| 1 | // -*- mode: cpp; mode: fold -*- |
| 2 | // Description /*{{{*/ |
| 3 | // $Id: tagfile.cc,v 1.26 2001/02/20 07:03:17 jgg Exp $ |
| 4 | /* ###################################################################### |
| 5 | |
| 6 | Fast scanner for RFC-822 type header information |
| 7 | |
| 8 | This uses a rotating buffer to load the package information into. |
| 9 | The scanner runs over it and isolates and indexes a single section. |
| 10 | |
| 11 | ##################################################################### */ |
| 12 | /*}}}*/ |
| 13 | // Include Files /*{{{*/ |
| 14 | #ifdef __GNUG__ |
| 15 | #pragma implementation "apt-pkg/tagfile.h" |
| 16 | #endif |
| 17 | |
| 18 | #include <apt-pkg/tagfile.h> |
| 19 | #include <apt-pkg/error.h> |
| 20 | #include <apt-pkg/strutl.h> |
| 21 | |
| 22 | #include <apti18n.h> |
| 23 | |
| 24 | #include <string> |
| 25 | #include <stdio.h> |
| 26 | /*}}}*/ |
| 27 | |
| 28 | // TagFile::pkgTagFile - Constructor /*{{{*/ |
| 29 | // --------------------------------------------------------------------- |
| 30 | /* */ |
| 31 | pkgTagFile::pkgTagFile(FileFd *pFd,unsigned long Size) : Fd(*pFd), Size(Size) |
| 32 | { |
| 33 | Buffer = new char[Size]; |
| 34 | Start = End = Buffer; |
| 35 | Left = Fd.Size(); |
| 36 | TotalSize = Fd.Size(); |
| 37 | iOffset = 0; |
| 38 | Fill(); |
| 39 | } |
| 40 | /*}}}*/ |
| 41 | // TagFile::~pkgTagFile - Destructor /*{{{*/ |
| 42 | // --------------------------------------------------------------------- |
| 43 | /* */ |
| 44 | pkgTagFile::~pkgTagFile() |
| 45 | { |
| 46 | delete [] Buffer; |
| 47 | } |
| 48 | /*}}}*/ |
| 49 | // TagFile::Step - Advance to the next section /*{{{*/ |
| 50 | // --------------------------------------------------------------------- |
| 51 | /* If the Section Scanner fails we refill the buffer and try again. */ |
| 52 | bool pkgTagFile::Step(pkgTagSection &Tag) |
| 53 | { |
| 54 | if (Tag.Scan(Start,End - Start) == false) |
| 55 | { |
| 56 | if (Fill() == false) |
| 57 | return false; |
| 58 | |
| 59 | if (Tag.Scan(Start,End - Start) == false) |
| 60 | return _error->Error(_("Unable to parse package file %s (1)"),Fd.Name().c_str()); |
| 61 | } |
| 62 | Start += Tag.size(); |
| 63 | iOffset += Tag.size(); |
| 64 | |
| 65 | Tag.Trim(); |
| 66 | |
| 67 | return true; |
| 68 | } |
| 69 | /*}}}*/ |
| 70 | // TagFile::Fill - Top up the buffer /*{{{*/ |
| 71 | // --------------------------------------------------------------------- |
| 72 | /* This takes the bit at the end of the buffer and puts it at the start |
| 73 | then fills the rest from the file */ |
| 74 | bool pkgTagFile::Fill() |
| 75 | { |
| 76 | unsigned long EndSize = End - Start; |
| 77 | |
| 78 | memmove(Buffer,Start,EndSize); |
| 79 | Start = Buffer; |
| 80 | End = Buffer + EndSize; |
| 81 | |
| 82 | if (Left == 0) |
| 83 | { |
| 84 | if (EndSize <= 3) |
| 85 | return false; |
| 86 | if (Size - (End - Buffer) < 4) |
| 87 | return true; |
| 88 | |
| 89 | // Append a double new line if one does not exist |
| 90 | unsigned int LineCount = 0; |
