[apt.git] / apt-pkg / policy.cc

// -*- 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 and ButAutomaticUpgrades sources
   0 -> 100    = NotAutomatic sources like experimental
   -inf -> 0   = Never selected   
   
   ##################################################################### */
									/*}}}*/
// Include Files							/*{{{*/
#include <apt-pkg/policy.h>
#include <apt-pkg/configuration.h>
#include <apt-pkg/tagfile.h>
#include <apt-pkg/strutl.h>
#include <apt-pkg/fileutl.h>
#include <apt-pkg/error.h>
#include <apt-pkg/sptr.h>

#include <apti18n.h>

#include <iostream>
#include <sstream>
									/*}}}*/

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)
{
   if (Owner == 0 || &(Owner->Head()) == 0)
      return;
   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)
   {
      bool found = false;
      // FIXME: make ExpressionMatches static to use it here easily
      pkgVersionMatch vm("", pkgVersionMatch::None);
      for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); ++F)
      {
	 if ((F->Archive != 0 && vm.ExpressionMatches(DefRel, F.Archive()) == true) ||
	     (F->Codename != 0 && vm.ExpressionMatches(DefRel, F.Codename()) == true) ||
	     (F->Version != 0 && vm.ExpressionMatches(DefRel, F.Version()) == true))
	    found = true;
      }
      if (found == false)
	 _error->Error(_("The value '%s' is invalid for APT::Default-Release as such a release is not available in the sources"), DefRel.c_str());
      else
	 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::ButAutomaticUpgrades) == pkgCache::Flag::ButAutomaticUpgrades)
	 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)
	 std::clog << "Prio of " << F.FileName() << ' ' << PFPriority[F->ID] << std::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 const &Pkg)
{
   // Look for a package pin and evaluate it.
   signed Max = GetPriority(Pkg);
   pkgCache::VerIterator Pref = GetMatch(Pkg);

   // Alternatives in case we can not find our package pin (Bug#512318).
   signed MaxAlt = 0;
   pkgCache::VerIterator PrefAlt;

   // no package = no candidate version
   if (Pkg.end() == true)
      return Pref;

   // packages with a pin lower than 0 have no newer candidate than the current version
   if (Max < 0)
      return Pkg.CurrentVer();

   /* 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)
   {
      /* Lets see if this version is the installed version */
      bool instVer = (Pkg.CurrentVer() == 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 &&
	     instVer == false)
	    continue;

	 signed Prio = PFPriority[VF.File()->ID];
	 if (Prio > Max)
	 {
	    Pref = Ver;
	    Max = Prio;
	 }
	 if (Prio > MaxAlt)
	 {
	    PrefAlt = Ver;
	    MaxAlt = Prio;
	 }	 
      }      
      
      if (instVer == true && 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;
      }            
   }
   // If we do not find our candidate, use the one with the highest pin.
   // This means that if there is a version available with pin > 0; there
   // will always be a candidate (Closes: #512318)
   if (!Pref.IsGood() && MaxAlt > 0)
       Pref = PrefAlt;

   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)
{
   if (Name.empty() == true)
   {
      Pin *P = &*Defaults.insert(Defaults.end(),Pin());
      P->Type = Type;
      P->Priority = Priority;
      P->Data = Data;
      return;
   }

   size_t found = Name.rfind(':');
   string Arch;
   if (found != string::npos) {
      Arch = Name.substr(found+1);
      Name.erase(found);
   }

   // Allow pinning by wildcards
   // TODO: Maybe we should always prefer specific pins over non-
   // specific ones.
   if (Name[0] == '/' || Name.find_first_of("*[?") != string::npos)
   {
      pkgVersionMatch match(Data, Type);
      for (pkgCache::GrpIterator G = Cache->GrpBegin(); G.end() != true; ++G)
	 if (match.ExpressionMatches(Name, G.Name()))
	 {
	    if (Arch.empty() == false)
	       CreatePin(Type, string(G.Name()).append(":").append(Arch), Data, Priority);
	    else
	       CreatePin(Type, G.Name(), Data, Priority);
	 }
      return;
   }

