apt-pkg/pkgcache.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: pkgcache.cc,v 1.37 2003/02/10 01:40:58 doogie Exp $
   4 /* ######################################################################
   5
   6    Package Cache - Accessor code for the cache
   7
   8    Please see doc/apt-pkg/cache.sgml for a more detailed description of
   9    this format. Also be sure to keep that file up-to-date!!
  10
  11    This is the general utility functions for cache managment. They provide
  12    a complete set of accessor functions for the cache. The cacheiterators
  13    header contains the STL-like iterators that can be used to easially
  14    navigate the cache as well as seemlessly dereference the mmap'd
  15    indexes. Use these always.
  16
  17    The main class provides for ways to get package indexes and some
  18    general lookup functions to start the iterators.
  19
  20    ##################################################################### */
  21                                                                         /*}}}*/
  22 // Include Files                                                        /*{{{*/
  23 #include <apt-pkg/pkgcache.h>
  24 #include <apt-pkg/policy.h>
  25 #include <apt-pkg/version.h>
  26 #include <apt-pkg/error.h>
  27 #include <apt-pkg/strutl.h>
  28 #include <apt-pkg/configuration.h>
  29 #include <apt-pkg/aptconfiguration.h>
  30 #include <apt-pkg/macros.h>
  31
  32 #include <apti18n.h>
  33
  34 #include <string>
  35 #include <sys/stat.h>
  36 #include <unistd.h>
  37
  38 #include <ctype.h>
  39                                                                         /*}}}*/
  40
  41 using std::string;
  42
  43
  44 // Cache::Header::Header - Constructor                                  /*{{{*/
  45 // ---------------------------------------------------------------------
  46 /* Simply initialize the header */
  47 pkgCache::Header::Header()
  48 {
  49    Signature = 0x98FE76DC;
  50
  51    /* Whenever the structures change the major version should be bumped,
  52       whenever the generator changes the minor version should be bumped. */
  53    MajorVersion = 8;
  54    MinorVersion = 0;
  55    Dirty = false;
  56
  57    HeaderSz = sizeof(pkgCache::Header);
  58    GroupSz = sizeof(pkgCache::Group);
  59    PackageSz = sizeof(pkgCache::Package);
  60    PackageFileSz = sizeof(pkgCache::PackageFile);
  61    VersionSz = sizeof(pkgCache::Version);
  62    DescriptionSz = sizeof(pkgCache::Description);
  63    DependencySz = sizeof(pkgCache::Dependency);
  64    ProvidesSz = sizeof(pkgCache::Provides);
  65    VerFileSz = sizeof(pkgCache::VerFile);
  66    DescFileSz = sizeof(pkgCache::DescFile);
  67
  68    GroupCount = 0;
  69    PackageCount = 0;
  70    VersionCount = 0;
  71    DescriptionCount = 0;
  72    DependsCount = 0;
  73    PackageFileCount = 0;
  74    VerFileCount = 0;
  75    DescFileCount = 0;
  76    ProvidesCount = 0;
  77    MaxVerFileSize = 0;
  78    MaxDescFileSize = 0;
  79
  80    FileList = 0;
  81    StringList = 0;
  82    VerSysName = 0;
  83    Architecture = 0;
  84    memset(PkgHashTable,0,sizeof(PkgHashTable));
  85    memset(GrpHashTable,0,sizeof(GrpHashTable));
  86    memset(Pools,0,sizeof(Pools));
  87 }
  88                                                                         /*}}}*/
  89 // Cache::Header::CheckSizes - Check if the two headers have same *sz   /*{{{*/
  90 // ---------------------------------------------------------------------
  91 /* */
  92 bool pkgCache::Header::CheckSizes(Header &Against) const
  93 {
  94    if (HeaderSz == Against.HeaderSz &&
  95        GroupSz == Against.GroupSz &&
  96        PackageSz == Against.PackageSz &&
  97        PackageFileSz == Against.PackageFileSz &&
  98        VersionSz == Against.VersionSz &&
  99        DescriptionSz == Against.DescriptionSz &&
 100        DependencySz == Against.DependencySz &&
 101        VerFileSz == Against.VerFileSz &&
 102        DescFileSz == Against.DescFileSz &&
 103        ProvidesSz == Against.ProvidesSz)
 104       return true;
 105    return false;
 106 }
 107                                                                         /*}}}*/
 108
 109 // Cache::pkgCache - Constructor                                        /*{{{*/
 110 // ---------------------------------------------------------------------
 111 /* */
 112 pkgCache::pkgCache(MMap *Map, bool DoMap) : Map(*Map)
 113 {
 114    MultiArchEnabled = APT::Configuration::getArchitectures().size() > 1;
 115    if (DoMap == true)
 116       ReMap();
 117 }
 118                                                                         /*}}}*/
 119 // Cache::ReMap - Reopen the cache file                                 /*{{{*/
 120 // ---------------------------------------------------------------------
 121 /* If the file is already closed then this will open it open it. */
 122 bool pkgCache::ReMap()
 123 {
 124    // Apply the typecasts.