| 91 | for (const char *E = End - 1; E - End < 6 && (*E == '\n' || *E == '\r'); E--) |
| 92 | if (*E == '\n') |
| 93 | LineCount++; |
| 94 | for (; LineCount < 2; LineCount++) |
| 95 | *End++ = '\n'; |
| 96 | |
| 97 | return true; |
| 98 | } |
| 99 | |
| 100 | // See if only a bit of the file is left |
| 101 | if (Left < Size - (End - Buffer)) |
| 102 | { |
| 103 | if (Fd.Read(End,Left) == false) |
| 104 | return false; |
| 105 | |
| 106 | End += Left; |
| 107 | Left = 0; |
| 108 | } |
| 109 | else |
| 110 | { |
| 111 | if (Fd.Read(End,Size - (End - Buffer)) == false) |
| 112 | return false; |
| 113 | |
| 114 | Left -= Size - (End - Buffer); |
| 115 | End = Buffer + Size; |
| 116 | } |
| 117 | return true; |
| 118 | } |
| 119 | /*}}}*/ |
| 120 | // TagFile::Jump - Jump to a pre-recorded location in the file /*{{{*/ |
| 121 | // --------------------------------------------------------------------- |
| 122 | /* This jumps to a pre-recorded file location and reads the record |
| 123 | that is there */ |
| 124 | bool pkgTagFile::Jump(pkgTagSection &Tag,unsigned long Offset) |
| 125 | { |
| 126 | // We are within a buffer space of the next hit.. |
| 127 | if (Offset >= iOffset && iOffset + (End - Start) > Offset) |
| 128 | { |
| 129 | unsigned long Dist = Offset - iOffset; |
| 130 | Start += Dist; |
| 131 | iOffset += Dist; |
| 132 | return Step(Tag); |
| 133 | } |
| 134 | |
| 135 | // Reposition and reload.. |
| 136 | iOffset = Offset; |
| 137 | Left = TotalSize - Offset; |
| 138 | if (Fd.Seek(Offset) == false) |
| 139 | return false; |
| 140 | End = Start = Buffer; |
| 141 | |
| 142 | if (Fill() == false) |
| 143 | return false; |
| 144 | |
| 145 | if (Tag.Scan(Start,End - Start) == true) |
| 146 | return true; |
| 147 | |
| 148 | // This appends a double new line (for the real eof handling) |
| 149 | if (Fill() == false) |
| 150 | return false; |
| 151 | |
| 152 | if (Tag.Scan(Start,End - Start) == false) |
| 153 | return _error->Error(_("Unable to parse package file %s (2)"),Fd.Name().c_str()); |
| 154 | |
| 155 | return true; |
| 156 | } |
| 157 | /*}}}*/ |
| 158 | // TagSection::Scan - Scan for the end of the header information /*{{{*/ |
| 159 | // --------------------------------------------------------------------- |
| 160 | /* This looks for the first double new line in the data stream. It also |
| 161 | indexes the tags in the section. This very simple hash function for the |
| 162 | first 3 letters gives very good performance on the debian package files */ |
| 163 | inline static unsigned long AlphaHash(const char *Text, const char *End = 0) |
| 164 | { |
| 165 | unsigned long Res = 0; |
| 166 | for (; Text != End && *Text != ':' && *Text != 0; Text++) |
| 167 | Res = (unsigned long)(*Text) ^ (Res << 2); |
| 168 | return Res & 0xFF; |
| 169 | } |
| 170 | |
| 171 | bool pkgTagSection::Scan(const char *Start,unsigned long MaxLength) |
| 172 | { |
| 173 | const char *End = Start + MaxLength; |
| 174 | Stop = Section = Start; |
| 175 | memset(AlphaIndexes,0,sizeof(AlphaIndexes)); |
