apt-pkg/pkgcachegen.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: pkgcachegen.cc,v 1.53.2.1 2003/12/24 23:09:17 mdz Exp $
   4 /* ######################################################################
   5
   6    Package Cache Generator - Generator for the cache structure.
   7
   8    This builds the cache structure from the abstract package list parser.
   9
  10    ##################################################################### */
  11                                                                         /*}}}*/
  12 // Include Files                                                        /*{{{*/
  13 #define APT_COMPATIBILITY 986
  14
  15 #include <apt-pkg/pkgcachegen.h>
  16 #include <apt-pkg/error.h>
  17 #include <apt-pkg/version.h>
  18 #include <apt-pkg/progress.h>
  19 #include <apt-pkg/sourcelist.h>
  20 #include <apt-pkg/configuration.h>
  21 #include <apt-pkg/aptconfiguration.h>
  22 #include <apt-pkg/strutl.h>
  23 #include <apt-pkg/sptr.h>
  24 #include <apt-pkg/pkgsystem.h>
  25 #include <apt-pkg/macros.h>
  26
  27 #include <apt-pkg/tagfile.h>
  28
  29 #include <apti18n.h>
  30
  31 #include <vector>
  32
  33 #include <sys/stat.h>
  34 #include <unistd.h>
  35 #include <errno.h>
  36 #include <stdio.h>
  37                                                                         /*}}}*/
  38 typedef vector<pkgIndexFile *>::iterator FileIterator;
  39 template <typename Iter> std::vector<Iter*> pkgCacheGenerator::Dynamic<Iter>::toReMap;
  40
  41 // CacheGenerator::pkgCacheGenerator - Constructor                      /*{{{*/
  42 // ---------------------------------------------------------------------
  43 /* We set the dirty flag and make sure that is written to the disk */
  44 pkgCacheGenerator::pkgCacheGenerator(DynamicMMap *pMap,OpProgress *Prog) :
  45                     Map(*pMap), Cache(pMap,false), Progress(Prog),
  46                     FoundFileDeps(0)
  47 {
  48    CurrentFile = 0;
  49    memset(UniqHash,0,sizeof(UniqHash));
  50
  51    if (_error->PendingError() == true)
  52       return;
  53
  54    if (Map.Size() == 0)
  55    {
  56       // Setup the map interface..
  57       Cache.HeaderP = (pkgCache::Header *)Map.Data();
  58       if (Map.RawAllocate(sizeof(pkgCache::Header)) == 0 && _error->PendingError() == true)
  59          return;
  60
  61       Map.UsePools(*Cache.HeaderP->Pools,sizeof(Cache.HeaderP->Pools)/sizeof(Cache.HeaderP->Pools[0]));
  62
  63       // Starting header
  64       *Cache.HeaderP = pkgCache::Header();
  65       map_ptrloc const idxVerSysName = WriteStringInMap(_system->VS->Label);
  66       Cache.HeaderP->VerSysName = idxVerSysName;
  67       map_ptrloc const idxArchitecture = WriteStringInMap(_config->Find("APT::Architecture"));
  68       Cache.HeaderP->Architecture = idxArchitecture;
  69       if (unlikely(idxVerSysName == 0 || idxArchitecture == 0))
  70          return;
  71       Cache.ReMap();
  72    }
  73    else
  74    {
  75       // Map directly from the existing file
  76       Cache.ReMap();
  77       Map.UsePools(*Cache.HeaderP->Pools,sizeof(Cache.HeaderP->Pools)/sizeof(Cache.HeaderP->Pools[0]));
  78       if (Cache.VS != _system->VS)
  79       {
  80          _error->Error(_("Cache has an incompatible versioning system"));
  81          return;
  82       }
  83    }
  84
  85    Cache.HeaderP->Dirty = true;
  86    Map.Sync(0,sizeof(pkgCache::Header));
  87 }
  88                                                                         /*}}}*/
  89 // CacheGenerator::~pkgCacheGenerator - Destructor                      /*{{{*/
  90 // ---------------------------------------------------------------------
  91 /* We sync the data then unset the dirty flag in two steps so as to
  92    advoid a problem during a crash */
  93 pkgCacheGenerator::~pkgCacheGenerator()
  94 {
  95    if (_error->PendingError() == true)
  96       return;
  97    if (Map.Sync() == false)
  98       return;
  99
 100    Cache.HeaderP->Dirty = false;
 101    Map.Sync(0,sizeof(pkgCache::Header));
 102 }
 103                                                                         /*}}}*/
 104 void pkgCacheGenerator::ReMap(void const * const oldMap, void const * const newMap) {/*{{{*/
 105    if (oldMap == newMap)
 106       return;
 107
 108    Cache.ReMap(false);
 109
 110    CurrentFile += (pkgCache::PackageFile*) newMap - (pkgCache::PackageFile*) oldMap;
 111
 112    for (size_t i = 0; i < _count(UniqHash); ++i)
 113       if (UniqHash[i] != 0)
 114          UniqHash[i] += (pkgCache::StringItem*) newMap - (pkgCache::StringItem*) oldMap;
 115
 116    for (std::vector<pkgCache::GrpIterator*>::const_iterator i = Dynamic<pkgCache::GrpIterator>::toReMap.begin();
 117         i != Dynamic<pkgCache::GrpIterator>::toReMap.end(); ++i)
 118       (*i)->ReMap(oldMap, newMap);
 119    for (std::vector<pkgCache::PkgIterator*>::const_iterator i = Dynamic<pkgCache::PkgIterator>::toReMap.begin();
 120         i != Dynamic<pkgCache::PkgIterator>::toReMap.end(); ++i)
 121       (*i)->ReMap(oldMap, newMap);
 122    for (std::vector<pkgCache::VerIterator*>::const_iterator i = Dynamic<pkgCache::VerIterator>::toReMap.begin();
 123         i != Dynamic<pkgCache::VerIterator>::toReMap.end(); ++i)
 124       (*i)->ReMap(oldMap, newMap);
 125    for (std::vector<pkgCache::DepIterator*>::const_iterator i = Dynamic<pkgCache::DepIterator>::toReMap.begin();
 126         i != Dynamic<pkgCache::DepIterator>::toReMap.end(); ++i)
 127       (*i)->ReMap(oldMap, newMap);
 128    for (std::vector<pkgCache::DescIterator*>::const_iterator i = Dynamic<pkgCache::DescIterator>::toReMap.begin();
 129         i != Dynamic<pkgCache::DescIterator>::toReMap.end(); ++i)
 130       (*i)->ReMap(oldMap, newMap);
 131    for (std::vector<pkgCache::PrvIterator*>::const_iterator i = Dynamic<pkgCache::PrvIterator>::toReMap.begin();
 132         i != Dynamic<pkgCache::PrvIterator>::toReMap.end(); ++i)
 133       (*i)->ReMap(oldMap, newMap);
 134    for (std::vector<pkgCache::PkgFileIterator*>::const_iterator i = Dynamic<pkgCache::PkgFileIterator>::toReMap.begin();