 125    HeaderP = (Header *)Map.Data();
 126    GrpP = (Group *)Map.Data();
 127    PkgP = (Package *)Map.Data();
 128    VerFileP = (VerFile *)Map.Data();
 129    DescFileP = (DescFile *)Map.Data();
 130    PkgFileP = (PackageFile *)Map.Data();
 131    VerP = (Version *)Map.Data();
 132    DescP = (Description *)Map.Data();
 133    ProvideP = (Provides *)Map.Data();
 134    DepP = (Dependency *)Map.Data();
 135    StringItemP = (StringItem *)Map.Data();
 136    StrP = (char *)Map.Data();
 137
 138    if (Map.Size() == 0 || HeaderP == 0)
 139       return _error->Error(_("Empty package cache"));
 140
 141    // Check the header
 142    Header DefHeader;
 143    if (HeaderP->Signature != DefHeader.Signature ||
 144        HeaderP->Dirty == true)
 145       return _error->Error(_("The package cache file is corrupted"));
 146
 147    if (HeaderP->MajorVersion != DefHeader.MajorVersion ||
 148        HeaderP->MinorVersion != DefHeader.MinorVersion ||
 149        HeaderP->CheckSizes(DefHeader) == false)
 150       return _error->Error(_("The package cache file is an incompatible version"));
 151
 152    // Locate our VS..
 153    if (HeaderP->VerSysName == 0 ||
 154        (VS = pkgVersioningSystem::GetVS(StrP + HeaderP->VerSysName)) == 0)
 155       return _error->Error(_("This APT does not support the versioning system '%s'"),StrP + HeaderP->VerSysName);
 156
 157    // Chcek the arhcitecture
 158    if (HeaderP->Architecture == 0 ||
 159        _config->Find("APT::Architecture") != StrP + HeaderP->Architecture)
 160       return _error->Error(_("The package cache was built for a different architecture"));
 161    return true;
 162 }
 163                                                                         /*}}}*/
 164 // Cache::Hash - Hash a string                                          /*{{{*/
 165 // ---------------------------------------------------------------------
 166 /* This is used to generate the hash entries for the HashTable. With my
 167    package list from bo this function gets 94% table usage on a 512 item
 168    table (480 used items) */
 169 unsigned long pkgCache::sHash(const string &Str) const
 170 {
 171    unsigned long Hash = 0;
 172    for (string::const_iterator I = Str.begin(); I != Str.end(); I++)
 173       Hash = 5*Hash + tolower_ascii(*I);
 174    return Hash % _count(HeaderP->PkgHashTable);
 175 }
 176
 177 unsigned long pkgCache::sHash(const char *Str) const
 178 {
 179    unsigned long Hash = 0;
 180    for (const char *I = Str; *I != 0; I++)
 181       Hash = 5*Hash + tolower_ascii(*I);
 182    return Hash % _count(HeaderP->PkgHashTable);
 183 }
 184
 185                                                                         /*}}}*/
 186 // Cache::SingleArchFindPkg - Locate a package by name                  /*{{{*/
 187 // ---------------------------------------------------------------------
 188 /* Returns 0 on error, pointer to the package otherwise
 189    The multiArch enabled methods will fallback to this one as it is (a bit)
 190    faster for single arch environments and realworld is mostly singlearch… */
 191 pkgCache::PkgIterator pkgCache::SingleArchFindPkg(const string &Name)
 192 {
 193    // Look at the hash bucket
 194    Package *Pkg = PkgP + HeaderP->PkgHashTable[Hash(Name)];
 195    for (; Pkg != PkgP; Pkg = PkgP + Pkg->NextPackage)
 196    {
 197       if (Pkg->Name != 0 && StrP[Pkg->Name] == Name[0] &&
 198           stringcasecmp(Name,StrP + Pkg->Name) == 0)
 199          return PkgIterator(*this,Pkg);
 200    }
 201    return PkgIterator(*this,0);
 202 }
 203                                                                         /*}}}*/
 204 // Cache::FindPkg - Locate a package by name                            /*{{{*/
 205 // ---------------------------------------------------------------------
 206 /* Returns 0 on error, pointer to the package otherwise */
 207 pkgCache::PkgIterator pkgCache::FindPkg(const string &Name) {
 208         if (MultiArchCache() == false)
 209                 return SingleArchFindPkg(Name);
 210         size_t const found = Name.find(':');
 211         if (found == string::npos)
 212                 return FindPkg(Name, "native");
 213         string const Arch = Name.substr(found+1);
 214         if (Arch == "any")
 215                 return FindPkg(Name, "any");
 216         return FindPkg(Name.substr(0, found), Arch);
 217 }
 218                                                                         /*}}}*/
 219 // Cache::FindPkg - Locate a package by name                            /*{{{*/
 220 // ---------------------------------------------------------------------
 221 /* Returns 0 on error, pointer to the package otherwise */
 222 pkgCache::PkgIterator pkgCache::FindPkg(const string &Name, string const &Arch) {
 223         if (MultiArchCache() == false) {
 224                 if (Arch == "native" || Arch == "all" || Arch == "any" ||
 225                     Arch == _config->Find("APT::Architecture"))
