apt-pkg/depcache.h

   1 // -*- mode: c++; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: depcache.h,v 1.14 2001/02/20 07:03:17 jgg Exp $
   4 /* ######################################################################
   5
   6    DepCache - Dependency Extension data for the cache
   7
   8    This class stores the cache data and a set of extension structures for
   9    monitoring the current state of all the packages. It also generates and
  10    caches the 'install' state of many things. This refers to the state of the
  11    package after an install has been run.
  12
  13    The StateCache::State field can be -1,0,1,2 which is <,=,>,no current.
  14    StateCache::Mode is which of the 3 fields is active.
  15
  16    This structure is important to support the readonly status of the cache
  17    file. When the data is saved the cache will be refereshed from our
  18    internal rep and written to disk. Then the actual persistant data
  19    files will be put on the disk.
  20
  21    Each dependency is compared against 3 target versions to produce to
  22    3 dependency results.
  23      Now - Compared using the Currently install version
  24      Install - Compared using the install version (final state)
  25      CVer - (Candidate Verion) Compared using the Candidate Version
  26    The candidate and now results are used to decide wheather a package
  27    should be automatically installed or if it should be left alone.
  28
  29    Remember, the Candidate Version is selected based on the distribution
  30    settings for the Package. The Install Version is selected based on the
  31    state (Delete, Keep, Install) field and can be either the Current Version
  32    or the Candidate version.
  33
  34    The Candidate version is what is shown the 'Install Version' field.
  35
  36    ##################################################################### */
  37                                                                         /*}}}*/
  38 #ifndef PKGLIB_DEPCACHE_H
  39 #define PKGLIB_DEPCACHE_H
  40
  41 #include <apt-pkg/configuration.h>
  42 #include <apt-pkg/pkgcache.h>
  43 #include <apt-pkg/progress.h>
  44 #include <apt-pkg/error.h>
  45
  46 #include <vector>
  47 #include <memory>
  48 #include <set>
  49
  50 class pkgDepCache : protected pkgCache::Namespace
  51 {
  52    public:
  53
  54    /** \brief An arbitrary predicate on packages. */
  55    class InRootSetFunc
  56    {
  57    public:
  58      virtual bool InRootSet(const pkgCache::PkgIterator &pkg) {return false;};
  59      virtual ~InRootSetFunc() {};
  60    };
  61
  62    private:
  63    /** \brief Mark a single package and all its unmarked important
  64     *  dependencies during mark-and-sweep.
  65     *
  66     *  Recursively invokes itself to mark all dependencies of the
  67     *  package.
  68     *
  69     *  \param pkg The package to mark.
  70     *
  71     *  \param ver The version of the package that is to be marked.
  72     *
  73     *  \param follow_recommends If \b true, recommendations of the
  74     *  package will be recursively marked.
  75     *
  76     *  \param follow_suggests If \b true, suggestions of the package
  77     *  will be recursively marked.
  78     */
  79    void MarkPackage(const pkgCache::PkgIterator &pkg,
  80                     const pkgCache::VerIterator &ver,
  81                     bool const &follow_recommends,
  82                     bool const &follow_suggests);
  83
  84    /** \brief Update the Marked field of all packages.
  85     *
  86     *  Each package's StateCache::Marked field will be set to \b true
  87     *  if and only if it can be reached from the root set.  By
  88     *  default, the root set consists of the set of manually installed
  89     *  or essential packages, but it can be extended using the
  90     *  parameter #rootFunc.
  91     *
  92     *  \param rootFunc A callback that can be used to add extra
  93     *  packages to the root set.
  94     *
  95     *  \return \b false if an error occurred.
  96     */
  97    bool MarkRequired(InRootSetFunc &rootFunc);
  98
  99    /** \brief Set the StateCache::Garbage flag on all packages that
 100     *  should be removed.
 101     *
 102     *  Packages that were not marked by the last call to #MarkRequired
 103     *  are tested to see whether they are actually garbage.  If so,
 104     *  they are marked as such.
 105     *
 106     *  \return \b false if an error occurred.