   // find the package (group) this pin applies to
   pkgCache::GrpIterator Grp;
   pkgCache::PkgIterator Pkg;
   if (Arch.empty() == false)
      Pkg = Cache->FindPkg(Name, Arch);
   else {
      Grp = Cache->FindGrp(Name);
      if (Grp.end() == false)
	 Pkg = Grp.PackageList();
   }

   if (Pkg.end() == true)
   {
      PkgPin *P = &*Unmatched.insert(Unmatched.end(),PkgPin(Name));
      if (Arch.empty() == false)
	 P->Pkg.append(":").append(Arch);
      P->Type = Type;
      P->Priority = Priority;
      P->Data = Data;
      return;
   }

   for (; Pkg.end() != true; Pkg = Grp.NextPkg(Pkg))
   {
      Pin *P = Pins + Pkg->ID;
      // the first specific stanza for a package is the ruler,
      // all others need to be ignored
      if (P->Type != pkgVersionMatch::None)
	 P = &*Unmatched.insert(Unmatched.end(),PkgPin(Pkg.FullName()));
      P->Type = Type;
      P->Priority = Priority;
      P->Data = Data;
      if (Grp.end() == true)
	 break;
   }
}
									/*}}}*/
// Policy::GetMatch - Get the matching version for a package pin	/*{{{*/
// ---------------------------------------------------------------------
/* */
pkgCache::VerIterator pkgPolicy::GetMatch(pkgCache::PkgIterator const &Pkg)
{
   const Pin &PPkg = Pins[Pkg->ID];
   if (PPkg.Type == pkgVersionMatch::None)
      return pkgCache::VerIterator(*Pkg.Cache());

   pkgVersionMatch Match(PPkg.Data,PPkg.Type);
   return Match.Find(Pkg);
}
									/*}}}*/
// 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;
}
									/*}}}*/
// PreferenceSection class - Overriding the default TrimRecord method	/*{{{*/
// ---------------------------------------------------------------------
/* The preference file is a user generated file so the parser should
   therefore be a bit more friendly by allowing comments and new lines
   all over the place rather than forcing a special format */
class PreferenceSection : public pkgTagSection
{
   void TrimRecord(bool BeforeRecord, const char* &End)
   {
      for (; Stop < End && (Stop[0] == '\n' || Stop[0] == '\r' || Stop[0] == '#'); Stop++)
	 if (Stop[0] == '#')
	    Stop = (const char*) memchr(Stop,'\n',End-Stop);
   }
};
									/*}}}*/
// ReadPinDir - Load the pin files from this dir into a Policy		/*{{{*/
// ---------------------------------------------------------------------
/* This will load each pin file in the given dir into a Policy. If the
   given dir is empty the dir set in Dir::Etc::PreferencesParts is used.
   Note also that this method will issue a warning if the dir does not
   exists but it will return true in this case! */
bool ReadPinDir(pkgPolicy &Plcy,string Dir)
{
   if (Dir.empty() == true)
      Dir = _config->FindDir("Dir::Etc::PreferencesParts");

   if (DirectoryExists(Dir) == false)
   {
      _error->WarningE("DirectoryExists",_("Unable to read %s"),Dir.c_str());
      return true;
   }

   vector<string> const List = GetListOfFilesInDir(Dir, "pref", true, true);

   // Read the files
   for (vector<string>::const_iterator I = List.begin(); I != List.end(); ++I)
      if (ReadPinFile(Plcy, *I) == false)
	 return false;
   return true;
}
									/*}}}*/
// 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 (RealFileExists(File) == false)
      return true;
   
   FileFd Fd(File,FileFd::ReadOnly);
   pkgTagFile TF(&Fd);
   if (_error->PendingError() == true)
      return false;
   
   PreferenceSection Tags;
   while (TF.Step(Tags) == true)
   {
      string Name = Tags.FindS("Package");
      if (Name.empty() == true)
	 return _error->Error(_("Invalid record in the preferences file %s, no Package header"), File.c_str());
      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;
      }

      istringstream s(Name);
      string pkg;
      while(!s.eof())
      {
	 s >> pkg;
         Plcy.CreatePin(Type, pkg, string(Word,End),priority);
      };
   }

