diff options
Diffstat (limited to 'apt-pkg/depcache.h')
| -rw-r--r-- | apt-pkg/depcache.h | 212 |
1 files changed, 207 insertions, 5 deletions
diff --git a/apt-pkg/depcache.h b/apt-pkg/depcache.h index 619daf8f6..fd935c268 100644 --- a/apt-pkg/depcache.h +++ b/apt-pkg/depcache.h @@ -1,4 +1,4 @@ -// -*- mode: cpp; mode: fold -*- +// -*- mode: c++; mode: fold -*- // Description /*{{{*/ // $Id: depcache.h,v 1.14 2001/02/20 07:03:17 jgg Exp $ /* ###################################################################### @@ -45,9 +45,71 @@ #include <apt-pkg/pkgcache.h> #include <apt-pkg/progress.h> +#include <regex.h> + +#include <vector> + class pkgDepCache : protected pkgCache::Namespace { public: + + /** \brief An arbitrary predicate on packages. */ + class InRootSetFunc + { + public: + virtual bool InRootSet(const pkgCache::PkgIterator &pkg) {return false;}; + virtual ~InRootSetFunc() {}; + }; + + private: + /** \brief Mark a single package and all its unmarked important + * dependencies during mark-and-sweep. + * + * Recursively invokes itself to mark all dependencies of the + * package. + * + * \param pkg The package to mark. + * + * \param ver The version of the package that is to be marked. + * + * \param follow_recommends If \b true, recommendations of the + * package will be recursively marked. + * + * \param follow_suggests If \b true, suggestions of the package + * will be recursively marked. + */ + void MarkPackage(const pkgCache::PkgIterator &pkg, + const pkgCache::VerIterator &ver, + bool follow_recommends, + bool follow_suggests); + + /** \brief Update the Marked field of all packages. + * + * Each package's StateCache::Marked field will be set to \b true + * if and only if it can be reached from the root set. By + * default, the root set consists of the set of manually installed + * or essential packages, but it can be extended using the + * parameter #rootFunc. + * + * \param rootFunc A callback that can be used to add extra + * packages to the root set. + * + * \return \b false if an error occured. + */ + bool MarkRequired(InRootSetFunc &rootFunc); + + /** \brief Set the StateCache::Garbage flag on all packages that + * should be removed. + * + * Packages that were not marked by the last call to #MarkRequired + * are tested to see whether they are actually garbage. If so, + * they are marked as such. + * + * \return \b false if an error occured. + */ + bool Sweep(); + + public: // These flags are used in DepState enum DepFlags {DepNow = (1 << 0),DepInstall = (1 << 1),DepCVer = (1 << 2), @@ -64,6 +126,83 @@ class pkgDepCache : protected pkgCache::Namespace enum VersionTypes {NowVersion, InstallVersion, CandidateVersion}; enum ModeList {ModeDelete = 0, ModeKeep = 1, ModeInstall = 2}; + /** \brief Represents an active action group. + * + * An action group is a group of actions that are currently being + * performed. While an active group is active, certain routine + * clean-up actions that would normally be performed after every + * cache operation are delayed until the action group is + * completed. This is necessary primarily to avoid inefficiencies + * when modifying a large number of packages at once. + * + * This class represents an active action group. Creating an + * instance will create an action group; destroying one will + * destroy the corresponding action group. + * + * The following operations are suppressed by this class: + * + * - Keeping the Marked and Garbage flags up to date. + * + * \note This can be used in the future to easily accumulate + * atomic actions for undo or to display "what apt did anyway"; + * e.g., change the counter of how many action groups are active + * to a std::set of pointers to them and use those to store + * information about what happened in a group in the group. + */ + class ActionGroup + { + pkgDepCache &cache; + + bool released; + + /** Action groups are noncopyable. */ + ActionGroup(const ActionGroup &other); + public: + /** \brief Create a new ActionGroup. + * + * \param cache The cache that this ActionGroup should + * manipulate. + * + * As