| 1 | // -*- mode: cpp; mode: fold -*- |
| 2 | // Description /*{{{*/ |
| 3 | // $Id: multicompress.cc,v 1.4 2003/02/10 07:34:41 doogie Exp $ |
| 4 | /* ###################################################################### |
| 5 | |
| 6 | MultiCompressor |
| 7 | |
| 8 | This class is very complicated in order to optimize for the common |
| 9 | case of its use, writing a large set of compressed files that are |
| 10 | different from the old set. It spawns off compressors in parallel |
| 11 | to maximize compression throughput and has a separate task managing |
| 12 | the data going into the compressors. |
| 13 | |
| 14 | ##################################################################### */ |
| 15 | /*}}}*/ |
| 16 | // Include Files /*{{{*/ |
| 17 | #include <config.h> |
| 18 | |
| 19 | #include <apt-pkg/strutl.h> |
| 20 | #include <apt-pkg/error.h> |
| 21 | #include <apt-pkg/md5.h> |
| 22 | |
| 23 | #include <sys/types.h> |
| 24 | #include <sys/stat.h> |
| 25 | #include <utime.h> |
| 26 | #include <unistd.h> |
| 27 | #include <iostream> |
| 28 | |
| 29 | #include "multicompress.h" |
| 30 | #include <apti18n.h> |
| 31 | /*}}}*/ |
| 32 | |
| 33 | using namespace std; |
| 34 | |
| 35 | |
| 36 | // MultiCompress::MultiCompress - Constructor /*{{{*/ |
| 37 | // --------------------------------------------------------------------- |
| 38 | /* Setup the file outputs, compression modes and fork the writer child */ |
| 39 | MultiCompress::MultiCompress(string const &Output,string const &Compress, |
| 40 | mode_t const &Permissions,bool const &Write) : |
| 41 | Permissions(Permissions) |
| 42 | { |
| 43 | Outputs = 0; |
| 44 | Outputter = -1; |
| 45 | Input = 0; |
| 46 | UpdateMTime = 0; |
| 47 | |
| 48 | /* Parse the compression string, a space separated lists of compresison |
| 49 | types */ |
| 50 | string::const_iterator I = Compress.begin(); |
| 51 | for (; I != Compress.end();) |
| 52 | { |
| 53 | for (; I != Compress.end() && isspace(*I); ++I); |
| 54 | |
| 55 | // Grab a word |
| 56 | string::const_iterator Start = I; |
| 57 | for (; I != Compress.end() && !isspace(*I); ++I); |
| 58 | |
| 59 | // Find the matching compressor |
| 60 | std::vector<APT::Configuration::Compressor> Compressors = APT::Configuration::getCompressors(); |
| 61 | std::vector<APT::Configuration::Compressor>::const_iterator Comp = Compressors.begin(); |
| 62 | for (; Comp != Compressors.end(); ++Comp) |
| 63 | if (stringcmp(Start,I,Comp->Name.c_str()) == 0) |
| 64 | break; |
| 65 | |
| 66 | // Hmm.. unknown. |
| 67 | if (Comp == Compressors.end()) |
| 68 | { |
| 69 | _error->Warning(_("Unknown compression algorithm '%s'"),string(Start,I).c_str()); |
| 70 | continue; |
| 71 | } |
| 72 | |
| 73 | // Create and link in a new output |
| 74 | Files *NewOut = new Files; |
| 75 | NewOut->Next = Outputs; |
| 76 | Outputs = NewOut; |
| 77 | NewOut->CompressProg = *Comp; |
| 78 | NewOut->Output = Output+Comp->Extension; |
| 79 | |
| 80 | struct stat St; |
| 81 | if (stat(NewOut->Output.c_str(),&St) == 0) |
| 82 | NewOut->OldMTime = St.st_mtime; |
| 83 | else |
| 84 | NewOut->OldMTime = 0; |
| 85 | } |
| 86 | |
| 87 | if (Write == false) |
| 88 | return; |
| 89 | |
| 90 | /* Open all the temp files now so we can report any errors. File is |
| 91 | made unreable to prevent people from touching it during creating. */ |
| 92 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 93 | I->TmpFile.Open(I->Output + ".new",FileFd::WriteEmpty,0600); |
