1 /*-
2 * Copyright 2003-2005 Colin Percival
3 * All rights reserved
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted providing that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
23 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24 * POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #if 0
28 __FBSDID("$FreeBSD: src/usr.bin/bsdiff/bsdiff/bsdiff.c,v 1.1 2005/08/06 01:59:05 cperciva Exp $");
29 #endif
30
31 #include <sys/types.h>
32
33 #include <bzlib.h>
34 #include <err.h>
35 #include <fcntl.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <unistd.h>
40
41 #define MIN(x,y) (((x)<(y)) ? (x) : (y))
42
split(off_t * I,off_t * V,off_t start,off_t len,off_t h)43 static void split(off_t *I,off_t *V,off_t start,off_t len,off_t h)
44 {
45 off_t i,j,k,x,tmp,jj,kk;
46
47 if(len<16) {
48 for(k=start;k<start+len;k+=j) {
49 j=1;x=V[I[k]+h];
50 for(i=1;k+i<start+len;i++) {
51 if(V[I[k+i]+h]<x) {
52 x=V[I[k+i]+h];
53 j=0;
54 };
55 if(V[I[k+i]+h]==x) {
56 tmp=I[k+j];I[k+j]=I[k+i];I[k+i]=tmp;
57 j++;
58 };
59 };
60 for(i=0;i<j;i++) V[I[k+i]]=k+j-1;
61 if(j==1) I[k]=-1;
62 };
63 return;
64 };
65
66 x=V[I[start+len/2]+h];
67 jj=0;kk=0;
68 for(i=start;i<start+len;i++) {
69 if(V[I[i]+h]<x) jj++;
70 if(V[I[i]+h]==x) kk++;
71 };
72 jj+=start;kk+=jj;
73
74 i=start;j=0;k=0;
75 while(i<jj) {
76 if(V[I[i]+h]<x) {
77 i++;
78 } else if(V[I[i]+h]==x) {
79 tmp=I[i];I[i]=I[jj+j];I[jj+j]=tmp;
80 j++;
81 } else {
82 tmp=I[i];I[i]=I[kk+k];I[kk+k]=tmp;
83 k++;
84 };
85 };
86
87 while(jj+j<kk) {
88 if(V[I[jj+j]+h]==x) {
89 j++;
90 } else {
91 tmp=I[jj+j];I[jj+j]=I[kk+k];I[kk+k]=tmp;
92 k++;
93 };
94 };
95
96 if(jj>start) split(I,V,start,jj-start,h);
97
98 for(i=0;i<kk-jj;i++) V[I[jj+i]]=kk-1;
99 if(jj==kk-1) I[jj]=-1;
100
101 if(start+len>kk) split(I,V,kk,start+len-kk,h);
102 }
103
qsufsort(off_t * I,off_t * V,u_char * old,off_t oldsize)104 static void qsufsort(off_t *I,off_t *V,u_char *old,off_t oldsize)
105 {
106 off_t buckets[256];
107 off_t i,h,len;
108
109 for(i=0;i<256;i++) buckets[i]=0;
110 for(i=0;i<oldsize;i++) buckets[old[i]]++;
111 for(i=1;i<256;i++) buckets[i]+=buckets[i-1];
112 for(i=255;i>0;i--) buckets[i]=buckets[i-1];
113 buckets[0]=0;
114
115 for(i=0;i<oldsize;i++) I[++buckets[old[i]]]=i;
116 I[0]=oldsize;
117 for(i=0;i<oldsize;i++) V[i]=buckets[old[i]];
118 V[oldsize]=0;
119 for(i=1;i<256;i++) if(buckets[i]==buckets[i-1]+1) I[buckets[i]]=-1;
120 I[0]=-1;
121
122 for(h=1;I[0]!=-(oldsize+1);h+=h) {
123 len=0;
124 for(i=0;i<oldsize+1;) {
125 if(I[i]<0) {
126 len-=I[i];
127 i-=I[i];
128 } else {
129 if(len) I[i-len]=-len;
130 len=V[I[i]]+1-i;
131 split(I,V,i,len,h);
132 i+=len;
133 len=0;
134 };
135 };
136 if(len) I[i-len]=-len;
137 };
138
139 for(i=0;i<oldsize+1;i++) I[V[i]]=i;
140 }
141
matchlen(u_char * old,off_t oldsize,u_char * new,off_t newsize)142 static off_t matchlen(u_char *old,off_t oldsize,u_char *new,off_t newsize)
143 {
144 off_t i;
145
146 for(i=0;(i<oldsize)&&(i<newsize);i++)
147 if(old[i]!=new[i]) break;
148
149 return i;
150 }
151
search(off_t * I,u_char * old,off_t oldsize,u_char * new,off_t newsize,off_t st,off_t en,off_t * pos)152 static off_t search(off_t *I,u_char *old,off_t oldsize,
153 u_char *new,off_t newsize,off_t st,off_t en,off_t *pos)
154 {
155 off_t x,y;
156
157 if(en-st<2) {
158 x=matchlen(old+I[st],oldsize-I[st],new,newsize);
159 y=matchlen(old+I[en],oldsize-I[en],new,newsize);
160
161 if(x>y) {
162 *pos=I[st];
163 return x;