   Plcy.InitDefaults();
   return true;
}
									/*}}}*/
Commit	Line	Data
b2e465d6 AL	1	// -- mode: cpp; mode: fold --
b2e465d6 AL	2	// Description /{{{/
56298634	3	// $Id: policy.cc,v 1.10 2003/08/12 00:17:37 mdz Exp $
b2e465d6 AL	4	/* ######################################################################
	5
	6	Package Version Policy implementation
	7
	8	This is just a really simple wrapper around pkgVersionMatch with
	9	some added goodies to manage the list of things..
	10
	11	Priority Table:
	12
	13	1000 -> inf = Downgradeable priorities
	14	1000 = The 'no downgrade' pseduo-status file
	15	100 -> 1000 = Standard priorities
	16	990 = Config file override package files
	17	989 = Start for preference auto-priorities
	18	500 = Default package files
5ed56f93	19	100 = The status file and ButAutomaticUpgrades sources
b2e465d6 AL	20	0 -> 100 = NotAutomatic sources like experimental
	21	-inf -> 0 = Never selected
	22
	23	##################################################################### */
	24	/}}}/
	25	// Include Files /{{{/
b2e465d6 AL	26	#include <apt-pkg/policy.h>
	27	#include <apt-pkg/configuration.h>
	28	#include <apt-pkg/tagfile.h>
	29	#include <apt-pkg/strutl.h>
46e39c8e	30	#include <apt-pkg/fileutl.h>
b2e465d6 AL	31	#include <apt-pkg/error.h>
b2e465d6 AL	32	#include <apt-pkg/sptr.h>
46e39c8e	33
b2e465d6	34	#include <apti18n.h>
e7b470ee AL	35
e7b470ee AL	36	#include <iostream>
1c62ab24	37	#include <sstream>
b2e465d6 AL	38	/}}}/
b2e465d6 AL	39
e7b470ee AL	40	using namespace std;
e7b470ee AL	41
b2e465d6 AL	42	// Policy::Init - Startup and bind to a cache /{{{/
	43	// ---------------------------------------------------------------------
	44	/* Set the defaults for operation. The default mode with no loaded policy
	45	file matches the V0 policy engine. */
	46	pkgPolicy::pkgPolicy(pkgCache *Owner) : Pins(0), PFPriority(0), Cache(Owner)
	47	{
c55b8a54 DK	48	if (Owner == 0 \|\| &(Owner->Head()) == 0)
c55b8a54 DK	49	return;
b2e465d6 AL	50	PFPriority = new signed short[Owner->Head().PackageFileCount];
	51	Pins = new Pin[Owner->Head().PackageCount];
	52
	53	for (unsigned long I = 0; I != Owner->Head().PackageCount; I++)
	54	Pins[I].Type = pkgVersionMatch::None;
	55
	56	// The config file has a master override.
	57	string DefRel = _config->Find("APT::Default-Release");
	58	if (DefRel.empty() == false)
a3bbbab7 DK	59	{
	60	bool found = false;
	61	// FIXME: make ExpressionMatches static to use it here easily
	62	pkgVersionMatch vm("", pkgVersionMatch::None);
	63	for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); ++F)
	64	{
	65	if ((F->Archive != 0 && vm.ExpressionMatches(DefRel, F.Archive()) == true) \|\|
	66	(F->Codename != 0 && vm.ExpressionMatches(DefRel, F.Codename()) == true) \|\|
	67	(F->Version != 0 && vm.ExpressionMatches(DefRel, F.Version()) == true))
	68	found = true;
	69	}
	70	if (found == false)
	71	_error->Error(_("The value '%s' is invalid for APT::Default-Release as such a release is not available in the sources"), DefRel.c_str());
	72	else
	73	CreatePin(pkgVersionMatch::Release,"",DefRel,990);
	74	}
b2e465d6 AL	75	InitDefaults();
	76	}
	77	/}}}/
	78	// Policy::InitDefaults - Compute the default selections /{{{/
	79	// ---------------------------------------------------------------------