| 94 | if (_error->PendingError() == true) |
| 95 | return; |
| 96 | |
| 97 | if (Outputs == 0) |
| 98 | { |
| 99 | _error->Error(_("Compressed output %s needs a compression set"),Output.c_str()); |
| 100 | return; |
| 101 | } |
| 102 | |
| 103 | Start(); |
| 104 | } |
| 105 | /*}}}*/ |
| 106 | // MultiCompress::~MultiCompress - Destructor /*{{{*/ |
| 107 | // --------------------------------------------------------------------- |
| 108 | /* Just erase the file linked list. */ |
| 109 | MultiCompress::~MultiCompress() |
| 110 | { |
| 111 | Die(); |
| 112 | |
| 113 | for (; Outputs != 0;) |
| 114 | { |
| 115 | Files *Tmp = Outputs->Next; |
| 116 | delete Outputs; |
| 117 | Outputs = Tmp; |
| 118 | } |
| 119 | } |
| 120 | /*}}}*/ |
| 121 | // MultiCompress::GetStat - Get stat information for compressed files /*{{{*/ |
| 122 | // --------------------------------------------------------------------- |
| 123 | /* This checks each compressed file to make sure it exists and returns |
| 124 | stat information for a random file from the collection. False means |
| 125 | one or more of the files is missing. */ |
| 126 | bool MultiCompress::GetStat(string const &Output,string const &Compress,struct stat &St) |
| 127 | { |
| 128 | /* Parse the compression string, a space separated lists of compresison |
| 129 | types */ |
| 130 | string::const_iterator I = Compress.begin(); |
| 131 | bool DidStat = false; |
| 132 | for (; I != Compress.end();) |
| 133 | { |
| 134 | for (; I != Compress.end() && isspace(*I); ++I); |
| 135 | |
| 136 | // Grab a word |
| 137 | string::const_iterator Start = I; |
| 138 | for (; I != Compress.end() && !isspace(*I); ++I); |
| 139 | |
| 140 | // Find the matching compressor |
| 141 | std::vector<APT::Configuration::Compressor> Compressors = APT::Configuration::getCompressors(); |
| 142 | std::vector<APT::Configuration::Compressor>::const_iterator Comp = Compressors.begin(); |
| 143 | for (; Comp != Compressors.end(); ++Comp) |
| 144 | if (stringcmp(Start,I,Comp->Name.c_str()) == 0) |
| 145 | break; |
| 146 | |
| 147 | // Hmm.. unknown. |
| 148 | if (Comp == Compressors.end()) |
| 149 | continue; |
| 150 | |
| 151 | string Name = Output+Comp->Extension; |
| 152 | if (stat(Name.c_str(),&St) != 0) |
| 153 | return false; |
| 154 | DidStat = true; |
| 155 | } |
| 156 | return DidStat; |
| 157 | } |
| 158 | /*}}}*/ |
| 159 | // MultiCompress::Start - Start up the writer child /*{{{*/ |
| 160 | // --------------------------------------------------------------------- |
| 161 | /* Fork a child and setup the communication pipe. */ |
| 162 | bool MultiCompress::Start() |
| 163 | { |
| 164 | // Create a data pipe |
| 165 | int Pipe[2] = {-1,-1}; |
| 166 | if (pipe(Pipe) != 0) |
| 167 | return _error->Errno("pipe",_("Failed to create IPC pipe to subprocess")); |
| 168 | for (int I = 0; I != 2; I++) |
| 169 | SetCloseExec(Pipe[I],true); |
| 170 | |
| 171 | // The child.. |
| 172 | Outputter = fork(); |
| 173 | if (Outputter == 0) |
| 174 | { |
| 175 | close(Pipe[1]); |
| 176 | Child(Pipe[0]); |
| 177 | if (_error->PendingError() == true) |
| 178 | { |
| 179 | _error->DumpErrors(); |
| 180 | _exit(100); |
| 181 | } |
| 182 | _exit(0); |
| 183 | }; |
| 184 | |
| 185 | /* Tidy up the temp files, we open them in the constructor so as to |
| 186 | get proper error reporting. Close them now. */ |