| 176 | |
| 177 | if (Stop == 0) |
| 178 | return false; |
| 179 | |
| 180 | TagCount = 0; |
| 181 | while (TagCount < sizeof(Indexes)/sizeof(Indexes[0]) && Stop < End) |
| 182 | { |
| 183 | // Start a new index and add it to the hash |
| 184 | if (isspace(Stop[0]) == 0) |
| 185 | { |
| 186 | Indexes[TagCount++] = Stop - Section; |
| 187 | AlphaIndexes[AlphaHash(Stop,End)] = TagCount; |
| 188 | } |
| 189 | |
| 190 | Stop = (const char *)memchr(Stop,'\n',End - Stop); |
| 191 | |
| 192 | if (Stop == 0) |
| 193 | return false; |
| 194 | |
| 195 | for (; Stop[1] == '\r' && Stop+1 < End; Stop++); |
| 196 | |
| 197 | // Double newline marks the end of the record |
| 198 | if (Stop+1 < End && Stop[1] == '\n') |
| 199 | { |
| 200 | Indexes[TagCount] = Stop - Section; |
| 201 | for (; (Stop[0] == '\n' || Stop[0] == '\r') && Stop < End; Stop++); |
| 202 | return true; |
| 203 | } |
| 204 | |
| 205 | Stop++; |
| 206 | } |
| 207 | |
| 208 | return false; |
| 209 | } |
| 210 | /*}}}*/ |
| 211 | // TagSection::Trim - Trim off any trailing garbage /*{{{*/ |
| 212 | // --------------------------------------------------------------------- |
| 213 | /* There should be exactly 1 newline at the end of the buffer, no more. */ |
| 214 | void pkgTagSection::Trim() |
| 215 | { |
| 216 | for (; Stop > Section + 2 && (Stop[-2] == '\n' || Stop[-2] == '\r'); Stop--); |
| 217 | } |
| 218 | /*}}}*/ |
| 219 | // TagSection::Find - Locate a tag /*{{{*/ |
| 220 | // --------------------------------------------------------------------- |
| 221 | /* This searches the section for a tag that matches the given string. */ |
| 222 | bool pkgTagSection::Find(const char *Tag,unsigned &Pos) const |
| 223 | { |
| 224 | unsigned int Length = strlen(Tag); |
| 225 | unsigned int I = AlphaIndexes[AlphaHash(Tag)]; |
| 226 | if (I == 0) |
| 227 | return false; |
| 228 | I--; |
| 229 | |
| 230 | for (unsigned int Counter = 0; Counter != TagCount; Counter++, |
| 231 | I = (I+1)%TagCount) |
| 232 | { |
| 233 | const char *St; |
| 234 | St = Section + Indexes[I]; |
| 235 | if (strncasecmp(Tag,St,Length) != 0) |
| 236 | continue; |
| 237 | |
| 238 | // Make sure the colon is in the right place |
| 239 | const char *C = St + Length; |
| 240 | for (; isspace(*C) != 0; C++); |
| 241 | if (*C != ':') |
| 242 | continue; |
| 243 | Pos = I; |
| 244 | return true; |
| 245 | } |
| 246 | |
| 247 | Pos = 0; |
| 248 | return false; |
| 249 | } |
| 250 | /*}}}*/ |
| 251 | // TagSection::Find - Locate a tag /*{{{*/ |
| 252 | // --------------------------------------------------------------------- |
| 253 | /* This searches the section for a tag that matches the given string. */ |
| 254 | bool pkgTagSection::Find(const char *Tag,const char *&Start, |
| 255 | const char *&End) const |
| 256 | { |
| 257 | unsigned int Length = strlen(Tag); |
| 258 | unsigned int I = AlphaIndexes[AlphaHash(Tag)]; |
| 259 | if (I == 0) |
| 260 | return false; |
| 261 | I--; |
| 262 | |
| 263 | for (unsigned int Counter = 0; Counter != TagCount; Counter++, |
| 264 | I = (I+1)%TagCount) |