	80	/* */
	81	bool pkgPolicy::InitDefaults()
	82	{
	83	// Initialize the priorities based on the status of the package file
f7f0d6c7	84	for (pkgCache::PkgFileIterator I = Cache->FileBegin(); I != Cache->FileEnd(); ++I)
b2e465d6 AL	85	{
	86	PFPriority[I->ID] = 500;
	87	if ((I->Flags & pkgCache::Flag::NotSource) == pkgCache::Flag::NotSource)
	88	PFPriority[I->ID] = 100;
5ed56f93 DK	89	else if ((I->Flags & pkgCache::Flag::ButAutomaticUpgrades) == pkgCache::Flag::ButAutomaticUpgrades)
	90	PFPriority[I->ID] = 100;
	91	else if ((I->Flags & pkgCache::Flag::NotAutomatic) == pkgCache::Flag::NotAutomatic)
	92	PFPriority[I->ID] = 1;
b2e465d6 AL	93	}
	94
	95	// Apply the defaults..
20ebd488	96	SPtrArray<bool> Fixed = new bool[Cache->HeaderP->PackageFileCount];
b2e465d6 AL	97	memset(Fixed,0,sizeof(Fixed)Cache->HeaderP->PackageFileCount);
	98	signed Cur = 989;
	99	StatusOverride = false;
	100	for (vector<Pin>::const_iterator I = Defaults.begin(); I != Defaults.end();
f7f0d6c7	101	++I, --Cur)
b2e465d6 AL	102	{
b2e465d6 AL	103	pkgVersionMatch Match(I->Data,I->Type);
f7f0d6c7	104	for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); ++F)
b2e465d6	105	{
b2e465d6 AL	106	if (Match.FileMatch(F) == true && Fixed[F->ID] == false)
	107	{
	108	if (I->Priority != 0 && I->Priority > 0)
	109	Cur = I->Priority;
	110
	111	if (I->Priority < 0)
	112	PFPriority[F->ID] = I->Priority;
	113	else
	114	PFPriority[F->ID] = Cur;
	115
	116	if (PFPriority[F->ID] > 1000)
	117	StatusOverride = true;
	118
	119	Fixed[F->ID] = true;
	120	}
	121	}
	122	}
	123
	124	if (_config->FindB("Debug::pkgPolicy",false) == true)
f7f0d6c7	125	for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); ++F)
4dec007b	126	std::clog << "Prio of " << F.FileName() << ' ' << PFPriority[F->ID] << std::endl;
b2e465d6 AL	127
	128	return true;
	129	}
	130	/}}}/
	131	// Policy::GetCandidateVer - Get the candidate install version /{{{/
	132	// ---------------------------------------------------------------------
	133	/* Evaluate the package pins and the default list to deteremine what the
	134	best package is. */
9ee8287e	135	pkgCache::VerIterator pkgPolicy::GetCandidateVer(pkgCache::PkgIterator const &Pkg)
b2e465d6	136	{
b2e465d6	137	// Look for a package pin and evaluate it.
af87ab54 AL	138	signed Max = GetPriority(Pkg);
af87ab54 AL	139	pkgCache::VerIterator Pref = GetMatch(Pkg);
e7b470ee	140
8f5525e9 JAK	141	// Alternatives in case we can not find our package pin (Bug#512318).
	142	signed MaxAlt = 0;
	143	pkgCache::VerIterator PrefAlt;
	144
9f5bf66a DK	145	// no package = no candidate version
	146	if (Pkg.end() == true)
	147	return Pref;
	148
	149	// packages with a pin lower than 0 have no newer candidate than the current version
	150	if (Max < 0)
	151	return Pkg.CurrentVer();
	152
b2e465d6 AL	153	/* Falling through to the default version.. Setting Max to zero
	154	effectively excludes everything <= 0 which are the non-automatic
	155	priorities.. The status file is given a prio of 100 which will exclude
	156	not-automatic sources, except in a single shot not-installed mode.
	157	The second pseduo-status file is at prio 1000, above which will permit
	158	the user to force-downgrade things.
	159
	160	The user pin is subject to the same priority rules as default
