apt-pkg/depcache.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: depcache.cc,v 1.25 2001/05/27 05:36:04 jgg Exp $
   4 /* ######################################################################
   5
   6    Dependency Cache - Caches Dependency information.
   7
   8    ##################################################################### */
   9                                                                         /*}}}*/
  10 // Include Files                                                        /*{{{*/
  11 #include<config.h>
  12
  13 #include <apt-pkg/depcache.h>
  14 #include <apt-pkg/version.h>
  15 #include <apt-pkg/versionmatch.h>
  16 #include <apt-pkg/error.h>
  17 #include <apt-pkg/sptr.h>
  18 #include <apt-pkg/algorithms.h>
  19 #include <apt-pkg/fileutl.h>
  20 #include <apt-pkg/strutl.h>
  21 #include <apt-pkg/configuration.h>
  22 #include <apt-pkg/aptconfiguration.h>
  23 #include <apt-pkg/pkgsystem.h>
  24 #include <apt-pkg/tagfile.h>
  25 #include <apt-pkg/progress.h>
  26
  27 #include <iostream>
  28 #include <sstream>
  29 #include <set>
  30
  31 #include <sys/stat.h>
  32
  33 #include <apti18n.h>
  34                                                                         /*}}}*/
  35
  36 using std::string;
  37
  38 // helper for Install-Recommends-Sections and Never-MarkAuto-Sections   /*{{{*/
  39 static bool
  40 ConfigValueInSubTree(const char* SubTree, const char *needle)
  41 {
  42    Configuration::Item const *Opts;
  43    Opts = _config->Tree(SubTree);
  44    if (Opts != 0 && Opts->Child != 0)
  45    {
  46       Opts = Opts->Child;
  47       for (; Opts != 0; Opts = Opts->Next)
  48       {
  49          if (Opts->Value.empty() == true)
  50             continue;
  51          if (strcmp(needle, Opts->Value.c_str()) == 0)
  52             return true;
  53       }
  54    }
  55    return false;
  56 }
  57                                                                         /*}}}*/
  58 pkgDepCache::ActionGroup::ActionGroup(pkgDepCache &cache) :             /*{{{*/
  59   cache(cache), released(false)
  60 {
  61   ++cache.group_level;
  62 }
  63
  64 void pkgDepCache::ActionGroup::release()
  65 {
  66   if(!released)
  67     {
  68       if(cache.group_level == 0)
  69         std::cerr << "W: Unbalanced action groups, expect badness" << std::endl;
  70       else
  71         {
  72           --cache.group_level;
  73
  74           if(cache.group_level == 0)
  75             cache.MarkAndSweep();
  76         }
  77
  78       released = true;
  79     }
  80 }
  81
  82 pkgDepCache::ActionGroup::~ActionGroup()
  83 {
  84   release();
  85 }
  86                                                                         /*}}}*/
  87 // DepCache::pkgDepCache - Constructors                                 /*{{{*/
  88 // ---------------------------------------------------------------------
  89 /* */
  90 pkgDepCache::pkgDepCache(pkgCache *pCache,Policy *Plcy) :
  91   group_level(0), Cache(pCache), PkgState(0), DepState(0)
  92 {
  93    DebugMarker = _config->FindB("Debug::pkgDepCache::Marker", false);
  94    DebugAutoInstall = _config->FindB("Debug::pkgDepCache::AutoInstall", false);
  95    delLocalPolicy = 0;
  96    LocalPolicy = Plcy;
  97    if (LocalPolicy == 0)
  98       delLocalPolicy = LocalPolicy = new Policy;
  99 }
 100                                                                         /*}}}*/
 101 // DepCache::~pkgDepCache - Destructor                                  /*{{{*/
 102 // ---------------------------------------------------------------------
 103 /* */
 104 pkgDepCache::~pkgDepCache()
 105 {
 106    delete [] PkgState;
 107    delete [] DepState;
 108    delete delLocalPolicy;
 109 }
 110                                                                         /*}}}*/
 111 // DepCache::Init - Generate the initial extra structures.              /*{{{*/
 112 // ---------------------------------------------------------------------
 113 /* This allocats the extension buffers and initializes them. */
 114 bool pkgDepCache::Init(OpProgress *Prog)
 115 {
 116    // Suppress mark updates during this operation (just in case) and
 117    // run a mark operation when Init terminates.
 118    ActionGroup actions(*this);
 119
 120    delete [] PkgState;
 121    delete [] DepState;
 122    PkgState = new StateCache[Head().PackageCount];
 123    DepState = new unsigned char[Head().DependsCount];
 124    memset(PkgState,0,sizeof(*PkgState)*Head().PackageCount);
 125    memset(DepState,0,sizeof(*DepState)*Head().DependsCount);
 126
 127    if (Prog != 0)
 128    {
 129       Prog->OverallProgress(0,2*Head().PackageCount,Head().PackageCount,
 130                             _("Building dependency tree"));
 131       Prog->SubProgress(Head().PackageCount,_("Candidate versions"));
 132    }
 133
 134    /* Set the current state of everything. In this state all of the
 135       packages are kept exactly as is. See AllUpgrade */
 136    int Done = 0;
 137    for (PkgIterator I = PkgBegin(); I.end() != true; ++I, ++Done)
 138    {
 139       if (Prog != 0 && Done%20 == 0)
 140          Prog->Progress(Done);
 141
 142       // Find the proper cache slot
 143       StateCache &State = PkgState[I->ID];
 144       State.iFlags = 0;
 145
 146       // Figure out the install version
 147       State.CandidateVer = GetCandidateVer(I);
 148       State.InstallVer = I.CurrentVer();
 149       State.Mode = ModeKeep;
 150
 151       State.Update(I,*this);
 152    }
 153
 154    if (Prog != 0)
 155    {
 156
 157       Prog->OverallProgress(Head().PackageCount,2*Head().PackageCount,
 158                             Head().PackageCount,
 159                             _("Building dependency tree"));
 160       Prog->SubProgress(Head().PackageCount,_("Dependency generation"));
 161    }
 162
 163    Update(Prog);
 164
 165    if(Prog != 0)
 166       Prog->Done();
 167
 168    return true;
 169 }
 170                                                                         /*}}}*/
 171 bool pkgDepCache::readStateFile(OpProgress *Prog)                       /*{{{*/
 172 {
 173    FileFd state_file;
 174    string const state = _config->FindFile("Dir::State::extended_states");
 175    if(RealFileExists(state)) {
 176       state_file.Open(state, FileFd::ReadOnly);
 177       off_t const file_size = state_file.Size();
 178       if(Prog != NULL)
 179          Prog->OverallProgress(0, file_size, 1,
 180                                _("Reading state information"));
 181
 182       pkgTagFile tagfile(&state_file);
 183       pkgTagSection section;
 184       off_t amt = 0;
 185       bool const debug_autoremove = _config->FindB("Debug::pkgAutoRemove",false);
 186       while(tagfile.Step(section)) {
 187          string const pkgname = section.FindS("Package");
 188          string pkgarch = section.FindS("Architecture");
 189          if (pkgarch.empty() == true)
 190             pkgarch = "any";
 191          pkgCache::PkgIterator pkg = Cache->FindPkg(pkgname, pkgarch);
 192          // Silently ignore unknown packages and packages with no actual version.
 193          if(pkg.end() == true || pkg->VersionList == 0)
 194             continue;
 195
 196          short const reason = section.FindI("Auto-Installed", 0);
 197          if(reason > 0)
 198          {
 199             PkgState[pkg->ID].Flags |= Flag::Auto;
 200             if (unlikely(debug_autoremove))
 201                std::clog << "Auto-Installed : " << pkg.FullName() << std::endl;
 202             if (pkgarch == "any")
 203             {
 204                pkgCache::GrpIterator G = pkg.Group();
 205                for (pkg = G.NextPkg(pkg); pkg.end() != true; pkg = G.NextPkg(pkg))
 206                   if (pkg->VersionList != 0)
 207                      PkgState[pkg->ID].Flags |= Flag::Auto;
 208             }
 209          }
 210          amt += section.size();
 211          if(Prog != NULL)
 212             Prog->OverallProgress(amt, file_size, 1,
 213                                   _("Reading state information"));
 214       }
 215       if(Prog != NULL)
 216          Prog->OverallProgress(file_size, file_size, 1,
 217                                _("Reading state information"));
 218    }
 219
 220    return true;
 221 }
 222                                                                         /*}}}*/
 223 bool pkgDepCache::writeStateFile(OpProgress *prog, bool InstalledOnly)  /*{{{*/
 224 {
 225    bool const debug_autoremove = _config->FindB("Debug::pkgAutoRemove",false);
 226
 227    if(debug_autoremove)
 228       std::clog << "pkgDepCache::writeStateFile()" << std::endl;
 229
 230    FileFd StateFile;
 231    string const state = _config->FindFile("Dir::State::extended_states");
 232
 233    // if it does not exist, create a empty one
 234    if(!RealFileExists(state))
 235    {
 236       StateFile.Open(state, FileFd::WriteAtomic);
 237       StateFile.Close();
 238    }
 239
 240    // open it
 241    if(!StateFile.Open(state, FileFd::ReadOnly))
 242       return _error->Error(_("Failed to open StateFile %s"),
 243                            state.c_str());
 244
 245    FILE *OutFile;
 246    string const outfile = state + ".tmp";
 247    if((OutFile = fopen(outfile.c_str(),"w")) == NULL)
 248       return _error->Error(_("Failed to write temporary StateFile %s"),
 249                            outfile.c_str());
 250
 251    // first merge with the existing sections
 252    pkgTagFile tagfile(&StateFile);
 253    pkgTagSection section;
 254    std::set<string> pkgs_seen;
 255    const char *nullreorderlist[] = {0};
 256    while(tagfile.Step(section)) {
 257          string const pkgname = section.FindS("Package");
 258          string pkgarch = section.FindS("Architecture");
 259          if (pkgarch.empty() == true)
 260             pkgarch = "native";
 261          // Silently ignore unknown packages and packages with no actual
 262          // version.