 107     */
 108    bool Sweep();
 109
 110    public:
 111
 112    // These flags are used in DepState
 113    enum DepFlags {DepNow = (1 << 0),DepInstall = (1 << 1),DepCVer = (1 << 2),
 114                   DepGNow = (1 << 3),DepGInstall = (1 << 4),DepGCVer = (1 << 5)};
 115
 116    // These flags are used in StateCache::DepState
 117    enum DepStateFlags {DepNowPolicy = (1 << 0), DepNowMin = (1 << 1),
 118                        DepInstPolicy = (1 << 2), DepInstMin = (1 << 3),
 119                        DepCandPolicy = (1 << 4), DepCandMin = (1 << 5)};
 120
 121    // These flags are used in StateCache::iFlags
 122    enum InternalFlags {AutoKept = (1 << 0), Purge = (1 << 1), ReInstall = (1 << 2), Protected = (1 << 3)};
 123
 124    enum VersionTypes {NowVersion, InstallVersion, CandidateVersion};
 125    enum ModeList {ModeDelete = 0, ModeKeep = 1, ModeInstall = 2};
 126
 127    /** \brief Represents an active action group.
 128     *
 129     *  An action group is a group of actions that are currently being
 130     *  performed.  While an active group is active, certain routine
 131     *  clean-up actions that would normally be performed after every
 132     *  cache operation are delayed until the action group is
 133     *  completed.  This is necessary primarily to avoid inefficiencies
 134     *  when modifying a large number of packages at once.
 135     *
 136     *  This class represents an active action group.  Creating an
 137     *  instance will create an action group; destroying one will
 138     *  destroy the corresponding action group.
 139     *
 140     *  The following operations are suppressed by this class:
 141     *
 142     *    - Keeping the Marked and Garbage flags up to date.
 143     *
 144     *  \note This can be used in the future to easily accumulate
 145     *  atomic actions for undo or to display "what apt did anyway";
 146     *  e.g., change the counter of how many action groups are active
 147     *  to a std::set of pointers to them and use those to store
 148     *  information about what happened in a group in the group.
 149     */
 150    class ActionGroup
 151    {
 152        pkgDepCache &cache;
 153
 154        bool released;
 155
 156        /** Action groups are noncopyable. */
 157        ActionGroup(const ActionGroup &other);
 158    public:
 159        /** \brief Create a new ActionGroup.
 160         *
 161         *  \param cache The cache that this ActionGroup should
 162         *  manipulate.
 163         *
 164         *  As long as this object exists, no automatic cleanup
 165         *  operations will be undertaken.
 166         */
 167        ActionGroup(pkgDepCache &cache);
 168
 169        /** \brief Clean up the action group before it is destroyed.
 170         *
 171         *  If it is destroyed later, no second cleanup wil be run.
 172         */
 173        void release();
 174
 175        /** \brief Destroy the action group.
 176         *
 177         *  If this is the last action group, the automatic cache
 178         *  cleanup operations will be undertaken.
 179         */
 180        ~ActionGroup();
 181    };
 182
 183    /** \brief Returns \b true for packages matching a regular
 184     *  expression in APT::NeverAutoRemove.
 185     */
 186    class DefaultRootSetFunc : public InRootSetFunc, public Configuration::MatchAgainstConfig
 187    {
 188    public:
 189      DefaultRootSetFunc() : Configuration::MatchAgainstConfig("APT::NeverAutoRemove") {};
 190      virtual ~DefaultRootSetFunc() {};
 191
 192      bool InRootSet(const pkgCache::PkgIterator &pkg) { return pkg.end() == false && Match(pkg.Name()); };
 193    };
 194
 195    struct StateCache
 196    {
 197       // Epoch stripped text versions of the two version fields
 198       const char *CandVersion;
 199       const char *CurVersion;
 200
 201       // Pointer to the candidate install version.
 202       Version *CandidateVer;
 203
 204       // Pointer to the install version.
 205       Version *InstallVer;
 206
 207       // Copy of Package::Flags
 208       unsigned short Flags;
 209       unsigned short iFlags;           // Internal flags
 210
 211       /** \brief \b true if this package can be reached from the root set. */
 212       bool Marked;
 213
 214       /** \brief \b true if this package is unused and should be removed.
 215        *
 216        *  This differs from !#Marked, because it is possible that some
 217        *  unreachable packages will be protected from becoming
 218        *  garbage.