| 187 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 188 | I->TmpFile.Close(); |
| 189 | |
| 190 | close(Pipe[0]); |
| 191 | Input = fdopen(Pipe[1],"w"); |
| 192 | if (Input == 0) |
| 193 | return _error->Errno("fdopen",_("Failed to create FILE*")); |
| 194 | |
| 195 | if (Outputter == -1) |
| 196 | return _error->Errno("fork",_("Failed to fork")); |
| 197 | return true; |
| 198 | } |
| 199 | /*}}}*/ |
| 200 | // MultiCompress::Die - Clean up the writer /*{{{*/ |
| 201 | // --------------------------------------------------------------------- |
| 202 | /* */ |
| 203 | bool MultiCompress::Die() |
| 204 | { |
| 205 | if (Input == 0) |
| 206 | return true; |
| 207 | |
| 208 | fclose(Input); |
| 209 | Input = 0; |
| 210 | bool Res = ExecWait(Outputter,_("Compress child"),false); |
| 211 | Outputter = -1; |
| 212 | return Res; |
| 213 | } |
| 214 | /*}}}*/ |
| 215 | // MultiCompress::Finalize - Finish up writing /*{{{*/ |
| 216 | // --------------------------------------------------------------------- |
| 217 | /* This is only necessary for statistics reporting. */ |
| 218 | bool MultiCompress::Finalize(unsigned long long &OutSize) |
| 219 | { |
| 220 | OutSize = 0; |
| 221 | if (Input == 0 || Die() == false) |
| 222 | return false; |
| 223 | |
| 224 | time_t Now; |
| 225 | time(&Now); |
| 226 | |
| 227 | // Check the mtimes to see if the files were replaced. |
| 228 | bool Changed = false; |
| 229 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 230 | { |
| 231 | struct stat St; |
| 232 | if (stat(I->Output.c_str(),&St) != 0) |
| 233 | return _error->Error(_("Internal error, failed to create %s"), |
| 234 | I->Output.c_str()); |
| 235 | |
| 236 | if (I->OldMTime != St.st_mtime) |
| 237 | Changed = true; |
| 238 | else |
| 239 | { |
| 240 | // Update the mtime if necessary |
| 241 | if (UpdateMTime > 0 && |
| 242 | (Now - St.st_mtime > (signed)UpdateMTime || St.st_mtime > Now)) |
| 243 | { |
| 244 | struct utimbuf Buf; |
| 245 | Buf.actime = Buf.modtime = Now; |
| 246 | utime(I->Output.c_str(),&Buf); |
| 247 | Changed = true; |
| 248 | } |
| 249 | } |
| 250 | |
| 251 | // Force the file permissions |
| 252 | if (St.st_mode != Permissions) |
| 253 | chmod(I->Output.c_str(),Permissions); |
| 254 | |
| 255 | OutSize += St.st_size; |
| 256 | } |
| 257 | |
| 258 | if (Changed == false) |
| 259 | OutSize = 0; |
| 260 | |
| 261 | return true; |
| 262 | } |
| 263 | /*}}}*/ |
| 264 | // MultiCompress::OpenCompress - Open the compressor /*{{{*/ |
| 265 | // --------------------------------------------------------------------- |
| 266 | /* This opens the compressor, either in compress mode or decompress |
| 267 | mode. FileFd is always the compressor input/output file, |
| 268 | OutFd is the created pipe, Input for Compress, Output for Decompress. */ |
| 269 | bool MultiCompress::OpenCompress(APT::Configuration::Compressor const &Prog, |
| 270 | pid_t &Pid,int const &FileFd,int &OutFd,bool const &Comp) |
| 271 | { |
| 272 | Pid = -1; |
| 273 | |
| 274 | // No compression |
| 275 | if (Prog.Binary.empty() == true) |
| 276 | { |
| 277 | OutFd = dup(FileFd); |
| 278 | return true; |
| 279 | } |
| 280 | |
| 281 | // Create a data pipe |
| 282 | int Pipe[2] = {-1,-1}; |
| 283 | if (pipe(Pipe) != 0) |
| 284 | return _error->Errno("pipe",_("Failed to create subprocess IPC")); |
| 285 | for (int J = 0; J != 2; J++) |
| 286 | SetCloseExec(Pipe[J],true); |
| 287 | |