| 265 | { |
| 266 | const char *St; |
| 267 | St = Section + Indexes[I]; |
| 268 | if (strncasecmp(Tag,St,Length) != 0) |
| 269 | continue; |
| 270 | |
| 271 | // Make sure the colon is in the right place |
| 272 | const char *C = St + Length; |
| 273 | for (; isspace(*C) != 0; C++); |
| 274 | if (*C != ':') |
| 275 | continue; |
| 276 | |
| 277 | // Strip off the gunk from the start end |
| 278 | Start = C; |
| 279 | End = Section + Indexes[I+1]; |
| 280 | if (Start >= End) |
| 281 | return _error->Error("Internal parsing error"); |
| 282 | |
| 283 | for (; (isspace(*Start) != 0 || *Start == ':') && Start < End; Start++); |
| 284 | for (; isspace(End[-1]) != 0 && End > Start; End--); |
| 285 | |
| 286 | return true; |
| 287 | } |
| 288 | |
| 289 | Start = End = 0; |
| 290 | return false; |
| 291 | } |
| 292 | /*}}}*/ |
| 293 | // TagSection::FindS - Find a string /*{{{*/ |
| 294 | // --------------------------------------------------------------------- |
| 295 | /* */ |
| 296 | string pkgTagSection::FindS(const char *Tag) const |
| 297 | { |
| 298 | const char *Start; |
| 299 | const char *End; |
| 300 | if (Find(Tag,Start,End) == false) |
| 301 | return string(); |
| 302 | return string(Start,End); |
| 303 | } |
| 304 | /*}}}*/ |
| 305 | // TagSection::FindI - Find an integer /*{{{*/ |
| 306 | // --------------------------------------------------------------------- |
| 307 | /* */ |
| 308 | signed int pkgTagSection::FindI(const char *Tag,signed long Default) const |
| 309 | { |
| 310 | const char *Start; |
| 311 | const char *Stop; |
| 312 | if (Find(Tag,Start,Stop) == false) |
| 313 | return Default; |
| 314 | |
| 315 | // Copy it into a temp buffer so we can use strtol |
| 316 | char S[300]; |
| 317 | if ((unsigned)(Stop - Start) >= sizeof(S)) |
| 318 | return Default; |
| 319 | strncpy(S,Start,Stop-Start); |
| 320 | S[Stop - Start] = 0; |
| 321 | |
| 322 | char *End; |
| 323 | signed long Result = strtol(S,&End,10); |
| 324 | if (S == End) |
| 325 | return Default; |
| 326 | return Result; |
| 327 | } |
| 328 | /*}}}*/ |
| 329 | // TagSection::FindFlag - Locate a yes/no type flag /*{{{*/ |
| 330 | // --------------------------------------------------------------------- |
| 331 | /* The bits marked in Flag are masked on/off in Flags */ |
| 332 | bool pkgTagSection::FindFlag(const char *Tag,unsigned long &Flags, |
| 333 | unsigned long Flag) const |
| 334 | { |
| 335 | const char *Start; |
| 336 | const char *Stop; |
| 337 | if (Find(Tag,Start,Stop) == false) |
| 338 | return true; |
| 339 | |
| 340 | switch (StringToBool(string(Start,Stop))) |
| 341 | { |
| 342 | case 0: |
| 343 | Flags &= ~Flag; |
| 344 | return true; |
| 345 | |
| 346 | case 1: |
| 347 | Flags |= Flag; |
| 348 | return true; |
| 349 | |
| 350 | default: |
| 351 | _error->Warning("Unknown flag value: %s",string(Start,Stop).c_str()); |
| 352 | return true; |
| 353 | } |
| 354 | return true; |
| 355 | } |
| 356 | /*}}}*/ |
| 357 | |
| 358 | // TFRewrite - Rewrite a control record /*{{{*/ |
