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 43static 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 104static 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 142static 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 152static 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 178static 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 196int 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