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 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 } 106 107 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 } 144 145 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 } 154 155 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 } 180 181 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 } 198 199 static void 200 usage(void) 201 { 202 203 fprintf(stderr, "usage: bsdiff oldfile newfile patchfile\n"); 204 exit(1); 205 } 206 207 int main(int argc,char *argv[]) 208 { 209 int fd; 210 u_char *old,*new; 211 off_t oldsize,newsize; 212 off_t *I,*V; 213 off_t scan,pos,len; 214 off_t lastscan,lastpos,lastoffset; 215 off_t oldscore,scsc; 216 off_t s,Sf,lenf,Sb,lenb; 217 off_t overlap,Ss,lens; 218 off_t i; 219 off_t dblen,eblen; 220 u_char *db,*eb; 221 u_char buf[8]; 222 u_char header[32]; 223 FILE * pf; 224 BZFILE * pfbz2; 225 int bz2err; 226 227 if (argc != 4) 228 usage(); 229 230 /* Allocate oldsize+1 bytes instead of oldsize bytes to ensure 231 that we never try to malloc(0) and get a NULL pointer */ 232 if(((fd=open(argv[1],O_RDONLY|O_BINARY,0))<0) || 233 ((oldsize=lseek(fd,0,SEEK_END))==-1) || 234 ((old=malloc(oldsize+1))==NULL) || 235 (lseek(fd,0,SEEK_SET)!=0) || 236 (read(fd,old,oldsize)!=oldsize) || 237 (close(fd)==-1)) err(1,"%s",argv[1]); 238 239 if(((I=malloc((oldsize+1)*sizeof(off_t)))==NULL) || 240 ((V=malloc((oldsize+1)*sizeof(off_t)))==NULL)) err(1,NULL); 241 242 qsufsort(I,V,old,oldsize); 243 244 free(V); 245 246 /* Allocate newsize+1 bytes instead of newsize bytes to ensure 247 that we never try to malloc(0) and get a NULL pointer */ 248 if(((fd=open(argv[2],O_RDONLY|O_BINARY,0))<0) || 249 ((newsize=lseek(fd,0,SEEK_END))==-1) || 250 ((new=malloc(newsize+1))==NULL) || 251 (lseek(fd,0,SEEK_SET)!=0) || 252 (read(fd,new,newsize)!=newsize) || 253 (close(fd)==-1)) err(1,"%s",argv[2]); 254 255 if(((db=malloc(newsize+1))==NULL) || 256 ((eb=malloc(newsize+1))==NULL)) err(1,NULL); 257 dblen=0; 258 eblen=0; 259 260 /* Create the patch file */ 261 if ((pf = fopen(argv[3], "wb")) == NULL) 262 err(1, "%s", argv[3]); 263 264 /* Header is 265 0 8 "BSDIFF40" 266 8 8 length of bzip2ed ctrl block 267 16 8 length of bzip2ed diff block 268 24 8 length of new file */ 269 /* File is 270 0 32 Header 271 32 ?? Bzip2ed ctrl block 272 ?? ?? Bzip2ed diff block 273 ?? ?? Bzip2ed extra block */ 274 memcpy(header,"BSDIFF40",8); 275 offtout(0, header + 8); 276 offtout(0, header + 16); 277 offtout(newsize, header + 24); 278 if (fwrite(header, 32, 1, pf) != 1) 279 err(1, "fwrite(%s)", argv[3]); 280 281 /* Compute the differences, writing ctrl as we go */ 282 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL) 283 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err); 284 scan=0;len=0;pos=0; 285 lastscan=0;lastpos=0;lastoffset=0; 286 while(scan<newsize) { 287 oldscore=0; 288 289 for(scsc=scan+=len;scan<newsize;scan++) { 290 len=search(I,old,oldsize,new+scan,newsize-scan, 291 0,oldsize,&pos); 292 293 for(;scsc<scan+len;scsc++) 294 if((scsc+lastoffset<oldsize) && 295 (old[scsc+lastoffset] == new[scsc])) 296 oldscore++; 297 298 if(((len==oldscore) && (len!=0)) || 299 (len>oldscore+8)) break; 300 301 if((scan+lastoffset<oldsize) && 302 (old[scan+lastoffset] == new[scan])) 303 oldscore--; 304 }; 305 306 if((len!