 219        */
 220       bool Garbage;
 221
 222       // Various tree indicators
 223       signed char Status;              // -1,0,1,2
 224       unsigned char Mode;              // ModeList
 225       unsigned char DepState;          // DepState Flags
 226
 227       // Update of candidate version
 228       const char *StripEpoch(const char *Ver);
 229       void Update(PkgIterator Pkg,pkgCache &Cache);
 230
 231       // Various test members for the current status of the package
 232       inline bool NewInstall() const {return Status == 2 && Mode == ModeInstall;};
 233       inline bool Delete() const {return Mode == ModeDelete;};
 234       inline bool Purge() const {return Delete() == true && (iFlags & pkgDepCache::Purge) == pkgDepCache::Purge; };
 235       inline bool Keep() const {return Mode == ModeKeep;};
 236       inline bool Protect() const {return (iFlags & Protected) == Protected;};
 237       inline bool Upgrade() const {return Status > 0 && Mode == ModeInstall;};
 238       inline bool Upgradable() const {return Status >= 1;};
 239       inline bool Downgrade() const {return Status < 0 && Mode == ModeInstall;};
 240       inline bool Held() const {return Status != 0 && Keep();};
 241       inline bool NowBroken() const {return (DepState & DepNowMin) != DepNowMin;};
 242       inline bool NowPolicyBroken() const {return (DepState & DepNowPolicy) != DepNowPolicy;};
 243       inline bool InstBroken() const {return (DepState & DepInstMin) != DepInstMin;};
 244       inline bool InstPolicyBroken() const {return (DepState & DepInstPolicy) != DepInstPolicy;};
 245       inline bool Install() const {return Mode == ModeInstall;};
 246       inline bool ReInstall() const {return Delete() == false && (iFlags & pkgDepCache::ReInstall) == pkgDepCache::ReInstall;};
 247       inline VerIterator InstVerIter(pkgCache &Cache)
 248                 {return VerIterator(Cache,InstallVer);};
 249       inline VerIterator CandidateVerIter(pkgCache &Cache)
 250                 {return VerIterator(Cache,CandidateVer);};
 251    };
 252
 253    // Helper functions
 254    void BuildGroupOrs(VerIterator const &V);
 255    void UpdateVerState(PkgIterator Pkg);
 256
 257    // User Policy control
 258    class Policy
 259    {
 260       public:
 261       Policy() {
 262          InstallRecommends = _config->FindB("APT::Install-Recommends", false);
 263          InstallSuggests = _config->FindB("APT::Install-Suggests", false);
 264       }
 265
 266       virtual VerIterator GetCandidateVer(PkgIterator const &Pkg);
 267       virtual bool IsImportantDep(DepIterator const &Dep);
 268       virtual signed short GetPriority(PkgIterator const &Pkg);
 269       virtual signed short GetPriority(PkgFileIterator const &File);
 270
 271       virtual ~Policy() {};
 272
 273       private:
 274       bool InstallRecommends;
 275       bool InstallSuggests;
 276    };
 277
 278    private:
 279    /** The number of open "action groups"; certain post-action
 280     *  operations are suppressed if this number is > 0.
 281     */
 282    int group_level;
 283
 284    friend class ActionGroup;
 285
 286    protected:
 287
 288    // State information
 289    pkgCache *Cache;
 290    StateCache *PkgState;
 291    unsigned char *DepState;
 292
 293    /** Stores the space changes after installation */
 294    signed long long iUsrSize;
 295    /** Stores how much we need to download to get the packages */
 296    unsigned long long iDownloadSize;
 297    unsigned long iInstCount;
 298    unsigned long iDelCount;
 299    unsigned long iKeepCount;
 300    unsigned long iBrokenCount;
 301    unsigned long iPolicyBrokenCount;
 302    unsigned long iBadCount;
 303
 304    bool DebugMarker;
 305    bool DebugAutoInstall;