| 359 | // --------------------------------------------------------------------- |
| 360 | /* This writes the control record to stdout rewriting it as necessary. The |
| 361 | override map item specificies the rewriting rules to follow. This also |
| 362 | takes the time to sort the feild list. */ |
| 363 | |
| 364 | /* The order of this list is taken from dpkg source lib/parse.c the fieldinfos |
| 365 | array. */ |
| 366 | static const char *iTFRewritePackageOrder[] = { |
| 367 | "Package", |
| 368 | "Essential", |
| 369 | "Status", |
| 370 | "Priority", |
| 371 | "Section", |
| 372 | "Installed-Size", |
| 373 | "Maintainer", |
| 374 | "Architecture", |
| 375 | "Source", |
| 376 | "Version", |
| 377 | "Revision", // Obsolete |
| 378 | "Config-Version", // Obsolete |
| 379 | "Replaces", |
| 380 | "Provides", |
| 381 | "Depends", |
| 382 | "Pre-Depends", |
| 383 | "Recommends", |
| 384 | "Suggests", |
| 385 | "Conflicts", |
| 386 | "Conffiles", |
| 387 | "Filename", |
| 388 | "Size", |
| 389 | "MD5Sum", |
| 390 | "MSDOS-Filename", // Obsolete |
| 391 | "Description", |
| 392 | 0}; |
| 393 | static const char *iTFRewriteSourceOrder[] = {"Package", |
| 394 | "Source", |
| 395 | "Binary", |
| 396 | "Version", |
| 397 | "Priority", |
| 398 | "Section", |
| 399 | "Maintainer", |
| 400 | "Build-Depends", |
| 401 | "Build-Depends-Indep", |
| 402 | "Build-Conflicts", |
| 403 | "Build-Conflicts-Indep", |
| 404 | "Architecture", |
| 405 | "Standards-Version", |
| 406 | "Format", |
| 407 | "Directory", |
| 408 | "Files", |
| 409 | 0}; |
| 410 | |
| 411 | /* Two levels of initialization are used because gcc will set the symbol |
| 412 | size of an array to the length of the array, causing dynamic relinking |
| 413 | errors. Doing this makes the symbol size constant */ |
| 414 | const char **TFRewritePackageOrder = iTFRewritePackageOrder; |
| 415 | const char **TFRewriteSourceOrder = iTFRewriteSourceOrder; |
| 416 | |
| 417 | bool TFRewrite(FILE *Output,pkgTagSection const &Tags,const char *Order[], |
| 418 | TFRewriteData *Rewrite) |
| 419 | { |
| 420 | unsigned char Visited[256]; // Bit 1 is Order, Bit 2 is Rewrite |
| 421 | for (unsigned I = 0; I != 256; I++) |
| 422 | Visited[I] = 0; |
| 423 | |
| 424 | // Set new tag up as necessary. |
| 425 | for (unsigned int J = 0; Rewrite != 0 && Rewrite[J].Tag != 0; J++) |
| 426 | { |
| 427 | if (Rewrite[J].NewTag == 0) |
| 428 | Rewrite[J].NewTag = Rewrite[J].Tag; |
| 429 | } |
| 430 | |
| 431 | // Write all all of the tags, in order. |
| 432 | for (unsigned int I = 0; Order[I] != 0; I++) |
| 433 | { |
| 434 | bool Rewritten = false; |
| 435 | |
| 436 | // See if this is a field that needs to be rewritten |
| 437 | for (unsigned int J = 0; Rewrite != 0 && Rewrite[J].Tag != 0; J++) |
| 438 | { |
| 439 | if (strcasecmp(Rewrite[J].Tag,Order[I]) == 0) |
| 440 | { |
| 441 | Visited[J] |= 2; |
| 442 | if (Rewrite[J].Rewrite != 0 && Rewrite[J].Rewrite[0] != 0) |
| 443 | { |
| 444 | if (isspace(Rewrite[J].Rewrite[0])) |
| 445 | fprintf(Output,"%s:%s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite); |