 226                         return SingleArchFindPkg(Name);
 227                 else
 228                         return PkgIterator(*this,0);
 229         }
 230         /* We make a detour via the GrpIterator here as
 231            on a multi-arch environment a group is easier to
 232            find than a package (less entries in the buckets) */
 233         pkgCache::GrpIterator Grp = FindGrp(Name);
 234         if (Grp.end() == true)
 235                 return PkgIterator(*this,0);
 236
 237         return Grp.FindPkg(Arch);
 238 }
 239                                                                         /*}}}*/
 240 // Cache::FindGrp - Locate a group by name                              /*{{{*/
 241 // ---------------------------------------------------------------------
 242 /* Returns End-Pointer on error, pointer to the group otherwise */
 243 pkgCache::GrpIterator pkgCache::FindGrp(const string &Name) {
 244         if (unlikely(Name.empty() == true))
 245                 return GrpIterator(*this,0);
 246
 247         // Look at the hash bucket for the group
 248         Group *Grp = GrpP + HeaderP->GrpHashTable[sHash(Name)];
 249         for (; Grp != GrpP; Grp = GrpP + Grp->Next) {
 250                 if (Grp->Name != 0 && StrP[Grp->Name] == Name[0] &&
 251                     stringcasecmp(Name, StrP + Grp->Name) == 0)
 252                         return GrpIterator(*this, Grp);
 253         }
 254
 255         return GrpIterator(*this,0);
 256 }
 257                                                                         /*}}}*/
 258 // Cache::CompTypeDeb - Return a string describing the compare type     /*{{{*/
 259 // ---------------------------------------------------------------------
 260 /* This returns a string representation of the dependency compare
 261    type in the weird debian style.. */
 262 const char *pkgCache::CompTypeDeb(unsigned char Comp)
 263 {
 264    const char *Ops[] = {"","<=",">=","<<",">>","=","!="};
 265    if ((unsigned)(Comp & 0xF) < 7)
 266       return Ops[Comp & 0xF];
 267    return "";
 268 }
 269                                                                         /*}}}*/
 270 // Cache::CompType - Return a string describing the compare type        /*{{{*/
 271 // ---------------------------------------------------------------------
 272 /* This returns a string representation of the dependency compare
 273    type */
 274 const char *pkgCache::CompType(unsigned char Comp)
 275 {
 276    const char *Ops[] = {"","<=",">=","<",">","=","!="};
 277    if ((unsigned)(Comp & 0xF) < 7)
 278       return Ops[Comp & 0xF];
 279    return "";
 280 }
 281                                                                         /*}}}*/
 282 // Cache::DepType - Return a string describing the dep type             /*{{{*/
 283 // ---------------------------------------------------------------------
 284 /* */
 285 const char *pkgCache::DepType(unsigned char Type)
 286 {
 287    const char *Types[] = {"",_("Depends"),_("PreDepends"),_("Suggests"),
 288                           _("Recommends"),_("Conflicts"),_("Replaces"),
 289                           _("Obsoletes"),_("Breaks"), _("Enhances")};
 290    if (Type < sizeof(Types)/sizeof(*Types))
 291       return Types[Type];
 292    return "";
 293 }
 294                                                                         /*}}}*/
 295 // Cache::Priority - Convert a priority value to a string               /*{{{*/
 296 // ---------------------------------------------------------------------
 297 /* */
 298 const char *pkgCache::Priority(unsigned char Prio)
 299 {
 300    const char *Mapping[] = {0,_("important"),_("required"),_("standard"),
 301                             _("optional"),_("extra")};
 302    if (Prio < _count(Mapping))
 303       return Mapping[Prio];
 304    return 0;
 305 }
 306                                                                         /*}}}*/
 307 // GrpIterator::FindPkg - Locate a package by arch                      /*{{{*/
 308 // ---------------------------------------------------------------------
 309 /* Returns an End-Pointer on error, pointer to the package otherwise */
 310 pkgCache::PkgIterator pkgCache::GrpIterator::FindPkg(string Arch) {
 311         if (unlikely(IsGood() == false || S->FirstPackage == 0))
 312                 return PkgIterator(*Owner, 0);
 313
 314         static string const myArch = _config->Find("APT::Architecture");
 315         /* Most of the time the package for our native architecture is
 316            the one we add at first to the cache, but this would be the
 317            last one we check, so we do it now. */
 318         if (Arch == "native" || Arch == myArch) {
 319                 Arch = myArch;
 320                 pkgCache::Package *Pkg = Owner->PkgP + S->LastPackage;
 321                 if (stringcasecmp(Arch, Owner->StrP + Pkg->Arch) == 0)
 322                         return PkgIterator(*Owner, Pkg);
 323         }
 324
 325         /* If we accept any package we simply return the "first"
