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
 262       virtual VerIterator GetCandidateVer(PkgIterator const &Pkg);
 263       virtual bool IsImportantDep(DepIterator const &Dep);
 264       virtual signed short GetPriority(PkgIterator const &Pkg);
 265       virtual signed short GetPriority(PkgFileIterator const &File);
 266
 267       virtual ~Policy() {};
 268    };
 269
 270    private:
 271    /** The number of open "action groups"; certain post-action
 272     *  operations are suppressed if this number is > 0.
 273     */
 274    int group_level;
 275
 276    friend class ActionGroup;
 277
 278    protected:
 279
 280    // State information
 281    pkgCache *Cache;
 282    StateCache *PkgState;
 283    unsigned char *DepState;
 284
 285    /** Stores the space changes after installation */
 286    signed long long iUsrSize;
 287    /** Stores how much we need to download to get the packages */
 288    unsigned long long iDownloadSize;
 289    unsigned long iInstCount;
 290    unsigned long iDelCount;
 291    unsigned long iKeepCount;
 292    unsigned long iBrokenCount;
 293    unsigned long iPolicyBrokenCount;
 294    unsigned long iBadCount;
 295
 296    bool DebugMarker;
 297    bool DebugAutoInstall;
 298
 299    Policy *delLocalPolicy;           // For memory clean up..
 300    Policy *LocalPolicy;
 301
 302    // Check for a matching provides
 303    bool CheckDep(DepIterator Dep,int Type,PkgIterator &Res);
 304    inline bool CheckDep(DepIterator Dep,int Type)
 305    {
 306       PkgIterator Res(*this,0);
 307       return CheckDep(Dep,Type,Res);
 308    }
 309
 310    // Computes state information for deps and versions (w/o storing)
 311    unsigned char DependencyState(DepIterator &D);
 312    unsigned char VersionState(DepIterator D,unsigned char Check,
 313                               unsigned char SetMin,
 314                               unsigned char SetPolicy);
 315
 316    // Recalculates various portions of the cache, call after changing something
 317    void Update(DepIterator Dep);           // Mostly internal
 318    void Update(PkgIterator const &P);
 319
 320    // Count manipulators
 321    void AddSizes(const PkgIterator &Pkg, bool const Invert = false);
 322    inline void RemoveSizes(const PkgIterator &Pkg) {AddSizes(Pkg, true);};
 323    void AddStates(const PkgIterator &Pkg, bool const Invert = false);
 324    inline void RemoveStates(const PkgIterator &Pkg) {AddStates(Pkg,true);};
 325
 326    public:
 327
 328    // Legacy.. We look like a pkgCache
 329    inline operator pkgCache &() {return *Cache;};
 330    inline Header &Head() {return *Cache->HeaderP;};
 331    inline GrpIterator GrpBegin() {return Cache->GrpBegin();};
 332    inline PkgIterator PkgBegin() {return Cache->PkgBegin();};
 333    inline GrpIterator FindGrp(string const &Name) {return Cache->FindGrp(Name);};
 334    inline PkgIterator FindPkg(string const &Name) {return Cache->FindPkg(Name);};
 335    inline PkgIterator FindPkg(string const &Name, string const &Arch) {return Cache->FindPkg(Name, Arch);};
 336
 337    inline pkgCache &GetCache() {return *Cache;};
 338    inline pkgVersioningSystem &VS() {return *Cache->VS;};
 339
 340    // Policy implementation
 341    inline VerIterator GetCandidateVer(PkgIterator const &Pkg) {return LocalPolicy->GetCandidateVer(Pkg);};
 342    inline bool IsImportantDep(DepIterator Dep) {return LocalPolicy->IsImportantDep(Dep);};
 343    inline Policy &GetPolicy() {return *LocalPolicy;};
 344
 345    // Accessors
 346    inline StateCache &operator [](PkgIterator const &I) {return PkgState[I->ID];};
 347    inline unsigned char &operator [](DepIterator const &I) {return DepState[I->ID];};
 348
 349    /** \return A function identifying packages in the root set other
 350     *  than manually installed packages and essential packages, or \b
 351     *  NULL if an error occurs.
 352     *
 353     *  \todo Is this the best place for this function?  Perhaps the
 354     *  settings for mark-and-sweep should be stored in a single
 355     *  external class?
 356     */
 357    virtual InRootSetFunc *GetRootSetFunc();
 358
 359    /** \return \b true if the garbage collector should follow recommendations.
 360     */
 361    virtual bool MarkFollowsRecommends();
 362
 363    /** \return \b true if the garbage collector should follow suggestions.
 364     */
 365    virtual bool MarkFollowsSuggests();
 366
 367    /** \brief Update the Marked and Garbage fields of all packages.
 368     *
 369     *  This routine is implicitly invoked after all state manipulators
 370     *  and when an ActionGroup is destroyed.  It invokes #MarkRequired
 371     *  and #Sweep to do its dirty work.
 372     *
 373     *  \param rootFunc A predicate that returns \b true for packages
 374     *  that should be added to the root set.
