* apt-pkg/cacheset.cc:

  - move them back to the library as they look stable now

3 files changed, 883 insertions, 2 deletions

diff --git a/apt-pkg/cacheset.cc b/apt-pkg/cacheset.cc
new file mode 100644
index 000000000..df7e99fd0
--- /dev/null
+++ b/apt-pkg/cacheset.cc
@@ -0,0 +1,506 @@
+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+/* ######################################################################
+
+   Simple wrapper around a std::set to provide a similar interface to
+   a set of cache structures as to the complete set of all structures
+   in the pkgCache. Currently only Package is supported.
+
+   ##################################################################### */
+									/*}}}*/
+// Include Files							/*{{{*/
+#include <apt-pkg/aptconfiguration.h>
+#include <apt-pkg/cachefilter.h>
+#include <apt-pkg/cacheset.h>
+#include <apt-pkg/error.h>
+#include <apt-pkg/strutl.h>
+#include <apt-pkg/versionmatch.h>
+
+#include <apti18n.h>
+
+#include <vector>
+
+#include <regex.h>
+									/*}}}*/
+namespace APT {
+// FromTask - Return all packages in the cache from a specific task	/*{{{*/
+PackageSet PackageSet::FromTask(pkgCacheFile &Cache, std::string pattern, CacheSetHelper &helper) {
+	size_t const archfound = pattern.find_last_of(':');
+	std::string arch = "native";
+	if (archfound != std::string::npos) {
+		arch = pattern.substr(archfound+1);
+		pattern.erase(archfound);
+	}
+
+	if (pattern[pattern.length() -1] != '^')
+		return APT::PackageSet(TASK);
+	pattern.erase(pattern.length()-1);
+
+	if (unlikely(Cache.GetPkgCache() == 0 || Cache.GetDepCache() == 0))
+		return APT::PackageSet(TASK);
+
+	PackageSet pkgset(TASK);
+	// get the records
+	pkgRecords Recs(Cache);
+
+	// build regexp for the task
+	regex_t Pattern;
+	char S[300];
+	snprintf(S, sizeof(S), "^Task:.*[, ]%s([, ]|$)", pattern.c_str());
+	if(regcomp(&Pattern,S, REG_EXTENDED | REG_NOSUB | REG_NEWLINE) != 0) {
+		_error->Error("Failed to compile task regexp");
+		return pkgset;
+	}
+
+	for (pkgCache::GrpIterator Grp = Cache->GrpBegin(); Grp.end() == false; ++Grp) {
+		pkgCache::PkgIterator Pkg = Grp.FindPkg(arch);
+		if (Pkg.end() == true)
+			continue;
+		pkgCache::VerIterator ver = Cache[Pkg].CandidateVerIter(Cache);
+		if(ver.end() == true)
+			continue;
+
+		pkgRecords::Parser &parser = Recs.Lookup(ver.FileList());
+		const char *start, *end;
+		parser.GetRec(start,end);
+		unsigned int const length = end - start;
+		char buf[length];
+		strncpy(buf, start, length);
+		buf[length-1] = '\0';
+		if (regexec(&Pattern, buf, 0, 0, 0) != 0)
+			continue;
+
+		pkgset.insert(Pkg);
+	}
+	regfree(&Pattern);
+
+	if (pkgset.empty() == true)
+		return helper.canNotFindTask(Cache, pattern);
+
+	helper.showTaskSelection(pkgset, pattern);
+	return pkgset;
+}
+									/*}}}*/
+// FromRegEx - Return all packages in the cache matching a pattern	/*{{{*/
+PackageSet PackageSet::FromRegEx(pkgCacheFile &Cache, std::string pattern, CacheSetHelper &helper) {
+	static const char * const isregex = ".?+*|[^$";
+	if (pattern.find_first_of(isregex) == std::string::npos)
+		return PackageSet(REGEX);
+
+	size_t archfound = pattern.find_last_of(':');
+	std::string arch = "native";
+	if (archfound != std::string::npos) {
+		arch = pattern.substr(archfound+1);
+		if (arch.find_first_of(isregex) == std::string::npos)
+			pattern.erase(archfound);
+		else
+			arch = "native";
+	}
+
+	if (unlikely(Cache.GetPkgCache() == 0))
+		return PackageSet(REGEX);
+
+	APT::CacheFilter::PackageNameMatchesRegEx regexfilter(pattern);
+
+	PackageSet pkgset(REGEX);
+	for (pkgCache::GrpIterator Grp = Cache.GetPkgCache()->GrpBegin(); Grp.end() == false; ++Grp) {
+		if (regexfilter(Grp) == false)
+			continue;
+		pkgCache::PkgIterator Pkg = Grp.FindPkg(arch);