 326            package in this group (the last one added). */
 327         if (Arch == "any")
 328                 return PkgIterator(*Owner, Owner->PkgP + S->FirstPackage);
 329
 330         /* Iterate over the list to find the matching arch
 331            unfortunately this list includes "package noise"
 332            (= different packages with same calculated hash),
 333            so we need to check the name also */
 334         for (pkgCache::Package *Pkg = PackageList(); Pkg != Owner->PkgP;
 335              Pkg = Owner->PkgP + Pkg->NextPackage) {
 336                 if (S->Name == Pkg->Name &&
 337                     stringcasecmp(Arch, Owner->StrP + Pkg->Arch) == 0)
 338                         return PkgIterator(*Owner, Pkg);
 339                 if ((Owner->PkgP + S->LastPackage) == Pkg)
 340                         break;
 341         }
 342
 343         return PkgIterator(*Owner, 0);
 344 }
 345                                                                         /*}}}*/
 346 // GrpIterator::FindPreferredPkg - Locate the "best" package            /*{{{*/
 347 // ---------------------------------------------------------------------
 348 /* Returns an End-Pointer on error, pointer to the package otherwise */
 349 pkgCache::PkgIterator pkgCache::GrpIterator::FindPreferredPkg() {
 350         pkgCache::PkgIterator Pkg = FindPkg("native");
 351         if (Pkg.end() == false)
 352                 return Pkg;
 353
 354         std::vector<std::string> const archs = APT::Configuration::getArchitectures();
 355         for (std::vector<std::string>::const_iterator a = archs.begin();
 356              a != archs.end(); ++a) {
 357                 Pkg = FindPkg(*a);
 358                 if (Pkg.end() == false)
 359                         return Pkg;
 360         }
 361
 362         return PkgIterator(*Owner, 0);
 363 }
 364                                                                         /*}}}*/
 365 // GrpIterator::NextPkg - Locate the next package in the group          /*{{{*/
 366 // ---------------------------------------------------------------------
 367 /* Returns an End-Pointer on error, pointer to the package otherwise.
 368    We can't simply ++ to the next as the next package of the last will
 369    be from a different group (with the same hash value) */
 370 pkgCache::PkgIterator pkgCache::GrpIterator::NextPkg(pkgCache::PkgIterator const &LastPkg) {
 371         if (unlikely(IsGood() == false || S->FirstPackage == 0 ||
 372             LastPkg.end() == true))
 373                 return PkgIterator(*Owner, 0);
 374
 375         if (S->LastPackage == LastPkg.Index())
 376                 return PkgIterator(*Owner, 0);
 377
 378         return PkgIterator(*Owner, Owner->PkgP + LastPkg->NextPackage);
 379 }
 380                                                                         /*}}}*/
 381 // GrpIterator::operator ++ - Postfix incr                              /*{{{*/
 382 // ---------------------------------------------------------------------
 383 /* This will advance to the next logical group in the hash table. */
 384 void pkgCache::GrpIterator::operator ++(int)
 385 {
 386    // Follow the current links
 387    if (S != Owner->GrpP)
 388       S = Owner->GrpP + S->Next;
 389
 390    // Follow the hash table
 391    while (S == Owner->GrpP && (HashIndex+1) < (signed)_count(Owner->HeaderP->GrpHashTable))
 392    {
 393       HashIndex++;
 394       S = Owner->GrpP + Owner->HeaderP->GrpHashTable[HashIndex];
 395    }
 396 };
 397                                                                         /*}}}*/
 398 // PkgIterator::operator ++ - Postfix incr                              /*{{{*/
 399 // ---------------------------------------------------------------------
 400 /* This will advance to the next logical package in the hash table. */
 401 void pkgCache::PkgIterator::operator ++(int)
 402 {
 403    // Follow the current links
 404    if (S != Owner->PkgP)
 405       S = Owner->PkgP + S->NextPackage;
 406
 407    // Follow the hash table
 408    while (S == Owner->PkgP && (HashIndex+1) < (signed)_count(Owner->HeaderP->PkgHashTable))
 409    {
 410       HashIndex++;
 411       S = Owner->PkgP + Owner->HeaderP->PkgHashTable[HashIndex];
 412    }
 413 };
 414                                                                         /*}}}*/
 415 // PkgIterator::State - Check the State of the package                  /*{{{*/
 416 // ---------------------------------------------------------------------
 417 /* By this we mean if it is either cleanly installed or cleanly removed. */
 418 pkgCache::PkgIterator::OkState pkgCache::PkgIterator::State() const
 419 {
 420    if (S->InstState == pkgCache::State::ReInstReq ||
 421        S->InstState == pkgCache::State::HoldReInstReq)
 422       return NeedsUnpack;
 423
 424    if (S->CurrentState == pkgCache::State::UnPacked ||
 425        S->CurrentState == pkgCache::State::HalfConfigured)
 426       // we leave triggers alone complettely. dpkg deals with