=oldscore) || (scan==newsize)) { 307 s=0;Sf=0;lenf=0; 308 for(i=0;(lastscan+i<scan)&&(lastpos+i<oldsize);) { 309 if(old[lastpos+i]==new[lastscan+i]) s++; 310 i++; 311 if(s*2-i>Sf*2-lenf) { Sf=s; lenf=i; }; 312 }; 313 314 lenb=0; 315 if(scan<newsize) { 316 s=0;Sb=0; 317 for(i=1;(scan>=lastscan+i)&&(pos>=i);i++) { 318 if(old[pos-i]==new[scan-i]) s++; 319 if(s*2-i>Sb*2-lenb) { Sb=s; lenb=i; }; 320 }; 321 }; 322 323 if(lastscan+lenf>scan-lenb) { 324 overlap=(lastscan+lenf)-(scan-lenb); 325 s=0;Ss=0;lens=0; 326 for(i=0;i<overlap;i++) { 327 if(new[lastscan+lenf-overlap+i]== 328 old[lastpos+lenf-overlap+i]) s++; 329 if(new[scan-lenb+i]== 330 old[pos-lenb+i]) s--; 331 if(s>Ss) { Ss=s; lens=i+1; }; 332 }; 333 334 lenf+=lens-overlap; 335 lenb-=lens; 336 }; 337 338 for(i=0;i<lenf;i++) 339 db[dblen+i]=new[lastscan+i]-old[lastpos+i]; 340 for(i=0;i<(scan-lenb)-(lastscan+lenf);i++) 341 eb[eblen+i]=new[lastscan+lenf+i]; 342 343 dblen+=lenf; 344 eblen+=(scan-lenb)-(lastscan+lenf); 345 346 offtout(lenf,buf); 347 BZ2_bzWrite(&bz2err, pfbz2, buf, 8); 348 if (bz2err != BZ_OK) 349 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 350 351 offtout((scan-lenb)-(lastscan+lenf),buf); 352 BZ2_bzWrite(&bz2err, pfbz2, buf, 8); 353 if (bz2err != BZ_OK) 354 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 355 356 offtout((pos-lenb)-(lastpos+lenf),buf); 357 BZ2_bzWrite(&bz2err, pfbz2, buf, 8); 358 if (bz2err != BZ_OK) 359 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 360 361 lastscan=scan-lenb; 362 lastpos=pos-lenb; 363 lastoffset=pos-scan; 364 }; 365 }; 366 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL); 367 if (bz2err != BZ_OK) 368 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err); 369 370 /* Compute size of compressed ctrl data */ 371 if ((len = ftello(pf)) == -1) 372 err(1, "ftello"); 373 offtout(len-32, header + 8); 374 375 /* Write compressed diff data */ 376 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL) 377 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err); 378 BZ2_bzWrite(&bz2err, pfbz2, db, dblen); 379 if (bz2err != BZ_OK) 380 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 381 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL); 382 if (bz2err != BZ_OK) 383 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err); 384 385 /* Compute size of compressed diff data */ 386 if ((newsize = ftello(pf)) == -1) 387 err(1, "ftello"); 388 offtout(newsize - len, header + 16); 389 390 /* Write compressed extra data */ 391 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL) 392 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err); 393 BZ2_bzWrite(&bz2err, pfbz2, eb, eblen); 394 if (bz2err != BZ_OK) 395 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 396 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL); 397 if (bz2err != BZ_OK) 398 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err); 399 400 /* Seek to the beginning, write the header, and close the file */ 401 if (fseeko(pf, 0, SEEK_SET)) 402 err(1, "fseeko"); 403 if (fwrite(header, 32, 1, pf) != 1) 404 err(1, "fwrite(%s)", argv[3]); 405 if (fclose(pf)) 406 err(1, "fclose"); 407 408 /* Free the memory we used */ 409 free(db); 410 free(eb); 411 free(I); 412 free(old); 413 free(new); 414 415 return 0; 416 } 417