	161	selections. Thus there are two ways to create a pin - a pin that
	162	tracks the default when the default is taken away, and a permanent
	163	pin that stays at that setting.
	164	*/
f7f0d6c7	165	for (pkgCache::VerIterator Ver = Pkg.VersionList(); Ver.end() == false; ++Ver)
10639577	166	{
9ee8287e DK	167	/* Lets see if this version is the installed version */
9ee8287e DK	168	bool instVer = (Pkg.CurrentVer() == Ver);
9ee8287e	169
f7f0d6c7	170	for (pkgCache::VerFileIterator VF = Ver.FileList(); VF.end() == false; ++VF)
b2e465d6	171	{
6aeda9fa AL	172	/* If this is the status file, and the current version is not the
	173	version in the status file (ie it is not installed, or somesuch)
	174	then it is not a candidate for installation, ever. This weeds
	175	out bogus entries that may be due to config-file states, or
	176	other. */
	177	if ((VF.File()->Flags & pkgCache::Flag::NotSource) == pkgCache::Flag::NotSource &&
9ee8287e	178	instVer == false)
6aeda9fa	179	continue;
9ee8287e	180
b2e465d6 AL	181	signed Prio = PFPriority[VF.File()->ID];
	182	if (Prio > Max)
	183	{
	184	Pref = Ver;
	185	Max = Prio;
8f5525e9 JAK	186	}
	187	if (Prio > MaxAlt)
	188	{
	189	PrefAlt = Ver;
	190	MaxAlt = Prio;
b2e465d6 AL	191	}
	192	}
	193
9ee8287e	194	if (instVer == true && Max < 1000)
b2e465d6 AL	195	{
	196	/* Elevate our current selection (or the status file itself)
	197	to the Pseudo-status priority. */
	198	if (Pref.end() == true)
	199	Pref = Ver;
	200	Max = 1000;
	201
	202	// Fast path optimize.
	203	if (StatusOverride == false)
	204	break;
	205	}
	206	}
8f5525e9 JAK	207	// If we do not find our candidate, use the one with the highest pin.
	208	// This means that if there is a version available with pin > 0; there
	209	// will always be a candidate (Closes: #512318)
	210	if (!Pref.IsGood() && MaxAlt > 0)
	211	Pref = PrefAlt;
9ee8287e	212
b2e465d6 AL	213	return Pref;
	214	}
	215	/}}}/
	216	// Policy::CreatePin - Create an entry in the pin table.. /{{{/
	217	// ---------------------------------------------------------------------
	218	/* For performance we have 3 tables, the default table, the main cache
	219	table (hashed to the cache). A blank package name indicates the pin
	220	belongs to the default table. Order of insertion matters here, the
	221	earlier defaults override later ones. */
	222	void pkgPolicy::CreatePin(pkgVersionMatch::MatchType Type,string Name,
	223	string Data,signed short Priority)
	224	{
b2e465d6	225	if (Name.empty() == true)
b2e465d6	226	{
00c6e1a3	227	Pin P = &Defaults.insert(Defaults.end(),Pin());
4a6d2163 DK	228	P->Type = Type;
	229	P->Priority = Priority;
	230	P->Data = Data;
	231	return;
	232	}
00c6e1a3 MV	233
	234	size_t found = Name.rfind(':');
	235	string Arch;
	236	if (found != string::npos) {
	237	Arch = Name.substr(found+1);
	238	Name.erase(found);
	239	}
	240
1a4c9766 JAK	241	// Allow pinning by wildcards
	242	// TODO: Maybe we should always prefer specific pins over non-
	243	// specific ones.
a8d7c101 DK	244	if (Name[0] == '/' \|\| Name.find_first_of("*[?") != string::npos)
	245	{
	246	pkgVersionMatch match(Data, Type);
	247	for (pkgCache::GrpIterator G = Cache->GrpBegin(); G.end() != true; ++G)
	248	if (match.ExpressionMatches(Name, G.Name()))
00c6e1a3 MV	249	{
	250	if (Arch.empty() == false)