+		if (Pkg.end() == true) {
+			if (archfound == std::string::npos) {
+				std::vector<std::string> archs = APT::Configuration::getArchitectures();
+				for (std::vector<std::string>::const_iterator a = archs.begin();
+				     a != archs.end() && Pkg.end() != true; ++a)
+					Pkg = Grp.FindPkg(*a);
+			}
+			if (Pkg.end() == true)
+				continue;
+		}
+
+		pkgset.insert(Pkg);
+	}
+
+	if (pkgset.empty() == true)
+		return helper.canNotFindRegEx(Cache, pattern);
+
+	helper.showRegExSelection(pkgset, pattern);
+	return pkgset;
+}
+									/*}}}*/
+// FromName - Returns the package defined  by this string		/*{{{*/
+pkgCache::PkgIterator PackageSet::FromName(pkgCacheFile &Cache,
+			std::string const &str, CacheSetHelper &helper) {
+	std::string pkg = str;
+	size_t archfound = pkg.find_last_of(':');
+	std::string arch;
+	if (archfound != std::string::npos) {
+		arch = pkg.substr(archfound+1);
+		pkg.erase(archfound);
+	}
+
+	if (Cache.GetPkgCache() == 0)
+		return pkgCache::PkgIterator(Cache, 0);
+
+	pkgCache::PkgIterator Pkg(Cache, 0);
+	if (arch.empty() == true) {
+		pkgCache::GrpIterator Grp = Cache.GetPkgCache()->FindGrp(pkg);
+		if (Grp.end() == false)
+			Pkg = Grp.FindPreferredPkg();
+	} else
+		Pkg = Cache.GetPkgCache()->FindPkg(pkg, arch);
+
+	if (Pkg.end() == true)
+		return helper.canNotFindPkgName(Cache, str);
+	return Pkg;
+}
+									/*}}}*/
+// GroupedFromCommandLine - Return all versions specified on commandline/*{{{*/
+std::map<unsigned short, PackageSet> PackageSet::GroupedFromCommandLine(
+		pkgCacheFile &Cache, const char **cmdline,
+		std::list<PackageSet::Modifier> const &mods,
+		unsigned short const &fallback, CacheSetHelper &helper) {
+	std::map<unsigned short, PackageSet> pkgsets;
+	for (const char **I = cmdline; *I != 0; ++I) {
+		unsigned short modID = fallback;
+		std::string str = *I;
+		bool modifierPresent = false;
+		for (std::list<PackageSet::Modifier>::const_iterator mod = mods.begin();
+		     mod != mods.end(); ++mod) {
+			size_t const alength = strlen(mod->Alias);
+			switch(mod->Pos) {
+			case PackageSet::Modifier::POSTFIX:
+				if (str.compare(str.length() - alength, alength,
+						mod->Alias, 0, alength) != 0)
+					continue;
+				str.erase(str.length() - alength);
+				modID = mod->ID;
+				break;
+			case PackageSet::Modifier::PREFIX:
+				continue;
+			case PackageSet::Modifier::NONE:
+				continue;
+			}
+			modifierPresent = true;
+			break;
+		}
+		if (modifierPresent == true) {
+			bool const errors = helper.showErrors(false);
+			pkgCache::PkgIterator Pkg = FromName(Cache, *I, helper);
+			helper.showErrors(errors);
+			if (Pkg.end() == false) {
+				pkgsets[fallback].insert(Pkg);
+				continue;
+			}
+		}
+		pkgsets[modID].insert(PackageSet::FromString(Cache, str, helper));
+	}
+	return pkgsets;
+}
+									/*}}}*/
+// FromCommandLine - Return all packages specified on commandline	/*{{{*/
+PackageSet PackageSet::FromCommandLine(pkgCacheFile &Cache, const char **cmdline, CacheSetHelper &helper) {
+	PackageSet pkgset;
+	for (const char **I = cmdline; *I != 0; ++I) {
+		PackageSet pset = FromString(Cache, *I, helper);
+		pkgset.insert(pset.begin(), pset.end());
+	}
+	return pkgset;
+}
+									/*}}}*/
+// FromString - Return all packages matching a specific string		/*{{{*/
+PackageSet PackageSet::FromString(pkgCacheFile &Cache, std::string const &str, CacheSetHelper &helper) {
+	_error->PushToStack();
+
+	PackageSet pkgset;
+	pkgCache::PkgIterator Pkg = FromName(Cache, str, helper);
+	if (Pkg.end() == false)
+		pkgset.insert(Pkg);
+	else {
+		pkgset = FromTask(Cache, str, helper);
+		if (pkgset.empty() == true) {
+			pkgset = FromRegEx(Cache, str, helper);
+			if (pkgset.empty() == true)
+				pkgset = helper.canNotFindPackage(Cache, str);