 427       // them in a hard-to-predict manner and if they get
 428       // resolved by dpkg before apt run dpkg --configure on
 429       // the TriggersPending package dpkg returns a error
 430       //Pkg->CurrentState == pkgCache::State::TriggersAwaited
 431       //Pkg->CurrentState == pkgCache::State::TriggersPending)
 432       return NeedsConfigure;
 433
 434    if (S->CurrentState == pkgCache::State::HalfInstalled ||
 435        S->InstState != pkgCache::State::Ok)
 436       return NeedsUnpack;
 437
 438    return NeedsNothing;
 439 }
 440                                                                         /*}}}*/
 441 // PkgIterator::CandVersion - Returns the candidate version string      /*{{{*/
 442 // ---------------------------------------------------------------------
 443 /* Return string representing of the candidate version. */
 444 const char *
 445 pkgCache::PkgIterator::CandVersion() const
 446 {
 447   //TargetVer is empty, so don't use it.
 448   VerIterator version = pkgPolicy(Owner).GetCandidateVer(*this);
 449   if (version.IsGood())
 450     return version.VerStr();
 451   return 0;
 452 };
 453                                                                         /*}}}*/
 454 // PkgIterator::CurVersion - Returns the current version string         /*{{{*/
 455 // ---------------------------------------------------------------------
 456 /* Return string representing of the current version. */
 457 const char *
 458 pkgCache::PkgIterator::CurVersion() const
 459 {
 460   VerIterator version = CurrentVer();
 461   if (version.IsGood())
 462     return CurrentVer().VerStr();
 463   return 0;
 464 };
 465                                                                         /*}}}*/
 466 // ostream operator to handle string representation of a package        /*{{{*/
 467 // ---------------------------------------------------------------------
 468 /* Output name < cur.rent.version -> candid.ate.version | new.est.version > (section)
 469    Note that the characters <|>() are all literal above. Versions will be ommited
 470    if they provide no new information (e.g. there is no newer version than candidate)
 471    If no version and/or section can be found "none" is used. */
 472 std::ostream&
 473 operator<<(ostream& out, pkgCache::PkgIterator Pkg)
 474 {
 475    if (Pkg.end() == true)
 476       return out << "invalid package";
 477
 478    string current = string(Pkg.CurVersion() == 0 ? "none" : Pkg.CurVersion());
 479    string candidate = string(Pkg.CandVersion() == 0 ? "none" : Pkg.CandVersion());
 480    string newest = string(Pkg.VersionList().end() ? "none" : Pkg.VersionList().VerStr());
 481
 482    out << Pkg.Name() << " [ " << Pkg.Arch() << " ] < " << current;
 483    if (current != candidate)
 484       out << " -> " << candidate;
 485    if ( newest != "none" && candidate != newest)
 486       out << " | " << newest;
 487    out << " > ( " << string(Pkg.Section()==0?"none":Pkg.Section()) << " )";
 488    return out;
 489 }
 490                                                                         /*}}}*/
 491 // PkgIterator::FullName - Returns Name and (maybe) Architecture        /*{{{*/
 492 // ---------------------------------------------------------------------
 493 /* Returns a name:arch string */
 494 std::string pkgCache::PkgIterator::FullName(bool const &Pretty) const
 495 {
 496    string fullname = Name();
 497    if (Pretty == false ||
 498        (strcmp(Arch(), "all") != 0 && _config->Find("APT::Architecture") != Arch()))
 499       return fullname.append(":").append(Arch());
 500    return fullname;
 501 }
 502                                                                         /*}}}*/
 503 // DepIterator::IsCritical - Returns true if the dep is important       /*{{{*/
 504 // ---------------------------------------------------------------------
 505 /* Currently critical deps are defined as depends, predepends and
 506    conflicts (including dpkg's Breaks fields). */
 507 bool pkgCache::DepIterator::IsCritical()
 508 {
 509    if (S->Type == pkgCache::Dep::Conflicts ||
 510        S->Type == pkgCache::Dep::DpkgBreaks ||
 511        S->Type == pkgCache::Dep::Obsoletes ||
 512        S->Type == pkgCache::Dep::Depends ||
 513        S->Type == pkgCache::Dep::PreDepends)
 514       return true;
 515    return false;
 516 }
 517                                                                         /*}}}*/
 518 // DepIterator::SmartTargetPkg - Resolve dep target pointers w/provides /*{{{*/
 519 // ---------------------------------------------------------------------
 520 /* This intellegently looks at dep target packages and tries to figure
 521    out which package should be used. This is needed to nicely handle
 522    provide mapping. If the target package has no other providing packages
 523    then it returned. Otherwise the providing list is looked at to
 524    see if there is one one unique providing package if so it is returned.