 263          pkgCache::PkgIterator pkg = Cache->FindPkg(pkgname, pkgarch);
 264          if(pkg.end() || pkg.VersionList().end())
 265             continue;
 266          StateCache const &P = PkgState[pkg->ID];
 267          bool newAuto = (P.Flags & Flag::Auto);
 268          // skip not installed or now-removed ones if requested
 269          if (InstalledOnly && (
 270              (pkg->CurrentVer == 0 && P.Mode != ModeInstall) ||
 271              (pkg->CurrentVer != 0 && P.Mode == ModeDelete)))
 272          {
 273             // The section is obsolete if it contains no other tag
 274             unsigned int const count = section.Count();
 275             if (count < 2 ||
 276                 (count == 2 && section.Exists("Auto-Installed")) ||
 277                 (count == 3 && section.Exists("Auto-Installed") && section.Exists("Architecture")))
 278                continue;
 279             else
 280                newAuto = false;
 281          }
 282          if(_config->FindB("Debug::pkgAutoRemove",false))
 283             std::clog << "Update existing AutoInstall info: "
 284                       << pkg.FullName() << std::endl;
 285          TFRewriteData rewrite[3];
 286          rewrite[0].Tag = "Architecture";
 287          rewrite[0].Rewrite = pkg.Arch();
 288          rewrite[0].NewTag = 0;
 289          rewrite[1].Tag = "Auto-Installed";
 290          rewrite[1].Rewrite = newAuto ? "1" : "0";
 291          rewrite[1].NewTag = 0;
 292          rewrite[2].Tag = 0;
 293          TFRewrite(OutFile, section, nullreorderlist, rewrite);
 294          fprintf(OutFile,"\n");
 295          pkgs_seen.insert(pkg.FullName());
 296    }
 297
 298    // then write the ones we have not seen yet
 299    std::ostringstream ostr;
 300    for(pkgCache::PkgIterator pkg=Cache->PkgBegin(); !pkg.end(); ++pkg) {
 301       StateCache const &P = PkgState[pkg->ID];
 302       if(P.Flags & Flag::Auto) {
 303          if (pkgs_seen.find(pkg.FullName()) != pkgs_seen.end()) {
 304             if(debug_autoremove)
 305                std::clog << "Skipping already written " << pkg.FullName() << std::endl;
 306             continue;
 307          }
 308          // skip not installed ones if requested
 309          if (InstalledOnly && (
 310              (pkg->CurrentVer == 0 && P.Mode != ModeInstall) ||
 311              (pkg->CurrentVer != 0 && P.Mode == ModeDelete)))
 312             continue;
 313          const char* const pkgarch = pkg.Arch();
 314          if (strcmp(pkgarch, "all") == 0)
 315             continue;
 316          if(debug_autoremove)
 317             std::clog << "Writing new AutoInstall: " << pkg.FullName() << std::endl;
 318          ostr.str(string(""));
 319          ostr << "Package: " << pkg.Name()
 320               << "\nArchitecture: " << pkgarch
 321               << "\nAuto-Installed: 1\n\n";
 322          fprintf(OutFile,"%s",ostr.str().c_str());
 323       }
 324    }
 325    fclose(OutFile);
 326
 327    // move the outfile over the real file and set permissions
 328    rename(outfile.c_str(), state.c_str());
 329    chmod(state.c_str(), 0644);
 330
 331    return true;
 332 }
 333                                                                         /*}}}*/
 334 // DepCache::CheckDep - Checks a single dependency                      /*{{{*/
 335 // ---------------------------------------------------------------------
 336 /* This first checks the dependency against the main target package and
 337    then walks along the package provides list and checks if each provides
 338    will be installed then checks the provides against the dep. Res will be
 339    set to the package which was used to satisfy the dep. */
 340 bool pkgDepCache::CheckDep(DepIterator Dep,int Type,PkgIterator &Res)
 341 {
 342    Res = Dep.TargetPkg();
 343
 344    /* Check simple depends. A depends -should- never self match but
 345       we allow it anyhow because dpkg does. Technically it is a packaging
 346       bug. Conflicts may never self match */
 347    if (Dep.TargetPkg() != Dep.ParentPkg() || Dep.IsNegative() == false)
 348    {
 349       PkgIterator Pkg = Dep.TargetPkg();
 350       // Check the base package
 351       if (Type == NowVersion && Pkg->CurrentVer != 0)
 352          if (VS().CheckDep(Pkg.CurrentVer().VerStr(),Dep->CompareOp,
 353                                  Dep.TargetVer()) == true)
 354             return true;
 355
 356       if (Type == InstallVersion && PkgState[Pkg->ID].InstallVer != 0)
 357          if (VS().CheckDep(PkgState[Pkg->ID].InstVerIter(*this).VerStr(),
 358                                  Dep->CompareOp,Dep.TargetVer()) == true)
 359             return true;
 360
 361       if (Type == CandidateVersion && PkgState[Pkg->ID].CandidateVer != 0)
 362          if (VS().CheckDep(PkgState[Pkg->ID].CandidateVerIter(*this).VerStr(),
 363                                  Dep->CompareOp,Dep.TargetVer()) == true)
 364             return true;
 365    }
 366
 367    if (Dep->Type == Dep::Obsoletes)
 368       return false;
 369
 370    // Check the providing packages
 371    PrvIterator P = Dep.TargetPkg().ProvidesList();
 372    PkgIterator Pkg = Dep.ParentPkg();
 373    for (; P.end() != true; ++P)
 374    {
 375       /* Provides may never be applied against the same package (or group)
 376          if it is a conflicts. See the comment above. */
 377       if (P.OwnerPkg()->Group == Pkg->Group && Dep.IsNegative() == true)
 378          continue;
 379
 380       // Check if the provides is a hit
 381       if (Type == NowVersion)
 382       {
 383          if (P.OwnerPkg().CurrentVer() != P.OwnerVer())
 384             continue;
 385       }
 386
 387       if (Type == InstallVersion)
 388       {
 389          StateCache &State = PkgState[P.OwnerPkg()->ID];
 390          if (State.InstallVer != (Version *)P.OwnerVer())
 391             continue;
 392       }
 393
 394       if (Type == CandidateVersion)
 395       {
 396          StateCache &State = PkgState[P.OwnerPkg()->ID];
 397          if (State.CandidateVer != (Version *)P.OwnerVer())
 398             continue;
 399       }
 400
 401       // Compare the versions.
