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
  42 #include <apt-pkg/pkgcache.h>
  43 #include <apt-pkg/progress.h>
  44
  45 #include <regex.h>
  46
  47 #include <vector>
  48
  49 class pkgDepCache : protected pkgCache::Namespace
  50 {
  51    public:
  52
  53    /** \brief An arbitrary predicate on packages. */
  54    class InRootSetFunc
  55    {
  56    public:
  57      virtual bool InRootSet(const pkgCache::PkgIterator &pkg) {return false;};
  58      virtual ~InRootSetFunc() {};
  59    };
  60
  61    private:
  62    /** \brief Mark a single package and all its unmarked important
  63     *  dependencies during mark-and-sweep.
  64     *
  65     *  Recursively invokes itself to mark all dependencies of the
  66     *  package.
  67     *
  68     *  \param pkg The package to mark.
  69     *
  70     *  \param ver The version of the package that is to be marked.
  71     *
  72     *  \param follow_recommends If \b true, recommendations of the
  73     *  package will be recursively marked.
  74     *
  75     *  \param follow_suggests If \b true, suggestions of the package
  76     *  will be recursively marked.
  77     */
  78    void MarkPackage(const pkgCache::PkgIterator &pkg,
  79                     const pkgCache::VerIterator &ver,
  80                     bool follow_recommends,
  81                     bool follow_suggests);
  82
  83    /** \brief Update the Marked field of all packages.
  84     *
  85     *  Each package's StateCache::Marked field will be set to \b true
  86     *  if and only if it can be reached from the root set.  By
  87     *  default, the root set consists of the set of manually installed
  88     *  or essential packages, but it can be extended using the
  89     *  parameter #rootFunc.
  90     *
  91     *  \param rootFunc A callback that can be used to add extra
  92     *  packages to the root set.
  93     *
  94     *  \return \b false if an error occured.
  95     */
  96    bool MarkRequired(InRootSetFunc &rootFunc);
  97
  98    /** \brief Set the StateCache::Garbage flag on all packages that
  99     *  should be removed.
 100     *
 101     *  Packages that were not marked by the last call to #MarkRequired
 102     *  are tested to see whether they are actually garbage.  If so,
 103     *  they are marked as such.
 104     *
 105     *  \return \b false if an error occured.
 106     */
 107    bool Sweep();
 108
 109    public:
 110
 111    // These flags are used in DepState
 112    enum DepFlags {DepNow = (1 << 0),DepInstall = (1 << 1),DepCVer = (1 << 2),
 113                   DepGNow = (1 << 3),DepGInstall = (1 << 4),DepGCVer = (1 << 5)};
 114
 115    // These flags are used in StateCache::DepState
 116    enum DepStateFlags {DepNowPolicy = (1 << 0), DepNowMin = (1 << 1),
 117                        DepInstPolicy = (1 << 2), DepInstMin = (1 << 3),
 118                        DepCandPolicy = (1 << 4), DepCandMin = (1 << 5)};
 119
 120    // These flags are used in StateCache::iFlags
 121    enum InternalFlags {AutoKept = (1 << 0), Purge = (1 << 1), ReInstall = (1 << 2)};
 122
 123    enum VersionTypes {NowVersion, InstallVersion, CandidateVersion};
 124    enum ModeList {ModeDelete = 0, ModeKeep = 1, ModeInstall = 2};
 125
 126    /** \brief Represents an active action group.
 127     *
 128     *  An action group is a group of actions that are currently being
 129     *  performed.  While an active group is active, certain routine
 130     *  clean-up actions that would normally be performed after every
 131     *  cache operation are delayed until the action group is
 132     *  completed.  This is necessary primarily to avoid inefficiencies
 133     *  when modifying a large number of packages at once.
 134     *
 135     *  This class represents an active action group.  Creating an
 136     *  instance will create an action group; destroying one will
 137     *  destroy the corresponding action group.
 138     *
 139     *  The following operations are suppressed by this class:
 140     *
 141     *    - Keeping the Marked and Garbage flags up to date.
 142     *
 143     *  \note This can be used in the future to easily accumulate
 144     *  atomic actions for undo or to display "what apt did anyway";
 145     *  e.g., change the counter of how many action groups are active
 146     *  to a std::set of pointers to them and use those to store
 147     *  information about what happened in a group in the group.
 148     */
 149    class ActionGroup
 150    {
 151        pkgDepCache &cache;
 152
 153        bool released;
 154
 155        /** Action groups are noncopyable. */
 156        ActionGroup(const ActionGroup &other);
 157    public:
 158        /** \brief Create a new ActionGroup.
 159         *
 160         *  \param cache The cache that this ActionGroup should
 161         *  manipulate.
 162         *
 163         *  As long as this object exists, no automatic cleanup
 164         *  operations will be undertaken.
 165         */
 166        ActionGroup(pkgDepCache &cache);
 167
 168        /** \brief Clean up the action group before it is destroyed.
 169         *
 170         *  If it is destroyed later, no second cleanup wil be run.
 171         */
 172        void release();
 173
 174        /** \brief Destroy the action group.
 175         *
 176         *  If this is the last action group, the automatic cache
 177         *  cleanup operations will be undertaken.
