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 #include <memory>
  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 follow_recommends,
  82                     bool 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 occured.
  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 occured.
 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)};
 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
 187    {
 188      std::vector<regex_t *> rootSetRegexp;
 189      bool constructedSuccessfully;
 190
 191    public:
 192      DefaultRootSetFunc();
 193      ~DefaultRootSetFunc();
 194
 195      /** \return \b true if the class initialized successfully, \b
 196       *  false otherwise.  Used to avoid throwing an exception, since
 197       *  APT classes generally don't.
 198       */
 199      bool wasConstructedSuccessfully() const { return constructedSuccessfully; }
 200
 201      bool InRootSet(const pkgCache::PkgIterator &pkg);
 202    };
 203
 204    struct StateCache
 205    {
 206       // Epoch stripped text versions of the two version fields
 207       const char *CandVersion;
 208       const char *CurVersion;
 209
 210       // Pointer to the candidate install version.
 211       Version *CandidateVer;
 212
 213       // Pointer to the install version.
 214       Version *InstallVer;
 215
 216       // Copy of Package::Flags
 217       unsigned short Flags;
 218       unsigned short iFlags;           // Internal flags
 219
 220       /** \brief \b true if this package can be reached from the root set. */
 221       bool Marked;
 222
 223       /** \brief \b true if this package is unused and should be removed.
 224        *
 225        *  This differs from !#Marked, because it is possible that some
 226        *  unreachable packages will be protected from becoming
 227        *  garbage.
 228        */
 229       bool Garbage;
 230
 231       // Various tree indicators
 232       signed char Status;              // -1,0,1,2
 233       unsigned char Mode;              // ModeList
 234       unsigned char DepState;          // DepState Flags
 235
 236       // Update of candidate version
 237       const char *StripEpoch(const char *Ver);
 238       void Update(PkgIterator Pkg,pkgCache &Cache);
 239
 240       // Various test members for the current status of the package
 241       inline bool NewInstall() const {return Status == 2 && Mode == ModeInstall;};
 242       inline bool Delete() const {return Mode == ModeDelete;};
 243       inline bool Keep() const {return Mode == ModeKeep;};
 244       inline bool Upgrade() const {return Status > 0 && Mode == ModeInstall;};
 245       inline bool Upgradable() const {return Status >= 1;};
 246       inline bool Downgrade() const {return Status < 0 && Mode == ModeInstall;};
 247       inline bool Held() const {return Status != 0 && Keep();};
 248       inline bool NowBroken() const {return (DepState & DepNowMin) != DepNowMin;};
 249       inline bool NowPolicyBroken() const {return (DepState & DepNowPolicy) != DepNowPolicy;};
 250       inline bool InstBroken() const {return (DepState & DepInstMin) != DepInstMin;};
 251       inline bool InstPolicyBroken() const {return (DepState & DepInstPolicy) != DepInstPolicy;};
 252       inline bool Install() const {return Mode == ModeInstall;};
 253       inline VerIterator InstVerIter(pkgCache &Cache)
 254                 {return VerIterator(Cache,InstallVer);};
 255       inline VerIterator CandidateVerIter(pkgCache &Cache)
 256                 {return VerIterator(Cache,CandidateVer);};
 257    };
 258
 259    // Helper functions
 260    void BuildGroupOrs(VerIterator const &V);
 261    void UpdateVerState(PkgIterator Pkg);
 262
 263    // User Policy control
 264    class Policy
 265    {
 266       public:
 267
 268       virtual VerIterator GetCandidateVer(PkgIterator Pkg);
 269       virtual bool IsImportantDep(DepIterator Dep);
 270
 271       virtual ~Policy() {};
 272    };
 273
 274    private:
 275    /** The number of open "action groups"; certain post-action
 276     *  operations are suppressed if this number is > 0.
 277     */
 278    int group_level;
 279
 280    friend class ActionGroup;
 281
 282    protected:
 283
 284    // State information
 285    pkgCache *Cache;
 286    StateCache *PkgState;
 287    unsigned char *DepState;
 288
 289    double iUsrSize;
 290    double iDownloadSize;
 291    unsigned long iInstCount;
 292    unsigned long iDelCount;
 293    unsigned long iKeepCount;
 294    unsigned long iBrokenCount;
 295    unsigned long iPolicyBrokenCount;
 296    unsigned long iBadCount;