 402       if (VS().CheckDep(P.ProvideVersion(),Dep->CompareOp,Dep.TargetVer()) == true)
 403       {
 404          Res = P.OwnerPkg();
 405          return true;
 406       }
 407    }
 408
 409    return false;
 410 }
 411                                                                         /*}}}*/
 412 // DepCache::AddSizes - Add the packages sizes to the counters          /*{{{*/
 413 // ---------------------------------------------------------------------
 414 /* Call with Inverse = true to preform the inverse opration */
 415 void pkgDepCache::AddSizes(const PkgIterator &Pkg, bool const Inverse)
 416 {
 417    StateCache &P = PkgState[Pkg->ID];
 418
 419    if (Pkg->VersionList == 0)
 420       return;
 421
 422    if (Pkg.State() == pkgCache::PkgIterator::NeedsConfigure &&
 423        P.Keep() == true)
 424       return;
 425
 426    // Compute the size data
 427    if (P.NewInstall() == true)
 428    {
 429       if (Inverse == false) {
 430          iUsrSize += P.InstVerIter(*this)->InstalledSize;
 431          iDownloadSize += P.InstVerIter(*this)->Size;
 432       } else {
 433          iUsrSize -= P.InstVerIter(*this)->InstalledSize;
 434          iDownloadSize -= P.InstVerIter(*this)->Size;
 435       }
 436       return;
 437    }
 438
 439    // Upgrading
 440    if (Pkg->CurrentVer != 0 &&
 441        (P.InstallVer != (Version *)Pkg.CurrentVer() ||
 442         (P.iFlags & ReInstall) == ReInstall) && P.InstallVer != 0)
 443    {
 444       if (Inverse == false) {
 445          iUsrSize -= Pkg.CurrentVer()->InstalledSize;
 446          iUsrSize += P.InstVerIter(*this)->InstalledSize;
 447          iDownloadSize += P.InstVerIter(*this)->Size;
 448       } else {
 449          iUsrSize -= P.InstVerIter(*this)->InstalledSize;
 450          iUsrSize += Pkg.CurrentVer()->InstalledSize;
 451          iDownloadSize -= P.InstVerIter(*this)->Size;
 452       }
 453       return;
 454    }
 455
 456    // Reinstall
 457    if (Pkg.State() == pkgCache::PkgIterator::NeedsUnpack &&
 458        P.Delete() == false)
 459    {
 460       if (Inverse == false)
 461          iDownloadSize += P.InstVerIter(*this)->Size;
 462       else
 463          iDownloadSize -= P.InstVerIter(*this)->Size;
 464       return;
 465    }
 466
 467    // Removing
 468    if (Pkg->CurrentVer != 0 && P.InstallVer == 0)
 469    {
 470       if (Inverse == false)
 471          iUsrSize -= Pkg.CurrentVer()->InstalledSize;
 472       else
 473          iUsrSize += Pkg.CurrentVer()->InstalledSize;
 474       return;
 475    }
 476 }
 477                                                                         /*}}}*/
 478 // DepCache::AddStates - Add the package to the state counter           /*{{{*/
 479 // ---------------------------------------------------------------------
 480 /* This routine is tricky to use, you must make sure that it is never
 481    called twice for the same package. This means the Remove/Add section
 482    should be as short as possible and not encompass any code that will
 483    calld Remove/Add itself. Remember, dependencies can be circular so
 484    while processing a dep for Pkg it is possible that Add/Remove
 485    will be called on Pkg */
 486 void pkgDepCache::AddStates(const PkgIterator &Pkg, bool const Invert)
 487 {
 488    signed char const Add = (Invert == false) ? 1 : -1;
 489    StateCache &State = PkgState[Pkg->ID];
 490
 491    // The Package is broken (either minimal dep or policy dep)
 492    if ((State.DepState & DepInstMin) != DepInstMin)
 493       iBrokenCount += Add;
 494    if ((State.DepState & DepInstPolicy) != DepInstPolicy)
 495       iPolicyBrokenCount += Add;
 496
 497    // Bad state
 498    if (Pkg.State() != PkgIterator::NeedsNothing)
 499       iBadCount += Add;
 500
 501    // Not installed
 502    if (Pkg->CurrentVer == 0)
 503    {
 504       if (State.Mode == ModeDelete &&
 505           (State.iFlags & Purge) == Purge && Pkg.Purge() == false)
 506          iDelCount += Add;
 507
 508       if (State.Mode == ModeInstall)
 509          iInstCount += Add;
 510       return;
 511    }
 512
 513    // Installed, no upgrade
 514    if (State.Status == 0)
 515    {
 516       if (State.Mode == ModeDelete)
 517          iDelCount += Add;
 518       else
 519          if ((State.iFlags & ReInstall) == ReInstall)
 520             iInstCount += Add;
 521
 522       return;
 523    }
 524
 525    // Alll 3 are possible
 526    if (State.Mode == ModeDelete)
 527       iDelCount += Add;
 528    if (State.Mode == ModeKeep)
 529       iKeepCount += Add;
 530    if (State.Mode == ModeInstall)
 531       iInstCount += Add;
 532 }
 533                                                                         /*}}}*/
 534 // DepCache::BuildGroupOrs - Generate the Or group dep data             /*{{{*/
 535 // ---------------------------------------------------------------------
 536 /* The or group results are stored in the last item of the or group. This
 537    allows easy detection of the state of a whole or'd group. */
 538 void pkgDepCache::BuildGroupOrs(VerIterator const &V)
 539 {
 540    unsigned char Group = 0;
 541
 542    for (DepIterator D = V.DependsList(); D.end() != true; ++D)
 543    {
 544       // Build the dependency state.
 545       unsigned char &State = DepState[D->ID];
 546
 547       /* Invert for Conflicts. We have to do this twice to get the
 548          right sense for a conflicts group */
 549       if (D.IsNegative() == true)
 550          State = ~State;
 551
 552       // Add to the group if we are within an or..
 553       State &= 0x7;
 554       Group |= State;
 555       State |= Group << 3;
 556       if ((D->CompareOp & Dep::Or) != Dep::Or)
 557          Group = 0;
 558
 559       // Invert for Conflicts
 560       if (D.IsNegative() == true)
 561          State = ~State;
 562    }
 563 }
 564                                                                         /*}}}*/
 565 // DepCache::VersionState - Perform a pass over a dependency list       /*{{{*/
 566 // ---------------------------------------------------------------------
 567 /* This is used to run over a dependency list and determine the dep
 568    state of the list, filtering it through both a Min check and a Policy
 569    check. The return result will have SetMin/SetPolicy low if a check
 570    fails. It uses the DepState cache for it's computations. */
 571 unsigned char pkgDepCache::VersionState(DepIterator D,unsigned char Check,
 572                                        unsigned char SetMin,
 573                                        unsigned char SetPolicy)
 574 {
 575    unsigned char Dep = 0xFF;
 576
 577    while (D.end() != true)
 578    {
 579       // Compute a single dependency element (glob or)
 580       DepIterator Start = D;
 581       unsigned char State = 0;
 582       for (bool LastOR = true; D.end() == false && LastOR == true; ++D)
 583       {
 584          State |= DepState[D->ID];
 585          LastOR = (D->CompareOp & Dep::Or) == Dep::Or;
 586       }
 587
 588       // Minimum deps that must be satisfied to have a working package
 589       if (Start.IsCritical() == true)
 590          if ((State & Check) != Check)
 591             Dep &= ~SetMin;
 592
 593       // Policy deps that must be satisfied to install the package
 594       if (IsImportantDep(Start) == true &&
 595           (State & Check) != Check)
 596          Dep &= ~SetPolicy;
 597    }
 598
 599    return Dep;
 600 }
 601                                                                         /*}}}*/
 602 // DepCache::DependencyState - Compute the 3 results for a dep          /*{{{*/
 603 // ---------------------------------------------------------------------
 604 /* This is the main dependency computation bit. It computes the 3 main
 605    results for a dependencys, Now, Install and Candidate. Callers must
 606    invert the result if dealing with conflicts. */
 607 unsigned char pkgDepCache::DependencyState(DepIterator &D)
 608 {
 609    unsigned char State = 0;
 610
 611    if (CheckDep(D,NowVersion) == true)
 612       State |= DepNow;
 613    if (CheckDep(D,InstallVersion) == true)
 614       State |= DepInstall;
 615    if (CheckDep(D,CandidateVersion) == true)
 616       State |= DepCVer;
 617
 618    return State;
 619 }
 620                                                                         /*}}}*/
 621 // DepCache::UpdateVerState - Compute the Dep member of the state       /*{{{*/
 622 // ---------------------------------------------------------------------
 623 /* This determines the combined dependency representation of a package
 624    for its two states now and install. This is done by using the pre-generated
 625    dependency information. */
 626 void pkgDepCache::UpdateVerState(PkgIterator Pkg)
 627 {
 628    // Empty deps are always true
 629    StateCache &State = PkgState[Pkg->ID];
 630    State.DepState = 0xFF;
 631
 632    // Check the Current state
 633    if (Pkg->CurrentVer != 0)
 634    {
 635       DepIterator D = Pkg.CurrentVer().DependsList();
 636       State.DepState &= VersionState(D,DepNow,DepNowMin,DepNowPolicy);
 637    }
 638
 639    /* Check the candidate state. We do not compare against the whole as
 640       a candidate state but check the candidate version against the
 641       install states */
 642    if (State.CandidateVer != 0)
 643    {
 644       DepIterator D = State.CandidateVerIter(*this).DependsList();
 645       State.DepState &= VersionState(D,DepInstall,DepCandMin,DepCandPolicy);
 646    }
 647
 648    // Check target state which can only be current or installed
 649    if (State.InstallVer != 0)
 650    {
 651       DepIterator D = State.InstVerIter(*this).DependsList();
 652       State.DepState &= VersionState(D,DepInstall,DepInstMin,DepInstPolicy);
 653    }
 654 }
 655                                                                         /*}}}*/
 656 // DepCache::Update - Figure out all the state information              /*{{{*/
 657 // ---------------------------------------------------------------------
 658 /* This will figure out the state of all the packages and all the
 659    dependencies based on the current policy. */
 660 void pkgDepCache::Update(OpProgress *Prog)
 661 {
 662    iUsrSize = 0;
 663    iDownloadSize = 0;
 664    iDelCount = 0;
 665    iInstCount = 0;
 666    iKeepCount = 0;
 667    iBrokenCount = 0;
 668    iBadCount = 0;
 669
 670    // Perform the depends pass
 671    int Done = 0;
 672    for (PkgIterator I = PkgBegin(); I.end() != true; ++I, ++Done)
 673    {
 674       if (Prog != 0 && Done%20 == 0)
 675          Prog->Progress(Done);
 676       for (VerIterator V = I.VersionList(); V.end() != true; ++V)
 677       {
 678          unsigned char Group = 0;
 679
 680          for (DepIterator D = V.DependsList(); D.end() != true; ++D)
 681          {
 682             // Build the dependency state.