 135         i != Dynamic<pkgCache::PkgFileIterator>::toReMap.end(); ++i)
 136       (*i)->ReMap(oldMap, newMap);
 137 }                                                                       /*}}}*/
 138 // CacheGenerator::WriteStringInMap                                     /*{{{*/
 139 map_ptrloc pkgCacheGenerator::WriteStringInMap(const char *String,
 140                                         const unsigned long &Len) {
 141    void const * const oldMap = Map.Data();
 142    map_ptrloc const index = Map.WriteString(String, Len);
 143    if (index != 0)
 144       ReMap(oldMap, Map.Data());
 145    return index;
 146 }
 147                                                                         /*}}}*/
 148 // CacheGenerator::WriteStringInMap                                     /*{{{*/
 149 map_ptrloc pkgCacheGenerator::WriteStringInMap(const char *String) {
 150    void const * const oldMap = Map.Data();
 151    map_ptrloc const index = Map.WriteString(String);
 152    if (index != 0)
 153       ReMap(oldMap, Map.Data());
 154    return index;
 155 }
 156                                                                         /*}}}*/
 157 map_ptrloc pkgCacheGenerator::AllocateInMap(const unsigned long &size) {/*{{{*/
 158    void const * const oldMap = Map.Data();
 159    map_ptrloc const index = Map.Allocate(size);
 160    if (index != 0)
 161       ReMap(oldMap, Map.Data());
 162    return index;
 163 }
 164                                                                         /*}}}*/
 165 // CacheGenerator::MergeList - Merge the package list                   /*{{{*/
 166 // ---------------------------------------------------------------------
 167 /* This provides the generation of the entries in the cache. Each loop
 168    goes through a single package record from the underlying parse engine. */
 169 bool pkgCacheGenerator::MergeList(ListParser &List,
 170                                   pkgCache::VerIterator *OutVer)
 171 {
 172    List.Owner = this;
 173
 174    unsigned int Counter = 0;
 175    while (List.Step() == true)
 176    {
 177       string const PackageName = List.Package();
 178       if (PackageName.empty() == true)
 179          return false;
 180
 181       string const Arch = List.Architecture();
 182
 183       // Get a pointer to the package structure
 184       pkgCache::PkgIterator Pkg;
 185       Dynamic<pkgCache::PkgIterator> DynPkg(Pkg);
 186       if (NewPackage(Pkg, PackageName, Arch) == false)
 187          return _error->Error(_("Error occurred while processing %s (NewPackage)"),PackageName.c_str());
 188       Counter++;
 189       if (Counter % 100 == 0 && Progress != 0)
 190          Progress->Progress(List.Offset());
 191
 192       /* Get a pointer to the version structure. We know the list is sorted
 193          so we use that fact in the search. Insertion of new versions is
 194          done with correct sorting */
 195       string Version = List.Version();
 196       if (Version.empty() == true)
 197       {
 198          // we first process the package, then the descriptions
 199          // (this has the bonus that we get MMap error when we run out
 200          //  of MMap space)
 201          pkgCache::VerIterator Ver(Cache);
 202          Dynamic<pkgCache::VerIterator> DynVer(Ver);
 203          if (List.UsePackage(Pkg, Ver) == false)
 204             return _error->Error(_("Error occurred while processing %s (UsePackage1)"),
 205                                  PackageName.c_str());
 206
 207          // Find the right version to write the description
 208          MD5SumValue CurMd5 = List.Description_md5();
 209          Ver = Pkg.VersionList();
 210
 211          for (; Ver.end() == false; ++Ver)
 212          {
 213             pkgCache::DescIterator Desc = Ver.DescriptionList();
 214             Dynamic<pkgCache::DescIterator> DynDesc(Desc);
 215             map_ptrloc *LastDesc = &Ver->DescriptionList;
 216             bool duplicate=false;
 217
 218             // don't add a new description if we have one for the given
 219             // md5 && language
 220             for ( ; Desc.end() == false; Desc++)
 221                if (MD5SumValue(Desc.md5()) == CurMd5 &&
 222                    Desc.LanguageCode() == List.DescriptionLanguage())
 223                   duplicate=true;
 224             if(duplicate)
 225                continue;
 226
 227             for (Desc = Ver.DescriptionList();
 228                  Desc.end() == false;
 229                  LastDesc = &Desc->NextDesc, Desc++)
 230             {
 231                if (MD5SumValue(Desc.md5()) == CurMd5)
 232                {
 233                   // Add new description
 234                   void const * const oldMap = Map.Data();
 235                   map_ptrloc const descindex = NewDescription(Desc, List.DescriptionLanguage(), CurMd5, *LastDesc);
 236                   if (oldMap != Map.Data())
 237                      LastDesc += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
 238                   *LastDesc = descindex;
 239                   Desc->ParentPkg = Pkg.Index();
 240
 241                   if ((*LastDesc == 0 && _error->PendingError()) || NewFileDesc(Desc,List) == false)
 242                      return _error->Error(_("Error occurred while processing %s (NewFileDesc1)"),PackageName.c_str());
 243                   break;
 244                }
 245             }
 246          }
 247
 248          continue;
 249       }
 250
 251       pkgCache::VerIterator Ver = Pkg.VersionList();
 252       Dynamic<pkgCache::VerIterator> DynVer(Ver);
 253       map_ptrloc *LastVer = &Pkg->VersionList;
 254       void const * oldMap = Map.Data();
 255       int Res = 1;
 256       unsigned long const Hash = List.VersionHash();
 257       for (; Ver.end() == false; LastVer = &Ver->NextVer, Ver++)
 258       {
 259          Res = Cache.VS->CmpVersion(Version,Ver.VerStr());
 260          // Version is higher as current version - insert here
 261          if (Res > 0)
 262             break;
 263          // Versionstrings are equal - is hash also equal?
