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 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <sys/types.h>
31
32 #include <bzlib.h>
33 #include <err.h>
34 #include <fcntl.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39
40 #ifndef O_BINARY
41 #define O_BINARY 0
42 #endif
43
44 #define MIN(x,y) (((x)<(y)) ? (x) : (y))
45
split(off_t * I,off_t * V,off_t start,off_t len,off_t h)46 static void split(off_t *I,off_t *V,off_t start,off_t len,off_t h)
47 {
48 off_t i,j,k,x,tmp,jj,kk;
49
50 if(len<16) {
51 for(k=start;k<start+len;k+=j) {
52 j=1;x=V[I[k]+h];
53 for(i=1;k+i<start+len;i++) {
54 if(V[I[k+i]+h]<x) {
55 x=V[I[k+i]+h];
56 j=0;
57 };
58 if(V[I[k+i]+h]==x) {
59 tmp=I[k+j];I[k+j]=I[k+i];I[k+i]=tmp;
60 j++;
61 };
62 };
63 for(i=0;i<j;i++) V[I[k+i]]=k+j-1;
64 if(j==1) I[k]=-1;
65 };
66 return;
67 };
68
69 x=V[I[start+len/2]+h];
70 jj=0;kk=0;
71 for(i=start;i<start+len;i++) {
72 if(V[I[i]+h]<x) jj++;
73 if(V[I[i]+h]==x) kk++;
74 };
75 jj+=start;kk+=jj;
76
77 i=start;j=0;k=0;
78 while(i<jj) {
79 if(V[I[i]+h]<x) {
80 i++;
81 } else if(V[I[i]+h]==x) {
82 tmp=I[i];I[i]=I[jj+j];I[jj+j]=tmp;
83 j++;
84 } else {
85 tmp=I[i];I[i]=I[kk+k];I[kk+k]=tmp;
86 k++;
87 };
88 };
89
90 while(jj+j<kk) {
91 if(V[I[jj+j]+h]==x) {
92 j++;
93 } else {
94 tmp=I[jj+j];I[jj+j]=I[kk+k];I[kk+k]=tmp;
95 k++;
96 };
97 };
98
99 if(jj>start) split(I,V,start,jj-start,h);
100
101 for(i=0;i<kk-jj;i++) V[I[jj+i]]=kk-1;
102 if(jj==kk-1) I[jj]=-1;
103
104 if(start+len>kk) split(I,V,kk,start+len-kk,h);
105 }
106
qsufsort(off_t * I,off_t * V,u_char * old,off_t oldsize)107 static void qsufsort(off_t *I,off_t *V,u_char *old,off_t oldsize)
108 {
109 off_t buckets[256];
110 off_t i,h,len;
111
112 for(i=0;i<256;i++) buckets[i]=0;
113 for(i=0;i<oldsize;i++) buckets[old[i]]++;
114 for(i=1;i<256;i++) buckets[i]+=buckets[i-1];
115 for(i=255;i>0;i--) buckets[i]=buckets[i-1];
116 buckets[0]=0;
117
118 for(i=0;i<oldsize;i++) I[++buckets[old[i]]]=i;
119 I[0]=oldsize;
120 for(i=0;i<oldsize;i++) V[i]=buckets[old[i]];
121 V[oldsize]=0;
122 for(i=1;i<256;i++) if(buckets[i]==buckets[i-1]+1) I[buckets[i]]=-1;
123 I[0]=-1;
124
125 for(h=1;I[0]!=-(oldsize+1);h+=h) {
126 len=0;
127 for(i=0;i<oldsize+1;) {
128 if(I[i]<0) {
129 len-=I[i];
130 i-=I[i];
131 } else {
132 if(len) I[i-len]=-len;
133 len=V[I[i]]+1-i;
134 split(I,V,i,len,h);
135 i+=len;
136 len=0;
137 };
138 };
139 if(len) I[i-len]=-len;
140 };
141
142 for(i=0;i<oldsize+1;i++) I[V[i]]=i;
143 }
144
matchlen(u_char * old,off_t oldsize,u_char * new,off_t newsize)145 static off_t matchlen(u_char *old,off_t oldsize,u_char *new,off_t newsize)
146 {
147 off_t i;
148
149 for(i=0;(i<oldsize)&&(i<newsize);i++)
150 if(old[i]!=new[i]) break;
151
152 return i;
153 }
154
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)155 static off_t search(off_t *I,u_char *old,off_t oldsize,
156 u_char *new,off_t newsize,off_t st,off_t en,off_t *pos)
157 {
158 off_t x,y;
159
160 if(en-st<2) {
161 x=matchlen(old+I[st],oldsize-I[st],new,newsize);
162 y=matchlen(old+I[en],oldsize-I[en],new,newsize);
163
164 if(x>y) {
165 *pos=I[st];
166 return x;
167 } else {
168 *pos=I[en];
169 return y;
170 }
171 };
172
173 x=st+(en-st)/2;
174 if(memcmp(old+I[x],new,MIN(oldsize-I[x],newsize))<0) {
175 return search(I,old,oldsize,new,newsize,x,en,pos);
176 } else {
177 return search(I,old,oldsize,new,newsize,st,x,pos);