 683             unsigned char &State = DepState[D->ID];
 684             State = DependencyState(D);
 685
 686             // Add to the group if we are within an or..
 687             Group |= State;
 688             State |= Group << 3;
 689             if ((D->CompareOp & Dep::Or) != Dep::Or)
 690                Group = 0;
 691
 692             // Invert for Conflicts
 693             if (D.IsNegative() == true)
 694                State = ~State;
 695          }
 696       }
 697
 698       // Compute the package dependency state and size additions
 699       AddSizes(I);
 700       UpdateVerState(I);
 701       AddStates(I);
 702    }
 703
 704    if (Prog != 0)
 705       Prog->Progress(Done);
 706
 707    readStateFile(Prog);
 708 }
 709                                                                         /*}}}*/
 710 // DepCache::Update - Update the deps list of a package                 /*{{{*/
 711 // ---------------------------------------------------------------------
 712 /* This is a helper for update that only does the dep portion of the scan.
 713    It is mainly meant to scan reverse dependencies. */
 714 void pkgDepCache::Update(DepIterator D)
 715 {
 716    // Update the reverse deps
 717    for (;D.end() != true; ++D)
 718    {
 719       unsigned char &State = DepState[D->ID];
 720       State = DependencyState(D);
 721
 722       // Invert for Conflicts
 723       if (D.IsNegative() == true)
 724          State = ~State;
 725
 726       RemoveStates(D.ParentPkg());
 727       BuildGroupOrs(D.ParentVer());
 728       UpdateVerState(D.ParentPkg());
 729       AddStates(D.ParentPkg());
 730    }
 731 }
 732                                                                         /*}}}*/
 733 // DepCache::Update - Update the related deps of a package              /*{{{*/
 734 // ---------------------------------------------------------------------
 735 /* This is called whenever the state of a package changes. It updates
 736    all cached dependencies related to this package. */
 737 void pkgDepCache::Update(PkgIterator const &Pkg)
 738 {
 739    // Recompute the dep of the package
 740    RemoveStates(Pkg);
 741    UpdateVerState(Pkg);
 742    AddStates(Pkg);
 743
 744    // Update the reverse deps
 745    Update(Pkg.RevDependsList());
 746
 747    // Update the provides map for the current ver
 748    if (Pkg->CurrentVer != 0)
 749       for (PrvIterator P = Pkg.CurrentVer().ProvidesList();
 750            P.end() != true; ++P)
 751          Update(P.ParentPkg().RevDependsList());
 752
 753    // Update the provides map for the candidate ver
 754    if (PkgState[Pkg->ID].CandidateVer != 0)
 755       for (PrvIterator P = PkgState[Pkg->ID].CandidateVerIter(*this).ProvidesList();
 756            P.end() != true; ++P)
 757          Update(P.ParentPkg().RevDependsList());
 758 }
 759                                                                         /*}}}*/
 760 // DepCache::MarkKeep - Put the package in the keep state               /*{{{*/
 761 // ---------------------------------------------------------------------
 762 /* */
 763 bool pkgDepCache::MarkKeep(PkgIterator const &Pkg, bool Soft, bool FromUser,
 764                            unsigned long Depth)
 765 {
 766    if (IsModeChangeOk(ModeKeep, Pkg, Depth, FromUser) == false)
 767       return false;
 768
 769    /* Reject an attempt to keep a non-source broken installed package, those
 770       must be upgraded */
 771    if (Pkg.State() == PkgIterator::NeedsUnpack &&
 772        Pkg.CurrentVer().Downloadable() == false)
 773       return false;
 774
 775    /* We changed the soft state all the time so the UI is a bit nicer
 776       to use */
 777    StateCache &P = PkgState[Pkg->ID];
 778
 779    // Check that it is not already kept
 780    if (P.Mode == ModeKeep)
 781       return true;
 782
 783    if (Soft == true)
 784       P.iFlags |= AutoKept;
 785    else
 786       P.iFlags &= ~AutoKept;
 787
 788    ActionGroup group(*this);
 789
 790 #if 0 // reseting the autoflag here means we lose the
 791       // auto-mark information if a user selects a package for removal
 792       // but changes  his mind then and sets it for keep again
 793       // - this makes sense as default when all Garbage dependencies
 794       //   are automatically marked for removal (as aptitude does).
 795       //   setting a package for keep then makes it no longer autoinstalled
 796       //   for all other use-case this action is rather suprising
 797    if(FromUser && !P.Marked)
 798      P.Flags &= ~Flag::Auto;
 799 #endif
 800
 801    if (DebugMarker == true)
 802       std::clog << OutputInDepth(Depth) << "MarkKeep " << Pkg << " FU=" << FromUser << std::endl;
 803
 804    RemoveSizes(Pkg);
 805    RemoveStates(Pkg);
 806
 807    P.Mode = ModeKeep;
 808    if (Pkg->CurrentVer == 0)
 809       P.InstallVer = 0;
 810    else
 811       P.InstallVer = Pkg.CurrentVer();
 812
 813    AddStates(Pkg);
 814    Update(Pkg);
 815    AddSizes(Pkg);
 816
 817    return true;
 818 }
 819                                                                         /*}}}*/
 820 // DepCache::MarkDelete - Put the package in the delete state           /*{{{*/
 821 // ---------------------------------------------------------------------
 822 /* */
 823 bool pkgDepCache::MarkDelete(PkgIterator const &Pkg, bool rPurge,
 824                              unsigned long Depth, bool FromUser)
 825 {
 826    if (IsModeChangeOk(ModeDelete, Pkg, Depth, FromUser) == false)
 827       return false;
 828
 829    StateCache &P = PkgState[Pkg->ID];
 830
 831    // Check that it is not already marked for delete
 832    if ((P.Mode == ModeDelete || P.InstallVer == 0) &&
 833        (Pkg.Purge() == true || rPurge == false))
 834       return true;
 835
 836    // check if we are allowed to remove the package
 837    if (IsDeleteOk(Pkg,rPurge,Depth,FromUser) == false)
 838       return false;
 839
 840    P.iFlags &= ~(AutoKept | Purge);
 841    if (rPurge == true)
 842       P.iFlags |= Purge;
 843
 844    ActionGroup group(*this);
 845
 846    if (DebugMarker == true)
 847       std::clog << OutputInDepth(Depth) << (rPurge ? "MarkPurge " : "MarkDelete ") << Pkg << " FU=" << FromUser << std::endl;
 848
 849    RemoveSizes(Pkg);
 850    RemoveStates(Pkg);
 851
 852    if (Pkg->CurrentVer == 0 && (Pkg.Purge() == true || rPurge == false))
 853       P.Mode = ModeKeep;
 854    else
 855       P.Mode = ModeDelete;
 856    P.InstallVer = 0;
 857
 858    AddStates(Pkg);
 859    Update(Pkg);
 860    AddSizes(Pkg);
 861
 862    return true;
 863 }
 864                                                                         /*}}}*/
 865 // DepCache::IsDeleteOk - check if it is ok to remove this package      /*{{{*/
 866 // ---------------------------------------------------------------------
 867 /* The default implementation tries to prevent deletion of install requests.
 868    dpkg holds are enforced by the private IsModeChangeOk */
 869 bool pkgDepCache::IsDeleteOk(PkgIterator const &Pkg,bool rPurge,
 870                               unsigned long Depth, bool FromUser)
 871 {
 872    if (FromUser == false && Pkg->CurrentVer == 0)
 873    {
 874       StateCache &P = PkgState[Pkg->ID];
 875       if (P.InstallVer != 0 && P.Status == 2 && (P.Flags & Flag::Auto) != Flag::Auto)
 876       {
 877          if (DebugMarker == true)
 878             std::clog << OutputInDepth(Depth) << "Manual install request prevents MarkDelete of " << Pkg << std::endl;
 879          return false;
 880       }
 881    }
 882    return true;
 883 }
 884                                                                         /*}}}*/
 885 // DepCache::IsModeChangeOk - check if it is ok to change the mode      /*{{{*/
 886 // ---------------------------------------------------------------------
 887 /* this is used by all Mark methods on the very first line to check sanity
 888    and prevents mode changes for packages on hold for example.