+		}
+	}
+
+	if (pkgset.empty() == false)
+		_error->RevertToStack();
+	else
+		_error->MergeWithStack();
+	return pkgset;
+}
+									/*}}}*/
+// GroupedFromCommandLine - Return all versions specified on commandline/*{{{*/
+std::map<unsigned short, VersionSet> VersionSet::GroupedFromCommandLine(
+		pkgCacheFile &Cache, const char **cmdline,
+		std::list<VersionSet::Modifier> const &mods,
+		unsigned short const &fallback, CacheSetHelper &helper) {
+	std::map<unsigned short, VersionSet> versets;
+	for (const char **I = cmdline; *I != 0; ++I) {
+		unsigned short modID = fallback;
+		VersionSet::Version select = VersionSet::NEWEST;
+		std::string str = *I;
+		bool modifierPresent = false;
+		for (std::list<VersionSet::Modifier>::const_iterator mod = mods.begin();
+		     mod != mods.end(); ++mod) {
+			if (modID == fallback && mod->ID == fallback)
+				select = mod->SelectVersion;
+			size_t const alength = strlen(mod->Alias);
+			switch(mod->Pos) {
+			case VersionSet::Modifier::POSTFIX:
+				if (str.compare(str.length() - alength, alength,
+						mod->Alias, 0, alength) != 0)
+					continue;
+				str.erase(str.length() - alength);
+				modID = mod->ID;
+				select = mod->SelectVersion;
+				break;
+			case VersionSet::Modifier::PREFIX:
+				continue;
+			case VersionSet::Modifier::NONE:
+				continue;
+			}
+			modifierPresent = true;
+			break;
+		}
+
+		if (modifierPresent == true) {
+			bool const errors = helper.showErrors(false);
+			VersionSet const vset = VersionSet::FromString(Cache, std::string(*I), select, helper, true);
+			helper.showErrors(errors);
+			if (vset.empty() == false) {
+				versets[fallback].insert(vset);
+				continue;
+			}
+		}
+		versets[modID].insert(VersionSet::FromString(Cache, str, select , helper));
+	}
+	return versets;
+}
+									/*}}}*/
+// FromCommandLine - Return all versions specified on commandline	/*{{{*/
+APT::VersionSet VersionSet::FromCommandLine(pkgCacheFile &Cache, const char **cmdline,
+		APT::VersionSet::Version const &fallback, CacheSetHelper &helper) {
+	VersionSet verset;
+	for (const char **I = cmdline; *I != 0; ++I)
+		verset.insert(VersionSet::FromString(Cache, *I, fallback, helper));
+	return verset;
+}
+									/*}}}*/
+// FromString - Returns all versions spedcified by a string		/*{{{*/
+APT::VersionSet VersionSet::FromString(pkgCacheFile &Cache, std::string pkg,
+		APT::VersionSet::Version const &fallback, CacheSetHelper &helper,
+		bool const &onlyFromName) {
+	std::string ver;
+	bool verIsRel = false;
+	size_t const vertag = pkg.find_last_of("/=");
+	if (vertag != string::npos) {
+		ver = pkg.substr(vertag+1);
+		verIsRel = (pkg[vertag] == '/');
+		pkg.erase(vertag);
+	}
+	PackageSet pkgset;
+	if (onlyFromName == false)
+		pkgset = PackageSet::FromString(Cache, pkg, helper);
+	else {
+		pkgset.insert(PackageSet::FromName(Cache, pkg, helper));
+	}
+
+	VersionSet verset;
+	bool errors = true;
+	if (pkgset.getConstructor() != PackageSet::UNKNOWN)
+		errors = helper.showErrors(false);
+	for (PackageSet::const_iterator P = pkgset.begin();
+	     P != pkgset.end(); ++P) {
+		if (vertag == string::npos) {
+			verset.insert(VersionSet::FromPackage(Cache, P, fallback, helper));
+			continue;
+		}
+		pkgCache::VerIterator V;
+		if (ver == "installed")
+			V = getInstalledVer(Cache, P, helper);
+		else if (ver == "candidate")
+			V = getCandidateVer(Cache, P, helper);
+		else {
+			pkgVersionMatch Match(ver, (verIsRel == true ? pkgVersionMatch::Release :
+					pkgVersionMatch::Version));
+			V = Match.Find(P);
+			if (V.end() == true) {
+				if (verIsRel == true)
+					_error->Error(_("Release '%s' for '%s' was not found"),
+							ver.c_str(), P.FullName(true).c_str());
+				else
+					_error->Error(_("Version '%s' for '%s' was not found"),
