 	FREE(J); FREE(ixold); FREE(ixnew);
419 5993a8f2 2003-11-23 devnull 	Bterm(b0); Bterm(b1);			/* ++++ */
420 5993a8f2 2003-11-23 devnull }