X-Git-Url: https://git.saurik.com/apt.git/blobdiff_plain/3e68f7e41022790619c698a32390a5256fadba7c..71c9e95b223517b5f51c4627f6ad4cce8af0d901:/apt-pkg/depcache.cc diff --git a/apt-pkg/depcache.cc b/apt-pkg/depcache.cc index 1332f3ee2..7b1448c73 100644 --- a/apt-pkg/depcache.cc +++ b/apt-pkg/depcache.cc @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -33,7 +34,6 @@ #include #include #include -#include #include #include @@ -64,7 +64,7 @@ ConfigValueInSubTree(const char* SubTree, const char *needle) } /*}}}*/ pkgDepCache::ActionGroup::ActionGroup(pkgDepCache &cache) : /*{{{*/ - cache(cache), released(false) + d(NULL), cache(cache), released(false) { ++cache.group_level; } @@ -95,8 +95,10 @@ pkgDepCache::ActionGroup::~ActionGroup() // DepCache::pkgDepCache - Constructors /*{{{*/ // --------------------------------------------------------------------- /* */ -pkgDepCache::pkgDepCache(pkgCache *pCache,Policy *Plcy) : - group_level(0), Cache(pCache), PkgState(0), DepState(0) +pkgDepCache::pkgDepCache(pkgCache * const pCache,Policy * const Plcy) : + group_level(0), Cache(pCache), PkgState(0), DepState(0), + iUsrSize(0), iDownloadSize(0), iInstCount(0), iDelCount(0), iKeepCount(0), + iBrokenCount(0), iPolicyBrokenCount(0), iBadCount(0), d(NULL) { DebugMarker = _config->FindB("Debug::pkgDepCache::Marker", false); DebugAutoInstall = _config->FindB("Debug::pkgDepCache::AutoInstall", false); @@ -119,7 +121,7 @@ pkgDepCache::~pkgDepCache() // DepCache::Init - Generate the initial extra structures. /*{{{*/ // --------------------------------------------------------------------- /* This allocats the extension buffers and initializes them. */ -bool pkgDepCache::Init(OpProgress *Prog) +bool pkgDepCache::Init(OpProgress * const Prog) { // Suppress mark updates during this operation (just in case) and // run a mark operation when Init terminates. @@ -130,7 +132,7 @@ bool pkgDepCache::Init(OpProgress *Prog) PkgState = new StateCache[Head().PackageCount]; DepState = new unsigned char[Head().DependsCount]; memset(PkgState,0,sizeof(*PkgState)*Head().PackageCount); - memset(DepState,0,sizeof(*DepState)*Head().DependsCount); + memset(DepState,0,sizeof(*DepState)*Head().DependsCount); if (Prog != 0) { @@ -138,7 +140,7 @@ bool pkgDepCache::Init(OpProgress *Prog) _("Building dependency tree")); Prog->SubProgress(Head().PackageCount,_("Candidate versions")); } - + /* Set the current state of everything. In this state all of the packages are kept exactly as is. See AllUpgrade */ int Done = 0; @@ -146,7 +148,7 @@ bool pkgDepCache::Init(OpProgress *Prog) { if (Prog != 0 && Done%20 == 0) Prog->Progress(Done); - + // Find the proper cache slot StateCache &State = PkgState[I->ID]; State.iFlags = 0; @@ -155,28 +157,27 @@ bool pkgDepCache::Init(OpProgress *Prog) State.CandidateVer = GetCandidateVer(I); State.InstallVer = I.CurrentVer(); State.Mode = ModeKeep; - + State.Update(I,*this); - } - + } + if (Prog != 0) { - Prog->OverallProgress(Head().PackageCount,2*Head().PackageCount, Head().PackageCount, _("Building dependency tree")); Prog->SubProgress(Head().PackageCount,_("Dependency generation")); } - + Update(Prog); if(Prog != 0) Prog->Done(); return true; -} +} /*}}}*/ -bool pkgDepCache::readStateFile(OpProgress *Prog) /*{{{*/ +bool pkgDepCache::readStateFile(OpProgress * const Prog) /*{{{*/ { FileFd state_file; string const state = _config->FindFile("Dir::State::extended_states"); @@ -184,7 +185,7 @@ bool pkgDepCache::readStateFile(OpProgress *Prog) /*{{{*/ state_file.Open(state, FileFd::ReadOnly); off_t const file_size = state_file.Size(); if(Prog != NULL) - Prog->OverallProgress(0, file_size, 1, + Prog->OverallProgress(0, file_size, 1, _("Reading state information")); pkgTagFile tagfile(&state_file); @@ -228,7 +229,7 @@ bool pkgDepCache::readStateFile(OpProgress *Prog) /*{{{*/ return true; } /*}}}*/ -bool pkgDepCache::writeStateFile(OpProgress * /*prog*/, bool InstalledOnly) /*{{{*/ +bool pkgDepCache::writeStateFile(OpProgress * const /*prog*/, bool const InstalledOnly) /*{{{*/ { bool const debug_autoremove = _config->FindB("Debug::pkgAutoRemove",false); @@ -237,9 +238,11 @@ bool pkgDepCache::writeStateFile(OpProgress * /*prog*/, bool InstalledOnly) /*{{ FileFd StateFile; string const state = _config->FindFile("Dir::State::extended_states"); + if (CreateAPTDirectoryIfNeeded(_config->FindDir("Dir::State"), flNotFile(state)) == false) + return false; // if it does not exist, create a empty one - if(!RealFileExists(state)) + if(!RealFileExists(state)) { StateFile.Open(state, FileFd::WriteAtomic); StateFile.Close(); @@ -250,17 +253,14 @@ bool pkgDepCache::writeStateFile(OpProgress * /*prog*/, bool InstalledOnly) /*{{ return _error->Error(_("Failed to open StateFile %s"), state.c_str()); - FILE *OutFile; - string const outfile = state + ".tmp"; - if((OutFile = fopen(outfile.c_str(),"w")) == NULL) - return _error->Error(_("Failed to write temporary StateFile %s"), - outfile.c_str()); + FileFd OutFile(state, FileFd::ReadWrite | FileFd::Atomic); + if (OutFile.IsOpen() == false || OutFile.Failed() == true) + return _error->Error(_("Failed to write temporary StateFile %s"), state.c_str()); // first merge with the existing sections pkgTagFile tagfile(&StateFile); pkgTagSection section; std::set pkgs_seen; - const char *nullreorderlist[] = {0}; while(tagfile.Step(section)) { string const pkgname = section.FindS("Package"); string pkgarch = section.FindS("Architecture"); @@ -269,7 +269,7 @@ bool pkgDepCache::writeStateFile(OpProgress * /*prog*/, bool InstalledOnly) /*{{ // Silently ignore unknown packages and packages with no actual // version. pkgCache::PkgIterator pkg = Cache->FindPkg(pkgname, pkgarch); - if(pkg.end() || pkg.VersionList().end()) + if(pkg.end() || pkg.VersionList().end()) continue; StateCache const &P = PkgState[pkg->ID]; bool newAuto = (P.Flags & Flag::Auto); @@ -290,21 +290,17 @@ bool pkgDepCache::writeStateFile(OpProgress * /*prog*/, bool InstalledOnly) /*{{ if(_config->FindB("Debug::pkgAutoRemove",false)) std::clog << "Update existing AutoInstall info: " << pkg.FullName() << std::endl; - TFRewriteData rewrite[3]; - rewrite[0].Tag = "Architecture"; - rewrite[0].Rewrite = pkg.Arch(); - rewrite[0].NewTag = 0; - rewrite[1].Tag = "Auto-Installed"; - rewrite[1].Rewrite = newAuto ? "1" : "0"; - rewrite[1].NewTag = 0; - rewrite[2].Tag = 0; - TFRewrite(OutFile, section, nullreorderlist, rewrite); - fprintf(OutFile,"\n"); + + std::vector rewrite; + rewrite.push_back(pkgTagSection::Tag::Rewrite("Architecture", pkg.Arch())); + rewrite.push_back(pkgTagSection::Tag::Rewrite("Auto-Installed", newAuto ? "1" : "0")); + section.Write(OutFile, NULL, rewrite); + if (OutFile.Write("\n", 1) == false) + return false; pkgs_seen.insert(pkg.FullName()); } - + // then write the ones we have not seen yet - std::ostringstream ostr; for(pkgCache::PkgIterator pkg=Cache->PkgBegin(); !pkg.end(); ++pkg) { StateCache const &P = PkgState[pkg->ID]; if(P.Flags & Flag::Auto) { @@ -323,19 +319,17 @@ bool pkgDepCache::writeStateFile(OpProgress * /*prog*/, bool InstalledOnly) /*{{ continue; if(debug_autoremove) std::clog << "Writing new AutoInstall: " << pkg.FullName() << std::endl; - ostr.str(string("")); - ostr << "Package: " << pkg.Name() - << "\nArchitecture: " << pkgarch - << "\nAuto-Installed: 1\n\n"; - fprintf(OutFile,"%s",ostr.str().c_str()); + std::string stanza = "Package: "; + stanza.append(pkg.Name()) + .append("\nArchitecture: ").append(pkgarch) + .append("\nAuto-Installed: 1\n\n"); + if (OutFile.Write(stanza.c_str(), stanza.length()) == false) + return false; } } - fclose(OutFile); - - // move the outfile over the real file and set permissions - rename(outfile.c_str(), state.c_str()); + if (OutFile.Close() == false) + return false; chmod(state.c_str(), 0644); - return true; } /*}}}*/ @@ -345,7 +339,7 @@ bool pkgDepCache::writeStateFile(OpProgress * /*prog*/, bool InstalledOnly) /*{{ then walks along the package provides list and checks if each provides will be installed then checks the provides against the dep. Res will be set to the package which was used to satisfy the dep. */ -bool pkgDepCache::CheckDep(DepIterator Dep,int Type,PkgIterator &Res) +bool pkgDepCache::CheckDep(DepIterator const &Dep,int const Type,PkgIterator &Res) { Res = Dep.TargetPkg(); @@ -354,24 +348,27 @@ bool pkgDepCache::CheckDep(DepIterator Dep,int Type,PkgIterator &Res) bug. Conflicts may never self match */ if (Dep.IsIgnorable(Res) == false) { - PkgIterator Pkg = Dep.TargetPkg(); // Check the base package - if (Type == NowVersion && Pkg->CurrentVer != 0) - if (Dep.IsSatisfied(Pkg.CurrentVer()) == true) + if (Type == NowVersion) + { + if (Res->CurrentVer != 0 && Dep.IsSatisfied(Res.CurrentVer()) == true) return true; - - if (Type == InstallVersion && PkgState[Pkg->ID].InstallVer != 0) - if (Dep.IsSatisfied(PkgState[Pkg->ID].InstVerIter(*this)) == true) + } + else if (Type == InstallVersion) + { + if (PkgState[Res->ID].InstallVer != 0 && + Dep.IsSatisfied(PkgState[Res->ID].InstVerIter(*this)) == true) return true; - - if (Type == CandidateVersion && PkgState[Pkg->ID].CandidateVer != 0) - if (Dep.IsSatisfied(PkgState[Pkg->ID].CandidateVerIter(*this)) == true) + } + else if (Type == CandidateVersion) + if (PkgState[Res->ID].CandidateVer != 0 && + Dep.IsSatisfied(PkgState[Res->ID].CandidateVerIter(*this)) == true) return true; } - + if (Dep->Type == Dep::Obsoletes) return false; - + // Check the providing packages PrvIterator P = Dep.TargetPkg().ProvidesList(); for (; P.end() != true; ++P) @@ -385,21 +382,19 @@ bool pkgDepCache::CheckDep(DepIterator Dep,int Type,PkgIterator &Res) if (P.OwnerPkg().CurrentVer() != P.OwnerVer()) continue; } - - if (Type == InstallVersion) + else if (Type == InstallVersion) { StateCache &State = PkgState[P.OwnerPkg()->ID]; if (State.InstallVer != (Version *)P.OwnerVer()) continue; } - - if (Type == CandidateVersion) + else if (Type == CandidateVersion) { StateCache &State = PkgState[P.OwnerPkg()->ID]; if (State.CandidateVer != (Version *)P.OwnerVer()) continue; } - + // Compare the versions. if (Dep.IsSatisfied(P) == true) { @@ -407,7 +402,7 @@ bool pkgDepCache::CheckDep(DepIterator Dep,int Type,PkgIterator &Res) return true; } } - + return false; } /*}}}*/ @@ -489,47 +484,46 @@ void pkgDepCache::AddStates(const PkgIterator &Pkg, bool const Invert) { signed char const Add = (Invert == false) ? 