 178         */
 179        ~ActionGroup();
 180    };
 181
 182    /** \brief Returns \b true for packages matching a regular
 183     *  expression in APT::NeverAutoRemove.
 184     */
 185    class DefaultRootSetFunc : public InRootSetFunc
 186    {
 187      std::vector<regex_t *> rootSetRegexp;
 188      bool constructedSuccessfully;
 189
 190    public:
 191      DefaultRootSetFunc();
 192      ~DefaultRootSetFunc();
 193
 194      /** \return \b true if the class initialized successfully, \b
 195       *  false otherwise.  Used to avoid throwing an exception, since
 196       *  APT classes generally don't.
 197       */
 198      bool wasConstructedSuccessfully() const { return constructedSuccessfully; }
 199
 200      bool InRootSet(const pkgCache::PkgIterator &pkg);
 201    };
 202
 203    struct StateCache
 204    {
 205       // Epoch stripped text versions of the two version fields
 206       const char *CandVersion;
 207       const char *CurVersion;
 208
 209       // Pointer to the candidate install version.
 210       Version *CandidateVer;
 211
 212       // Pointer to the install version.
 213       Version *InstallVer;
 214
 215       // Copy of Package::Flags
 216       unsigned short Flags;
 217       unsigned short iFlags;           // Internal flags
 218
 219       /** \brief \b true if this package can be reached from the root set. */
 220       bool Marked;
 221
 222       /** \brief \b true if this package is unused and should be removed.
 223        *
 224        *  This differs from !#Marked, because it is possible that some
 225        *  unreachable packages will be protected from becoming
 226        *  garbage.
 227        */
 228       bool Garbage;
 229
 230       // Various tree indicators
 231       signed char Status;              // -1,0,1,2
 232       unsigned char Mode;              // ModeList
 233       unsigned char DepState;          // DepState Flags
 234
 235       // Update of candidate version
 236       const char *StripEpoch(const char *Ver);
 237       void Update(PkgIterator Pkg,pkgCache &Cache);
 238
 239       // Various test members for the current status of the package
 240       inline bool NewInstall() const {return Status == 2 && Mode == ModeInstall;};
 241       inline bool Delete() const {return Mode == ModeDelete;};
 242       inline bool Keep() const {return Mode == ModeKeep;};
 243       inline bool Upgrade() const {return Status > 0 && Mode == ModeInstall;};
 244       inline bool Upgradable() const {return Status >= 1;};
 245       inline bool Downgrade() const {return Status < 0 && Mode == ModeInstall;};
 246       inline bool Held() const {return Status != 0 && Keep();};
 247       inline bool NowBroken() const {return (DepState & DepNowMin) != DepNowMin;};
 248       inline bool NowPolicyBroken() const {return (DepState & DepNowPolicy) != DepNowPolicy;};
 249       inline bool InstBroken() const {return (DepState & DepInstMin) != DepInstMin;};
 250       inline bool InstPolicyBroken() const {return (DepState & DepInstPolicy) != DepInstPolicy;};
 251       inline bool Install() const {return Mode == ModeInstall;};
 252       inline VerIterator InstVerIter(pkgCache &Cache)
 253                 {return VerIterator(Cache,InstallVer);};
 254       inline VerIterator CandidateVerIter(pkgCache &Cache)
 255                 {return VerIterator(Cache,CandidateVer);};
 256    };
 257
 258    // Helper functions
 259    void BuildGroupOrs(VerIterator const &V);
 260    void UpdateVerState(PkgIterator Pkg);
 261
 262    // User Policy control
 263    class Policy
 264    {
 265       public:
 266
 267       virtual VerIterator GetCandidateVer(PkgIterator Pkg);
 268       virtual bool IsImportantDep(DepIterator Dep);
 269
 270       virtual ~Policy() {};
 271    };
 272
 273    private:
 274    /** The number of open "action groups"; certain post-action
 275     *  operations are suppressed if this number is > 0.
 276     */
 277    int group_level;
 278
 279    friend class ActionGroup;
 280
 281    protected:
 282
 283    // State information
 284    pkgCache *Cache;
 285    StateCache *PkgState;
 286    unsigned char *DepState;
 287
 288    double iUsrSize;
 289    double iDownloadSize;
 290    unsigned long iInstCount;
 291    unsigned long iDelCount;
 292    unsigned long iKeepCount;
 293    unsigned long iBrokenCount;
 294    unsigned long iPolicyBrokenCount;
 295    unsigned long iBadCount;
