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