| 446 | else |
| 447 | fprintf(Output,"%s: %s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite); |
| 448 | } |
| 449 | |
| 450 | Rewritten = true; |
| 451 | break; |
| 452 | } |
| 453 | } |
| 454 | |
| 455 | // See if it is in the fragment |
| 456 | unsigned Pos; |
| 457 | if (Tags.Find(Order[I],Pos) == false) |
| 458 | continue; |
| 459 | Visited[Pos] |= 1; |
| 460 | |
| 461 | if (Rewritten == true) |
| 462 | continue; |
| 463 | |
| 464 | /* Write out this element, taking a moment to rewrite the tag |
| 465 | in case of changes of case. */ |
| 466 | const char *Start; |
| 467 | const char *Stop; |
| 468 | Tags.Get(Start,Stop,Pos); |
| 469 | |
| 470 | if (fputs(Order[I],Output) < 0) |
| 471 | return _error->Errno("fputs","IO Error to output"); |
| 472 | Start += strlen(Order[I]); |
| 473 | if (fwrite(Start,Stop - Start,1,Output) != 1) |
| 474 | return _error->Errno("fwrite","IO Error to output"); |
| 475 | if (Stop[-1] != '\n') |
| 476 | fprintf(Output,"\n"); |
| 477 | } |
| 478 | |
| 479 | // Now write all the old tags that were missed. |
| 480 | for (unsigned int I = 0; I != Tags.Count(); I++) |
| 481 | { |
| 482 | if ((Visited[I] & 1) == 1) |
| 483 | continue; |
| 484 | |
| 485 | const char *Start; |
| 486 | const char *Stop; |
| 487 | Tags.Get(Start,Stop,I); |
| 488 | const char *End = Start; |
| 489 | for (; End < Stop && *End != ':'; End++); |
| 490 | |
| 491 | // See if this is a field that needs to be rewritten |
| 492 | bool Rewritten = false; |
| 493 | for (unsigned int J = 0; Rewrite != 0 && Rewrite[J].Tag != 0; J++) |
| 494 | { |
| 495 | if (stringcasecmp(Start,End,Rewrite[J].Tag) == 0) |
| 496 | { |
| 497 | Visited[J] |= 2; |
| 498 | if (Rewrite[J].Rewrite != 0 && Rewrite[J].Rewrite[0] != 0) |
| 499 | { |
| 500 | if (isspace(Rewrite[J].Rewrite[0])) |
| 501 | fprintf(Output,"%s:%s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite); |
| 502 | else |
| 503 | fprintf(Output,"%s: %s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite); |
| 504 | } |
| 505 | |
| 506 | Rewritten = true; |
| 507 | break; |
| 508 | } |
| 509 | } |
| 510 | |
| 511 | if (Rewritten == true) |
| 512 | continue; |
| 513 | |
| 514 | // Write out this element |
| 515 | if (fwrite(Start,Stop - Start,1,Output) != 1) |
| 516 | return _error->Errno("fwrite","IO Error to output"); |
| 517 | if (Stop[-1] != '\n') |
| 518 | fprintf(Output,"\n"); |
| 519 | } |
| 520 | |
| 521 | // Now write all the rewrites that were missed |
| 522 | for (unsigned int J = 0; Rewrite != 0 && Rewrite[J].Tag != 0; J++) |
| 523 | { |
| 524 | if ((Visited[J] & 2) == 2) |
| 525 | continue; |
| 526 | |
| 527 | if (Rewrite[J].Rewrite != 0 && Rewrite[J].Rewrite[0] != 0) |
| 528 | { |
| 529 | if (isspace(Rewrite[J].Rewrite[0])) |
| 530 | fprintf(Output,"%s:%s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite); |
| 531 | else |
| 532 | fprintf(Output,"%s: %s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite); |
| 533 | } |
| 534 | } |
| 535 | |
| 536 | return true; |
| 537 | } |
| 538 | /*}}}*/ |