 264          if (Res == 0 && Ver->Hash == Hash)
 265             break;
 266          // proceed with the next till we have either the right
 267          // or we found another version (which will be lower)
 268       }
 269
 270       /* We already have a version for this item, record that we saw it */
 271       if (Res == 0 && Ver.end() == false && Ver->Hash == Hash)
 272       {
 273          if (List.UsePackage(Pkg,Ver) == false)
 274             return _error->Error(_("Error occurred while processing %s (UsePackage2)"),
 275                                  PackageName.c_str());
 276
 277          if (NewFileVer(Ver,List) == false)
 278             return _error->Error(_("Error occurred while processing %s (NewFileVer1)"),
 279                                  PackageName.c_str());
 280
 281          // Read only a single record and return
 282          if (OutVer != 0)
 283          {
 284             *OutVer = Ver;
 285             FoundFileDeps |= List.HasFileDeps();
 286             return true;
 287          }
 288
 289          continue;
 290       }
 291
 292       // Add a new version
 293       map_ptrloc const verindex = NewVersion(Ver,Version,*LastVer);
 294       if (verindex == 0 && _error->PendingError())
 295          return _error->Error(_("Error occurred while processing %s (NewVersion%d)"),
 296                               PackageName.c_str(), 1);
 297
 298       if (oldMap != Map.Data())
 299          LastVer += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
 300       *LastVer = verindex;
 301       Ver->ParentPkg = Pkg.Index();
 302       Ver->Hash = Hash;
 303
 304       if (List.NewVersion(Ver) == false)
 305          return _error->Error(_("Error occurred while processing %s (NewVersion%d)"),
 306                               PackageName.c_str(), 2);
 307
 308       if (List.UsePackage(Pkg,Ver) == false)
 309          return _error->Error(_("Error occurred while processing %s (UsePackage3)"),
 310                               PackageName.c_str());
 311
 312       if (NewFileVer(Ver,List) == false)
 313          return _error->Error(_("Error occurred while processing %s (NewVersion%d)"),
 314                               PackageName.c_str(), 3);
 315
 316       // Read only a single record and return
 317       if (OutVer != 0)
 318       {
 319          *OutVer = Ver;
 320          FoundFileDeps |= List.HasFileDeps();
 321          return true;
 322       }
 323
 324       /* Record the Description data. Description data always exist in
 325          Packages and Translation-* files. */
 326       pkgCache::DescIterator Desc = Ver.DescriptionList();
 327       Dynamic<pkgCache::DescIterator> DynDesc(Desc);
 328       map_ptrloc *LastDesc = &Ver->DescriptionList;
 329
 330       // Skip to the end of description set
 331       for (; Desc.end() == false; LastDesc = &Desc->NextDesc, Desc++);
 332
 333       // Add new description
 334       oldMap = Map.Data();
 335       map_ptrloc const descindex = NewDescription(Desc, List.DescriptionLanguage(), List.Description_md5(), *LastDesc);
 336       if (oldMap != Map.Data())
 337          LastDesc += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
 338       *LastDesc = descindex;
 339       Desc->ParentPkg = Pkg.Index();
 340
 341       if ((*LastDesc == 0 && _error->PendingError()) || NewFileDesc(Desc,List) == false)
 342          return _error->Error(_("Error occurred while processing %s (NewFileDesc2)"),PackageName.c_str());
 343    }
 344
 345    FoundFileDeps |= List.HasFileDeps();
 346
 347    if (Cache.HeaderP->PackageCount >= (1ULL<<sizeof(Cache.PkgP->ID)*8)-1)
 348       return _error->Error(_("Wow, you exceeded the number of package "
 349                              "names this APT is capable of."));
 350    if (Cache.HeaderP->VersionCount >= (1ULL<<(sizeof(Cache.VerP->ID)*8))-1)
 351       return _error->Error(_("Wow, you exceeded the number of versions "
 352                              "this APT is capable of."));
 353    if (Cache.HeaderP->DescriptionCount >= (1ULL<<(sizeof(Cache.DescP->ID)*8))-1)
 354       return _error->Error(_("Wow, you exceeded the number of descriptions "
 355                              "this APT is capable of."));
 356    if (Cache.HeaderP->DependsCount >= (1ULL<<(sizeof(Cache.DepP->ID)*8))-1ULL)
 357       return _error->Error(_("Wow, you exceeded the number of dependencies "
 358                              "this APT is capable of."));
 359    return true;
 360 }
 361                                                                         /*}}}*/
 362 // CacheGenerator::MergeFileProvides - Merge file provides              /*{{{*/
 363 // ---------------------------------------------------------------------
 364 /* If we found any file depends while parsing the main list we need to
 365    resolve them. Since it is undesired to load the entire list of files
 366    into the cache as virtual packages we do a two stage effort. MergeList
 367    identifies the file depends and this creates Provdies for them by
 368    re-parsing all the indexs. */
 369 bool pkgCacheGenerator::MergeFileProvides(ListParser &List)
 370 {
 371    List.Owner = this;
 372
 373    unsigned int Counter = 0;
 374    while (List.Step() == true)
 375    {
 376       string PackageName = List.Package();
 377       if (PackageName.empty() == true)
 378          return false;
 379       string Version = List.Version();
 380       if (Version.empty() == true)
 381          continue;
 382
 383       pkgCache::PkgIterator Pkg = Cache.FindPkg(PackageName);
 384       Dynamic<pkgCache::PkgIterator> DynPkg(Pkg);
 385       if (Pkg.end() == true)
 386          return _error->Error(_("Error occurred while processing %s (FindPkg)"),
 387                                 PackageName.c_str());
 388       Counter++;
 389       if (Counter % 100 == 0 && Progress != 0)
 390          Progress->Progress(List.Offset());
 391
 392       unsigned long Hash = List.VersionHash();
 393       pkgCache::VerIterator Ver = Pkg.VersionList();
 394       Dynamic<pkgCache::VerIterator> DynVer(Ver);
 395       for (; Ver.end() == false; Ver++)
 396       {
 397          if (Ver->Hash == Hash && Version.c_str() == Ver.VerStr())
 398          {
 399             if (List.CollectFileProvides(Cache,Ver) == false)
 400                return _error->Error(_("Error occurred while processing %s (CollectFileProvides)"),PackageName.c_str());
 401             break;
 402          }
 403       }
 404
 405       if (Ver.end() == true)
 406          _error->Warning(_("Package %s %s was not found while processing file dependencies"),PackageName.c_str(),Version.c_str());
 407    }
 408
 409    return true;
 410 }
 411                                                                         /*}}}*/
 412 // CacheGenerator::NewGroup - Add a new group                           /*{{{*/
 413 // ---------------------------------------------------------------------
 414 /* This creates a new group structure and adds it to the hash table */
 415 bool pkgCacheGenerator::NewGroup(pkgCache::GrpIterator &Grp, const string &Name)
 416 {
 417    Grp = Cache.FindGrp(Name);
 418    if (Grp.end() == false)
 419       return true;
 420
 421    // Get a structure
 422    map_ptrloc const Group = AllocateInMap(sizeof(pkgCache::Group));
 423    if (unlikely(Group == 0))
 424       return false;
 425
 426    Grp = pkgCache::GrpIterator(Cache, Cache.GrpP + Group);
 427    map_ptrloc const idxName = WriteStringInMap(Name);
 428    if (unlikely(idxName == 0))
 429       return false;
 430    Grp->Name = idxName;
 431
 432    // Insert it into the hash table
 433    unsigned long const Hash = Cache.Hash(Name);