 525    Otherwise true is returned and the target package is set. The return
 526    result indicates whether the node should be expandable
 527
 528    In Conjunction with the DepCache the value of Result may not be
 529    super-good since the policy may have made it uninstallable. Using
 530    AllTargets is better in this case. */
 531 bool pkgCache::DepIterator::SmartTargetPkg(PkgIterator &Result)
 532 {
 533    Result = TargetPkg();
 534
 535    // No provides at all
 536    if (Result->ProvidesList == 0)
 537       return false;
 538
 539    // There is the Base package and the providing ones which is at least 2
 540    if (Result->VersionList != 0)
 541       return true;
 542
 543    /* We have to skip over indirect provisions of the package that
 544       owns the dependency. For instance, if libc5-dev depends on the
 545       virtual package libc-dev which is provided by libc5-dev and libc6-dev
 546       we must ignore libc5-dev when considering the provides list. */
 547    PrvIterator PStart = Result.ProvidesList();
 548    for (; PStart.end() != true && PStart.OwnerPkg() == ParentPkg(); PStart++);
 549
 550    // Nothing but indirect self provides
 551    if (PStart.end() == true)
 552       return false;
 553
 554    // Check for single packages in the provides list
 555    PrvIterator P = PStart;
 556    for (; P.end() != true; P++)
 557    {
 558       // Skip over self provides
 559       if (P.OwnerPkg() == ParentPkg())
 560          continue;
 561       if (PStart.OwnerPkg() != P.OwnerPkg())
 562          break;
 563    }
 564
 565    Result = PStart.OwnerPkg();
 566
 567    // Check for non dups
 568    if (P.end() != true)
 569       return true;
 570
 571    return false;
 572 }
 573                                                                         /*}}}*/
 574 // DepIterator::AllTargets - Returns the set of all possible targets    /*{{{*/
 575 // ---------------------------------------------------------------------
 576 /* This is a more useful version of TargetPkg() that follows versioned
 577    provides. It includes every possible package-version that could satisfy
 578    the dependency. The last item in the list has a 0. The resulting pointer
 579    must be delete [] 'd */
 580 pkgCache::Version **pkgCache::DepIterator::AllTargets()
 581 {
 582    Version **Res = 0;
 583    unsigned long Size =0;
 584    while (1)
 585    {
 586       Version **End = Res;
 587       PkgIterator DPkg = TargetPkg();
 588
 589       // Walk along the actual package providing versions
 590       for (VerIterator I = DPkg.VersionList(); I.end() == false; I++)
 591       {
 592          if (Owner->VS->CheckDep(I.VerStr(),S->CompareOp,TargetVer()) == false)
 593             continue;
 594
 595          if ((S->Type == pkgCache::Dep::Conflicts ||
 596               S->Type == pkgCache::Dep::DpkgBreaks ||
 597               S->Type == pkgCache::Dep::Obsoletes) &&
 598              ParentPkg() == I.ParentPkg())
 599             continue;
 600
 601          Size++;
 602          if (Res != 0)
 603             *End++ = I;
 604       }
 605
 606       // Follow all provides
 607       for (PrvIterator I = DPkg.ProvidesList(); I.end() == false; I++)
 608       {
 609          if (Owner->VS->CheckDep(I.ProvideVersion(),S->CompareOp,TargetVer()) == false)
 610             continue;
 611
 612          if ((S->Type == pkgCache::Dep::Conflicts ||
 613               S->Type == pkgCache::Dep::DpkgBreaks ||
 614               S->Type == pkgCache::Dep::Obsoletes) &&
 615              ParentPkg() == I.OwnerPkg())
 616             continue;
 617
 618          Size++;
 619          if (Res != 0)
 620             *End++ = I.OwnerVer();
 621       }
 622
 623       // Do it again and write it into the array
 624       if (Res == 0)
 625       {
 626          Res = new Version *[Size+1];
 627          Size = 0;
 628       }
 629       else
 630       {
 631          *End = 0;
 632          break;
 633       }
 634    }
 635
 636    return Res;
 637 }
 638                                                                         /*}}}*/
 639 // DepIterator::GlobOr - Compute an OR group                            /*{{{*/
 640 // ---------------------------------------------------------------------
 641 /* This Takes an iterator, iterates past the current dependency grouping
 642    and returns Start and End so that so End is the final element
 643    in the group, if End == Start then D is End++ and End is the
 644    dependency D was pointing to. Use in loops to iterate sensibly. */
 645 void pkgCache::DepIterator::GlobOr(DepIterator &Start,DepIterator &End)
 646 {
 647    // Compute a single dependency element (glob or)
 648    Start = *this;
 649    End = *this;
 650    for (bool LastOR = true; end() == false && LastOR == true;)
 651    {