	251	CreatePin(Type, string(G.Name()).append(":").append(Arch), Data, Priority);
	252	else
	253	CreatePin(Type, G.Name(), Data, Priority);
	254	}
1a4c9766 JAK	255	return;
1a4c9766 JAK	256	}
4a6d2163	257
00c6e1a3 MV	258	// find the package (group) this pin applies to
	259	pkgCache::GrpIterator Grp;
	260	pkgCache::PkgIterator Pkg;
	261	if (Arch.empty() == false)
	262	Pkg = Cache->FindPkg(Name, Arch);
	263	else {
	264	Grp = Cache->FindGrp(Name);
	265	if (Grp.end() == false)
	266	Pkg = Grp.PackageList();
	267	}
	268
	269	if (Pkg.end() == true)
4a6d2163	270	{
00c6e1a3 MV	271	PkgPin P = &Unmatched.insert(Unmatched.end(),PkgPin(Name));
	272	if (Arch.empty() == false)
	273	P->Pkg.append(":").append(Arch);
	274	P->Type = Type;
	275	P->Priority = Priority;
	276	P->Data = Data;
	277	return;
	278	}
4a6d2163	279
00c6e1a3 MV	280	for (; Pkg.end() != true; Pkg = Grp.NextPkg(Pkg))
	281	{
	282	Pin *P = Pins + Pkg->ID;
	283	// the first specific stanza for a package is the ruler,
	284	// all others need to be ignored
	285	if (P->Type != pkgVersionMatch::None)
	286	P = &*Unmatched.insert(Unmatched.end(),PkgPin(Pkg.FullName()));
4a6d2163 DK	287	P->Type = Type;
	288	P->Priority = Priority;
	289	P->Data = Data;
00c6e1a3 MV	290	if (Grp.end() == true)
00c6e1a3 MV	291	break;
b2e465d6	292	}
b2e465d6 AL	293	}
b2e465d6 AL	294	/}}}/
af87ab54 AL	295	// Policy::GetMatch - Get the matching version for a package pin /{{{/
	296	// ---------------------------------------------------------------------
	297	/* */
9ee8287e	298	pkgCache::VerIterator pkgPolicy::GetMatch(pkgCache::PkgIterator const &Pkg)
af87ab54 AL	299	{
af87ab54 AL	300	const Pin &PPkg = Pins[Pkg->ID];
9ee8287e DK	301	if (PPkg.Type == pkgVersionMatch::None)
	302	return pkgCache::VerIterator(*Pkg.Cache());
	303
	304	pkgVersionMatch Match(PPkg.Data,PPkg.Type);
	305	return Match.Find(Pkg);
af87ab54 AL	306	}
	307	/}}}/
	308	// Policy::GetPriority - Get the priority of the package pin /{{{/
	309	// ---------------------------------------------------------------------
	310	/* */
	311	signed short pkgPolicy::GetPriority(pkgCache::PkgIterator const &Pkg)
	312	{
	313	if (Pins[Pkg->ID].Type != pkgVersionMatch::None)
	314	{
	315	// In this case 0 means default priority
	316	if (Pins[Pkg->ID].Priority == 0)
	317	return 989;
	318	return Pins[Pkg->ID].Priority;
	319	}
	320
	321	return 0;
	322	}
	323	/}}}/
81e9789b MV	324	// PreferenceSection class - Overriding the default TrimRecord method /{{{/
	325	// ---------------------------------------------------------------------
	326	/* The preference file is a user generated file so the parser should
	327	therefore be a bit more friendly by allowing comments and new lines
	328	all over the place rather than forcing a special format */
	329	class PreferenceSection : public pkgTagSection
	330	{
	331	void TrimRecord(bool BeforeRecord, const char* &End)
	332	{
	333	for (; Stop < End && (Stop[0] == '\n' \|\| Stop[0] == '\r' \|\| Stop[0] == '#'); Stop++)
	334	if (Stop[0] == '#')
	335	Stop = (const char*) memchr(Stop,'\n',End-Stop);
	336	}
	337	};
	338	/}}}/
ef1dff93 DK	339	// ReadPinDir - Load the pin files from this dir into a Policy /{{{/
ef1dff93 DK	340	// ---------------------------------------------------------------------