 434    Grp->Next = Cache.HeaderP->GrpHashTable[Hash];
 435    Cache.HeaderP->GrpHashTable[Hash] = Group;
 436
 437    Grp->ID = Cache.HeaderP->GroupCount++;
 438    return true;
 439 }
 440                                                                         /*}}}*/
 441 // CacheGenerator::NewPackage - Add a new package                       /*{{{*/
 442 // ---------------------------------------------------------------------
 443 /* This creates a new package structure and adds it to the hash table */
 444 bool pkgCacheGenerator::NewPackage(pkgCache::PkgIterator &Pkg,const string &Name,
 445                                         const string &Arch) {
 446    pkgCache::GrpIterator Grp;
 447    Dynamic<pkgCache::GrpIterator> DynGrp(Grp);
 448    if (unlikely(NewGroup(Grp, Name) == false))
 449       return false;
 450
 451    Pkg = Grp.FindPkg(Arch);
 452       if (Pkg.end() == false)
 453          return true;
 454
 455    // Get a structure
 456    map_ptrloc const Package = AllocateInMap(sizeof(pkgCache::Package));
 457    if (unlikely(Package == 0))
 458       return false;
 459    Pkg = pkgCache::PkgIterator(Cache,Cache.PkgP + Package);
 460
 461    // Insert the package into our package list
 462    if (Grp->FirstPackage == 0) // the group is new
 463    {
 464       // Insert it into the hash table
 465       unsigned long const Hash = Cache.Hash(Name);
 466       Pkg->NextPackage = Cache.HeaderP->PkgHashTable[Hash];
 467       Cache.HeaderP->PkgHashTable[Hash] = Package;
 468       Grp->FirstPackage = Package;
 469    }
 470    else // Group the Packages together
 471    {
 472       // this package is the new last package
 473       pkgCache::PkgIterator LastPkg(Cache, Cache.PkgP + Grp->LastPackage);
 474       Pkg->NextPackage = LastPkg->NextPackage;
 475       LastPkg->NextPackage = Package;
 476    }
 477    Grp->LastPackage = Package;
 478
 479    // Set the name, arch and the ID
 480    Pkg->Name = Grp->Name;
 481    Pkg->Group = Grp.Index();
 482    // all is mapped to the native architecture
 483    map_ptrloc const idxArch = (Arch == "all") ? Cache.HeaderP->Architecture : WriteUniqString(Arch.c_str());
 484    if (unlikely(idxArch == 0))
 485       return false;
 486    Pkg->Arch = idxArch;
 487    Pkg->ID = Cache.HeaderP->PackageCount++;
 488
 489    return true;
 490 }
 491                                                                         /*}}}*/
 492 // CacheGenerator::NewFileVer - Create a new File<->Version association /*{{{*/
 493 // ---------------------------------------------------------------------
 494 /* */
 495 bool pkgCacheGenerator::NewFileVer(pkgCache::VerIterator &Ver,
 496                                    ListParser &List)
 497 {
 498    if (CurrentFile == 0)
 499       return true;
 500
 501    // Get a structure
 502    map_ptrloc const VerFile = AllocateInMap(sizeof(pkgCache::VerFile));
 503    if (VerFile == 0)
 504       return 0;
 505
 506    pkgCache::VerFileIterator VF(Cache,Cache.VerFileP + VerFile);
 507    VF->File = CurrentFile - Cache.PkgFileP;
 508
 509    // Link it to the end of the list
 510    map_ptrloc *Last = &Ver->FileList;
 511    for (pkgCache::VerFileIterator V = Ver.FileList(); V.end() == false; V++)
 512       Last = &V->NextFile;
 513    VF->NextFile = *Last;
 514    *Last = VF.Index();
 515
 516    VF->Offset = List.Offset();
 517    VF->Size = List.Size();
 518    if (Cache.HeaderP->MaxVerFileSize < VF->Size)
 519       Cache.HeaderP->MaxVerFileSize = VF->Size;
 520    Cache.HeaderP->VerFileCount++;
 521
 522    return true;
 523 }
 524                                                                         /*}}}*/
 525 // CacheGenerator::NewVersion - Create a new Version                    /*{{{*/
 526 // ---------------------------------------------------------------------
 527 /* This puts a version structure in the linked list */
 528 unsigned long pkgCacheGenerator::NewVersion(pkgCache::VerIterator &Ver,
 529                                             const string &VerStr,
 530                                             unsigned long Next)
 531 {
 532    // Get a structure
 533    map_ptrloc const Version = AllocateInMap(sizeof(pkgCache::Version));
 534    if (Version == 0)
 535       return 0;
 536
 537    // Fill it in
 538    Ver = pkgCache::VerIterator(Cache,Cache.VerP + Version);
 539    Ver->NextVer = Next;
 540    Ver->ID = Cache.HeaderP->VersionCount++;
 541    map_ptrloc const idxVerStr = WriteStringInMap(VerStr);
 542    if (unlikely(idxVerStr == 0))
 543       return 0;
 544    Ver->VerStr = idxVerStr;
 545
 546    return Version;
 547 }
 548                                                                         /*}}}*/
 549 // CacheGenerator::NewFileDesc - Create a new File<->Desc association   /*{{{*/
 550 // ---------------------------------------------------------------------
 551 /* */
 552 bool pkgCacheGenerator::NewFileDesc(pkgCache::DescIterator &Desc,
 553                                    ListParser &List)
 554 {
 555    if (CurrentFile == 0)
 556       return true;
 557
 558    // Get a structure
 559    map_ptrloc const DescFile = AllocateInMap(sizeof(pkgCache::DescFile));
 560    if (DescFile == 0)
 561       return false;
 562
 563    pkgCache::DescFileIterator DF(Cache,Cache.DescFileP + DescFile);
 564    DF->File = CurrentFile - Cache.PkgFileP;
 565
 566    // Link it to the end of the list
 567    map_ptrloc *Last = &Desc->FileList;
 568    for (pkgCache::DescFileIterator D = Desc.FileList(); D.end() == false; D++)
 569       Last = &D->NextFile;
 570
 571    DF->NextFile = *Last;
 572    *Last = DF.Index();
 573
 574    DF->Offset = List.Offset();
 575    DF->Size = List.Size();
 576    if (Cache.HeaderP->MaxDescFileSize < DF->Size)
 577       Cache.HeaderP->MaxDescFileSize = DF->Size;
 578    Cache.HeaderP->DescFileCount++;
 579
 580    return true;
 581 }
 582                                                                         /*}}}*/
 583 // CacheGenerator::NewDescription - Create a new Description            /*{{{*/
 584 // ---------------------------------------------------------------------
 585 /* This puts a description structure in the linked list */
 586 map_ptrloc pkgCacheGenerator::NewDescription(pkgCache::DescIterator &Desc,
 587                                             const string &Lang,
 588                                             const MD5SumValue &md5sum,
 589                                             map_ptrloc Next)
 590 {
 591    // Get a structure
 592    map_ptrloc const Description = AllocateInMap(sizeof(pkgCache::Description));
 593    if (Description == 0)
 594       return 0;
 595
 596    // Fill it in
 597    Desc = pkgCache::DescIterator(Cache,Cache.DescP + Description);
 598    Desc->NextDesc = Next;
 599    Desc->ID = Cache.HeaderP->DescriptionCount++;
 600    map_ptrloc const idxlanguage_code = WriteStringInMap(Lang);
 601    map_ptrloc const idxmd5sum = WriteStringInMap(md5sum.Value());
 602    if (unlikely(idxlanguage_code == 0 || idxmd5sum == 0))
 603       return 0;
 604    Desc->language_code = idxlanguage_code;
 605    Desc->md5sum = idxmd5sum;
 606
 607    return Description;
 608 }
 609                                                                         /*}}}*/
 610 // CacheGenerator::FinishCache - do various finish operations           /*{{{*/
 611 // ---------------------------------------------------------------------
 612 /* This prepares the Cache for delivery */
 613 bool pkgCacheGenerator::FinishCache(OpProgress *Progress)
 614 {
 615    // FIXME: add progress reporting for this operation
 616    // Do we have different architectures in your groups ?