1 : -1; StateCache &State = PkgState[Pkg->ID]; - + // The Package is broken (either minimal dep or policy dep) if ((State.DepState & DepInstMin) != DepInstMin) iBrokenCount += Add; if ((State.DepState & DepInstPolicy) != DepInstPolicy) iPolicyBrokenCount += Add; - + // Bad state if (Pkg.State() != PkgIterator::NeedsNothing) iBadCount += Add; - + // Not installed if (Pkg->CurrentVer == 0) { if (State.Mode == ModeDelete && (State.iFlags & Purge) == Purge && Pkg.Purge() == false) iDelCount += Add; - + if (State.Mode == ModeInstall) iInstCount += Add; return; } - + // Installed, no upgrade if (State.Status == 0) - { + { if (State.Mode == ModeDelete) iDelCount += Add; else if ((State.iFlags & ReInstall) == ReInstall) iInstCount += Add; - return; } - + // Alll 3 are possible if (State.Mode == ModeDelete) - iDelCount += Add; - if (State.Mode == ModeKeep) + iDelCount += Add; + else if (State.Mode == ModeKeep) iKeepCount += Add; - if (State.Mode == ModeInstall) + else if (State.Mode == ModeInstall) iInstCount += Add; } /*}}}*/ @@ -540,7 +534,6 @@ void pkgDepCache::AddStates(const PkgIterator &Pkg, bool const Invert) void pkgDepCache::BuildGroupOrs(VerIterator const &V) { unsigned char Group = 0; - for (DepIterator D = V.DependsList(); D.end() != true; ++D) { // Build the dependency state. @@ -550,18 +543,18 @@ void pkgDepCache::BuildGroupOrs(VerIterator const &V) right sense for a conflicts group */ if (D.IsNegative() == true) State = ~State; - + // Add to the group if we are within an or.. State &= 0x7; Group |= State; State |= Group << 3; if ((D->CompareOp & Dep::Or) != Dep::Or) Group = 0; - + // Invert for Conflicts if (D.IsNegative() == true) State = ~State; - } + } } /*}}}*/ // DepCache::VersionState - Perform a pass over a dependency list /*{{{*/ @@ -570,34 +563,31 @@ void pkgDepCache::BuildGroupOrs(VerIterator const &V) state of the list, filtering it through both a Min check and a Policy check. The return result will have SetMin/SetPolicy low if a check fails. It uses the DepState cache for it's computations. */ -unsigned char pkgDepCache::VersionState(DepIterator D,unsigned char Check, - unsigned char SetMin, - unsigned char SetPolicy) +unsigned char pkgDepCache::VersionState(DepIterator D, unsigned char const Check, + unsigned char const SetMin, + unsigned char const SetPolicy) const { unsigned char Dep = 0xFF; - while (D.end() != true) { - // Compute a single dependency element (glob or) - DepIterator Start = D; - unsigned char State = 0; - for (bool LastOR = true; D.end() == false && LastOR == true; ++D) - { - State |= DepState[D->ID]; - LastOR = (D->CompareOp & Dep::Or) == Dep::Or; - } - + // the last or-dependency has the state of all previous or'ed + DepIterator Start, End; + D.GlobOr(Start, End); + // ignore if we are called with Dep{Install,…} or DepG{Install,…} + // the later would be more correct, but the first is what we get + unsigned char const State = DepState[End->ID] | (DepState[End->ID] >> 3); + // Minimum deps that must be satisfied to have a working package if (Start.IsCritical() == true) + { if ((State & Check) != Check) - Dep &= ~SetMin; - + return Dep &= ~(SetMin | SetPolicy); + } // Policy deps that must be satisfied to install the package - if (IsImportantDep(Start) == true && + else if (IsImportantDep(Start) == true && (State & Check) != Check) Dep &= ~SetPolicy; } - return Dep; } /*}}}*/ @@ -606,17 +596,17 @@ unsigned char pkgDepCache::VersionState(DepIterator D,unsigned char Check, /* This is the main dependency computation bit. It computes the 3 main results for a dependencys, Now, Install and Candidate. Callers must invert the result if dealing with conflicts. */ -unsigned char pkgDepCache::DependencyState(DepIterator &D) +unsigned char pkgDepCache::DependencyState(DepIterator const &D) { unsigned char State = 0; - + if (CheckDep(D,NowVersion) == true) State |= DepNow; if (CheckDep(D,InstallVersion) == true) State |= DepInstall; if (CheckDep(D,CandidateVersion) == true) State |= DepCVer; - + return State; } /*}}}*/ @@ -625,7 +615,7 @@ unsigned char pkgDepCache::DependencyState(DepIterator &D) /* This determines the combined dependency representation of a package for its two states now and install. This is done by using the pre-generated dependency information. */ -void pkgDepCache::UpdateVerState(PkgIterator Pkg) +void pkgDepCache::UpdateVerState(PkgIterator const &Pkg) { // Empty deps are always true StateCache &State = PkgState[Pkg->ID]; @@ -659,7 +649,7 @@ void pkgDepCache::UpdateVerState(PkgIterator Pkg) // --------------------------------------------------------------------- /* This will figure out the state of all the packages and all the dependencies based on the current policy. */ -void pkgDepCache::Update(OpProgress *Prog) +void pkgDepCache::Update(OpProgress * const Prog) { iUsrSize = 0; iDownloadSize = 0; @@ -955,7 +945,7 @@ bool pkgDepCache::IsModeChangeOk(ModeList const mode, PkgIterator const &Pkg, /* */ struct CompareProviders { pkgCache::PkgIterator const Pkg; - CompareProviders(pkgCache::DepIterator const &Dep) : Pkg(Dep.TargetPkg()) {}; + explicit CompareProviders(pkgCache::DepIterator const &Dep) : Pkg(Dep.TargetPkg()) {}; //bool operator() (APT::VersionList::iterator const &AV, APT::VersionList::iterator const &BV) bool operator() (pkgCache::VerIterator const &AV, pkgCache::VerIterator const &BV) { @@ -1195,18 +1185,8 @@ bool pkgDepCache::MarkInstall(PkgIterator const &Pkg,bool AutoInst, fixing the problem for "positive" dependencies */ if (Start.IsNegative() == false && (DepState[Start->ID] & DepCVer) == DepCVer) { - APT::VersionList verlist; - pkgCache::VerIterator Cand = PkgState[Start.TargetPkg()->ID].CandidateVerIter(*this); - if (Cand.end() == false && Start.IsSatisfied(Cand) == true) - verlist.insert(Cand); - for (PrvIterator Prv = Start.TargetPkg().ProvidesList(); Prv.end() != true; ++Prv) - { - pkgCache::VerIterator V = Prv.OwnerVer(); - pkgCache::VerIterator Cand = PkgState[Prv.OwnerPkg()->ID].CandidateVerIter(*this); - if (Cand.end() == true || V != Cand || Start.IsSatisfied(Prv) == false) - continue; - verlist.insert(Cand); - } + pkgCacheFile CacheFile(this); + APT::VersionList verlist = APT::VersionList::FromDependency(CacheFile, Start, APT::CacheSetHelper::CANDIDATE); CompareProviders comp(Start); do { @@ -1313,14 +1293,18 @@ bool pkgDepCache::IsInstallOkMultiArchSameVersionSynced(PkgIterator const &Pkg, GrpIterator const Grp = Pkg.Group(); for (PkgIterator P = Grp.PackageList(); P.end() == false; P = Grp.NextPkg(P)) { - // not installed or version synced: fine by definition + // not installed or self-check: fine by definition + if (P->CurrentVer == 0 || P == Pkg) + continue; + + // not having a candidate or being in sync // (simple string-compare as stuff like '1' == '0:1-0' can't happen here) - if (P->CurrentVer == 0 || strcmp(Pkg.CandVersion(), P.CandVersion()) == 0) + VerIterator CV = PkgState[P->ID].CandidateVerIter(*this); + if (CV.end() == true || strcmp(Pkg.CandVersion(), CV.VerStr()) == 0) continue; + // packages losing M-A:same can be out-of-sync - VerIterator CV = PkgState[P->ID].CandidateVerIter(*this); - if (unlikely(CV.end() == true) || - (CV->MultiArch & pkgCache::Version::Same) != pkgCache::Version::Same) + if ((CV->MultiArch & pkgCache::Version::Same) != pkgCache::Version::Same) continue; // not downloadable means the package is obsolete, so allow out-of-sync @@ -1330,7 +1314,8 @@ bool pkgDepCache::IsInstallOkMultiArchSameVersionSynced(PkgIterator const &Pkg, PkgState[Pkg->ID].iFlags |= AutoKept; if (unlikely(DebugMarker == true)) std::clog << OutputInDepth(Depth) << "Ignore MarkInstall of " << Pkg - << " as its M-A:same siblings are not version-synced" << std::endl; + << " as it is not in sync with its M-A:same sibling " << P + << " (" << Pkg.CandVersion() << " != " << CV.VerStr() << ")" << std::endl; return false; } @@ -1665,10 +1650,10 @@ const char *pkgDepCache::StateCache::StripEpoch(const char *Ver) return 0; // Strip any epoch - for (const char *I = Ver; *I != 0; I++) - if (*I == ':') - return I + 1; - return Ver; + char const * const I = strchr(Ver, ':'); + if (I == nullptr) + return Ver; + return I + 1; } /*}}}*/ // Policy::GetCandidateVer - Returns the Candidate install version /*{{{*/ @@ -1688,13 +1673,13 @@ pkgCache::VerIterator pkgDepCache::Policy::GetCandidateVer(PkgIterator const &Pk for (VerFileIterator J = I.FileList(); J.end() == false; ++J) { - if ((J.File()->Flags & Flag::NotSource) != 0) + if (J.File().Flagged(Flag::NotSource)) continue; /* Stash the highest version of a not-automatic source, we use it if there is nothing better */ - if ((J.File()->Flags & Flag::NotAutomatic) != 0 || - (J.File()->Flags & Flag::ButAutomaticUpgrades) != 0) + if (J.File().Flagged(Flag::NotAutomatic) || + J.File().Flagged(Flag::ButAutomaticUpgrades)) { if (Last.end() == true) Last = I; @@ -1711,17 +1696,17 @@ pkgCache::VerIterator pkgDepCache::Policy::GetCandidateVer(PkgIterator const &Pk // Policy::IsImportantDep - True if the dependency is important /*{{{*/ // --------------------------------------------------------------------- /* */ -bool pkgDepCache::Policy::IsImportantDep(DepIterator const &Dep) +bool pkgDepCache::Policy::IsImportantDep(DepIterator const &Dep) const { if(Dep.IsCritical()) return true; - else if(Dep->Type == pkgCache::Dep::Recommends) + else if(Dep->Type == pkgCache::Dep::Recommends) { if (InstallRecommends) return true; // we suport a special mode to only install-recommends for certain // sections - // FIXME: this is a meant as a temporarly solution until the + // FIXME: this is a meant as a temporarly solution until the // recommends are cleaned up const char *sec = Dep.ParentVer().Section(); if (sec && ConfigValueInSubTree("APT::Install-Recommends-Sections", sec)) @@ -1767,24 +1752,22 @@ bool pkgDepCache::MarkRequired(InRootSetFunc &userFunc) if (_config->Find("APT::Solver", "internal") != "internal") return true; - bool follow_recommends; - bool follow_suggests; - bool debug_autoremove = _config->FindB("Debug::pkgAutoRemove",false); + bool const debug_autoremove = _config->FindB("Debug::pkgAutoRemove",false); // init the states - for(PkgIterator p = PkgBegin(); !p.end(); ++p) + map_id_t const PackagesCount = Head().PackageCount; + for(map_id_t i = 0; i < PackagesCount; ++i) { - PkgState[p->ID].Marked = false; - PkgState[p->ID].Garbage = false; - - // debug output - if(debug_autoremove && PkgState[p->ID].Flags & Flag::Auto) - std::clog << "AutoDep: " << p.FullName() << std::endl; + PkgState[i].Marked = false; + PkgState[i].Garbage = false; } + if (debug_autoremove) + for(PkgIterator p = PkgBegin(); !p.end(); ++p) + if(PkgState[p->ID].Flags & Flag::Auto) + std::clog << "AutoDep: " << p.FullName() << std::endl; - // init vars - follow_recommends = MarkFollowsRecommends(); - follow_suggests = MarkFollowsSuggests(); + bool const follow_recommends = MarkFollowsRecommends(); + bool const follow_suggests = MarkFollowsSuggests(); // do the mark part, this is the core bit of the algorithm for(PkgIterator p = PkgBegin(); !p.end(); ++p)