 652       LastOR = (S->CompareOp & pkgCache::Dep::Or) == pkgCache::Dep::Or;
 653       (*this)++;
 654       if (LastOR == true)
 655          End = (*this);
 656    }
 657 }
 658                                                                         /*}}}*/
 659 // VerIterator::CompareVer - Fast version compare for same pkgs         /*{{{*/
 660 // ---------------------------------------------------------------------
 661 /* This just looks over the version list to see if B is listed before A. In
 662    most cases this will return in under 4 checks, ver lists are short. */
 663 int pkgCache::VerIterator::CompareVer(const VerIterator &B) const
 664 {
 665    // Check if they are equal
 666    if (*this == B)
 667       return 0;
 668    if (end() == true)
 669       return -1;
 670    if (B.end() == true)
 671       return 1;
 672
 673    /* Start at A and look for B. If B is found then A > B otherwise
 674       B was before A so A < B */
 675    VerIterator I = *this;
 676    for (;I.end() == false; I++)
 677       if (I == B)
 678          return 1;
 679    return -1;
 680 }
 681                                                                         /*}}}*/
 682 // VerIterator::Downloadable - Checks if the version is downloadable    /*{{{*/
 683 // ---------------------------------------------------------------------
 684 /* */
 685 bool pkgCache::VerIterator::Downloadable() const
 686 {
 687    VerFileIterator Files = FileList();
 688    for (; Files.end() == false; Files++)
 689       if ((Files.File()->Flags & pkgCache::Flag::NotSource) != pkgCache::Flag::NotSource)
 690          return true;
 691    return false;
 692 }
 693                                                                         /*}}}*/
 694 // VerIterator::Automatic - Check if this version is 'automatic'        /*{{{*/
 695 // ---------------------------------------------------------------------
 696 /* This checks to see if any of the versions files are not NotAutomatic.
 697    True if this version is selectable for automatic installation. */
 698 bool pkgCache::VerIterator::Automatic() const
 699 {
 700    VerFileIterator Files = FileList();
 701    for (; Files.end() == false; Files++)
 702       if ((Files.File()->Flags & pkgCache::Flag::NotAutomatic) != pkgCache::Flag::NotAutomatic)
 703          return true;
 704    return false;
 705 }
 706                                                                         /*}}}*/
 707 // VerIterator::Pseudo - Check if this version is a pseudo one          /*{{{*/
 708 // ---------------------------------------------------------------------
 709 /* Sometimes you have the need to express dependencies with versions
 710    which doesn't really exist or exist multiply times for "different"
 711    packages. We need these versions for dependency resolution but they
 712    are a problem everytime we need to download/install something. */
 713 bool pkgCache::VerIterator::Pseudo() const
 714 {
 715    if (S->MultiArch == pkgCache::Version::All &&
 716            strcmp(Arch(true),"all") != 0)
 717    {
 718            GrpIterator const Grp = ParentPkg().Group();
 719            return (Grp->LastPackage != Grp->FirstPackage);
 720    }
 721    return false;
 722 }
 723                                                                         /*}}}*/
 724 // VerIterator::NewestFile - Return the newest file version relation    /*{{{*/
 725 // ---------------------------------------------------------------------
 726 /* This looks at the version numbers associated with all of the sources
 727    this version is in and returns the highest.*/
 728 pkgCache::VerFileIterator pkgCache::VerIterator::NewestFile() const
 729 {
 730    VerFileIterator Files = FileList();
 731    VerFileIterator Highest = Files;
 732    for (; Files.end() == false; Files++)
 733    {
 734       if (Owner->VS->CmpReleaseVer(Files.File().Version(),Highest.File().Version()) > 0)
 735          Highest = Files;
 736    }
 737
 738    return Highest;
 739 }
 740                                                                         /*}}}*/
 741 // VerIterator::RelStr - Release description string                     /*{{{*/
 742 // ---------------------------------------------------------------------
 743 /* This describes the version from a release-centric manner. The output is a
 744    list of Label:Version/Archive */
 745 string pkgCache::VerIterator::RelStr() const
 746 {
 747    bool First = true;
 748    string Res;
 749    for (pkgCache::VerFileIterator I = this->FileList(); I.end() == false; I++)
 750    {
 751       // Do not print 'not source' entries'
 752       pkgCache::PkgFileIterator File = I.File();
 753       if ((File->Flags & pkgCache::Flag::NotSource) == pkgCache::Flag::NotSource)
 754          continue;
 755
 756       // See if we have already printed this out..