 889    If you want to check Mode specific stuff you can use the virtual public
 890    Is<Mode>Ok methods instead */
 891 char const* PrintMode(char const mode)
 892 {
 893          switch (mode)
 894          {
 895          case pkgDepCache::ModeInstall: return "Install";
 896          case pkgDepCache::ModeKeep: return "Keep";
 897          case pkgDepCache::ModeDelete: return "Delete";
 898          default: return "UNKNOWN";
 899          }
 900 }
 901 bool pkgDepCache::IsModeChangeOk(ModeList const mode, PkgIterator const &Pkg,
 902                                  unsigned long const Depth, bool const FromUser)
 903 {
 904    // we are not trying to hard…
 905    if (unlikely(Depth > 100))
 906       return false;
 907
 908    // general sanity
 909    if (unlikely(Pkg.end() == true || Pkg->VersionList == 0))
 910       return false;
 911
 912    // the user is always right
 913    if (FromUser == true)
 914       return true;
 915
 916    StateCache &P = PkgState[Pkg->ID];
 917
 918    // if previous state was set by user only user can reset it
 919    if ((P.iFlags & Protected) == Protected)
 920    {
 921       if (unlikely(DebugMarker == true) && P.Mode != mode)
 922          std::clog << OutputInDepth(Depth) << "Ignore Mark" << PrintMode(mode)
 923                    << " of " << Pkg << " as its mode (" << PrintMode(P.Mode)
 924                    << ") is protected" << std::endl;
 925       return false;
 926    }
 927    // enforce dpkg holds
 928    else if (mode != ModeKeep && Pkg->SelectedState == pkgCache::State::Hold &&
 929             _config->FindB("APT::Ignore-Hold",false) == false)
 930    {
 931       if (unlikely(DebugMarker == true) && P.Mode != mode)
 932          std::clog << OutputInDepth(Depth) << "Hold prevents Mark" << PrintMode(mode)
 933                    << " of " << Pkg << std::endl;
 934       return false;
 935    }
 936
 937    return true;
 938 }
 939                                                                         /*}}}*/
 940 // DepCache::MarkInstall - Put the package in the install state         /*{{{*/
 941 // ---------------------------------------------------------------------
 942 /* */
 943 bool pkgDepCache::MarkInstall(PkgIterator const &Pkg,bool AutoInst,
 944                               unsigned long Depth, bool FromUser,
 945                               bool ForceImportantDeps)
 946 {
 947    if (IsModeChangeOk(ModeInstall, Pkg, Depth, FromUser) == false)
 948       return false;
 949
 950    StateCache &P = PkgState[Pkg->ID];
 951
 952    // See if there is even any possible instalation candidate
 953    if (P.CandidateVer == 0)
 954       return false;
 955
 956    /* Check that it is not already marked for install and that it can be
 957       installed */
 958    if ((P.InstPolicyBroken() == false && P.InstBroken() == false) &&
 959        (P.Mode == ModeInstall ||
 960         P.CandidateVer == (Version *)Pkg.CurrentVer()))
 961    {
 962       if (P.CandidateVer == (Version *)Pkg.CurrentVer() && P.InstallVer == 0)
 963          return MarkKeep(Pkg, false, FromUser, Depth+1);
 964       return true;
 965    }
 966
 967    // check if we are allowed to install the package
 968    if (IsInstallOk(Pkg,AutoInst,Depth,FromUser) == false)
 969       return false;
 970
 971    ActionGroup group(*this);
 972    P.iFlags &= ~AutoKept;
 973
 974    /* Target the candidate version and remove the autoflag. We reset the
 975       autoflag below if this was called recursively. Otherwise the user
 976       should have the ability to de-auto a package by changing its state */
 977    RemoveSizes(Pkg);
 978    RemoveStates(Pkg);
 979
 980    P.Mode = ModeInstall;
 981    P.InstallVer = P.CandidateVer;
 982
 983    if(FromUser)
 984      {
 985        // Set it to manual if it's a new install or already installed,
 986        // but only if its not marked by the autoremover (aptitude depend on this behavior)
 987        // or if we do automatic installation (aptitude never does it)
 988        if(P.Status == 2 || (Pkg->CurrentVer != 0 && (AutoInst == true || P.Marked == false)))
 989          P.Flags &= ~Flag::Auto;
 990      }
 991    else
 992      {
 993        // Set it to auto if this is a new install.
 994        if(P.Status == 2)
 995          P.Flags |= Flag::Auto;
 996      }
 997    if (P.CandidateVer == (Version *)Pkg.CurrentVer())
 998       P.Mode = ModeKeep;
 999
1000    AddStates(Pkg);
1001    Update(Pkg);
1002    AddSizes(Pkg);
1003
1004    if (AutoInst == false || _config->Find("APT::Solver", "internal") != "internal")
1005       return true;
1006
1007    if (DebugMarker == true)
1008       std::clog << OutputInDepth(Depth) << "MarkInstall " << Pkg << " FU=" << FromUser << std::endl;
1009
1010    DepIterator Dep = P.InstVerIter(*this).DependsList();
1011    for (; Dep.end() != true;)
1012    {
1013       // Grok or groups
1014       DepIterator Start = Dep;
1015       bool Result = true;
1016       unsigned Ors = 0;
1017       for (bool LastOR = true; Dep.end() == false && LastOR == true; ++Dep, ++Ors)
1018       {
1019          LastOR = (Dep->CompareOp & Dep::Or) == Dep::Or;
1020
1021          if ((DepState[Dep->ID] & DepInstall) == DepInstall)
1022             Result = false;
1023       }
1024
1025       // Dep is satisfied okay.
1026       if (Result == false)
1027          continue;
1028
1029       /* Check if this dep should be consider for install. If it is a user
1030          defined important dep and we are installed a new package then
1031          it will be installed. Otherwise we only check for important
1032          deps that have changed from the installed version
1033       */
1034       if (IsImportantDep(Start) == false)
1035          continue;
1036
1037       /* If we are in an or group locate the first or that can
1038          succeed. We have already cached this.. */
1039       for (; Ors > 1 && (DepState[Start->ID] & DepCVer) != DepCVer; --Ors)
1040          ++Start;
1041       if (Ors == 1 && (DepState[Start->ID] &DepCVer) != DepCVer && Start.IsNegative() == false)
1042       {
1043          if(DebugAutoInstall == true)
1044             std::clog << OutputInDepth(Depth) << Start << " can't be satisfied!" << std::endl;
1045          if (Start.IsCritical() == false)
1046             continue;
1047          // if the dependency was critical, we can't install it, so remove it again
1048          MarkDelete(Pkg,false,Depth + 1, false);
1049          return false;
1050       }
1051
1052       /* Check if any ImportantDep() (but not Critical) were added
1053        * since we installed the package.  Also check for deps that
1054        * were satisfied in the past: for instance, if a version
1055        * restriction in a Recommends was tightened, upgrading the
1056        * package should follow that Recommends rather than causing the
1057        * dependency to be removed. (bug #470115)
1058        */
1059       if (Pkg->CurrentVer != 0 && ForceImportantDeps == false && Start.IsCritical() == false)
1060       {
1061          bool isNewImportantDep = true;
1062          bool isPreviouslySatisfiedImportantDep = false;
1063          for (DepIterator D = Pkg.CurrentVer().DependsList(); D.end() != true; ++D)
1064          {
1065             //FIXME: Should we handle or-group better here?
1066             // We do not check if the package we look for is part of the same or-group
1067             // we might find while searching, but could that really be a problem?
1068             if (D.IsCritical() == true || IsImportantDep(D) == false ||
1069                 Start.TargetPkg() != D.TargetPkg())
1070                continue;
1071
1072             isNewImportantDep = false;
1073
1074             while ((D->CompareOp & Dep::Or) != 0)
1075                ++D;
1076
1077             isPreviouslySatisfiedImportantDep = (((*this)[D] & DepGNow) != 0);
1078             if (isPreviouslySatisfiedImportantDep == true)
1079                break;
1080          }
1081
1082          if(isNewImportantDep == true)
1083          {
1084             if (DebugAutoInstall == true)
1085                std::clog << OutputInDepth(Depth) << "new important dependency: "
1086                          << Start.TargetPkg().FullName() << std::endl;
1087          }
1088          else if(isPreviouslySatisfiedImportantDep == true)
1089          {
1090             if (DebugAutoInstall == true)
1091                std::clog << OutputInDepth(Depth) << "previously satisfied important dependency on "
1092                          << Start.TargetPkg().FullName() << std::endl;
1093          }
1094          else
1095          {
1096             if (DebugAutoInstall == true)
1097                std::clog << OutputInDepth(Depth) << "ignore old unsatisfied important dependency on "
1098                          << Start.TargetPkg().FullName() << std::endl;
1099             continue;
1100          }
1101       }
1102
1103       /* This bit is for processing the possibilty of an install/upgrade
1104          fixing the problem */
1105       SPtrArray<Version *> List = Start.AllTargets();
1106       if (Start->Type != Dep::DpkgBreaks &&
1107           (DepState[Start->ID] & DepCVer) == DepCVer)
1108       {
1109          // Right, find the best version to install..