 297
 298    Policy *delLocalPolicy;           // For memory clean up..
 299    Policy *LocalPolicy;
 300
 301    // Check for a matching provides
 302    bool CheckDep(DepIterator Dep,int Type,PkgIterator &Res);
 303    inline bool CheckDep(DepIterator Dep,int Type)
 304    {
 305       PkgIterator Res(*this,0);
 306       return CheckDep(Dep,Type,Res);
 307    }
 308
 309    // Computes state information for deps and versions (w/o storing)
 310    unsigned char DependencyState(DepIterator &D);
 311    unsigned char VersionState(DepIterator D,unsigned char Check,
 312                               unsigned char SetMin,
 313                               unsigned char SetPolicy);
 314
 315    // Recalculates various portions of the cache, call after changing something
 316    void Update(DepIterator Dep);           // Mostly internal
 317    void Update(PkgIterator const &P);
 318
 319    // Count manipulators
 320    void AddSizes(const PkgIterator &Pkg,signed long Mult = 1);
 321    inline void RemoveSizes(const PkgIterator &Pkg) {AddSizes(Pkg,-1);};
 322    void AddStates(const PkgIterator &Pkg,int Add = 1);
 323    inline void RemoveStates(const PkgIterator &Pkg) {AddStates(Pkg,-1);};
 324
 325    public:
 326
 327    // Legacy.. We look like a pkgCache
 328    inline operator pkgCache &() {return *Cache;};
 329    inline Header &Head() {return *Cache->HeaderP;};
 330    inline PkgIterator PkgBegin() {return Cache->PkgBegin();};
 331    inline PkgIterator FindPkg(string const &Name) {return Cache->FindPkg(Name);};
 332
 333    inline pkgCache &GetCache() {return *Cache;};
 334    inline pkgVersioningSystem &VS() {return *Cache->VS;};
 335
 336    // Policy implementation
 337    inline VerIterator GetCandidateVer(PkgIterator Pkg) {return LocalPolicy->GetCandidateVer(Pkg);};
 338    inline bool IsImportantDep(DepIterator Dep) {return LocalPolicy->IsImportantDep(Dep);};
 339    inline Policy &GetPolicy() {return *LocalPolicy;};
 340
 341    // Accessors
 342    inline StateCache &operator [](PkgIterator const &I) {return PkgState[I->ID];};
 343    inline unsigned char &operator [](DepIterator const &I) {return DepState[I->ID];};
 344
 345    /** \return A function identifying packages in the root set other
 346     *  than manually installed packages and essential packages, or \b
 347     *  NULL if an error occurs.
 348     *
 349     *  \todo Is this the best place for this function?  Perhaps the
 350     *  settings for mark-and-sweep should be stored in a single
 351     *  external class?
 352     */
 353    virtual InRootSetFunc *GetRootSetFunc();
 354
 355    /** \return \b true if the garbage collector should follow recommendations.
 356     */
 357    virtual bool MarkFollowsRecommends();
 358
 359    /** \return \b true if the garbage collector should follow suggestions.
 360     */
 361    virtual bool MarkFollowsSuggests();
 362
 363    /** \brief Update the Marked and Garbage fields of all packages.
 364     *
 365     *  This routine is implicitly invoked after all state manipulators
 366     *  and when an ActionGroup is destroyed.  It invokes #MarkRequired
 367     *  and #Sweep to do its dirty work.
 368     *
 369     *  \param rootFunc A predicate that returns \b true for packages
 370     *  that should be added to the root set.
 371     */
 372    bool MarkAndSweep(InRootSetFunc &rootFunc)
 373    {
 374      return MarkRequired(rootFunc) && Sweep();
 375    }
 376
 377    bool MarkAndSweep()
 378    {
 379      std::auto_ptr<InRootSetFunc> f(GetRootSetFunc());
 380      if(f.get() != NULL)
 381        return MarkAndSweep(*f.get());
 382      else
 383        return false;
 384    }
 385
 386    /** \name State Manipulators
 387     */
 388    // @{
 389    void MarkKeep(PkgIterator const &Pkg, bool Soft = false,
 390                  bool FromUser = true);
 391    void MarkDelete(PkgIterator const &Pkg,bool Purge = false);
 392    void MarkInstall(PkgIterator const &Pkg,bool AutoInst = true,
 393                     unsigned long Depth = 0, bool FromUser = true,
 394                     bool ForceImportantDeps = false);
 395    void SetReInstall(PkgIterator const &Pkg,bool To);
 396    void SetCandidateVersion(VerIterator TargetVer);
 397
 398    /** Set the "is automatically installed" flag of Pkg. */
 399    void MarkAuto(const PkgIterator &Pkg, bool Auto);
 400    // @}
 401
 402    // This is for debuging
 403    void Update(OpProgress *Prog = 0);
 404
 405    // read persistent states
 406    bool readStateFile(OpProgress *prog);
 407    bool writeStateFile(OpProgress *prog, bool InstalledOnly=false);
 408
 409    // Size queries
 410    inline double UsrSize() {return iUsrSize;};
 411    inline double DebSize() {return iDownloadSize;};
 412    inline unsigned long DelCount() {return iDelCount;};
 413    inline unsigned long KeepCount() {return iKeepCount;};
 414    inline unsigned long InstCount() {return iInstCount;};
 415    inline unsigned long BrokenCount() {return iBrokenCount;};
 416    inline unsigned long PolicyBrokenCount() {return iPolicyBrokenCount;};
 417    inline unsigned long BadCount() {return iBadCount;};
 418
 419    bool Init(OpProgress *Prog);
 420
 421    pkgDepCache(pkgCache *Cache,Policy *Plcy = 0);
 422    virtual ~pkgDepCache();
 423 };
 424
 425 #endif