 306
 307    Policy *delLocalPolicy;           // For memory clean up..
 308    Policy *LocalPolicy;
 309
 310    // Check for a matching provides
 311    bool CheckDep(DepIterator Dep,int Type,PkgIterator &Res);
 312    inline bool CheckDep(DepIterator Dep,int Type)
 313    {
 314       PkgIterator Res(*this,0);
 315       return CheckDep(Dep,Type,Res);
 316    }
 317
 318    // Computes state information for deps and versions (w/o storing)
 319    unsigned char DependencyState(DepIterator &D);
 320    unsigned char VersionState(DepIterator D,unsigned char Check,
 321                               unsigned char SetMin,
 322                               unsigned char SetPolicy);
 323
 324    // Recalculates various portions of the cache, call after changing something
 325    void Update(DepIterator Dep);           // Mostly internal
 326    void Update(PkgIterator const &P);
 327
 328    // Count manipulators
 329    void AddSizes(const PkgIterator &Pkg, bool const Invert = false);
 330    inline void RemoveSizes(const PkgIterator &Pkg) {AddSizes(Pkg, true);};
 331    void AddStates(const PkgIterator &Pkg, bool const Invert = false);
 332    inline void RemoveStates(const PkgIterator &Pkg) {AddStates(Pkg,true);};
 333
 334    public:
 335
 336    // Legacy.. We look like a pkgCache
 337    inline operator pkgCache &() {return *Cache;};
 338    inline Header &Head() {return *Cache->HeaderP;};
 339    inline GrpIterator GrpBegin() {return Cache->GrpBegin();};
 340    inline PkgIterator PkgBegin() {return Cache->PkgBegin();};
 341    inline GrpIterator FindGrp(string const &Name) {return Cache->FindGrp(Name);};
 342    inline PkgIterator FindPkg(string const &Name) {return Cache->FindPkg(Name);};
 343    inline PkgIterator FindPkg(string const &Name, string const &Arch) {return Cache->FindPkg(Name, Arch);};
 344
 345    inline pkgCache &GetCache() {return *Cache;};
 346    inline pkgVersioningSystem &VS() {return *Cache->VS;};
 347
 348    // Policy implementation
 349    inline VerIterator GetCandidateVer(PkgIterator const &Pkg) {return LocalPolicy->GetCandidateVer(Pkg);};
 350    inline bool IsImportantDep(DepIterator Dep) {return LocalPolicy->IsImportantDep(Dep);};
 351    inline Policy &GetPolicy() {return *LocalPolicy;};
 352
 353    // Accessors
 354    inline StateCache &operator [](PkgIterator const &I) {return PkgState[I->ID];};
 355    inline unsigned char &operator [](DepIterator const &I) {return DepState[I->ID];};
 356
 357    /** \return A function identifying packages in the root set other
 358     *  than manually installed packages and essential packages, or \b
 359     *  NULL if an error occurs.
 360     *
 361     *  \todo Is this the best place for this function?  Perhaps the
 362     *  settings for mark-and-sweep should be stored in a single
 363     *  external class?
 364     */
 365    virtual InRootSetFunc *GetRootSetFunc();
 366
 367    /** \return \b true if the garbage collector should follow recommendations.
 368     */
 369    virtual bool MarkFollowsRecommends();
 370
 371    /** \return \b true if the garbage collector should follow suggestions.
 372     */
 373    virtual bool MarkFollowsSuggests();
 374
 375    /** \brief Update the Marked and Garbage fields of all packages.
 376     *
 377     *  This routine is implicitly invoked after all state manipulators
 378     *  and when an ActionGroup is destroyed.  It invokes #MarkRequired
 379     *  and #Sweep to do its dirty work.
 380     *
 381     *  \param rootFunc A predicate that returns \b true for packages
 382     *  that should be added to the root set.
 383     */
 384    bool MarkAndSweep(InRootSetFunc &rootFunc)
 385    {
 386      return MarkRequired(rootFunc) && Sweep();
 387    }
 388
 389    bool MarkAndSweep()
 390    {
 391      std::auto_ptr<InRootSetFunc> f(GetRootSetFunc());
 392      if(f.get() != NULL)
 393        return MarkAndSweep(*f.get());
 394      else
 395        return false;
 396    }
 397
 398    /** \name State Manipulators
 399     */
 400    // @{
 401    bool MarkKeep(PkgIterator const &Pkg, bool Soft = false,
 402                  bool FromUser = true, unsigned long Depth = 0);
 403    bool MarkDelete(PkgIterator const &Pkg, bool Purge = false,
 404                    unsigned long Depth = 0, bool FromUser = true);
 405    bool MarkInstall(PkgIterator const &Pkg,bool AutoInst = true,
 406                     unsigned long Depth = 0, bool FromUser = true,
 407                     bool ForceImportantDeps = false);
 408    void MarkProtected(PkgIterator const &Pkg) { PkgState[Pkg->ID].iFlags |= Protected; };
 409
 410    void SetReInstall(PkgIterator const &Pkg,bool To);
 411    void SetCandidateVersion(VerIterator TargetVer);
 412    bool SetCandidateRelease(pkgCache::VerIterator TargetVer,
 413                                 std::string const &TargetRel);
 414    /** Set the candidate version for dependencies too if needed.