 617    vector<string> archs = APT::Configuration::getArchitectures();
 618    if (archs.size() > 1)
 619    {
 620       // Create Conflicts in between the group
 621       pkgCache::GrpIterator G = GetCache().GrpBegin();
 622       Dynamic<pkgCache::GrpIterator> DynG(G);
 623       for (; G.end() != true; G++)
 624       {
 625          string const PkgName = G.Name();
 626          pkgCache::PkgIterator P = G.PackageList();
 627          Dynamic<pkgCache::PkgIterator> DynP(P);
 628          for (; P.end() != true; P = G.NextPkg(P))
 629          {
 630             pkgCache::PkgIterator allPkg;
 631             Dynamic<pkgCache::PkgIterator> DynallPkg(allPkg);
 632             pkgCache::VerIterator V = P.VersionList();
 633             Dynamic<pkgCache::VerIterator> DynV(V);
 634             for (; V.end() != true; V++)
 635             {
 636                char const * const Arch = P.Arch();
 637                map_ptrloc *OldDepLast = NULL;
 638                /* MultiArch handling introduces a lot of implicit Dependencies:
 639                 - MultiArch: same → Co-Installable if they have the same version
 640                 - Architecture: all → Need to be Co-Installable for internal reasons
 641                 - All others conflict with all other group members */
 642                bool const coInstall = ((V->MultiArch & pkgCache::Version::Same) == pkgCache::Version::Same);
 643                for (vector<string>::const_iterator A = archs.begin(); A != archs.end(); ++A)
 644                {
 645                   if (*A == Arch)
 646                      continue;
 647                   /* We allow only one installed arch at the time
 648                      per group, therefore each group member conflicts
 649                      with all other group members */
 650                   pkgCache::PkgIterator D = G.FindPkg(*A);
 651                   Dynamic<pkgCache::PkgIterator> DynD(D);
 652                   if (D.end() == true)
 653                      continue;
 654                   if (coInstall == true)
 655                   {
 656                      // Replaces: ${self}:other ( << ${binary:Version})
 657                      NewDepends(D, V, V.VerStr(),
 658                                 pkgCache::Dep::Less, pkgCache::Dep::Replaces,
 659                                 OldDepLast);
 660                      // Breaks: ${self}:other (!= ${binary:Version})
 661                      NewDepends(D, V, V.VerStr(),
 662                                 pkgCache::Dep::NotEquals, pkgCache::Dep::DpkgBreaks,
 663                                 OldDepLast);
 664                   } else {
 665                         // Conflicts: ${self}:other
 666                         NewDepends(D, V, "",
 667                                    pkgCache::Dep::NoOp, pkgCache::Dep::Conflicts,
 668                                    OldDepLast);
 669                   }
 670                }
 671             }
 672          }
 673       }
 674    }
 675    return true;
 676 }
 677                                                                         /*}}}*/
 678 // CacheGenerator::NewDepends - Create a dependency element             /*{{{*/
 679 // ---------------------------------------------------------------------
 680 /* This creates a dependency element in the tree. It is linked to the
 681    version and to the package that it is pointing to. */
 682 bool pkgCacheGenerator::NewDepends(pkgCache::PkgIterator &Pkg,
 683                                    pkgCache::VerIterator &Ver,
 684                                    string const &Version,
 685                                    unsigned int const &Op,
 686                                    unsigned int const &Type,
 687                                    map_ptrloc *OldDepLast)
 688 {
 689    void const * const oldMap = Map.Data();
 690    // Get a structure
 691    map_ptrloc const Dependency = AllocateInMap(sizeof(pkgCache::Dependency));
 692    if (unlikely(Dependency == 0))
 693       return false;
 694
 695    // Fill it in
 696    pkgCache::DepIterator Dep(Cache,Cache.DepP + Dependency);
 697    Dynamic<pkgCache::DepIterator> DynDep(Dep);
 698    Dep->ParentVer = Ver.Index();
 699    Dep->Type = Type;
 700    Dep->CompareOp = Op;
 701    Dep->ID = Cache.HeaderP->DependsCount++;
 702
 703    // Probe the reverse dependency list for a version string that matches
 704    if (Version.empty() == false)
 705    {
 706 /*      for (pkgCache::DepIterator I = Pkg.RevDependsList(); I.end() == false; I++)
 707          if (I->Version != 0 && I.TargetVer() == Version)
 708             Dep->Version = I->Version;*/
 709       if (Dep->Version == 0) {
 710          map_ptrloc const index = WriteStringInMap(Version);
 711          if (unlikely(index == 0))
 712             return false;
 713          Dep->Version = index;
 714       }
 715    }
 716
 717    // Link it to the package
 718    Dep->Package = Pkg.Index();
 719    Dep->NextRevDepends = Pkg->RevDepends;
 720    Pkg->RevDepends = Dep.Index();
 721
 722    // Do we know where to link the Dependency to?
 723    if (OldDepLast == NULL)
 724    {
 725       OldDepLast = &Ver->DependsList;
 726       for (pkgCache::DepIterator D = Ver.DependsList(); D.end() == false; D++)
 727          OldDepLast = &D->NextDepends;
 728    } else if (oldMap != Map.Data())
 729       OldDepLast += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
 730
 731    Dep->NextDepends = *OldDepLast;
 732    *OldDepLast = Dep.Index();
 733    OldDepLast = &Dep->NextDepends;
 734
 735    return true;
 736 }
 737                                                                         /*}}}*/
 738 // ListParser::NewDepends - Create the environment for a new dependency /*{{{*/
 739 // ---------------------------------------------------------------------
 740 /* This creates a Group and the Package to link this dependency to if
 741    needed and handles also the caching of the old endpoint */
 742 bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator &Ver,
 743                                                const string &PackageName,
 744                                                const string &Arch,
 745                                                const string &Version,
 746                                                unsigned int Op,
 747                                                unsigned int Type)
 748 {
 749    pkgCache::GrpIterator Grp;
 750    Dynamic<pkgCache::GrpIterator> DynGrp(Grp);
 751    if (unlikely(Owner->NewGroup(Grp, PackageName) == false))
 752       return false;
 753
 754    // Locate the target package
 755    pkgCache::PkgIterator Pkg = Grp.FindPkg(Arch);
 756    Dynamic<pkgCache::PkgIterator> DynPkg(Pkg);
 757    if (Pkg.end() == true) {
 758       if (unlikely(Owner->NewPackage(Pkg, PackageName, Arch) == false))
 759          return false;
 760    }
 761
 762    // Is it a file dependency?