1110          Version **Cur = List;
1111          PkgIterator P = Start.TargetPkg();
1112          PkgIterator InstPkg(*Cache,0);
1113
1114          // See if there are direct matches (at the start of the list)
1115          for (; *Cur != 0 && (*Cur)->ParentPkg == P.Index(); Cur++)
1116          {
1117             PkgIterator Pkg(*Cache,Cache->PkgP + (*Cur)->ParentPkg);
1118             if (PkgState[Pkg->ID].CandidateVer != *Cur)
1119                continue;
1120             InstPkg = Pkg;
1121             break;
1122          }
1123
1124          // Select the highest priority providing package
1125          if (InstPkg.end() == true)
1126          {
1127             pkgPrioSortList(*Cache,Cur);
1128             for (; *Cur != 0; Cur++)
1129             {
1130                PkgIterator Pkg(*Cache,Cache->PkgP + (*Cur)->ParentPkg);
1131                if (PkgState[Pkg->ID].CandidateVer != *Cur)
1132                   continue;
1133                InstPkg = Pkg;
1134                break;
1135             }
1136          }
1137
1138          if (InstPkg.end() == false)
1139          {
1140             if(DebugAutoInstall == true)
1141                std::clog << OutputInDepth(Depth) << "Installing " << InstPkg.Name()
1142                          << " as " << Start.DepType() << " of " << Pkg.Name()
1143                          << std::endl;
1144             // now check if we should consider it a automatic dependency or not
1145             if(Pkg.Section() && ConfigValueInSubTree("APT::Never-MarkAuto-Sections", Pkg.Section()))
1146             {
1147                if(DebugAutoInstall == true)
1148                   std::clog << OutputInDepth(Depth) << "Setting NOT as auto-installed (direct "
1149                             << Start.DepType() << " of pkg in APT::Never-MarkAuto-Sections)" << std::endl;
1150                MarkInstall(InstPkg,true,Depth + 1, true);
1151             }
1152             else
1153             {
1154                // mark automatic dependency
1155                MarkInstall(InstPkg,true,Depth + 1, false, ForceImportantDeps);
1156                // Set the autoflag, after MarkInstall because MarkInstall unsets it
1157                if (P->CurrentVer == 0)
1158                   PkgState[InstPkg->ID].Flags |= Flag::Auto;
1159             }
1160          }
1161          continue;
1162       }
1163
1164       /* For conflicts we just de-install the package and mark as auto,
1165          Conflicts may not have or groups.  For dpkg's Breaks we try to
1166          upgrade the package. */
1167       if (Start.IsNegative() == true)
1168       {
1169          for (Version **I = List; *I != 0; I++)
1170          {
1171             VerIterator Ver(*this,*I);
1172             PkgIterator Pkg = Ver.ParentPkg();
1173
1174             /* The List includes all packages providing this dependency,
1175                even providers which are not installed, so skip them. */
1176             if (PkgState[Pkg->ID].InstallVer == 0)
1177                continue;
1178
1179             if (PkgState[Pkg->ID].CandidateVer != *I &&
1180                 Start->Type == Dep::DpkgBreaks &&
1181                 MarkInstall(Pkg,true,Depth + 1, false, ForceImportantDeps) == true)
1182                continue;
1183             else if (MarkDelete(Pkg,false,Depth + 1, false) == false)
1184                break;
1185          }
1186          continue;
1187       }
1188    }
1189
1190    return Dep.end() == true;
1191 }
1192                                                                         /*}}}*/
1193 // DepCache::IsInstallOk - check if it is ok to install this package    /*{{{*/
1194 // ---------------------------------------------------------------------
1195 /* The default implementation does nothing.
1196    dpkg holds are enforced by the private IsModeChangeOk */
1197 bool pkgDepCache::IsInstallOk(PkgIterator const &Pkg,bool AutoInst,
1198                               unsigned long Depth, bool FromUser)
1199 {
1200    return true;
1201 }
1202                                                                         /*}}}*/
1203 // DepCache::SetReInstall - Set the reinstallation flag                 /*{{{*/
1204 // ---------------------------------------------------------------------
1205 /* */
1206 void pkgDepCache::SetReInstall(PkgIterator const &Pkg,bool To)
1207 {
1208    if (unlikely(Pkg.end() == true))
1209       return;
1210
1211    ActionGroup group(*this);
1212
1213    RemoveSizes(Pkg);
1214    RemoveStates(Pkg);
1215
1216    StateCache &P = PkgState[Pkg->ID];
1217    if (To == true)
1218       P.iFlags |= ReInstall;
1219    else
1220       P.iFlags &= ~ReInstall;
1221
1222    AddStates(Pkg);
1223    AddSizes(Pkg);
1224 }
1225                                                                         /*}}}*/
1226 // DepCache::SetCandidateVersion - Change the candidate version         /*{{{*/
1227 // ---------------------------------------------------------------------
1228 /* */
1229 void pkgDepCache::SetCandidateVersion(VerIterator TargetVer)
1230 {
1231    pkgCache::PkgIterator Pkg = TargetVer.ParentPkg();
1232    StateCache &P = PkgState[Pkg->ID];
1233
1234    if (P.CandidateVer == TargetVer)
1235       return;
1236
1237    ActionGroup group(*this);
1238
1239    RemoveSizes(Pkg);
1240    RemoveStates(Pkg);
1241
1242    if (P.CandidateVer == P.InstallVer && P.Install() == true)
1243       P.InstallVer = (Version *)TargetVer;
1244    P.CandidateVer = (Version *)TargetVer;
1245    P.Update(Pkg,*this);
1246
1247    AddStates(Pkg);
1248    Update(Pkg);
1249    AddSizes(Pkg);
1250
1251 }
1252                                                                         /*}}}*/
1253 // DepCache::SetCandidateRelease - Change the candidate version         /*{{{*/
1254 // ---------------------------------------------------------------------
1255 /* changes the candidate of a package and walks over all its dependencies
1256    to check if it needs to change the candidate of the dependency, too,
1257    to reach a installable versionstate */
1258 bool pkgDepCache::SetCandidateRelease(pkgCache::VerIterator TargetVer,
1259                                         std::string const &TargetRel)
1260 {
1261    std::list<std::pair<pkgCache::VerIterator, pkgCache::VerIterator> > Changed;
1262    return SetCandidateRelease(TargetVer, TargetRel, Changed);
1263 }
1264 bool pkgDepCache::SetCandidateRelease(pkgCache::VerIterator TargetVer,
1265                                         std::string const &TargetRel,
1266                                         std::list<std::pair<pkgCache::VerIterator, pkgCache::VerIterator> > &Changed)
1267 {
1268    ActionGroup group(*this);
1269    SetCandidateVersion(TargetVer);
1270
1271    if (TargetRel == "installed" || TargetRel == "candidate") // both doesn't make sense in this context
1272       return true;
1273
1274    pkgVersionMatch Match(TargetRel, pkgVersionMatch::Release);
1275    // save the position of the last element we will not undo - if we have to
1276    std::list<std::pair<pkgCache::VerIterator, pkgCache::VerIterator> >::iterator newChanged = --(Changed.end());
1277
1278    for (pkgCache::DepIterator D = TargetVer.DependsList(); D.end() == false; ++D)
1279    {
1280       if (D->Type != pkgCache::Dep::PreDepends && D->Type != pkgCache::Dep::Depends &&
1281           ((D->Type != pkgCache::Dep::Recommends && D->Type != pkgCache::Dep::Suggests) ||
1282            IsImportantDep(D) == false))
1283          continue;
1284
1285       // walk over an or-group and check if we need to do anything
1286       // for simpilicity no or-group is handled as a or-group including one dependency
1287       pkgCache::DepIterator Start = D;
1288       bool itsFine = false;
1289       for (bool stillOr = true; stillOr == true; ++Start)
1290       {
1291          stillOr = (Start->CompareOp & Dep::Or) == Dep::Or;
1292          pkgCache::PkgIterator const P = Start.TargetPkg();
1293          // virtual packages can't be a solution
1294          if (P.end() == true || (P->ProvidesList == 0 && P->VersionList == 0))
1295             continue;
1296          pkgCache::VerIterator const Cand = PkgState[P->ID].CandidateVerIter(*this);
1297          // no versioned dependency - but is it installable?