 415     *
 416     *  Sets not only the candidate version as SetCandidateVersion does,
 417     *  but walks also down the dependency tree and checks if it is required
 418     *  to set the candidate of the dependency to a version from the given
 419     *  release, too.
 420     *
 421     *  \param TargetVer new candidate version of the package
 422     *  \param TargetRel try to switch to this release if needed
 423     *  \param[out] Changed a list of pairs consisting of the \b old
 424     *              version of the changed package and the version which
 425     *              required the switch of this dependency
 426     *  \return \b true if the switch was successful, \b false otherwise
 427     */
 428    bool SetCandidateRelease(pkgCache::VerIterator TargetVer,
 429                             std::string const &TargetRel,
 430                             std::list<std::pair<pkgCache::VerIterator, pkgCache::VerIterator> > &Changed);
 431
 432    /** Set the "is automatically installed" flag of Pkg. */
 433    void MarkAuto(const PkgIterator &Pkg, bool Auto);
 434    // @}
 435
 436    /** \return \b true if it's OK for MarkInstall to install
 437     *  the given package.
 438     *
 439     *  See the default implementation for a simple example how this
 440     *  method can be used.
 441     *  Overriding implementations should use the hold-state-flag to cache
 442     *  results from previous checks of this package - also it should
 443     *  be used if the default resolver implementation is also used to
 444     *  ensure that these packages are handled like "normal" dpkg holds.
 445     *
 446     *  The parameters are the same as in the calling MarkInstall:
 447     *  \param Pkg       the package that MarkInstall wants to install.
 448     *  \param AutoInst  needs a previous MarkInstall this package?
 449     *  \param Depth     recursive deep of this Marker call
 450     *  \param FromUser  was the install requested by the user?
 451     */
 452    virtual bool IsInstallOk(const PkgIterator &Pkg,bool AutoInst = true,
 453                             unsigned long Depth = 0, bool FromUser = true);
 454
 455    /** \return \b true if it's OK for MarkDelete to remove
 456     *  the given package.
 457     *
 458     *  See the default implementation for a simple example how this
 459     *  method can be used.
 460     *  Overriding implementations should use the hold-state-flag to cache
 461     *  results from previous checks of this package - also it should
 462     *  be used if the default resolver implementation is also used to
 463     *  ensure that these packages are handled like "normal" dpkg holds.
 464     *
 465     *  The parameters are the same as in the calling MarkDelete:
 466     *  \param Pkg       the package that MarkDelete wants to remove.
 467     *  \param Purge     should we purge instead of "only" remove?
 468     *  \param Depth     recursive deep of this Marker call
 469     *  \param FromUser  was the remove requested by the user?
 470     */
 471    virtual bool IsDeleteOk(const PkgIterator &Pkg,bool Purge = false,
 472                             unsigned long Depth = 0, bool FromUser = true);
 473
 474    // read persistent states
 475    bool readStateFile(OpProgress *prog);
 476    bool writeStateFile(OpProgress *prog, bool InstalledOnly=true);
 477
 478    // Size queries
 479    inline signed long long UsrSize() {return iUsrSize;};
 480    inline unsigned long long DebSize() {return iDownloadSize;};
 481    inline unsigned long DelCount() {return iDelCount;};
 482    inline unsigned long KeepCount() {return iKeepCount;};
 483    inline unsigned long InstCount() {return iInstCount;};
 484    inline unsigned long BrokenCount() {return iBrokenCount;};
 485    inline unsigned long PolicyBrokenCount() {return iPolicyBrokenCount;};
 486    inline unsigned long BadCount() {return iBadCount;};
 487
 488    bool Init(OpProgress *Prog);
 489    // Generate all state information
 490    void Update(OpProgress *Prog = 0);
 491
 492    pkgDepCache(pkgCache *Cache,Policy *Plcy = 0);
 493    virtual ~pkgDepCache();
 494
 495    private:
 496    bool IsModeChangeOk(ModeList const mode, PkgIterator const &Pkg,
 497                         unsigned long const Depth, bool const FromUser);
 498 };
 499
 500 #endif