+							ver.c_str(), P.FullName(true).c_str());
+				continue;
+			}
+		}
+		if (V.end() == true)
+			continue;
+		helper.showSelectedVersion(P, V, ver, verIsRel);
+		verset.insert(V);
+	}
+	if (pkgset.getConstructor() != PackageSet::UNKNOWN)
+		helper.showErrors(errors);
+	return verset;
+}
+									/*}}}*/
+// FromPackage - versions from package based on fallback		/*{{{*/
+VersionSet VersionSet::FromPackage(pkgCacheFile &Cache, pkgCache::PkgIterator const &P,
+		VersionSet::Version const &fallback, CacheSetHelper &helper) {
+	VersionSet verset;
+	pkgCache::VerIterator V;
+	bool showErrors;
+	switch(fallback) {
+	case VersionSet::ALL:
+		if (P->VersionList != 0)
+			for (V = P.VersionList(); V.end() != true; ++V)
+				verset.insert(V);
+		else
+			verset.insert(helper.canNotFindAllVer(Cache, P));
+		break;
+	case VersionSet::CANDANDINST:
+		verset.insert(getInstalledVer(Cache, P, helper));
+		verset.insert(getCandidateVer(Cache, P, helper));
+		break;
+	case VersionSet::CANDIDATE:
+		verset.insert(getCandidateVer(Cache, P, helper));
+		break;
+	case VersionSet::INSTALLED:
+		verset.insert(getInstalledVer(Cache, P, helper));
+		break;
+	case VersionSet::CANDINST:
+		showErrors = helper.showErrors(false);
+		V = getCandidateVer(Cache, P, helper);
+		if (V.end() == true)
+			V = getInstalledVer(Cache, P, helper);
+		helper.showErrors(showErrors);
+		if (V.end() == false)
+			verset.insert(V);
+		else
+			verset.insert(helper.canNotFindInstCandVer(Cache, P));
+		break;
+	case VersionSet::INSTCAND:
+		showErrors = helper.showErrors(false);
+		V = getInstalledVer(Cache, P, helper);
+		if (V.end() == true)
+			V = getCandidateVer(Cache, P, helper);
+		helper.showErrors(showErrors);
+		if (V.end() == false)
+			verset.insert(V);
+		else
+			verset.insert(helper.canNotFindInstCandVer(Cache, P));
+		break;
+	case VersionSet::NEWEST:
+		if (P->VersionList != 0)
+			verset.insert(P.VersionList());
+		else
+			verset.insert(helper.canNotFindNewestVer(Cache, P));
+		break;
+	}
+	return verset;
+}
+									/*}}}*/
+// getCandidateVer - Returns the candidate version of the given package	/*{{{*/
+pkgCache::VerIterator VersionSet::getCandidateVer(pkgCacheFile &Cache,
+		pkgCache::PkgIterator const &Pkg, CacheSetHelper &helper) {
+	pkgCache::VerIterator Cand;
+	if (Cache.IsPolicyBuilt() == true || Cache.IsDepCacheBuilt() == false)
+	{
+		if (unlikely(Cache.GetPolicy() == 0))
+			return pkgCache::VerIterator(Cache);
+		Cand = Cache.GetPolicy()->GetCandidateVer(Pkg);
+	} else {
+		Cand = Cache[Pkg].CandidateVerIter(Cache);
+	}
+	if (Cand.end() == true)
+		return helper.canNotFindCandidateVer(Cache, Pkg);
+	return Cand;
+}
+									/*}}}*/
+// getInstalledVer - Returns the installed version of the given package	/*{{{*/
+pkgCache::VerIterator VersionSet::getInstalledVer(pkgCacheFile &Cache,
+		pkgCache::PkgIterator const &Pkg, CacheSetHelper &helper) {
+	if (Pkg->CurrentVer == 0)
+		return helper.canNotFindInstalledVer(Cache, Pkg);
+	return Pkg.CurrentVer();
+}
+									/*}}}*/
+// canNotFindPkgName - handle the case no package has this name		/*{{{*/
+pkgCache::PkgIterator CacheSetHelper::canNotFindPkgName(pkgCacheFile &Cache,
+			std::string const &str) {
+	if (ShowError == true)
+		_error->Error(_("Unable to locate package %s"), str.c_str());
+	return pkgCache::PkgIterator(Cache, 0);
+}
+									/*}}}*/
+// canNotFindTask - handle the case no package is found for a task	/*{{{*/
+PackageSet CacheSetHelper::canNotFindTask(pkgCacheFile &Cache, std::string pattern) {
+	if (ShowError == true)
+		_error->Error(_("Couldn't find task '%s'"), pattern.c_str());
+	return PackageSet();
+}
+									/*}}}*/
+// canNotFindRegEx - handle the case no package is found by a regex	/*{{{*/