1298          if (Start.TargetVer() == 0 || Start.TargetVer()[0] == '\0')
1299          {
1300             // Check if one of the providers is installable
1301             if (P->ProvidesList != 0)
1302             {
1303                pkgCache::PrvIterator Prv = P.ProvidesList();
1304                for (; Prv.end() == false; ++Prv)
1305                {
1306                   pkgCache::VerIterator const C = PkgState[Prv.OwnerPkg()->ID].CandidateVerIter(*this);
1307                   if (C.end() == true || C != Prv.OwnerVer() ||
1308                       (VersionState(C.DependsList(), DepInstall, DepCandMin, DepCandPolicy) & DepCandMin) != DepCandMin)
1309                      continue;
1310                   break;
1311                }
1312                if (Prv.end() == true)
1313                   continue;
1314             }
1315             // no providers, so check if we have an installable candidate version
1316             else if (Cand.end() == true ||
1317                 (VersionState(Cand.DependsList(), DepInstall, DepCandMin, DepCandPolicy) & DepCandMin) != DepCandMin)
1318                continue;
1319             itsFine = true;
1320             break;
1321          }
1322          if (Cand.end() == true)
1323             continue;
1324          // check if the current candidate is enough for the versioned dependency - and installable?
1325          if (VS().CheckDep(P.CandVersion(), Start->CompareOp, Start.TargetVer()) == true &&
1326              (VersionState(Cand.DependsList(), DepInstall, DepCandMin, DepCandPolicy) & DepCandMin) == DepCandMin)
1327          {
1328             itsFine = true;
1329             break;
1330          }
1331       }
1332
1333       if (itsFine == true) {
1334          // something in the or-group was fine, skip all other members
1335          for (; (D->CompareOp & Dep::Or) == Dep::Or; ++D);
1336          continue;
1337       }
1338
1339       // walk again over the or-group and check each if a candidate switch would help
1340       itsFine = false;
1341       for (bool stillOr = true; stillOr == true; ++D)
1342       {
1343          stillOr = (D->CompareOp & Dep::Or) == Dep::Or;
1344          // changing candidate will not help if the dependency is not versioned
1345          if (D.TargetVer() == 0 || D.TargetVer()[0] == '\0')
1346          {
1347             if (stillOr == true)
1348                continue;
1349             break;
1350          }
1351
1352          pkgCache::VerIterator V;
1353          if (TargetRel == "newest")
1354             V = D.TargetPkg().VersionList();
1355          else
1356             V = Match.Find(D.TargetPkg());
1357
1358          // check if the version from this release could satisfy the dependency
1359          if (V.end() == true || VS().CheckDep(V.VerStr(), D->CompareOp, D.TargetVer()) == false)
1360          {
1361             if (stillOr == true)
1362                continue;
1363             break;
1364          }
1365
1366          pkgCache::VerIterator oldCand = PkgState[D.TargetPkg()->ID].CandidateVerIter(*this);
1367          if (V == oldCand)
1368          {
1369             // Do we already touched this Version? If so, their versioned dependencies are okay, no need to check again
1370             for (std::list<std::pair<pkgCache::VerIterator, pkgCache::VerIterator> >::const_iterator c = Changed.begin();
1371                  c != Changed.end(); ++c)
1372             {
1373                if (c->first->ParentPkg != V->ParentPkg)
1374                   continue;
1375                itsFine = true;
1376                break;
1377             }
1378          }
1379
1380          if (itsFine == false)
1381          {
1382             // change the candidate
1383             Changed.push_back(make_pair(oldCand, TargetVer));
1384             if (SetCandidateRelease(V, TargetRel, Changed) == false)
1385             {
1386                if (stillOr == false)
1387                   break;
1388                // undo the candidate changing
1389                SetCandidateVersion(oldCand);
1390                Changed.pop_back();
1391                continue;
1392             }
1393             itsFine = true;
1394          }
1395
1396          // something in the or-group was fine, skip all other members
1397          for (; (D->CompareOp & Dep::Or) == Dep::Or; ++D);
1398          break;
1399       }
1400
1401       if (itsFine == false && (D->Type == pkgCache::Dep::PreDepends || D->Type == pkgCache::Dep::Depends))
1402       {
1403          // undo all changes which aren't lead to a solution
1404          for (std::list<std::pair<pkgCache::VerIterator, pkgCache::VerIterator> >::const_iterator c = ++newChanged;
1405               c != Changed.end(); ++c)
1406             SetCandidateVersion(c->first);
1407          Changed.erase(newChanged, Changed.end());
1408          return false;
1409       }
1410    }
1411    return true;
1412 }
1413                                                                         /*}}}*/
1414 // DepCache::MarkAuto - set the Auto flag for a package                 /*{{{*/
1415 // ---------------------------------------------------------------------
1416 /* */
1417 void pkgDepCache::MarkAuto(const PkgIterator &Pkg, bool Auto)
1418 {
1419   StateCache &state = PkgState[Pkg->ID];
1420
1421   ActionGroup group(*this);
1422
1423   if(Auto)
1424     state.Flags |= Flag::Auto;
1425   else
1426     state.Flags &= ~Flag::Auto;
1427 }
1428                                                                         /*}}}*/
1429 // StateCache::Update - Compute the various static display things       /*{{{*/
1430 // ---------------------------------------------------------------------
1431 /* This is called whenever the Candidate version changes. */
1432 void pkgDepCache::StateCache::Update(PkgIterator Pkg,pkgCache &Cache)
1433 {
1434    // Some info
1435    VerIterator Ver = CandidateVerIter(Cache);
1436
1437    // Use a null string or the version string
1438    if (Ver.end() == true)
1439       CandVersion = "";
1440    else
1441       CandVersion = Ver.VerStr();
1442
1443    // Find the current version
1444    CurVersion = "";
1445    if (Pkg->CurrentVer != 0)
1446       CurVersion = Pkg.CurrentVer().VerStr();
1447
1448    // Strip off the epochs for display
1449    CurVersion = StripEpoch(CurVersion);
1450    CandVersion = StripEpoch(CandVersion);
1451
1452    // Figure out if its up or down or equal
1453    Status = Ver.CompareVer(Pkg.CurrentVer());
1454    if (Pkg->CurrentVer == 0 || Pkg->VersionList == 0 || CandidateVer == 0)
1455      Status = 2;
1456 }
1457                                                                         /*}}}*/
1458 // StateCache::StripEpoch - Remove the epoch specifier from the version /*{{{*/
1459 // ---------------------------------------------------------------------
1460 /* */
1461 const char *pkgDepCache::StateCache::StripEpoch(const char *Ver)
1462 {
1463    if (Ver == 0)
1464       return 0;
1465
1466    // Strip any epoch
1467    for (const char *I = Ver; *I != 0; I++)
1468       if (*I == ':')
1469          return I + 1;
1470    return Ver;
1471 }
1472                                                                         /*}}}*/
1473 // Policy::GetCandidateVer - Returns the Candidate install version      /*{{{*/
1474 // ---------------------------------------------------------------------
1475 /* The default just returns the highest available version that is not
1476    a source and automatic. */
1477 pkgCache::VerIterator pkgDepCache::Policy::GetCandidateVer(PkgIterator const &Pkg)
1478 {
1479    /* Not source/not automatic versions cannot be a candidate version
1480       unless they are already installed */
1481    VerIterator Last(*(pkgCache *)this,0);
1482
1483    for (VerIterator I = Pkg.VersionList(); I.end() == false; ++I)
1484    {
1485       if (Pkg.CurrentVer() == I)
1486          return I;
1487
1488       for (VerFileIterator J = I.FileList(); J.end() == false; ++J)
1489       {
1490          if ((J.File()->Flags & Flag::NotSource) != 0)
1491             continue;
1492
1493          /* Stash the highest version of a not-automatic source, we use it
1494             if there is nothing better */
1495          if ((J.File()->Flags & Flag::NotAutomatic) != 0 ||
1496              (J.File()->Flags & Flag::ButAutomaticUpgrades) != 0)
1497          {
1498             if (Last.end() == true)
1499                Last = I;
1500             continue;
1501          }
1502
1503          return I;
1504       }
1505    }
1506
1507    return Last;
1508 }
1509                                                                         /*}}}*/
1510 // Policy::IsImportantDep - True if the dependency is important         /*{{{*/
1511 // ---------------------------------------------------------------------
1512 /* */
1513 bool pkgDepCache::Policy::IsImportantDep(DepIterator const &Dep)
1514 {
1515    if(Dep.IsCritical())
1516       return true;
1517    else if(Dep->Type == pkgCache::Dep::Recommends)
1518    {
1519       if (InstallRecommends)
1520          return true;
1521       // we suport a special mode to only install-recommends for certain
1522       // sections
1523       // FIXME: this is a meant as a temporarly solution until the
1524       //        recommends are cleaned up
1525       const char *sec = Dep.ParentVer().Section();
1526       if (sec && ConfigValueInSubTree("APT::Install-Recommends-Sections", sec))
1527          return true;
