+ /** \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, unsigned long Depth = 0);
+ void MarkDelete(PkgIterator const &Pkg, bool Purge = false,
+ unsigned long Depth = 0, bool FromUser = true);
+ void MarkInstall(PkgIterator const &Pkg,bool AutoInst = true,
+ unsigned long Depth = 0, bool FromUser = true,
+ bool ForceImportantDeps = false);
+
+ 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);
+ // @}
+
+ /** \return \b true if it's OK for MarkInstall to install
+ * the given package.
+ *
+ * See the default implementation for a simple example how this
+ * method can be used.
+ * Overriding implementations should use the hold-state-flag to cache
+ * results from previous checks of this package - also it should
+ * be used if the default resolver implementation is also used to
+ * ensure that these packages are handled like "normal" dpkg holds.
+ *
+ * The parameters are the same as in the calling MarkInstall:
+ * \param Pkg the package that MarkInstall wants to install.
+ * \param AutoInst needs a previous MarkInstall this package?
+ * \param Depth recursive deep of this Marker call
+ * \param FromUser was the install requested by the user?
+ */
+ virtual bool IsInstallOk(const PkgIterator &Pkg,bool AutoInst = true,
+ unsigned long Depth = 0, bool FromUser = true);
+
+ /** \return \b true if it's OK for MarkDelete to remove
+ * the given package.
+ *
+ * See the default implementation for a simple example how this
+ * method can be used.
+ * Overriding implementations should use the hold-state-flag to cache
+ * results from previous checks of this package - also it should
+ * be used if the default resolver implementation is also used to
+ * ensure that these packages are handled like "normal" dpkg holds.
+ *
+ * The parameters are the same as in the calling MarkDelete:
+ * \param Pkg the package that MarkDelete wants to remove.
+ * \param Purge should we purge instead of "only" remove?
+ * \param Depth recursive deep of this Marker call
+ * \param FromUser was the remove requested by the user?
+ */
+ virtual bool IsDeleteOk(const PkgIterator &Pkg,bool Purge = false,
+ unsigned long Depth = 0, bool FromUser = true);
+
+ // read persistent states
+ bool readStateFile(OpProgress *prog);
+ bool writeStateFile(OpProgress *prog, bool InstalledOnly=true);