+PackageSet CacheSetHelper::canNotFindRegEx(pkgCacheFile &Cache, std::string pattern) {
+	if (ShowError == true)
+		_error->Error(_("Couldn't find any package by regex '%s'"), pattern.c_str());
+	return PackageSet();
+}
+									/*}}}*/
+// canNotFindPackage - handle the case no package is found from a string/*{{{*/
+PackageSet CacheSetHelper::canNotFindPackage(pkgCacheFile &Cache, std::string const &str) {
+	return PackageSet();
+}
+									/*}}}*/
+// canNotFindAllVer							/*{{{*/
+VersionSet CacheSetHelper::canNotFindAllVer(pkgCacheFile &Cache,
+		pkgCache::PkgIterator const &Pkg) {
+	if (ShowError == true)
+		_error->Error(_("Can't select versions from package '%s' as it purely virtual"), Pkg.FullName(true).c_str());
+	return VersionSet();
+}
+									/*}}}*/
+// canNotFindInstCandVer						/*{{{*/
+VersionSet CacheSetHelper::canNotFindInstCandVer(pkgCacheFile &Cache,
+		pkgCache::PkgIterator const &Pkg) {
+	if (ShowError == true)
+		_error->Error(_("Can't select installed nor candidate version from package '%s' as it has neither of them"), Pkg.FullName(true).c_str());
+	return VersionSet();
+}
+									/*}}}*/
+// canNotFindInstCandVer						/*{{{*/
+VersionSet CacheSetHelper::canNotFindCandInstVer(pkgCacheFile &Cache,
+		pkgCache::PkgIterator const &Pkg) {
+	if (ShowError == true)
+		_error->Error(_("Can't select installed nor candidate version from package '%s' as it has neither of them"), Pkg.FullName(true).c_str());
+	return VersionSet();
+}
+									/*}}}*/
+// canNotFindNewestVer							/*{{{*/
+pkgCache::VerIterator CacheSetHelper::canNotFindNewestVer(pkgCacheFile &Cache,
+		pkgCache::PkgIterator const &Pkg) {
+	if (ShowError == true)
+		_error->Error(_("Can't select newest version from package '%s' as it is purely virtual"), Pkg.FullName(true).c_str());
+	return pkgCache::VerIterator(Cache, 0);
+}
+									/*}}}*/
+// canNotFindCandidateVer						/*{{{*/
+pkgCache::VerIterator CacheSetHelper::canNotFindCandidateVer(pkgCacheFile &Cache,
+		pkgCache::PkgIterator const &Pkg) {
+	if (ShowError == true)
+		_error->Error(_("Can't select candidate version from package %s as it has no candidate"), Pkg.FullName(true).c_str());
+	return pkgCache::VerIterator(Cache, 0);
+}
+									/*}}}*/
+// canNotFindInstalledVer						/*{{{*/
+pkgCache::VerIterator CacheSetHelper::canNotFindInstalledVer(pkgCacheFile &Cache,
+		pkgCache::PkgIterator const &Pkg) {
+	if (ShowError == true)
+		_error->Error(_("Can't select installed version from package %s as it is not installed"), Pkg.FullName(true).c_str());
+	return pkgCache::VerIterator(Cache, 0);
+}
+									/*}}}*/
+}
diff --git a/apt-pkg/cacheset.h b/apt-pkg/cacheset.h
new file mode 100644
index 000000000..c8c3dd096
--- /dev/null
+++ b/apt-pkg/cacheset.h
@@ -0,0 +1,375 @@
+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+/** \file cacheset.h
+   Wrappers around std::set to have set::iterators which behave
+   similar to the Iterators of the cache structures.
+
+   Provides also a few helper methods which work with these sets */
+									/*}}}*/
+#ifndef APT_CACHESET_H
+#define APT_CACHESET_H
+// Include Files							/*{{{*/
+#include <iostream>
+#include <fstream>
+#include <list>
+#include <map>
+#include <set>
+#include <string>
+
+#include <apt-pkg/cachefile.h>
+#include <apt-pkg/pkgcache.h>
+									/*}}}*/
+namespace APT {
+class PackageSet;
+class VersionSet;
+class CacheSetHelper {							/*{{{*/
+/** \class APT::CacheSetHelper
+    Simple base class with a lot of virtual methods which can be overridden
+    to alter the behavior or the output of the CacheSets.
+
+    This helper is passed around by the static methods in the CacheSets and
+    used every time they hit an error condition or something could be
+    printed out.