| 288 | if (Comp == true) |
| 289 | OutFd = Pipe[1]; |
| 290 | else |
| 291 | OutFd = Pipe[0]; |
| 292 | |
| 293 | // The child.. |
| 294 | Pid = ExecFork(); |
| 295 | if (Pid == 0) |
| 296 | { |
| 297 | if (Comp == true) |
| 298 | { |
| 299 | dup2(FileFd,STDOUT_FILENO); |
| 300 | dup2(Pipe[0],STDIN_FILENO); |
| 301 | } |
| 302 | else |
| 303 | { |
| 304 | dup2(FileFd,STDIN_FILENO); |
| 305 | dup2(Pipe[1],STDOUT_FILENO); |
| 306 | } |
| 307 | |
| 308 | SetCloseExec(STDOUT_FILENO,false); |
| 309 | SetCloseExec(STDIN_FILENO,false); |
| 310 | |
| 311 | std::vector<char const*> Args; |
| 312 | Args.push_back(Prog.Binary.c_str()); |
| 313 | std::vector<std::string> const * const addArgs = |
| 314 | (Comp == true) ? &(Prog.CompressArgs) : &(Prog.UncompressArgs); |
| 315 | for (std::vector<std::string>::const_iterator a = addArgs->begin(); |
| 316 | a != addArgs->end(); ++a) |
| 317 | Args.push_back(a->c_str()); |
| 318 | Args.push_back(NULL); |
| 319 | |
| 320 | execvp(Args[0],(char **)&Args[0]); |
| 321 | cerr << _("Failed to exec compressor ") << Args[0] << endl; |
| 322 | _exit(100); |
| 323 | }; |
| 324 | if (Comp == true) |
| 325 | close(Pipe[0]); |
| 326 | else |
| 327 | close(Pipe[1]); |
| 328 | return true; |
| 329 | } |
| 330 | /*}}}*/ |
| 331 | // MultiCompress::OpenOld - Open an old file /*{{{*/ |
| 332 | // --------------------------------------------------------------------- |
| 333 | /* This opens one of the original output files, possibly decompressing it. */ |
| 334 | bool MultiCompress::OpenOld(int &Fd,pid_t &Proc) |
| 335 | { |
| 336 | Files *Best = Outputs; |
| 337 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 338 | if (Best->CompressProg.Cost > I->CompressProg.Cost) |
| 339 | Best = I; |
| 340 | |
| 341 | // Open the file |
| 342 | FileFd F(Best->Output,FileFd::ReadOnly); |
| 343 | if (_error->PendingError() == true) |
| 344 | return false; |
| 345 | |
| 346 | // Decompress the file so we can read it |
| 347 | if (OpenCompress(Best->CompressProg,Proc,F.Fd(),Fd,false) == false) |
| 348 | return false; |
| 349 | |
| 350 | return true; |
| 351 | } |
| 352 | /*}}}*/ |
| 353 | // MultiCompress::CloseOld - Close the old file /*{{{*/ |
| 354 | // --------------------------------------------------------------------- |
| 355 | /* */ |
| 356 | bool MultiCompress::CloseOld(int Fd,pid_t Proc) |
| 357 | { |
| 358 | close(Fd); |
| 359 | if (Proc != -1) |
| 360 | if (ExecWait(Proc,_("decompressor"),false) == false) |
| 361 | return false; |
| 362 | return true; |
| 363 | } |
| 364 | /*}}}*/ |
| 365 | // MultiCompress::Child - The writer child /*{{{*/ |
| 366 | // --------------------------------------------------------------------- |
| 367 | /* The child process forks a bunch of compression children and takes |
| 368 | input on FD and passes it to all the compressor child. On the way it |
| 369 | computes the MD5 of the raw data. After this the raw data in the |
| 370 | original files is compared to see if this data is new. If the data |
| 371 | is new then the temp files are renamed, otherwise they are erased. */ |
| 372 | bool MultiCompress::Child(int const &FD) |
| 373 | { |
| 374 | // Start the compression children. |
| 375 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 376 | { |
| 377 | if (OpenCompress(I->CompressProg,I->CompressProc,I->TmpFile.Fd(), |
| 378 | I->Fd,true) == false) |
| 379 | return false; |
| 380 | } |
| 381 | |
