Show policy.cc syntax highlighted
// -*- mode: cpp; mode: fold -*-
// Description /*{{{*/
// $Id: policy.cc,v 1.10 2003/08/12 00:17:37 mdz Exp $
/* ######################################################################
Package Version Policy implementation
This is just a really simple wrapper around pkgVersionMatch with
some added goodies to manage the list of things..
Priority Table:
1000 -> inf = Downgradeable priorities
1000 = The 'no downgrade' pseduo-status file
100 -> 1000 = Standard priorities
990 = Config file override package files
989 = Start for preference auto-priorities
500 = Default package files
100 = The status file
0 -> 100 = NotAutomatic sources like experimental
-inf -> 0 = Never selected
##################################################################### */
/*}}}*/
// Include Files /*{{{*/
#ifdef __GNUG__
#pragma implementation "apt-pkg/policy.h"
#endif
#include <apt-pkg/policy.h>
#include <apt-pkg/configuration.h>
#include <apt-pkg/tagfile.h>
#include <apt-pkg/strutl.h>
#include <apt-pkg/error.h>
#include <apt-pkg/sptr.h>
#include <apti18n.h>
#include <iostream>
/*}}}*/
using namespace std;
// Policy::Init - Startup and bind to a cache /*{{{*/
// ---------------------------------------------------------------------
/* Set the defaults for operation. The default mode with no loaded policy
file matches the V0 policy engine. */
pkgPolicy::pkgPolicy(pkgCache *Owner) : Pins(0), PFPriority(0), Cache(Owner)
{
PFPriority = new signed short[Owner->Head().PackageFileCount];
Pins = new Pin[Owner->Head().PackageCount];
for (unsigned long I = 0; I != Owner->Head().PackageCount; I++)
Pins[I].Type = pkgVersionMatch::None;
// The config file has a master override.
string DefRel = _config->Find("APT::Default-Release");
if (DefRel.empty() == false)
CreatePin(pkgVersionMatch::Release,"",DefRel,990);
InitDefaults();
}
/*}}}*/
// Policy::InitDefaults - Compute the default selections /*{{{*/
// ---------------------------------------------------------------------
/* */
bool pkgPolicy::InitDefaults()
{
// Initialize the priorities based on the status of the package file
for (pkgCache::PkgFileIterator I = Cache->FileBegin(); I != Cache->FileEnd(); I++)
{
PFPriority[I->ID] = 500;
if ((I->Flags & pkgCache::Flag::NotSource) == pkgCache::Flag::NotSource)
PFPriority[I->ID] = 100;
else
if ((I->Flags & pkgCache::Flag::NotAutomatic) == pkgCache::Flag::NotAutomatic)
PFPriority[I->ID] = 1;
}
// Apply the defaults..
SPtrArray<bool> Fixed = new bool[Cache->HeaderP->PackageFileCount];
memset(Fixed,0,sizeof(*Fixed)*Cache->HeaderP->PackageFileCount);
signed Cur = 989;
StatusOverride = false;
for (vector<Pin>::const_iterator I = Defaults.begin(); I != Defaults.end();
I++, Cur--)
{
pkgVersionMatch Match(I->Data,I->Type);
for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); F++)
{
if (Match.FileMatch(F) == true && Fixed[F->ID] == false)
{
if (I->Priority != 0 && I->Priority > 0)
Cur = I->Priority;
if (I->Priority < 0)
PFPriority[F->ID] = I->Priority;
else
PFPriority[F->ID] = Cur;
if (PFPriority[F->ID] > 1000)
StatusOverride = true;
Fixed[F->ID] = true;
}
}
}
if (_config->FindB("Debug::pkgPolicy",false) == true)
for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); F++)
cout << "Prio of " << F.FileName() << ' ' << PFPriority[F->ID] << endl;
return true;
}
/*}}}*/
// Policy::GetCandidateVer - Get the candidate install version /*{{{*/
// ---------------------------------------------------------------------
/* Evaluate the package pins and the default list to deteremine what the
best package is. */
pkgCache::VerIterator pkgPolicy::GetCandidateVer(pkgCache::PkgIterator Pkg)
{
// Look for a package pin and evaluate it.
signed Max = GetPriority(Pkg);
pkgCache::VerIterator Pref = GetMatch(Pkg);
/* Falling through to the default version.. Setting Max to zero
effectively excludes everything <= 0 which are the non-automatic
priorities.. The status file is given a prio of 100 which will exclude
not-automatic sources, except in a single shot not-installed mode.
The second pseduo-status file is at prio 1000, above which will permit
the user to force-downgrade things.
The user pin is subject to the same priority rules as default
selections. Thus there are two ways to create a pin - a pin that
tracks the default when the default is taken away, and a permanent
pin that stays at that setting.