164 } else {
165 *pos=I[en];
166 return y;
167 }
168 };
169
170 x=st+(en-st)/2;
171 if(memcmp(old+I[x],new,MIN(oldsize-I[x],newsize))<0) {
172 return search(I,old,oldsize,new,newsize,x,en,pos);
173 } else {
174 return search(I,old,oldsize,new,newsize,st,x,pos);
175 };
176 }
177
offtout(off_t x,u_char * buf)178 static void offtout(off_t x,u_char *buf)
179 {
180 off_t y;
181
182 if(x<0) y=-x; else y=x;
183
184 buf[0]=y%256;y-=buf[0];
185 y=y/256;buf[1]=y%256;y-=buf[1];
186 y=y/256;buf[2]=y%256;y-=buf[2];
187 y=y/256;buf[3]=y%256;y-=buf[3];
188 y=y/256;buf[4]=y%256;y-=buf[4];
189 y=y/256;buf[5]=y%256;y-=buf[5];
190 y=y/256;buf[6]=y%256;y-=buf[6];
191 y=y/256;buf[7]=y%256;
192
193 if(x<0) buf[7]|=0x80;
194 }
195
main(int argc,char * argv[])196 int main(int argc,char *argv[])
197 {
198 int fd;
199 u_char *old,*new;
200 off_t oldsize,newsize;
201 off_t *I,*V;
202 off_t scan,pos,len;
203 off_t lastscan,lastpos,lastoffset;
204 off_t oldscore,scsc;
205 off_t s,Sf,lenf,Sb,lenb;
206 off_t overlap,Ss,lens;
207 off_t i;
208 off_t dblen,eblen;
209 u_char *db,*eb;
210 u_char buf[8];
211 u_char header[32];
212 FILE * pf;
213 BZFILE * pfbz2;
214 int bz2err;
215
216 if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile\n",argv[0]);
217
218 /* Allocate oldsize+1 bytes instead of oldsize bytes to ensure
219 that we never try to malloc(0) and get a NULL pointer */
220 if(((fd=open(argv[1],O_RDONLY,0))<0) ||
221 ((oldsize=lseek(fd,0,SEEK_END))==-1) ||
222 ((old=malloc(oldsize+1))==NULL) ||
223 (lseek(fd,0,SEEK_SET)!=0) ||
224 (read(fd,old,oldsize)!=oldsize) ||
225 (close(fd)==-1)) err(1,"%s",argv[1]);
226
227 if(((I=malloc((oldsize+1)*sizeof(off_t)))==NULL) ||
228 ((V=malloc((oldsize+1)*sizeof(off_t)))==NULL)) err(1,NULL);
229
230 qsufsort(I,V,old,oldsize);
231
232 free(V);
233
234 /* Allocate newsize+1 bytes instead of newsize bytes to ensure
235 that we never try to malloc(0) and get a NULL pointer */
236 if(((fd=open(argv[2],O_RDONLY,0))<0) ||
237 ((newsize=lseek(fd,0,SEEK_END))==-1) ||
238 ((new=malloc(newsize+1))==NULL) ||
239 (lseek(fd,0,SEEK_SET)!=0) ||
240 (read(fd,new,newsize)!=newsize) ||
241 (close(fd)==-1)) err(1,"%s",argv[2]);
242
243 if(((db=malloc(newsize+1))==NULL) ||
244 ((eb=malloc(newsize+1))==NULL)) err(1,NULL);
245 dblen=0;
246 eblen=0;
247
248 /* Create the patch file */
249 if ((pf = fopen(argv[3], "w")) == NULL)
250 err(1, "%s", argv[3]);
251
252 /* Header is
253 0 8 "BSDIFF40"
254 8 8 length of bzip2ed ctrl block
255 16 8 length of bzip2ed diff block
256 24 8 length of new file */
257 /* File is
258 0 32 Header
259 32 ?? Bzip2ed ctrl block
260 ?? ?? Bzip2ed diff block
261 ?? ?? Bzip2ed extra block */
262 memcpy(header,"BSDIFF40",8);
263 offtout(0, header + 8);
264 offtout(0, header + 16);
265 offtout(newsize, header + 24);
266 if (fwrite(header, 32, 1, pf) != 1)
267 err(1, "fwrite(%s)", argv[3]);
268
269 /* Compute the differences, writing ctrl as we go */
270 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
271 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
272 scan=0;len=0;
273 lastscan=0;lastpos=0;lastoffset=0;
274 while(scan<newsize) {
275 oldscore=0;
276
277 for(scsc=scan+=len;scan<newsize;scan++) {
278 len=search(I,old,oldsize,new+scan,newsize-scan,
279 0,oldsize,&pos);
280
281 for(;scsc<scan+len;scsc++)
282 if((scsc+lastoffset<oldsize) &&
283 (old[scsc+lastoffset] == new[scsc]))
284 oldscore++;
285
286 if(((len==oldscore) && (len!=0)) ||