178 };
179 }
180
offtout(off_t x,u_char * buf)181 static void offtout(off_t x,u_char *buf)
182 {
183 off_t y;
184
185 if(x<0) y=-x; else y=x;
186
187 buf[0]=y%256;y-=buf[0];
188 y=y/256;buf[1]=y%256;y-=buf[1];
189 y=y/256;buf[2]=y%256;y-=buf[2];
190 y=y/256;buf[3]=y%256;y-=buf[3];
191 y=y/256;buf[4]=y%256;y-=buf[4];
192 y=y/256;buf[5]=y%256;y-=buf[5];
193 y=y/256;buf[6]=y%256;y-=buf[6];
194 y=y/256;buf[7]=y%256;
195
196 if(x<0) buf[7]|=0x80;
197 }
198
main(int argc,char * argv[])199 int main(int argc,char *argv[])
200 {
201 int fd;
202 u_char *old,*new;
203 off_t oldsize,newsize;
204 off_t *I,*V;
205 off_t scan,pos,len;
206 off_t lastscan,lastpos,lastoffset;
207 off_t oldscore,scsc;
208 off_t s,Sf,lenf,Sb,lenb;
209 off_t overlap,Ss,lens;
210 off_t i;
211 off_t dblen,eblen;
212 u_char *db,*eb;
213 u_char buf[8];
214 u_char header[32];
215 FILE * pf;
216 BZFILE * pfbz2;
217 int bz2err;
218
219 if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile\n",argv[0]);
220
221 /* Allocate oldsize+1 bytes instead of oldsize bytes to ensure
222 that we never try to malloc(0) and get a NULL pointer */
223 if(((fd=open(argv[1],O_RDONLY|O_BINARY,0))<0) ||
224 ((oldsize=lseek(fd,0,SEEK_END))==-1) ||
225 ((old=malloc(oldsize+1))==NULL) ||
226 (lseek(fd,0,SEEK_SET)!=0) ||
227 (read(fd,old,oldsize)!=oldsize) ||
228 (close(fd)==-1)) err(1,"%s",argv[1]);
229
230 if(((I=malloc((oldsize+1)*sizeof(off_t)))==NULL) ||
231 ((V=malloc((oldsize+1)*sizeof(off_t)))==NULL)) err(1,NULL);
232
233 qsufsort(I,V,old,oldsize);
234
235 free(V);
236
237 /* Allocate newsize+1 bytes instead of newsize bytes to ensure
238 that we never try to malloc(0) and get a NULL pointer */
239 if(((fd=open(argv[2],O_RDONLY|O_BINARY,0))<0) ||
240 ((newsize=lseek(fd,0,SEEK_END))==-1) ||
241 ((new=malloc(newsize+1))==NULL) ||
242 (lseek(fd,0,SEEK_SET)!=0) ||
243 (read(fd,new,newsize)!=newsize) ||
244 (close(fd)==-1)) err(1,"%s",argv[2]);
245
246 if(((db=malloc(newsize+1))==NULL) ||
247 ((eb=malloc(newsize+1))==NULL)) err(1,NULL);
248 dblen=0;
249 eblen=0;
250
251 /* Create the patch file */
252 if ((pf = fopen(argv[3], "wb")) == NULL)
253 err(1, "%s", argv[3]);
254
255 /* Header is
256 0 8 "BSDIFF40"
257 8 8 length of bzip2ed ctrl block
258 16 8 length of bzip2ed diff block
259 24 8 length of new file */
260 /* File is
261 0 32 Header
262 32 ?? Bzip2ed ctrl block
263 ?? ?? Bzip2ed diff block
264 ?? ?? Bzip2ed extra block */
265 memcpy(header,"BSDIFF40",8);
266 offtout(0, header + 8);
267 offtout(0, header + 16);
268 offtout(newsize, header + 24);
269 if (fwrite(header, 32, 1, pf) != 1)
270 err(1, "fwrite(%s)", argv[3]);
271
272 /* Compute the differences, writing ctrl as we go */
273 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
274 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
275 scan=0;len=0;pos=0;
276 lastscan=0;lastpos=0;lastoffset=0;
277 while(scan<newsize) {
278 oldscore=0;
279
280 for(scsc=scan+=len;scan<newsize;scan++) {
281 len=search(I,old,oldsize,new+scan,newsize-scan,
282 0,oldsize,&pos);
283
284 for(;scsc<scan+len;scsc++)
285 if((scsc+lastoffset<oldsize) &&
286 (old[scsc+lastoffset] == new[scsc]))
287 oldscore++;
288
289 if(((len==oldscore) && (len!=0)) ||
290 (len>oldscore+8)) break;
291
292 if((scan+lastoffset<oldsize) &&
293 (old[scan+lastoffset] == new[scan]))