+*/
+public:									/*{{{*/
+	CacheSetHelper(bool const &ShowError = true) : ShowError(ShowError) {};
+	virtual ~CacheSetHelper() {};
+
+	virtual void showTaskSelection(PackageSet const &pkgset, string const &pattern) {};
+	virtual void showRegExSelection(PackageSet const &pkgset, string const &pattern) {};
+	virtual void showSelectedVersion(pkgCache::PkgIterator const &Pkg, pkgCache::VerIterator const Ver,
+				 string const &ver, bool const &verIsRel) {};
+
+	virtual pkgCache::PkgIterator canNotFindPkgName(pkgCacheFile &Cache, std::string const &str);
+	virtual PackageSet canNotFindTask(pkgCacheFile &Cache, std::string pattern);
+	virtual PackageSet canNotFindRegEx(pkgCacheFile &Cache, std::string pattern);
+	virtual PackageSet canNotFindPackage(pkgCacheFile &Cache, std::string const &str);
+	virtual VersionSet canNotFindAllVer(pkgCacheFile &Cache, pkgCache::PkgIterator const &Pkg);
+	virtual VersionSet canNotFindInstCandVer(pkgCacheFile &Cache,
+				pkgCache::PkgIterator const &Pkg);
+	virtual VersionSet canNotFindCandInstVer(pkgCacheFile &Cache,
+				pkgCache::PkgIterator const &Pkg);
+	virtual pkgCache::VerIterator canNotFindNewestVer(pkgCacheFile &Cache,
+				pkgCache::PkgIterator const &Pkg);
+	virtual pkgCache::VerIterator canNotFindCandidateVer(pkgCacheFile &Cache,
+				pkgCache::PkgIterator const &Pkg);
+	virtual pkgCache::VerIterator canNotFindInstalledVer(pkgCacheFile &Cache,
+				pkgCache::PkgIterator const &Pkg);
+
+	bool showErrors() const { return ShowError; };
+	bool showErrors(bool const &newValue) { if (ShowError == newValue) return ShowError; else return ((ShowError = newValue) == false); };
+									/*}}}*/
+protected:
+	bool ShowError;
+};									/*}}}*/
+class PackageSet : public std::set<pkgCache::PkgIterator> {		/*{{{*/
+/** \class APT::PackageSet
+
+    Simple wrapper around a std::set to provide a similar interface to
+    a set of packages as to the complete set of all packages in the
+    pkgCache. */
+public:									/*{{{*/
+	/** \brief smell like a pkgCache::PkgIterator */
+	class const_iterator : public std::set<pkgCache::PkgIterator>::const_iterator {/*{{{*/
+	public:
+		const_iterator(std::set<pkgCache::PkgIterator>::const_iterator x) :
+			 std::set<pkgCache::PkgIterator>::const_iterator(x) {}
+
+		operator pkgCache::PkgIterator(void) { return **this; }
+
+		inline const char *Name() const {return (**this).Name(); }
+		inline std::string FullName(bool const &Pretty) const { return (**this).FullName(Pretty); }
+		inline std::string FullName() const { return (**this).FullName(); }
+		inline const char *Section() const {return (**this).Section(); }
+		inline bool Purge() const {return (**this).Purge(); }
+		inline const char *Arch() const {return (**this).Arch(); }
+		inline pkgCache::GrpIterator Group() const { return (**this).Group(); }
+		inline pkgCache::VerIterator VersionList() const { return (**this).VersionList(); }
+		inline pkgCache::VerIterator CurrentVer() const { return (**this).CurrentVer(); }
+		inline pkgCache::DepIterator RevDependsList() const { return (**this).RevDependsList(); }
+		inline pkgCache::PrvIterator ProvidesList() const { return (**this).ProvidesList(); }
+		inline pkgCache::PkgIterator::OkState State() const { return (**this).State(); }
+		inline const char *CandVersion() const { return (**this).CandVersion(); }
+		inline const char *CurVersion() const { return (**this).CurVersion(); }
+		inline pkgCache *Cache() const { return (**this).Cache(); };
+		inline unsigned long Index() const {return (**this).Index();};
+		// we have only valid iterators here
+		inline bool end() const { return false; };
+
+		friend std::ostream& operator<<(std::ostream& out, const_iterator i) { return operator<<(out, (*i)); }
+
+		inline pkgCache::Package const * operator->() const {
+			return &***this;
+		};
+	};
+	// 103. set::iterator is required to be modifiable, but this allows modification of keys
+	typedef APT::PackageSet::const_iterator iterator;
+									/*}}}*/
+
+	using std::set<pkgCache::PkgIterator>::insert;
+	inline void insert(pkgCache::PkgIterator const &P) { if (P.end() == false) std::set<pkgCache::PkgIterator>::insert(P); };
+	inline void insert(PackageSet const &pkgset) { insert(pkgset.begin(), pkgset.end()); };
+
+	/** \brief returns all packages in the cache who belong to the given task
+
+	    A simple helper responsible for search for all members of a task
+	    in the cache. Optional it prints a a notice about the
+	    packages chosen cause of the given task.