 757       bool Seen = false;
 758       for (pkgCache::VerFileIterator J = this->FileList(); I != J; J++)
 759       {
 760          pkgCache::PkgFileIterator File2 = J.File();
 761          if (File2->Label == 0 || File->Label == 0)
 762             continue;
 763
 764          if (strcmp(File.Label(),File2.Label()) != 0)
 765             continue;
 766
 767          if (File2->Version == File->Version)
 768          {
 769             Seen = true;
 770             break;
 771          }
 772          if (File2->Version == 0 || File->Version == 0)
 773             break;
 774          if (strcmp(File.Version(),File2.Version()) == 0)
 775             Seen = true;
 776       }
 777
 778       if (Seen == true)
 779          continue;
 780
 781       if (First == false)
 782          Res += ", ";
 783       else
 784          First = false;
 785
 786       if (File->Label != 0)
 787          Res = Res + File.Label() + ':';
 788
 789       if (File->Archive != 0)
 790       {
 791          if (File->Version == 0)
 792             Res += File.Archive();
 793          else
 794             Res = Res + File.Version() + '/' +  File.Archive();
 795       }
 796       else
 797       {
 798          // No release file, print the host name that this came from
 799          if (File->Site == 0 || File.Site()[0] == 0)
 800             Res += "localhost";
 801          else
 802             Res += File.Site();
 803       }
 804    }
 805    if (S->ParentPkg != 0)
 806       Res.append(" [").append(Arch()).append("]");
 807    return Res;
 808 }
 809                                                                         /*}}}*/
 810 // PkgFileIterator::IsOk - Checks if the cache is in sync with the file /*{{{*/
 811 // ---------------------------------------------------------------------
 812 /* This stats the file and compares its stats with the ones that were
 813    stored during generation. Date checks should probably also be
 814    included here. */
 815 bool pkgCache::PkgFileIterator::IsOk()
 816 {
 817    struct stat Buf;
 818    if (stat(FileName(),&Buf) != 0)
 819       return false;
 820
 821    if (Buf.st_size != (signed)S->Size || Buf.st_mtime != S->mtime)
 822       return false;
 823
 824    return true;
 825 }
 826                                                                         /*}}}*/
 827 // PkgFileIterator::RelStr - Return the release string                  /*{{{*/
 828 // ---------------------------------------------------------------------
 829 /* */
 830 string pkgCache::PkgFileIterator::RelStr()
 831 {
 832    string Res;
 833    if (Version() != 0)
 834       Res = Res + (Res.empty() == true?"v=":",v=") + Version();
 835    if (Origin() != 0)
 836       Res = Res + (Res.empty() == true?"o=":",o=")  + Origin();
 837    if (Archive() != 0)
 838       Res = Res + (Res.empty() == true?"a=":",a=")  + Archive();
 839    if (Codename() != 0)
 840       Res = Res + (Res.empty() == true?"n=":",n=")  + Codename();
 841    if (Label() != 0)
 842       Res = Res + (Res.empty() == true?"l=":",l=")  + Label();
 843    if (Component() != 0)
 844       Res = Res + (Res.empty() == true?"c=":",c=")  + Component();
 845    if (Architecture() != 0)
 846       Res = Res + (Res.empty() == true?"b=":",b=")  + Architecture();
 847    return Res;
 848 }
 849                                                                         /*}}}*/
 850 // VerIterator::TranslatedDescription - Return the a DescIter for locale/*{{{*/
 851 // ---------------------------------------------------------------------
 852 /* return a DescIter for the current locale or the default if none is
 853  * found
 854  */
 855 pkgCache::DescIterator pkgCache::VerIterator::TranslatedDescription() const
 856 {
 857    std::vector<string> const lang = APT::Configuration::getLanguages();
 858    for (std::vector<string>::const_iterator l = lang.begin();
 859         l != lang.end(); l++)
 860    {
 861       pkgCache::DescIterator DescDefault = DescriptionList();
 862       pkgCache::DescIterator Desc = DescDefault;
 863
 864       for (; Desc.end() == false; Desc++)
 865          if (*l == Desc.LanguageCode())
 866             break;
 867       if (Desc.end() == true)
 868          Desc = DescDefault;
 869       return Desc;
 870    }
 871
 872    return DescriptionList();
 873 };
 874
 875                                                                         /*}}}*/