294 oldscore--;
295 };
296
297 if((len!=oldscore) || (scan==newsize)) {
298 s=0;Sf=0;lenf=0;
299 for(i=0;(lastscan+i<scan)&&(lastpos+i<oldsize);) {
300 if(old[lastpos+i]==new[lastscan+i]) s++;
301 i++;
302 if(s*2-i>Sf*2-lenf) { Sf=s; lenf=i; };
303 };
304
305 lenb=0;
306 if(scan<newsize) {
307 s=0;Sb=0;
308 for(i=1;(scan>=lastscan+i)&&(pos>=i);i++) {
309 if(old[pos-i]==new[scan-i]) s++;
310 if(s*2-i>Sb*2-lenb) { Sb=s; lenb=i; };
311 };
312 };
313
314 if(lastscan+lenf>scan-lenb) {
315 overlap=(lastscan+lenf)-(scan-lenb);
316 s=0;Ss=0;lens=0;
317 for(i=0;i<overlap;i++) {
318 if(new[lastscan+lenf-overlap+i]==
319 old[lastpos+lenf-overlap+i]) s++;
320 if(new[scan-lenb+i]==
321 old[pos-lenb+i]) s--;
322 if(s>Ss) { Ss=s; lens=i+1; };
323 };
324
325 lenf+=lens-overlap;
326 lenb-=lens;
327 };
328
329 for(i=0;i<lenf;i++)
330 db[dblen+i]=new[lastscan+i]-old[lastpos+i];
331 for(i=0;i<(scan-lenb)-(lastscan+lenf);i++)
332 eb[eblen+i]=new[lastscan+lenf+i];
333
334 dblen+=lenf;
335 eblen+=(scan-lenb)-(lastscan+lenf);
336
337 offtout(lenf,buf);
338 BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
339 if (bz2err != BZ_OK)
340 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
341
342 offtout((scan-lenb)-(lastscan+lenf),buf);
343 BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
344 if (bz2err != BZ_OK)
345 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
346
347 offtout((pos-lenb)-(lastpos+lenf),buf);
348 BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
349 if (bz2err != BZ_OK)
350 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
351
352 lastscan=scan-lenb;
353 lastpos=pos-lenb;
354 lastoffset=pos-scan;
355 };
356 };
357 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
358 if (bz2err != BZ_OK)
359 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
360
361 /* Compute size of compressed ctrl data */
362 if ((len = ftello(pf)) == -1)
363 err(1, "ftello");
364 offtout(len-32, header + 8);
365
366 /* Write compressed diff data */
367 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
368 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
369 BZ2_bzWrite(&bz2err, pfbz2, db, dblen);
370 if (bz2err != BZ_OK)
371 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
372 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
373 if (bz2err != BZ_OK)
374 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
375
376 /* Compute size of compressed diff data */
377 if ((newsize = ftello(pf)) == -1)
378 err(1, "ftello");
379 offtout(newsize - len, header + 16);
380
381 /* Write compressed extra data */
382 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
383 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
384 BZ2_bzWrite(&bz2err, pfbz2, eb, eblen);
385 if (bz2err != BZ_OK)
386 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
387 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
388 if (bz2err != BZ_OK)
389 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
390
391 /* Seek to the beginning, write the header, and close the file */
392 if (fseeko(pf, 0, SEEK_SET))
393 err(1, "fseeko");
394 if (fwrite(header, 32, 1, pf) != 1)
395 err(1, "fwrite(%s)", argv[3]);
396 if (fclose(pf))
397 err(1, "fclose");
398
399 /* Free the memory we used */
400 free(db);
401 free(eb);
402 free(I);
403 free(old);
404 free(new);
405
406 return 0;
407 }
408