long as this object exists, no automatic cleanup + * operations will be undertaken. + */ + ActionGroup(pkgDepCache &cache); + + /** \brief Clean up the action group before it is destroyed. + * + * If it is destroyed later, no second cleanup wil be run. + */ + void release(); + + /** \brief Destroy the action group. + * + * If this is the last action group, the automatic cache + * cleanup operations will be undertaken. + */ + ~ActionGroup(); + }; + + /** \brief Returns \b true for packages matching a regular + * expression in APT::NeverAutoRemove. + */ + class DefaultRootSetFunc : public InRootSetFunc + { + std::vector<regex_t *> rootSetRegexp; + bool constructedSuccessfully; + + public: + DefaultRootSetFunc(); + ~DefaultRootSetFunc(); + + /** \return \b true if the class initialized successfully, \b + * false otherwise. Used to avoid throwing an exception, since + * APT classes generally don't. + */ + bool wasConstructedSuccessfully() const { return constructedSuccessfully; } + + bool InRootSet(const pkgCache::PkgIterator &pkg); + }; + struct StateCache { // Epoch stripped text versions of the two version fields @@ -80,8 +219,15 @@ class pkgDepCache : protected pkgCache::Namespace unsigned short Flags; unsigned short iFlags; // Internal flags - // mark and sweep flags + /** \brief \b true if this package can be reached from the root set. */ bool Marked; + + /** \brief \b true if this package is unused and should be removed. + * + * This differs from !#Marked, because it is possible that some + * unreachable packages will be protected from becoming + * garbage. + */ bool Garbage; // Various tree indicators @@ -124,6 +270,14 @@ class pkgDepCache : protected pkgCache::Namespace virtual ~Policy() {}; }; + + private: + /** The number of open "action groups"; certain post-action + * operations are suppressed if this number is > 0. + */ + int group_level; + + friend class ActionGroup; protected: @@ -187,13 +341,61 @@ class pkgDepCache : protected pkgCache::Namespace inline StateCache &operator [](PkgIterator const &I) {return PkgState[I->ID];}; inline unsigned char &operator [](DepIterator const &I) {return DepState[I->ID];}; - // Manipulators - void MarkKeep(PkgIterator const &Pkg,bool Soft = false); + /** \return A function identifying packages in the root set other + * than manually installed packages and essential packages, or \b + * NULL if an error occurs. + * + * \todo Is this the best place for this function? Perhaps the + * settings for mark-and-sweep should be stored in a single + * external class? + */ + virtual InRootSetFunc *GetRootSetFunc(); + + /** \return \b true if the garbage collector should follow recommendations. + */ + virtual bool MarkFollowsRecommends(); + + /** \return \b true if the garbage collector should follow suggestions. + */ + virtual bool MarkFollowsSuggests(); + + /** \brief Update the Marked and Garbage fields of all packages. + * + * This routine is implicitly invoked after all state manipulators + * and when an ActionGroup is destroyed. It invokes #MarkRequired + * and #Sweep to do its dirty work. + * + * \param rootFunc A predicate that returns \b true for packages + * that should be added to the root set. + */ + bool MarkAndSweep(InRootSetFunc &rootFunc) + { + return MarkRequired(rootFunc) && Sweep(); + } + + bool MarkAndSweep() + { + std::auto_ptr<InRootSetFunc> f(GetRootSetFunc()); + if(f.get() != NULL) + return MarkAndSweep(*f.get()); + else + return false; + } + + /** \name State Manipulators + */ + // @{ + void MarkKeep(PkgIterator const &Pkg, bool Soft = false, + bool FromUser = true); void MarkDelete(PkgIterator const &Pkg,bool Purge = false); void MarkInstall(PkgIterator const &Pkg,bool AutoInst = true, - unsigned long Depth = 0); + unsigned long Depth = 0, bool FromUser = true); void SetReInstall(PkgIterator const &Pkg,bool To); void SetCandidateVersion(VerIterator TargetVer); + + /** Set the "is automatically installed" flag of Pkg. */ + void MarkAuto(const PkgIterator &Pkg, bool Auto); + // @} // This is for debuging void Update(OpProgress *Prog = 0); |