 763    if (unlikely(PackageName[0] == '/'))
 764       FoundFileDeps = true;
 765
 766    /* Caching the old end point speeds up generation substantially */
 767    if (OldDepVer != Ver) {
 768       OldDepLast = NULL;
 769       OldDepVer = Ver;
 770    }
 771
 772    return Owner->NewDepends(Pkg, Ver, Version, Op, Type, OldDepLast);
 773 }
 774                                                                         /*}}}*/
 775 // ListParser::NewProvides - Create a Provides element                  /*{{{*/
 776 // ---------------------------------------------------------------------
 777 /* */
 778 bool pkgCacheGenerator::ListParser::NewProvides(pkgCache::VerIterator &Ver,
 779                                                 const string &PkgName,
 780                                                 const string &PkgArch,
 781                                                 const string &Version)
 782 {
 783    pkgCache &Cache = Owner->Cache;
 784
 785    // We do not add self referencing provides
 786    if (Ver.ParentPkg().Name() == PkgName && (PkgArch == Ver.ParentPkg().Arch() ||
 787         (PkgArch == "all" && strcmp((Cache.StrP + Cache.HeaderP->Architecture), Ver.ParentPkg().Arch()) == 0)))
 788       return true;
 789
 790    // Get a structure
 791    map_ptrloc const Provides = Owner->AllocateInMap(sizeof(pkgCache::Provides));
 792    if (unlikely(Provides == 0))
 793       return false;
 794    Cache.HeaderP->ProvidesCount++;
 795
 796    // Fill it in
 797    pkgCache::PrvIterator Prv(Cache,Cache.ProvideP + Provides,Cache.PkgP);
 798    Dynamic<pkgCache::PrvIterator> DynPrv(Prv);
 799    Prv->Version = Ver.Index();
 800    Prv->NextPkgProv = Ver->ProvidesList;
 801    Ver->ProvidesList = Prv.Index();
 802    if (Version.empty() == false && unlikely((Prv->ProvideVersion = WriteString(Version)) == 0))
 803       return false;
 804
 805    // Locate the target package
 806    pkgCache::PkgIterator Pkg;
 807    Dynamic<pkgCache::PkgIterator> DynPkg(Pkg);
 808    if (unlikely(Owner->NewPackage(Pkg,PkgName, PkgArch) == false))
 809       return false;
 810
 811    // Link it to the package
 812    Prv->ParentPkg = Pkg.Index();
 813    Prv->NextProvides = Pkg->ProvidesList;
 814    Pkg->ProvidesList = Prv.Index();
 815
 816    return true;
 817 }
 818                                                                         /*}}}*/
 819 // CacheGenerator::SelectFile - Select the current file being parsed    /*{{{*/
 820 // ---------------------------------------------------------------------
 821 /* This is used to select which file is to be associated with all newly
 822    added versions. The caller is responsible for setting the IMS fields. */
 823 bool pkgCacheGenerator::SelectFile(const string &File,const string &Site,
 824                                    const pkgIndexFile &Index,
 825                                    unsigned long Flags)
 826 {
 827    // Get some space for the structure
 828    map_ptrloc const idxFile = AllocateInMap(sizeof(*CurrentFile));
 829    if (unlikely(idxFile == 0))
 830       return false;
 831    CurrentFile = Cache.PkgFileP + idxFile;
 832
 833    // Fill it in
 834    map_ptrloc const idxFileName = WriteStringInMap(File);
 835    map_ptrloc const idxSite = WriteUniqString(Site);
 836    if (unlikely(idxFileName == 0 || idxSite == 0))
 837       return false;
 838    CurrentFile->FileName = idxFileName;
 839    CurrentFile->Site = idxSite;
 840    CurrentFile->NextFile = Cache.HeaderP->FileList;
 841    CurrentFile->Flags = Flags;
 842    CurrentFile->ID = Cache.HeaderP->PackageFileCount;
 843    map_ptrloc const idxIndexType = WriteUniqString(Index.GetType()->Label);
 844    if (unlikely(idxIndexType == 0))
 845       return false;
 846    CurrentFile->IndexType = idxIndexType;
 847    PkgFileName = File;
 848    Cache.HeaderP->FileList = CurrentFile - Cache.PkgFileP;
 849    Cache.HeaderP->PackageFileCount++;
 850
 851    if (Progress != 0)
 852       Progress->SubProgress(Index.Size());
 853    return true;
 854 }
 855                                                                         /*}}}*/
 856 // CacheGenerator::WriteUniqueString - Insert a unique string           /*{{{*/
 857 // ---------------------------------------------------------------------
 858 /* This is used to create handles to strings. Given the same text it
 859    always returns the same number */
 860 unsigned long pkgCacheGenerator::WriteUniqString(const char *S,
 861                                                  unsigned int Size)
 862 {
 863    /* We use a very small transient hash table here, this speeds up generation
 864       by a fair amount on slower machines */
 865    pkgCache::StringItem *&Bucket = UniqHash[(S[0]*5 + S[1]) % _count(UniqHash)];
 866    if (Bucket != 0 &&
 867        stringcmp(S,S+Size,Cache.StrP + Bucket->String) == 0)
 868       return Bucket->String;
 869
 870    // Search for an insertion point
 871    pkgCache::StringItem *I = Cache.StringItemP + Cache.HeaderP->StringList;
 872    int Res = 1;
 873    map_ptrloc *Last = &Cache.HeaderP->StringList;
 874    for (; I != Cache.StringItemP; Last = &I->NextItem,
 875         I = Cache.StringItemP + I->NextItem)
 876    {
 877       Res = stringcmp(S,S+Size,Cache.StrP + I->String);
 878       if (Res >= 0)
 879          break;
 880    }
 881
 882    // Match
 883    if (Res == 0)
 884    {
 885       Bucket = I;
 886       return I->String;
 887    }
 888
 889    // Get a structure
 890    void const * const oldMap = Map.Data();
 891    map_ptrloc const Item = AllocateInMap(sizeof(pkgCache::StringItem));
 892    if (Item == 0)
 893       return 0;
 894
 895    map_ptrloc const idxString = WriteStringInMap(S,Size);
 896    if (unlikely(idxString == 0))
 897       return 0;
 898    if (oldMap != Map.Data()) {
 899       Last += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
 900       I += (pkgCache::StringItem*) Map.Data() - (pkgCache::StringItem*) oldMap;
 901    }
 902    *Last = Item;
 903
 904    // Fill in the structure
 905    pkgCache::StringItem *ItemP = Cache.StringItemP + Item;
 906    ItemP->NextItem = I - Cache.StringItemP;
 907    ItemP->String = idxString;
 908
 909    Bucket = ItemP;
 910    return ItemP->String;
 911 }
 912                                                                         /*}}}*/
 913 // CheckValidity - Check that a cache is up-to-date                     /*{{{*/
 914 // ---------------------------------------------------------------------
 915 /* This just verifies that each file in the list of index files exists,
 916    has matching attributes with the cache and the cache does not have
 917    any extra files. */
 918 static bool CheckValidity(const string &CacheFile, FileIterator Start,
 919                           FileIterator End,MMap **OutMap = 0)
 920 {
 921    bool const Debug = _config->FindB("Debug::pkgCacheGen", false);
 922    // No file, certainly invalid
 923    if (CacheFile.empty() == true || FileExists(CacheFile) == false)
 924    {
 925       if (Debug == true)
 926          std::clog << "CacheFile doesn't exist" << std::endl;
 927       return false;
 928    }
 929
 930    // Map it
 931    FileFd CacheF(CacheFile,FileFd::ReadOnly);
 932    SPtr<MMap> Map = new MMap(CacheF,0);
 933    pkgCache Cache(Map);
 934    if (_error->PendingError() == true || Map->Size() == 0)
 935    {
 936       if (Debug == true)
 937          std::clog << "Errors are pending or Map is empty()" << std::endl;
 938       _error->Discard();
 939       return false;
 940    }
 941
 942    /* Now we check every index file, see if it is in the cache,
 943       verify the IMS data and check that it is on the disk too.. */
 944    SPtrArray<bool> Visited = new bool[Cache.HeaderP->PackageFileCount];
 945    memset(Visited,0,sizeof(*Visited)*Cache.HeaderP->PackageFileCount);
 946    for (; Start != End; Start++)
 947    {
 948       if (Debug == true)
 949          std::clog << "Checking PkgFile " << (*Start)->Describe() << ": ";
 950       if ((*Start)->HasPackages() == false)
 951       {
 952          if (Debug == true)
 953             std::clog << "Has NO packages" << std::endl;
 954          continue;
 955       }
 956
 957       if ((*Start)->Exists() == false)
 958       {
 959 #if 0 // mvo: we no longer give a message here (Default Sources spec)
 960          _error->WarningE("stat",_("Couldn't stat source package list %s"),
 961                           (*Start)->Describe().c_str());
 962 #endif
 963          if (Debug == true)
 964             std::clog << "file doesn't exist" << std::endl;
 965          continue;
 966       }
 967
 968       // FindInCache is also expected to do an IMS check.