+	    \param Cache the packages are in
+	    \param pattern name of the task
+	    \param helper responsible for error and message handling */
+	static APT::PackageSet FromTask(pkgCacheFile &Cache, std::string pattern, CacheSetHelper &helper);
+	static APT::PackageSet FromTask(pkgCacheFile &Cache, std::string const &pattern) {
+		CacheSetHelper helper;
+		return APT::PackageSet::FromTask(Cache, pattern, helper);
+	}
+
+	/** \brief returns all packages in the cache whose name matchs a given pattern
+
+	    A simple helper responsible for executing a regular expression on all
+	    package names in the cache. Optional it prints a a notice about the
+	    packages chosen cause of the given package.
+	    \param Cache the packages are in
+	    \param pattern regular expression for package names
+	    \param helper responsible for error and message handling */
+	static APT::PackageSet FromRegEx(pkgCacheFile &Cache, std::string pattern, CacheSetHelper &helper);
+	static APT::PackageSet FromRegEx(pkgCacheFile &Cache, std::string const &pattern) {
+		CacheSetHelper helper;
+		return APT::PackageSet::FromRegEx(Cache, pattern, helper);
+	}
+
+	/** \brief returns all packages specified by a string
+
+	    \param Cache the packages are in
+	    \param string String the package name(s) should be extracted from
+	    \param helper responsible for error and message handling */
+	static APT::PackageSet FromString(pkgCacheFile &Cache, std::string const &string, CacheSetHelper &helper);
+	static APT::PackageSet FromString(pkgCacheFile &Cache, std::string const &string) {
+		CacheSetHelper helper;
+		return APT::PackageSet::FromString(Cache, string, helper);
+	}
+
+	/** \brief returns a package specified by a string
+
+	    \param Cache the package is in
+	    \param string String the package name should be extracted from
+	    \param helper responsible for error and message handling */
+	static pkgCache::PkgIterator FromName(pkgCacheFile &Cache, std::string const &string, CacheSetHelper &helper);
+	static pkgCache::PkgIterator FromName(pkgCacheFile &Cache, std::string const &string) {
+		CacheSetHelper helper;
+		return APT::PackageSet::FromName(Cache, string, helper);
+	}
+
+	/** \brief returns all packages specified on the commandline
+
+	    Get all package names from the commandline and executes regex's if needed.
+	    No special package command is supported, just plain names.
+	    \param Cache the packages are in
+	    \param cmdline Command line the package names should be extracted from
+	    \param helper responsible for error and message handling */
+	static APT::PackageSet FromCommandLine(pkgCacheFile &Cache, const char **cmdline, CacheSetHelper &helper);
+	static APT::PackageSet FromCommandLine(pkgCacheFile &Cache, const char **cmdline) {
+		CacheSetHelper helper;
+		return APT::PackageSet::FromCommandLine(Cache, cmdline, helper);
+	}
+
+	struct Modifier {
+		enum Position { NONE, PREFIX, POSTFIX };
+		unsigned short ID;
+		const char * const Alias;
+		Position Pos;
+		Modifier (unsigned short const &id, const char * const alias, Position const &pos) : ID(id), Alias(alias), Pos(pos) {};
+	};
+
+	/** \brief group packages by a action modifiers
+
+	    At some point it is needed to get from the same commandline
+	    different package sets grouped by a modifier. Take
+		apt-get install apt awesome-
+	    as an example.
