policy.h
// -*- mode: cpp; mode: fold -*-
// Description /*{{{*/
/* ######################################################################
Package Version Policy implementation
This implements the more advanced 'Version 4' APT policy engine. The
standard 'Version 0' engine is included inside the DepCache which is
it's historical location.
The V4 engine allows the user to completely control all aspects of
version selection. There are three primary means to choose a version
* Selection by version match
* Selection by Release file match
* Selection by origin server
Each package may be 'pinned' with a single criteria, which will ultimately
result in the selection of a single version, or no version, for each
package.
Furthermore, the default selection can be influenced by specifying
the ordering of package files. The order is derived by reading the
package file preferences and assigning a priority to each package
file.
A special flag may be set to indicate if no version should be returned
if no matching versions are found, otherwise the default matching
rules are used to locate a hit.
##################################################################### */
/*}}}*/
#ifndef PKGLIB_POLICY_H
#define PKGLIB_POLICY_H
#include <apt-pkg/depcache.h>
#include <apt-pkg/pkgcache.h>
#include <apt-pkg/versionmatch.h>
#include <memory>
#include <string>
#include <vector>
class APT_PUBLIC pkgPolicy : public pkgDepCache::Policy
{
protected:
struct Pin
{
pkgVersionMatch::MatchType Type;
std::string Data;
signed short Priority;
Pin() : Type(pkgVersionMatch::None), Priority(0) {};
};
struct PkgPin : Pin
{
std::string Pkg;
explicit PkgPin(std::string const &Pkg) : Pin(), Pkg(Pkg) {};
};
std::unique_ptr<Pin[]> SrcVerPins;
std::unique_ptr<Pin[]> VerPins;
std::unique_ptr<signed short[]> PFPriority;
std::vector<Pin> Defaults;
std::vector<PkgPin> Unmatched;
pkgCache *Cache;
bool StatusOverride;
public:
// Things for manipulating pins
void CreatePin(pkgVersionMatch::MatchType Type,std::string Pkg,
std::string Data,signed short Priority);
// Things for the cache interface.
pkgCache::VerIterator GetCandidateVer(pkgCache::PkgIterator const &Pkg) override;
signed short GetPriority(pkgCache::VerIterator const &Ver, bool ConsiderFiles = true) override;
signed short GetPriority(pkgCache::PkgFileIterator const &File) override;
void SetPriority(pkgCache::VerIterator const &Ver, signed short Priority);
void SetPriority(pkgCache::PkgFileIterator const &File, signed short Priority);
bool InitDefaults();
explicit pkgPolicy(pkgCache *Owner);
virtual ~pkgPolicy();
private:
struct Private;
std::unique_ptr<Private> const d;
};
APT_PUBLIC bool ReadPinFile(pkgPolicy &Plcy, std::string File = "");
APT_PUBLIC bool ReadPinDir(pkgPolicy &Plcy, std::string Dir = "");
#endif
pkgCache::PkgFileIterator
Definition cacheiterators.h:496
pkgCache::PkgIterator
Definition cacheiterators.h:147
pkgCache::VerIterator
Definition cacheiterators.h:218
pkgCache
Definition pkgcache.h:126
pkgDepCache::Policy
Definition depcache.h:250
pkgPolicy
Definition policy.h:45
pkgcache.h
pkgCache - Structure definitions for the cache file
pkgPolicy::Private
Definition policy.cc:47