 375     */
 376    bool MarkAndSweep(InRootSetFunc &rootFunc)
 377    {
 378      return MarkRequired(rootFunc) && Sweep();
 379    }
 380
 381    bool MarkAndSweep()
 382    {
 383      std::auto_ptr<InRootSetFunc> f(GetRootSetFunc());
 384      if(f.get() != NULL)
 385        return MarkAndSweep(*f.get());
 386      else
 387        return false;
 388    }
 389
 390    /** \name State Manipulators
 391     */
 392    // @{
 393    bool MarkKeep(PkgIterator const &Pkg, bool Soft = false,
 394                  bool FromUser = true, unsigned long Depth = 0);
 395    bool MarkDelete(PkgIterator const &Pkg, bool Purge = false,
 396                    unsigned long Depth = 0, bool FromUser = true);
 397    bool MarkInstall(PkgIterator const &Pkg,bool AutoInst = true,
 398                     unsigned long Depth = 0, bool FromUser = true,
 399                     bool ForceImportantDeps = false);
 400    void MarkProtected(PkgIterator const &Pkg) { PkgState[Pkg->ID].iFlags |= Protected; };
 401
 402    void SetReInstall(PkgIterator const &Pkg,bool To);
 403    void SetCandidateVersion(VerIterator TargetVer);
 404    bool SetCandidateRelease(pkgCache::VerIterator TargetVer,
 405                                 std::string const &TargetRel);
 406    /** Set the candidate version for dependencies too if needed.
 407     *
 408     *  Sets not only the candidate version as SetCandidateVersion does,
 409     *  but walks also down the dependency tree and checks if it is required
 410     *  to set the candidate of the dependency to a version from the given
 411     *  release, too.
 412     *
 413     *  \param TargetVer new candidate version of the package
 414     *  \param TargetRel try to switch to this release if needed
 415     *  \param[out] Changed a list of pairs consisting of the \b old
 416     *              version of the changed package and the version which
 417     *              required the switch of this dependency
 418     *  \return \b true if the switch was successful, \b false otherwise
 419     */
 420    bool SetCandidateRelease(pkgCache::VerIterator TargetVer,
 421                             std::string const &TargetRel,
 422                             std::list<std::pair<pkgCache::VerIterator, pkgCache::VerIterator> > &Changed);
 423
 424    /** Set the "is automatically installed" flag of Pkg. */
 425    void MarkAuto(const PkgIterator &Pkg, bool Auto);
 426    // @}
 427
 428    /** \return \b true if it's OK for MarkInstall to install
 429     *  the given package.
 430     *
 431     *  See the default implementation for a simple example how this
 432     *  method can be used.
 433     *  Overriding implementations should use the hold-state-flag to cache
 434     *  results from previous checks of this package - also it should
 435     *  be used if the default resolver implementation is also used to
 436     *  ensure that these packages are handled like "normal" dpkg holds.
 437     *
 438     *  The parameters are the same as in the calling MarkInstall:
 439     *  \param Pkg       the package that MarkInstall wants to install.
 440     *  \param AutoInst  needs a previous MarkInstall this package?
 441     *  \param Depth     recursive deep of this Marker call
 442     *  \param FromUser  was the install requested by the user?
 443     */
 444    virtual bool IsInstallOk(const PkgIterator &Pkg,bool AutoInst = true,
 445                             unsigned long Depth = 0, bool FromUser = true);
 446
 447    /** \return \b true if it's OK for MarkDelete to remove
 448     *  the given package.
 449     *
 450     *  See the default implementation for a simple example how this
 451     *  method can be used.
 452     *  Overriding implementations should use the hold-state-flag to cache
 453     *  results from previous checks of this package - also it should
 454     *  be used if the default resolver implementation is also used to
 455     *  ensure that these packages are handled like "normal" dpkg holds.
 456     *
 457     *  The parameters are the same as in the calling MarkDelete:
 458     *  \param Pkg       the package that MarkDelete wants to remove.
 459     *  \param Purge     should we purge instead of "only" remove?
 460     *  \param Depth     recursive deep of this Marker call
 461     *  \param FromUser  was the remove requested by the user?
 462     */
 463    virtual bool IsDeleteOk(const PkgIterator &Pkg,bool Purge = false,
 464                             unsigned long Depth = 0, bool FromUser = true);
 465
 466    // read persistent states
 467    bool readStateFile(OpProgress *prog);
 468    bool writeStateFile(OpProgress *prog, bool InstalledOnly=true);
 469
 470    // Size queries
 471    inline signed long long UsrSize() {return iUsrSize;};
 472    inline unsigned long long DebSize() {return iDownloadSize;};
 473    inline unsigned long DelCount() {return iDelCount;};
 474    inline unsigned long KeepCount() {return iKeepCount;};
 475    inline unsigned long InstCount() {return iInstCount;};
 476    inline unsigned long BrokenCount() {return iBrokenCount;};
 477    inline unsigned long PolicyBrokenCount() {return iPolicyBrokenCount;};
 478    inline unsigned long BadCount() {return iBadCount;};
 479
 480    bool Init(OpProgress *Prog);
 481    // Generate all state information
 482    void Update(OpProgress *Prog = 0);
 483
 484    pkgDepCache(pkgCache *Cache,Policy *Plcy = 0);
 485    virtual ~pkgDepCache();
 486
 487    private:
 488    bool IsModeChangeOk(ModeList const mode, PkgIterator const &Pkg,
 489                         unsigned long const Depth, bool const FromUser);
 490 };
 491
 492 #endif