287 (len>oldscore+8)) break;
288
289 if((scan+lastoffset<oldsize) &&
290 (old[scan+lastoffset] == new[scan]))
291 oldscore--;
292 };
293
294 if((len!=oldscore) || (scan==newsize)) {
295 s=0;Sf=0;lenf=0;
296 for(i=0;(lastscan+i<scan)&&(lastpos+i<oldsize);) {
297 if(old[lastpos+i]==new[lastscan+i]) s++;
298 i++;
299 if(s*2-i>Sf*2-lenf) { Sf=s; lenf=i; };
300 };
301
302 lenb=0;
303 if(scan<newsize) {
304 s=0;Sb=0;
305 for(i=1;(scan>=lastscan+i)&&(pos>=i);i++) {
306 if(old[pos-i]==new[scan-i]) s++;
307 if(s*2-i>Sb*2-lenb) { Sb=s; lenb=i; };
308 };
309 };
310
311 if(lastscan+lenf>scan-lenb) {
312 overlap=(lastscan+lenf)-(scan-lenb);
313 s=0;Ss=0;lens=0;
314 for(i=0;i<overlap;i++) {
315 if(new[lastscan+lenf-overlap+i]==
316 old[lastpos+lenf-overlap+i]) s++;
317 if(new[scan-lenb+i]==
318 old[pos-lenb+i]) s--;
319 if(s>Ss) { Ss=s; lens=i+1; };
320 };
321
322 lenf+=lens-overlap;
323 lenb-=lens;
324 };
325
326 for(i=0;i<lenf;i++)
327 db[dblen+i]=new[lastscan+i]-old[lastpos+i];
328 for(i=0;i<(scan-lenb)-(lastscan+lenf);i++)
329 eb[eblen+i]=new[lastscan+lenf+i];
330
331 dblen+=lenf;
332 eblen+=(scan-lenb)-(lastscan+lenf);
333
334 offtout(lenf,buf);
335 BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
336 if (bz2err != BZ_OK)
337 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
338
339 offtout((scan-lenb)-(lastscan+lenf),buf);
340 BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
341 if (bz2err != BZ_OK)
342 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
343
344 offtout((pos-lenb)-(lastpos+lenf),buf);
345 BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
346 if (bz2err != BZ_OK)
347 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
348
349 lastscan=scan-lenb;
350 lastpos=pos-lenb;
351 lastoffset=pos-scan;
352 };
353 };
354 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
355 if (bz2err != BZ_OK)
356 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
357
358 /* Compute size of compressed ctrl data */
359 if ((len = ftello(pf)) == -1)
360 err(1, "ftello");
361 offtout(len-32, header + 8);
362
363 /* Write compressed diff data */
364 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
365 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
366 BZ2_bzWrite(&bz2err, pfbz2, db, dblen);
367 if (bz2err != BZ_OK)
368 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
369 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
370 if (bz2err != BZ_OK)
371 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
372
373 /* Compute size of compressed diff data */
374 if ((newsize = ftello(pf)) == -1)
375 err(1, "ftello");
376 offtout(newsize - len, header + 16);
377
378 /* Write compressed extra data */
379 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
380 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
381 BZ2_bzWrite(&bz2err, pfbz2, eb, eblen);
382 if (bz2err != BZ_OK)
383 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
384 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
385 if (bz2err != BZ_OK)
386 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
387
388 /* Seek to the beginning, write the header, and close the file */
389 if (fseeko(pf, 0, SEEK_SET))
390 err(1, "fseeko");
391 if (fwrite(header, 32, 1, pf) != 1)
392 err(1, "fwrite(%s)", argv[3]);
393 if (fclose(pf))
394 err(1, "fclose");
395
396 /* Free the memory we used */
397 free(db);
398 free(eb);
399 free(I);
400 free(old);
401 free(new);
402
403 return 0;
404 }
405