 969       pkgCache::PkgFileIterator File = (*Start)->FindInCache(Cache);
 970       if (File.end() == true)
 971       {
 972          if (Debug == true)
 973             std::clog << "FindInCache returned end-Pointer" << std::endl;
 974          return false;
 975       }
 976
 977       Visited[File->ID] = true;
 978       if (Debug == true)
 979          std::clog << "with ID " << File->ID << " is valid" << std::endl;
 980    }
 981
 982    for (unsigned I = 0; I != Cache.HeaderP->PackageFileCount; I++)
 983       if (Visited[I] == false)
 984       {
 985          if (Debug == true)
 986             std::clog << "File with ID" << I << " wasn't visited" << std::endl;
 987          return false;
 988       }
 989
 990    if (_error->PendingError() == true)
 991    {
 992       if (Debug == true)
 993       {
 994          std::clog << "Validity failed because of pending errors:" << std::endl;
 995          _error->DumpErrors();
 996       }
 997       _error->Discard();
 998       return false;
 999    }
1000
1001    if (OutMap != 0)
1002       *OutMap = Map.UnGuard();
1003    return true;
1004 }
1005                                                                         /*}}}*/
1006 // ComputeSize - Compute the total size of a bunch of files             /*{{{*/
1007 // ---------------------------------------------------------------------
1008 /* Size is kind of an abstract notion that is only used for the progress
1009    meter */
1010 static unsigned long ComputeSize(FileIterator Start,FileIterator End)
1011 {
1012    unsigned long TotalSize = 0;
1013    for (; Start != End; Start++)
1014    {
1015       if ((*Start)->HasPackages() == false)
1016          continue;
1017       TotalSize += (*Start)->Size();
1018    }
1019    return TotalSize;
1020 }
1021                                                                         /*}}}*/
1022 // BuildCache - Merge the list of index files into the cache            /*{{{*/
1023 // ---------------------------------------------------------------------
1024 /* */
1025 static bool BuildCache(pkgCacheGenerator &Gen,
1026                        OpProgress *Progress,
1027                        unsigned long &CurrentSize,unsigned long TotalSize,
1028                        FileIterator Start, FileIterator End)
1029 {
1030    FileIterator I;
1031    for (I = Start; I != End; I++)
1032    {
1033       if ((*I)->HasPackages() == false)
1034          continue;
1035
1036       if ((*I)->Exists() == false)
1037          continue;
1038
1039       if ((*I)->FindInCache(Gen.GetCache()).end() == false)
1040       {
1041          _error->Warning("Duplicate sources.list entry %s",
1042                          (*I)->Describe().c_str());
1043          continue;
1044       }
1045
1046       unsigned long Size = (*I)->Size();
1047       if (Progress != NULL)
1048          Progress->OverallProgress(CurrentSize,TotalSize,Size,_("Reading package lists"));
1049       CurrentSize += Size;
1050
1051       if ((*I)->Merge(Gen,Progress) == false)
1052          return false;
1053    }
1054
1055    if (Gen.HasFileDeps() == true)
1056    {
1057       if (Progress != NULL)
1058          Progress->Done();
1059       TotalSize = ComputeSize(Start, End);
1060       CurrentSize = 0;
1061       for (I = Start; I != End; I++)
1062       {
1063          unsigned long Size = (*I)->Size();
1064          if (Progress != NULL)
1065             Progress->OverallProgress(CurrentSize,TotalSize,Size,_("Collecting File Provides"));
1066          CurrentSize += Size;
1067          if ((*I)->MergeFileProvides(Gen,Progress) == false)
1068             return false;
1069       }
1070    }
1071
1072    return true;
1073 }
1074                                                                         /*}}}*/
1075 // CacheGenerator::CreateDynamicMMap - load an mmap with configuration options  /*{{{*/
1076 DynamicMMap* pkgCacheGenerator::CreateDynamicMMap(FileFd *CacheF, unsigned long Flags) {
1077    unsigned long const MapStart = _config->FindI("APT::Cache-Start", 24*1024*1024);
1078    unsigned long const MapGrow = _config->FindI("APT::Cache-Grow", 1*1024*1024);
1079    unsigned long const MapLimit = _config->FindI("APT::Cache-Limit", 0);
1080    Flags |= MMap::Moveable;
1081    if (_config->FindB("APT::Cache-Fallback", false) == true)
1082       Flags |= MMap::Fallback;
1083    if (CacheF != NULL)
1084       return new DynamicMMap(*CacheF, Flags, MapStart, MapGrow, MapLimit);
1085    else
1086       return new DynamicMMap(Flags, MapStart, MapGrow, MapLimit);
1087 }
1088                                                                         /*}}}*/
1089 // CacheGenerator::MakeStatusCache - Construct the status cache         /*{{{*/
1090 // ---------------------------------------------------------------------
1091 /* This makes sure that the status cache (the cache that has all
1092    index files from the sources list and all local ones) is ready
1093    to be mmaped. If OutMap is not zero then a MMap object representing
1094    the cache will be stored there. This is pretty much mandetory if you
1095    are using AllowMem. AllowMem lets the function be run as non-root
1096    where it builds the cache 'fast' into a memory buffer. */
1097 __deprecated bool pkgMakeStatusCache(pkgSourceList &List,OpProgress &Progress,
1098                         MMap **OutMap, bool AllowMem)
1099    { return pkgCacheGenerator::MakeStatusCache(List, &Progress, OutMap, AllowMem); }
1100 bool pkgCacheGenerator::MakeStatusCache(pkgSourceList &List,OpProgress *Progress,
1101                         MMap **OutMap,bool AllowMem)
1102 {
1103    bool const Debug = _config->FindB("Debug::pkgCacheGen", false);
1104
1105    vector<pkgIndexFile *> Files;
1106    for (vector<metaIndex *>::const_iterator i = List.begin();
1107         i != List.end();
1108         i++)
1109    {
1110       vector <pkgIndexFile *> *Indexes = (*i)->GetIndexFiles();
1111       for (vector<pkgIndexFile *>::const_iterator j = Indexes->begin();
1112            j != Indexes->end();
1113            j++)
1114          Files.push_back (*j);
1115    }
1116
1117    unsigned long const EndOfSource = Files.size();
1118    if (_system->AddStatusFiles(Files) == false)
1119       return false;
1120
1121    // Decide if we can write to the files..
1122    string const CacheFile = _config->FindFile("Dir::Cache::pkgcache");
1123    string const SrcCacheFile = _config->FindFile("Dir::Cache::srcpkgcache");
1124
1125    // ensure the cache directory exists
1126    if (CacheFile.empty() == false || SrcCacheFile.empty() == false)
1127    {
1128       string dir = _config->FindDir("Dir::Cache");
1129       size_t const len = dir.size();
1130       if (len > 5 && dir.find("/apt/", len - 6, 5) == len - 5)
1131          dir = dir.substr(0, len - 5);
1132       if (CacheFile.empty() == false)
1133          CreateDirectory(dir, flNotFile(CacheFile));
1134       if (SrcCacheFile.empty() == false)
1135          CreateDirectory(dir, flNotFile(SrcCacheFile));
1136    }
1137
1138    // Decide if we can write to the cache
1139    bool Writeable = false;
1140    if (CacheFile.empty() == false)
1141       Writeable = access(flNotFile(CacheFile).c_str(),W_OK) == 0;
1142    else
1143       if (SrcCacheFile.empty() == false)
1144          Writeable = access(flNotFile(SrcCacheFile).c_str(),W_OK) == 0;
1145    if (Debug == true)
1146       std::clog << "Do we have write-access to the cache files? " << (Writeable ? "YES" : "NO") << std::endl;
1147
1148    if (Writeable == false && AllowMem == false && CacheFile.empty() == false)
1149       return _error->Error(_("Unable to write to %s"),flNotFile(CacheFile).c_str());
1150
1151    if (Progress != NULL)
1152       Progress->OverallProgress(0,1,1,_("Reading package lists"));
1153
1154    // Cache is OK, Fin.