| 382 | /* Okay, now we just feed data from FD to all the other FDs. Also |
| 383 | stash a hash of the data to use later. */ |
| 384 | SetNonBlock(FD,false); |
| 385 | unsigned char Buffer[32*1024]; |
| 386 | unsigned long long FileSize = 0; |
| 387 | MD5Summation MD5; |
| 388 | while (1) |
| 389 | { |
| 390 | WaitFd(FD,false); |
| 391 | int Res = read(FD,Buffer,sizeof(Buffer)); |
| 392 | if (Res == 0) |
| 393 | break; |
| 394 | if (Res < 0) |
| 395 | continue; |
| 396 | |
| 397 | MD5.Add(Buffer,Res); |
| 398 | FileSize += Res; |
| 399 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 400 | { |
| 401 | if (write(I->Fd,Buffer,Res) != Res) |
| 402 | { |
| 403 | _error->Errno("write",_("IO to subprocess/file failed")); |
| 404 | break; |
| 405 | } |
| 406 | } |
| 407 | } |
| 408 | |
| 409 | // Close all the writers |
| 410 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 411 | close(I->Fd); |
| 412 | |
| 413 | // Wait for the compressors to exit |
| 414 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 415 | { |
| 416 | if (I->CompressProc != -1) |
| 417 | ExecWait(I->CompressProc, I->CompressProg.Binary.c_str(), false); |
| 418 | } |
| 419 | |
| 420 | if (_error->PendingError() == true) |
| 421 | return false; |
| 422 | |
| 423 | /* Now we have to copy the files over, or erase them if they |
| 424 | have not changed. First find the cheapest decompressor */ |
| 425 | bool Missing = false; |
| 426 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 427 | { |
| 428 | if (I->OldMTime == 0) |
| 429 | { |
| 430 | Missing = true; |
| 431 | break; |
| 432 | } |
| 433 | } |
| 434 | |
| 435 | // Check the MD5 of the lowest cost entity. |
| 436 | while (Missing == false) |
| 437 | { |
| 438 | int CompFd = -1; |
| 439 | pid_t Proc = -1; |
| 440 | if (OpenOld(CompFd,Proc) == false) |
| 441 | { |
| 442 | _error->Discard(); |
| 443 | break; |
| 444 | } |
| 445 | |
| 446 | // Compute the hash |
| 447 | MD5Summation OldMD5; |
| 448 | unsigned long long NewFileSize = 0; |
| 449 | while (1) |
| 450 | { |
| 451 | int Res = read(CompFd,Buffer,sizeof(Buffer)); |
| 452 | if (Res == 0) |
| 453 | break; |
| 454 | if (Res < 0) |
| 455 | return _error->Errno("read",_("Failed to read while computing MD5")); |
| 456 | NewFileSize += Res; |
| 457 | OldMD5.Add(Buffer,Res); |
| 458 | } |
| 459 | |
| 460 | // Tidy the compressor |
| 461 | if (CloseOld(CompFd,Proc) == false) |
| 462 | return false; |
| 463 | |
| 464 | // Check the hash |
| 465 | if (OldMD5.Result() == MD5.Result() && |
| 466 | FileSize == NewFileSize) |
| 467 | { |
| 468 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 469 | { |
| 470 | I->TmpFile.Close(); |
| 471 | if (unlink(I->TmpFile.Name().c_str()) != 0) |
| 472 | _error->Errno("unlink",_("Problem unlinking %s"), |
| 473 | I->TmpFile.Name().c_str()); |
| 474 | } |
| 475 | return !_error->PendingError(); |
| 476 | } |
| 477 | break; |
| 478 | } |
| 479 | |
| 480 | // Finalize |
| 481 | for (Files *I = Outputs; I != 0; I = I->Next) |
| 482 | { |
| 483 | // Set the correct file modes |
| 484 | fchmod(I->TmpFile.Fd(),Permissions); |
| 485 | |
| 486 | if (rename(I->TmpFile.Name().c_str(),I->Output.c_str()) != 0) |
| 487 | _error->Errno("rename",_("Failed to rename %s to %s"), |
| 488 | I->TmpFile.Name().c_str(),I->Output.c_str()); |
| 489 | I->TmpFile.Close(); |
| 490 | } |
| 491 | |
| 492 | return !_error->PendingError(); |
| 493 | } |
| 494 | /*}}}*/ |
| 495 | |