 296
 297    Policy *delLocalPolicy;           // For memory clean up..
 298    Policy *LocalPolicy;
 299
 300    // Check for a matching provides
 301    bool CheckDep(DepIterator Dep,int Type,PkgIterator &Res);
 302    inline bool CheckDep(DepIterator Dep,int Type)
 303    {
 304       PkgIterator Res(*this,0);
 305       return CheckDep(Dep,Type,Res);
 306    }
 307
 308    // Computes state information for deps and versions (w/o storing)
 309    unsigned char DependencyState(DepIterator &D);
 310    unsigned char VersionState(DepIterator D,unsigned char Check,
 311                               unsigned char SetMin,
 312                               unsigned char SetPolicy);
 313
 314    // Recalculates various portions of the cache, call after changing something
 315    void Update(DepIterator Dep);           // Mostly internal
 316    void Update(PkgIterator const &P);
 317
 318    // Count manipulators
 319    void AddSizes(const PkgIterator &Pkg,signed long Mult = 1);
 320    inline void RemoveSizes(const PkgIterator &Pkg) {AddSizes(Pkg,-1);};
 321    void AddStates(const PkgIterator &Pkg,int Add = 1);
 322    inline void RemoveStates(const PkgIterator &Pkg) {AddStates(Pkg,-1);};
 323
 324    public:
 325
 326    // Legacy.. We look like a pkgCache
 327    inline operator pkgCache &() {return *Cache;};
 328    inline Header &Head() {return *Cache->HeaderP;};
 329    inline PkgIterator PkgBegin() {return Cache->PkgBegin();};
 330    inline PkgIterator FindPkg(string const &Name) {return Cache->FindPkg(Name);};
 331
 332    inline pkgCache &GetCache() {return *Cache;};
 333    inline pkgVersioningSystem &VS() {return *Cache->VS;};
 334
 335    // Policy implementation
 336    inline VerIterator GetCandidateVer(PkgIterator Pkg) {return LocalPolicy->GetCandidateVer(Pkg);};
 337    inline bool IsImportantDep(DepIterator Dep) {return LocalPolicy->IsImportantDep(Dep);};
 338    inline Policy &GetPolicy() {return *LocalPolicy;};
 339
 340    // Accessors
 341    inline StateCache &operator [](PkgIterator const &I) {return PkgState[I->ID];};
 342    inline unsigned char &operator [](DepIterator const &I) {return DepState[I->ID];};
 343
 344    /** \return A function identifying packages in the root set other
 345     *  than manually installed packages and essential packages, or \b
 346     *  NULL if an error occurs.
 347     *
 348     *  \todo Is this the best place for this function?  Perhaps the
 349     *  settings for mark-and-sweep should be stored in a single
 350     *  external class?
 351     */
 352    virtual InRootSetFunc *GetRootSetFunc();
 353
 354    /** \return \b true if the garbage collector should follow recommendations.
 355     */
 356    virtual bool MarkFollowsRecommends();
 357
 358    /** \return \b true if the garbage collector should follow suggestions.
 359     */
 360    virtual bool MarkFollowsSuggests();
 361
 362    /** \brief Update the Marked and Garbage fields of all packages.
 363     *
 364     *  This routine is implicitly invoked after all state manipulators
 365     *  and when an ActionGroup is destroyed.  It invokes #MarkRequired
 366     *  and #Sweep to do its dirty work.
 367     *
 368     *  \param rootFunc A predicate that returns \b true for packages
 369     *  that should be added to the root set.
 370     */
 371    bool MarkAndSweep(InRootSetFunc &rootFunc)
 372    {
 373      return MarkRequired(rootFunc) && Sweep();
 374    }
 375
 376    bool MarkAndSweep()
 377    {
 378      std::auto_ptr<InRootSetFunc> f(GetRootSetFunc());
 379      if(f.get() != NULL)
 380        return MarkAndSweep(*f.get());
 381      else
 382        return false;
 383    }
 384
 385    /** \name State Manipulators
 386     */
 387    // @{
 388    void MarkKeep(PkgIterator const &Pkg, bool Soft = false,
 389                  bool FromUser = true);
 390    void MarkDelete(PkgIterator const &Pkg,bool Purge = false);
 391    void MarkInstall(PkgIterator const &Pkg,bool AutoInst = true,
 392                     unsigned long Depth = 0, bool FromUser = true,
 393                     bool ForceImportantDeps = false);
 394    void SetReInstall(PkgIterator const &Pkg,bool To);
 395    void SetCandidateVersion(VerIterator TargetVer);
 396
 397    /** Set the "is automatically installed" flag of Pkg. */
 398    void MarkAuto(const PkgIterator &Pkg, bool Auto);
 399    // @}
 400
 401    // This is for debuging
 402    void Update(OpProgress *Prog = 0);
 403
 404    // read persistent states
 405    bool readStateFile(OpProgress *prog);
 406    bool writeStateFile(OpProgress *prog, bool InstalledOnly=false);
 407
 408    // Size queries
 409    inline double UsrSize() {return iUsrSize;};
 410    inline double DebSize() {return iDownloadSize;};
 411    inline unsigned long DelCount() {return iDelCount;};
 412    inline unsigned long KeepCount() {return iKeepCount;};
 413    inline unsigned long InstCount() {return iInstCount;};
 414    inline unsigned long BrokenCount() {return iBrokenCount;};
 415    inline unsigned long PolicyBrokenCount() {return iPolicyBrokenCount;};
 416    inline unsigned long BadCount() {return iBadCount;};
 417
 418    bool Init(OpProgress *Prog);
 419
 420    pkgDepCache(pkgCache *Cache,Policy *Plcy = 0);
 421    virtual ~pkgDepCache();
 422 };
 423
 424 #endif