1528    }
1529    else if(Dep->Type == pkgCache::Dep::Suggests)
1530       return InstallSuggests;
1531
1532    return false;
1533 }
1534                                                                         /*}}}*/
1535 // Policy::GetPriority - Get the priority of the package pin            /*{{{*/
1536 signed short pkgDepCache::Policy::GetPriority(pkgCache::PkgIterator const &Pkg)
1537 { return 0; };
1538 signed short pkgDepCache::Policy::GetPriority(pkgCache::PkgFileIterator const &File)
1539 { return 0; };
1540                                                                         /*}}}*/
1541 pkgDepCache::InRootSetFunc *pkgDepCache::GetRootSetFunc()               /*{{{*/
1542 {
1543   DefaultRootSetFunc *f = new DefaultRootSetFunc;
1544   if(f->wasConstructedSuccessfully())
1545     return f;
1546   else
1547     {
1548       delete f;
1549       return NULL;
1550     }
1551 }
1552                                                                         /*}}}*/
1553 bool pkgDepCache::MarkFollowsRecommends()
1554 {
1555   return _config->FindB("APT::AutoRemove::RecommendsImportant", true);
1556 }
1557
1558 bool pkgDepCache::MarkFollowsSuggests()
1559 {
1560   return _config->FindB("APT::AutoRemove::SuggestsImportant", true);
1561 }
1562
1563 // pkgDepCache::MarkRequired - the main mark algorithm                  /*{{{*/
1564 bool pkgDepCache::MarkRequired(InRootSetFunc &userFunc)
1565 {
1566    if (_config->Find("APT::Solver", "internal") != "internal")
1567       return true;
1568
1569    bool follow_recommends;
1570    bool follow_suggests;
1571    bool debug_autoremove = _config->FindB("Debug::pkgAutoRemove",false);
1572
1573    // init the states
1574    for(PkgIterator p = PkgBegin(); !p.end(); ++p)
1575    {
1576       PkgState[p->ID].Marked  = false;
1577       PkgState[p->ID].Garbage = false;
1578
1579       // debug output
1580       if(debug_autoremove && PkgState[p->ID].Flags & Flag::Auto)
1581          std::clog << "AutoDep: " << p.FullName() << std::endl;
1582    }
1583
1584    // init vars
1585    follow_recommends = MarkFollowsRecommends();
1586    follow_suggests   = MarkFollowsSuggests();
1587
1588
1589
1590    // do the mark part, this is the core bit of the algorithm
1591    for(PkgIterator p = PkgBegin(); !p.end(); ++p)
1592    {
1593       if(!(PkgState[p->ID].Flags & Flag::Auto) ||
1594           (p->Flags & Flag::Essential) ||
1595           userFunc.InRootSet(p) ||
1596           // be nice even then a required package violates the policy (#583517)
1597           // and do the full mark process also for required packages
1598           (p.CurrentVer().end() != true &&
1599            p.CurrentVer()->Priority == pkgCache::State::Required))
1600       {
1601          // the package is installed (and set to keep)
1602          if(PkgState[p->ID].Keep() && !p.CurrentVer().end())
1603             MarkPackage(p, p.CurrentVer(),
1604                         follow_recommends, follow_suggests);
1605          // the package is to be installed
1606          else if(PkgState[p->ID].Install())
1607             MarkPackage(p, PkgState[p->ID].InstVerIter(*this),
1608                         follow_recommends, follow_suggests);
1609       }
1610    }
1611
1612    return true;
1613 }
1614                                                                         /*}}}*/
1615 // MarkPackage - mark a single package in Mark-and-Sweep                /*{{{*/
1616 void pkgDepCache::MarkPackage(const pkgCache::PkgIterator &pkg,
1617                               const pkgCache::VerIterator &ver,
1618                               bool const &follow_recommends,
1619                               bool const &follow_suggests)
1620 {
1621    pkgDepCache::StateCache &state = PkgState[pkg->ID];
1622
1623    // if we are marked already we are done
1624    if(state.Marked)
1625       return;
1626
1627    VerIterator const currver = pkg.CurrentVer();
1628    VerIterator const instver = state.InstVerIter(*this);
1629
1630 #if 0
1631    VerIterator const candver = state.CandidateVerIter(*this);
1632
1633    // If a package was garbage-collected but is now being marked, we
1634    // should re-select it
1635    // For cases when a pkg is set to upgrade and this trigger the
1636    // removal of a no-longer used dependency.  if the pkg is set to
1637    // keep again later it will result in broken deps
1638    if(state.Delete() && state.RemoveReason = Unused)
1639    {
1640       if(ver==candver)
1641          mark_install(pkg, false, false, NULL);
1642       else if(ver==pkg.CurrentVer())
1643          MarkKeep(pkg, false, false);
1644
1645       instver=state.InstVerIter(*this);
1646    }
1647 #endif
1648
1649    // For packages that are not going to be removed, ignore versions
1650    // other than the InstVer.  For packages that are going to be
1651    // removed, ignore versions other than the current version.
1652    if(!(ver == instver && !instver.end()) &&
1653       !(ver == currver && instver.end() && !ver.end()))
1654       return;
1655
1656    bool const debug_autoremove = _config->FindB("Debug::pkgAutoRemove", false);
1657
1658    if(debug_autoremove)
1659      {
1660        std::clog << "Marking: " << pkg.FullName();
1661        if(!ver.end())
1662          std::clog << " " << ver.VerStr();
1663        if(!currver.end())
1664          std::clog << ", Curr=" << currver.VerStr();
1665        if(!instver.end())
1666          std::clog << ", Inst=" << instver.VerStr();
1667        std::clog << std::endl;
1668      }
1669
1670    state.Marked=true;
1671
1672    if(ver.end() == true)
1673       return;
1674
1675      for(DepIterator d = ver.DependsList(); !d.end(); ++d)
1676      {
1677         if(d->Type == Dep::Depends ||
1678            d->Type == Dep::PreDepends ||
1679            (follow_recommends &&
1680             d->Type == Dep::Recommends) ||
1681            (follow_suggests &&
1682             d->Type == Dep::Suggests))
1683         {
1684            // Try all versions of this package.
1685            for(VerIterator V = d.TargetPkg().VersionList();
1686                !V.end(); ++V)
1687            {
1688               if(_system->VS->CheckDep(V.VerStr(), d->CompareOp, d.TargetVer()))
1689               {
1690                 if(debug_autoremove)
1691                   {
1692                     std::clog << "Following dep: " << d.ParentPkg().FullName()
1693                               << " " << d.ParentVer().VerStr() << " "
1694                               << d.DepType() << " " << d.TargetPkg().FullName();
1695                     if((d->CompareOp & ~pkgCache::Dep::Or) != pkgCache::Dep::NoOp)
1696                       {
1697                         std::clog << " (" << d.CompType() << " "
1698                                   << d.TargetVer() << ")";
1699                       }
1700                     std::clog << std::endl;
1701                   }
1702                  MarkPackage(V.ParentPkg(), V,
1703                              follow_recommends, follow_suggests);
1704               }
1705            }
1706            // Now try virtual packages
1707            for(PrvIterator prv=d.TargetPkg().ProvidesList();
1708                !prv.end(); ++prv)
1709            {
1710               if(_system->VS->CheckDep(prv.ProvideVersion(), d->CompareOp,
1711                                        d.TargetVer()))
1712               {
1713                 if(debug_autoremove)
1714                   {
1715                     std::clog << "Following dep: " << d.ParentPkg().FullName() << " "
1716                               << d.ParentVer().VerStr() << " "
1717                               << d.DepType() << " " << d.TargetPkg().FullName() << " ";
1718                     if((d->CompareOp & ~pkgCache::Dep::Or) != pkgCache::Dep::NoOp)
1719                       {
1720                         std::clog << " (" << d.CompType() << " "
1721                                   << d.TargetVer() << ")";
1722                       }
1723                     std::clog << ", provided by "
1724                               << prv.OwnerPkg().FullName() << " "
1725                               << prv.OwnerVer().VerStr()
1726                               << std::endl;
1727                   }
1728
1729                  MarkPackage(prv.OwnerPkg(), prv.OwnerVer(),
1730                              follow_recommends, follow_suggests);
1731               }
1732            }
1733         }
1734      }
1735 }
1736                                                                         /*}}}*/
1737 bool pkgDepCache::Sweep()                                               /*{{{*/
1738 {
1739    bool debug_autoremove = _config->FindB("Debug::pkgAutoRemove",false);
1740
1741    // do the sweep
1742    for(PkgIterator p=PkgBegin(); !p.end(); ++p)
1743    {
1744      StateCache &state=PkgState[p->ID];
1745
1746      // skip required packages
1747      if (!p.CurrentVer().end() &&
1748          (p.CurrentVer()->Priority == pkgCache::State::Required))
1749         continue;
1750
1751      // if it is not marked and it is installed, it's garbage
1752      if(!state.Marked && (!p.CurrentVer().end() || state.Install()))
1753      {
1754         state.Garbage=true;
1755         if(debug_autoremove)
1756            std::clog << "Garbage: " << p.FullName() << std::endl;
1757      }
1758   }
1759
1760    return true;
1761 }
1762                                                                         /*}}}*/