6009e60d DK	341	/* This will load each pin file in the given dir into a Policy. If the
	342	given dir is empty the dir set in Dir::Etc::PreferencesParts is used.
	343	Note also that this method will issue a warning if the dir does not
	344	exists but it will return true in this case! */
e68ca100 JAK	345	bool ReadPinDir(pkgPolicy &Plcy,string Dir)
	346	{
	347	if (Dir.empty() == true)
	348	Dir = _config->FindDir("Dir::Etc::PreferencesParts");
	349
448eaf8b	350	if (DirectoryExists(Dir) == false)
6009e60d	351	{
448eaf8b	352	_error->WarningE("DirectoryExists",_("Unable to read %s"),Dir.c_str());
6009e60d DK	353	return true;
	354	}
	355
b39c1859	356	vector<string> const List = GetListOfFilesInDir(Dir, "pref", true, true);
e68ca100 JAK	357
e68ca100 JAK	358	// Read the files
f7f0d6c7	359	for (vector<string>::const_iterator I = List.begin(); I != List.end(); ++I)
e68ca100 JAK	360	if (ReadPinFile(Plcy, *I) == false)
	361	return false;
	362	return true;
	363	}
81e9789b	364	/}}}/
b2e465d6 AL	365	// ReadPinFile - Load the pin file into a Policy /{{{/
	366	// ---------------------------------------------------------------------
	367	/* I'd like to see the preferences file store more than just pin information
	368	but right now that is the only stuff I have to store. Later there will
	369	have to be some kind of combined super parser to get the data into all
	370	the right classes.. */
	371	bool ReadPinFile(pkgPolicy &Plcy,string File)
	372	{
	373	if (File.empty() == true)
	374	File = _config->FindFile("Dir::Etc::Preferences");
	375
36f1098a	376	if (RealFileExists(File) == false)
b2e465d6 AL	377	return true;
	378
	379	FileFd Fd(File,FileFd::ReadOnly);
	380	pkgTagFile TF(&Fd);
	381	if (_error->PendingError() == true)
	382	return false;
	383
81e9789b	384	PreferenceSection Tags;
b2e465d6 AL	385	while (TF.Step(Tags) == true)
	386	{
	387	string Name = Tags.FindS("Package");
	388	if (Name.empty() == true)
e68ca100	389	return _error->Error(_("Invalid record in the preferences file %s, no Package header"), File.c_str());
b2e465d6 AL	390	if (Name == "*")
	391	Name = string();
	392
	393	const char *Start;
	394	const char *End;
	395	if (Tags.Find("Pin",Start,End) == false)
	396	continue;
	397
	398	const char *Word = Start;
	399	for (; Word != End && isspace(*Word) == 0; Word++);
	400
	401	// Parse the type..
	402	pkgVersionMatch::MatchType Type;
	403	if (stringcasecmp(Start,Word,"version") == 0 && Name.empty() == false)
	404	Type = pkgVersionMatch::Version;
	405	else if (stringcasecmp(Start,Word,"release") == 0)
	406	Type = pkgVersionMatch::Release;
	407	else if (stringcasecmp(Start,Word,"origin") == 0)
	408	Type = pkgVersionMatch::Origin;
	409	else
	410	{
	411	_error->Warning(_("Did not understand pin type %s"),string(Start,Word).c_str());
	412	continue;
	413	}
	414	for (; Word != End && isspace(*Word) != 0; Word++);
	415
56298634 AL	416	short int priority = Tags.FindI("Pin-Priority", 0);
	417	if (priority == 0)
	418	{
	419	_error->Warning(_("No priority (or zero) specified for pin"));
	420	continue;
	421	}
	422
1c62ab24 MV	423	istringstream s(Name);
	424	string pkg;
	425	while(!s.eof())
	426	{
	427	s >> pkg;
	428	Plcy.CreatePin(Type, pkg, string(Word,End),priority);
	429	};
b2e465d6 AL	430	}
	431
	432	Plcy.InitDefaults();
	433	return true;
	434	}
	435	/}}}/