zypp/ProblemSolution.h

   1 /**
   2  *
   3  * Easy-to use interface to the ZYPP dependency resolver
   4  *
   5  * Author: Stefan Hundhammer <sh@suse.de>
   6  *
   7  **/
   8
   9 #ifndef ZYPP_PROBLEMSOLUTION_H
  10 #define ZYPP_PROBLEMSOLUTION_H
  11
  12 #include <list>
  13 #include <string>
  14
  15 #include "zypp/base/ReferenceCounted.h"
  16 #include "zypp/base/PtrTypes.h"
  17 #include "zypp/solver/detail/Resolver.h"
  18 #include "zypp/ResolverProblem.h"
  19 #include "zypp/solver/detail/SolutionAction.h"
  20 #include "zypp/solver/detail/Types.h"
  21
  22 /////////////////////////////////////////////////////////////////////////
  23 namespace zypp
  24 { ///////////////////////////////////////////////////////////////////////
  25
  26
  27     /**
  28      * Class representing one possible solution to one problem found during resolving
  29      *
  30      * All problems should have at least 2-3 (mutually exclusive) solutions:
  31      *
  32      *    -      Undo: Do not perform the offending transaction
  33      *   (do not install the package that had unsatisfied requirements,
  34      *    do not remove  the package that would break other packages' requirements)
  35      *
  36      *    - Remove referrers: Remove all packages that would break because
  37      *  they depend on the package that is requested to be removed
  38      *
  39      *    - Ignore: Inject artificial "provides" for a missing requirement
  40      *  (pretend that requirement is satisfied)
  41      **/
  42     class ProblemSolution : public base::ReferenceCounted
  43     {
  44     protected:
  45
  46         /**
  47          * Clear all data.
  48          * In particular, delete all members of _actions.
  49          **/
  50         void clear();
  51
  52         //
  53         // Data members
  54         //
  55         ResolverProblem_Ptr     _problem;
  56         solver::detail::CSolutionActionList     _actions;
  57         std::string             _description;
  58         std::string             _details;
  59
  60     public:
  61
  62         /**
  63          * Constructor.
  64          **/
  65         ProblemSolution( ResolverProblem_Ptr parent, const  std::string & description, const std::string & details );
  66
  67         /**
  68          * Destructor.
  69          **/
  70         ~ProblemSolution();
  71
  72         // ---------------------------------- I/O
  73
  74         friend std::ostream& operator<<(std::ostream&, const ProblemSolution & solution);
  75         friend std::ostream& operator<<(std::ostream&, const ProblemSolutionList & solutionlist);
  76         friend std::ostream& operator<<(std::ostream&, const CProblemSolutionList & solutionlist);
  77
  78         // ---------------------------------- accessors
  79         /**
  80          * Return a one-line text description of this solution.
  81          **/
  82         std::string description() const { return _description; }
  83
  84         /**
  85          * Return a (possibly multi-line) detailed description of this
  86          * solution or an empty string if there are no useful details.
  87          **/
  88         std::string details() const { return _details; }
  89
  90         /**
  91          * Return the parent dependency problem.
  92          **/
  93         ResolverProblem_Ptr problem() const { return _problem; }
  94
  95         // ---------------------------------- methods
  96
  97         /**
  98          * Apply this solution, i.e. execute all of its actions.
  99          *
 100          * Returns 'true' on success, 'false' if actions could not be performed.
 101          **/
 102         bool apply (solver::detail::Resolver & resolver);
 103
 104         /**
 105          * Add an action to the actions list.
 106          **/
 107         void addAction( solver::detail::SolutionAction_constPtr action );
 108
 109         solver::detail::CSolutionActionList actions() {return _actions;}
 110
 111     };
 112
 113
 114     ///////////////////////////////////////////////////////////////////////
 115 };// namespace zypp
 116 /////////////////////////////////////////////////////////////////////////
 117
 118 #endif // ZYPP_PROBLEMSOLUTION_H
 119