1155    if (CheckValidity(CacheFile,Files.begin(),Files.end(),OutMap) == true)
1156    {
1157       if (Progress != NULL)
1158          Progress->OverallProgress(1,1,1,_("Reading package lists"));
1159       if (Debug == true)
1160          std::clog << "pkgcache.bin is valid - no need to build anything" << std::endl;
1161       return true;
1162    }
1163    else if (Debug == true)
1164          std::clog << "pkgcache.bin is NOT valid" << std::endl;
1165
1166    /* At this point we know we need to reconstruct the package cache,
1167       begin. */
1168    SPtr<FileFd> CacheF;
1169    SPtr<DynamicMMap> Map;
1170    if (Writeable == true && CacheFile.empty() == false)
1171    {
1172       unlink(CacheFile.c_str());
1173       CacheF = new FileFd(CacheFile,FileFd::WriteAtomic);
1174       fchmod(CacheF->Fd(),0644);
1175       Map = CreateDynamicMMap(CacheF, MMap::Public);
1176       if (_error->PendingError() == true)
1177          return false;
1178       if (Debug == true)
1179          std::clog << "Open filebased MMap" << std::endl;
1180    }
1181    else
1182    {
1183       // Just build it in memory..
1184       Map = CreateDynamicMMap(NULL);
1185       if (Debug == true)
1186          std::clog << "Open memory Map (not filebased)" << std::endl;
1187    }
1188
1189    // Lets try the source cache.
1190    unsigned long CurrentSize = 0;
1191    unsigned long TotalSize = 0;
1192    if (CheckValidity(SrcCacheFile,Files.begin(),
1193                      Files.begin()+EndOfSource) == true)
1194    {
1195       if (Debug == true)
1196          std::clog << "srcpkgcache.bin is valid - populate MMap with it." << std::endl;
1197       // Preload the map with the source cache
1198       FileFd SCacheF(SrcCacheFile,FileFd::ReadOnly);
1199       unsigned long const alloc = Map->RawAllocate(SCacheF.Size());
1200       if ((alloc == 0 && _error->PendingError())
1201                 || SCacheF.Read((unsigned char *)Map->Data() + alloc,
1202                                 SCacheF.Size()) == false)
1203          return false;
1204
1205       TotalSize = ComputeSize(Files.begin()+EndOfSource,Files.end());
1206
1207       // Build the status cache
1208       pkgCacheGenerator Gen(Map.Get(),Progress);
1209       if (_error->PendingError() == true)
1210          return false;
1211       if (BuildCache(Gen,Progress,CurrentSize,TotalSize,
1212                      Files.begin()+EndOfSource,Files.end()) == false)
1213          return false;
1214
1215       // FIXME: move me to a better place
1216       Gen.FinishCache(Progress);
1217    }
1218    else
1219    {
1220       if (Debug == true)
1221          std::clog << "srcpkgcache.bin is NOT valid - rebuild" << std::endl;
1222       TotalSize = ComputeSize(Files.begin(),Files.end());
1223
1224       // Build the source cache
1225       pkgCacheGenerator Gen(Map.Get(),Progress);
1226       if (_error->PendingError() == true)
1227          return false;
1228       if (BuildCache(Gen,Progress,CurrentSize,TotalSize,
1229                      Files.begin(),Files.begin()+EndOfSource) == false)
1230          return false;
1231
1232       // Write it back
1233       if (Writeable == true && SrcCacheFile.empty() == false)
1234       {
1235          FileFd SCacheF(SrcCacheFile,FileFd::WriteAtomic);
1236          if (_error->PendingError() == true)
1237             return false;
1238
1239          fchmod(SCacheF.Fd(),0644);
1240
1241          // Write out the main data
1242          if (SCacheF.Write(Map->Data(),Map->Size()) == false)
1243             return _error->Error(_("IO Error saving source cache"));
1244          SCacheF.Sync();
1245
1246          // Write out the proper header
1247          Gen.GetCache().HeaderP->Dirty = false;
1248          if (SCacheF.Seek(0) == false ||
1249              SCacheF.Write(Map->Data(),sizeof(*Gen.GetCache().HeaderP)) == false)
1250             return _error->Error(_("IO Error saving source cache"));
1251          Gen.GetCache().HeaderP->Dirty = true;
1252          SCacheF.Sync();
1253       }
1254
1255       // Build the status cache
1256       if (BuildCache(Gen,Progress,CurrentSize,TotalSize,
1257                      Files.begin()+EndOfSource,Files.end()) == false)
1258          return false;
1259
1260       // FIXME: move me to a better place
1261       Gen.FinishCache(Progress);
1262    }
1263    if (Debug == true)
1264       std::clog << "Caches are ready for shipping" << std::endl;
1265
1266    if (_error->PendingError() == true)
1267       return false;
1268    if (OutMap != 0)
1269    {
1270       if (CacheF != 0)
1271       {
1272          delete Map.UnGuard();
1273          *OutMap = new MMap(*CacheF,0);
1274       }
1275       else
1276       {
1277          *OutMap = Map.UnGuard();
1278       }
1279    }
1280
1281    return true;
1282 }
1283                                                                         /*}}}*/
1284 // CacheGenerator::MakeOnlyStatusCache - Build only a status files cache/*{{{*/
1285 // ---------------------------------------------------------------------
1286 /* */
1287 __deprecated bool pkgMakeOnlyStatusCache(OpProgress &Progress,DynamicMMap **OutMap)
1288    { return pkgCacheGenerator::MakeOnlyStatusCache(&Progress, OutMap); }
1289 bool pkgCacheGenerator::MakeOnlyStatusCache(OpProgress *Progress,DynamicMMap **OutMap)
1290 {
1291    vector<pkgIndexFile *> Files;
1292    unsigned long EndOfSource = Files.size();
1293    if (_system->AddStatusFiles(Files) == false)
1294       return false;
1295
1296    SPtr<DynamicMMap> Map = CreateDynamicMMap(NULL);
1297    unsigned long CurrentSize = 0;
1298    unsigned long TotalSize = 0;
1299
1300    TotalSize = ComputeSize(Files.begin()+EndOfSource,Files.end());
1301
1302    // Build the status cache
1303    if (Progress != NULL)
1304       Progress->OverallProgress(0,1,1,_("Reading package lists"));
1305    pkgCacheGenerator Gen(Map.Get(),Progress);
1306    if (_error->PendingError() == true)
1307       return false;
1308    if (BuildCache(Gen,Progress,CurrentSize,TotalSize,
1309                   Files.begin()+EndOfSource,Files.end()) == false)
1310       return false;
1311
1312    // FIXME: move me to a better place
1313    Gen.FinishCache(Progress);
1314
1315    if (_error->PendingError() == true)
1316       return false;
1317    *OutMap = Map.UnGuard();
1318
1319    return true;
1320 }
1321                                                                         /*}}}*/