*/
for (pkgCache::VerIterator Ver = Pkg.VersionList(); Ver.end() == false; Ver++)
{
for (pkgCache::VerFileIterator VF = Ver.FileList(); VF.end() == false; VF++)
{
/* If this is the status file, and the current version is not the
version in the status file (ie it is not installed, or somesuch)
then it is not a candidate for installation, ever. This weeds
out bogus entries that may be due to config-file states, or
other. */
if ((VF.File()->Flags & pkgCache::Flag::NotSource) == pkgCache::Flag::NotSource &&
Pkg.CurrentVer() != Ver)
continue;
signed Prio = PFPriority[VF.File()->ID];
if (Prio > Max)
{
Pref = Ver;
Max = Prio;
}
}
if (Pkg.CurrentVer() == Ver && Max < 1000)
{
/* Elevate our current selection (or the status file itself)
to the Pseudo-status priority. */
if (Pref.end() == true)
Pref = Ver;
Max = 1000;
// Fast path optimize.
if (StatusOverride == false)
break;
}
}
return Pref;
}
/*}}}*/
// Policy::CreatePin - Create an entry in the pin table.. /*{{{*/
// ---------------------------------------------------------------------
/* For performance we have 3 tables, the default table, the main cache
table (hashed to the cache). A blank package name indicates the pin
belongs to the default table. Order of insertion matters here, the
earlier defaults override later ones. */
void pkgPolicy::CreatePin(pkgVersionMatch::MatchType Type,string Name,
string Data,signed short Priority)
{
Pin *P = 0;
if (Name.empty() == true)
P = &*Defaults.insert(Defaults.end(),PkgPin());
else
{
// Get a spot to put the pin
pkgCache::PkgIterator Pkg = Cache->FindPkg(Name);
if (Pkg.end() == true)
{
// Check the unmatched table
for (vector<PkgPin>::iterator I = Unmatched.begin();
I != Unmatched.end() && P == 0; I++)
if (I->Pkg == Name)
P = &*I;
if (P == 0)
P = &*Unmatched.insert(Unmatched.end(),PkgPin());
}
else
{
P = Pins + Pkg->ID;
}
}
// Set..
P->Type = Type;
P->Priority = Priority;
P->Data = Data;
}
/*}}}*/
// Policy::GetMatch - Get the matching version for a package pin /*{{{*/
// ---------------------------------------------------------------------
/* */
pkgCache::VerIterator pkgPolicy::GetMatch(pkgCache::PkgIterator Pkg)
{
const Pin &PPkg = Pins[Pkg->ID];
if (PPkg.Type != pkgVersionMatch::None)
{
pkgVersionMatch Match(PPkg.Data,PPkg.Type);
return Match.Find(Pkg);
}
return pkgCache::VerIterator(*Pkg.Cache());
}
/*}}}*/
// Policy::GetPriority - Get the priority of the package pin /*{{{*/
// ---------------------------------------------------------------------
/* */
signed short pkgPolicy::GetPriority(pkgCache::PkgIterator const &Pkg)
{
if (Pins[Pkg->ID].Type != pkgVersionMatch::None)
{
// In this case 0 means default priority
if (Pins[Pkg->ID].Priority == 0)
return 989;
return Pins[Pkg->ID].Priority;
}
return 0;
}
/*}}}*/
// ReadPinFile - Load the pin file into a Policy /*{{{*/
// ---------------------------------------------------------------------
/* I'd like to see the preferences file store more than just pin information
but right now that is the only stuff I have to store. Later there will
have to be some kind of combined super parser to get the data into all
the right classes.. */
bool ReadPinFile(pkgPolicy &Plcy,string File)
{
if (File.empty() == true)
File = _config->FindFile("Dir::Etc::Preferences");
if (FileExists(File) == false)
return true;
FileFd Fd(File,FileFd::ReadOnly);
pkgTagFile TF(&Fd);
if (_error->PendingError() == true)
return false;
pkgTagSection Tags;
while (TF.Step(Tags) == true)
{
string Name = Tags.FindS("Package");
if (Name.empty() == true)
return _error->Error(_("Invalid record in the preferences file, no Package header"));
if (Name == "*")
Name = string();
const char *Start;
const char *End;
if (Tags.Find("Pin",Start,End) == false)
continue;
const char *Word = Start;
for (; Word != End && isspace(*Word) == 0; Word++);
// Parse the type..
pkgVersionMatch::MatchType Type;
if (stringcasecmp(Start,Word,"version") == 0 && Name.empty() == false)
Type = pkgVersionMatch::Version;
else if (stringcasecmp(Start,Word,"release") == 0)
Type = pkgVersionMatch::Release;
else if (stringcasecmp(Start,Word,"origin") == 0)
Type = pkgVersionMatch::Origin;
else
{
_error->Warning(_("Did not understand pin type %s"),string(Start,Word).c_str());
continue;
}
for (; Word != End && isspace(*Word) != 0; Word++);
short int priority = Tags.FindI("Pin-Priority", 0);
if (priority == 0)
{
_error->Warning(_("No priority (or zero) specified for pin"));
continue;
}
Plcy.CreatePin(Type,Name,string(Word,End),priority);
}
Plcy.InitDefaults();
return true;
}
/*}}}*/
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