apt-pkg/policy.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: policy.h,v 1.4 2001/05/07 04:24:08 jgg Exp $
   4 /* ######################################################################
   5
   6    Package Version Policy implementation
   7
   8    This implements the more advanced 'Version 4' APT policy engine. The
   9    standard 'Version 0' engine is included inside the DepCache which is
  10    it's historical location.
  11
  12    The V4 engine allows the user to completly control all aspects of
  13    version selection. There are three primary means to choose a version
  14     * Selection by version match
  15     * Selection by Release file match
  16     * Selection by origin server
  17
  18    Each package may be 'pinned' with a single criteria, which will ultimately
  19    result in the selection of a single version, or no version, for each
  20    package.
  21
  22    Furthermore, the default selection can be influenced by specifying
  23    the ordering of package files. The order is derived by reading the
  24    package file preferences and assigning a priority to each package
  25    file.
  26
  27    A special flag may be set to indicate if no version should be returned
  28    if no matching versions are found, otherwise the default matching
  29    rules are used to locate a hit.
  30
  31    ##################################################################### */
  32                                                                         /*}}}*/
  33 #ifndef PKGLIB_POLICY_H
  34 #define PKGLIB_POLICY_H
  35
  36
  37 #include <apt-pkg/depcache.h>
  38 #include <apt-pkg/versionmatch.h>
  39 #include <vector>
  40
  41 using std::vector;
  42
  43 class pkgPolicy : public pkgDepCache::Policy
  44 {
  45    protected:
  46
  47    struct Pin
  48    {
  49       pkgVersionMatch::MatchType Type;
  50       string Data;
  51       signed short Priority;
  52       Pin() : Type(pkgVersionMatch::None), Priority(0) {};
  53    };
  54
  55    struct PkgPin : Pin
  56    {
  57       string Pkg;
  58    };
  59
  60    Pin *Pins;
  61    signed short *PFPriority;
  62    vector<Pin> Defaults;
  63    vector<PkgPin> Unmatched;
  64    pkgCache *Cache;
  65    bool StatusOverride;
  66
  67    public:
  68
  69    // Things for manipulating pins
  70    void CreatePin(pkgVersionMatch::MatchType Type,string Pkg,
  71                   string Data,signed short Priority);
  72    inline signed short GetPriority(pkgCache::PkgFileIterator const &File)
  73        {return PFPriority[File->ID];};
  74    signed short GetPriority(pkgCache::PkgIterator const &Pkg);
  75    pkgCache::VerIterator GetMatch(pkgCache::PkgIterator Pkg);
  76
  77    // Things for the cache interface.
  78    virtual pkgCache::VerIterator GetCandidateVer(pkgCache::PkgIterator Pkg);
  79    virtual bool IsImportantDep(pkgCache::DepIterator Dep) {return pkgDepCache::Policy::IsImportantDep(Dep);};
  80    bool InitDefaults();
  81
  82    pkgPolicy(pkgCache *Owner);
  83    virtual ~pkgPolicy() {delete [] PFPriority; delete [] Pins;};
  84 };
  85
  86 bool ReadPinFile(pkgPolicy &Plcy,string File = "");
  87 bool ReadPinDir(pkgPolicy &Plcy,string Dir = "");
  88
  89 #endif