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