+	    \param Cache the packages are in
+	    \param cmdline Command line the package names should be extracted from
+	    \param mods list of modifiers the method should accept
+	    \param fallback the default modifier group for a package
+	    \param helper responsible for error and message handling */
+	static std::map<unsigned short, PackageSet> GroupedFromCommandLine(
+		pkgCacheFile &Cache, const char **cmdline,
+		std::list<PackageSet::Modifier> const &mods,
+		unsigned short const &fallback, CacheSetHelper &helper);
+	static std::map<unsigned short, PackageSet> GroupedFromCommandLine(
+		pkgCacheFile &Cache, const char **cmdline,
+		std::list<PackageSet::Modifier> const &mods,
+		unsigned short const &fallback) {
+		CacheSetHelper helper;
+		return APT::PackageSet::GroupedFromCommandLine(Cache, cmdline,
+				mods, fallback, helper);
+	}
+
+	enum Constructor { UNKNOWN, REGEX, TASK };
+	Constructor getConstructor() const { return ConstructedBy; };
+
+	PackageSet() : ConstructedBy(UNKNOWN) {};
+	PackageSet(Constructor const &by) : ConstructedBy(by) {};
+									/*}}}*/
+private:								/*{{{*/
+	Constructor ConstructedBy;
+									/*}}}*/
+};									/*}}}*/
+class VersionSet : public std::set<pkgCache::VerIterator> {		/*{{{*/
+/** \class APT::VersionSet
+
+    Simple wrapper around a std::set to provide a similar interface to
+    a set of versions as to the complete set of all versions in the
+    pkgCache. */
+public:									/*{{{*/
+	/** \brief smell like a pkgCache::VerIterator */
+	class const_iterator : public std::set<pkgCache::VerIterator>::const_iterator {/*{{{*/
+	public:
+		const_iterator(std::set<pkgCache::VerIterator>::const_iterator x) :
+			 std::set<pkgCache::VerIterator>::const_iterator(x) {}
+
+		operator pkgCache::VerIterator(void) { return **this; }
+
+		inline pkgCache *Cache() const { return (**this).Cache(); };
+		inline unsigned long Index() const {return (**this).Index();};
+		// we have only valid iterators here
+		inline bool end() const { return false; };
+
+		inline pkgCache::Version const * operator->() const {
+			return &***this;
+		};
+
+		inline int CompareVer(const pkgCache::VerIterator &B) const { return (**this).CompareVer(B); };
+		inline const char *VerStr() const { return (**this).VerStr(); };
+		inline const char *Section() const { return (**this).Section(); };
+		inline const char *Arch() const { return (**this).Arch(); };
+		inline const char *Arch(bool const pseudo) const { return (**this).Arch(pseudo); };
+		inline pkgCache::PkgIterator ParentPkg() const { return (**this).ParentPkg(); };
+		inline pkgCache::DescIterator DescriptionList() const { return (**this).DescriptionList(); };
+		inline pkgCache::DescIterator TranslatedDescription() const { return (**this).TranslatedDescription(); };
+		inline pkgCache::DepIterator DependsList() const { return (**this).DependsList(); };
+		inline pkgCache::PrvIterator ProvidesList() const { return (**this).ProvidesList(); };
+		inline pkgCache::VerFileIterator FileList() const { return (**this).FileList(); };
+		inline bool Downloadable() const { return (**this).Downloadable(); };
+		inline const char *PriorityType() const { return (**this).PriorityType(); };
+		inline string RelStr() const { return (**this).RelStr(); };
+		inline bool Automatic() const { return (**this).Automatic(); };
+		inline bool Pseudo() const { return (**this).Pseudo(); };
+		inline pkgCache::VerFileIterator NewestFile() const { return (**this).NewestFile(); };
+	};
+									/*}}}*/
+	// 103. set::iterator is required to be modifiable, but this allows modification of keys
+	typedef APT::VersionSet::const_iterator iterator;
+
+	using std::set<pkgCache::VerIterator>::insert;
+	inline void insert(pkgCache::VerIterator const &V) { if (V.end() == false) std::set<pkgCache::VerIterator>::insert(V); };
+	inline void insert(VersionSet const &verset) { insert(verset.begin(), verset.end()); };
+
+	/** \brief specifies which version(s) will be returned if non is given */
+	enum Version {
+		/** All versions */
+		ALL,
+		/** Candidate and installed version */
+		CANDANDINST,
+		/** Candidate version */
+		CANDIDATE,
+		/** Installed version */
+		INSTALLED,
+		/** Candidate or if non installed version */
+		CANDINST,
+		/** Installed or if non candidate version */
+		INSTCAND,
+		/** Newest version */
+		NEWEST
+	};
+
+	/** \brief returns all versions specified on the commandline
+
+	    Get all versions from the commandline, uses given default version if
+	    non specifically requested  and executes regex's if needed on names.
+	    \param Cache the packages and versions are in
+	    \param cmdline Command line the versions should be extracted from
+	    \param helper responsible for error and message handling */
+	static APT::VersionSet FromCommandLine(pkgCacheFile &Cache, const char **cmdline,
+			APT::VersionSet::Version const &fallback, CacheSetHelper &helper);
+	static APT::VersionSet FromCommandLine(pkgCacheFile &Cache, const char **cmdline,
+			APT::VersionSet::Version const &fallback) {
+		CacheSetHelper helper;
+		return APT::VersionSet::FromCommandLine(Cache, cmdline, fallback, helper);
+	}
+	static APT::VersionSet FromCommandLine(pkgCacheFile &Cache, const char **cmdline) {
+		return APT::VersionSet::FromCommandLine(Cache, cmdline, CANDINST);
+	}
+
+	static APT::VersionSet FromString(pkgCacheFile &Cache, std::string pkg,
+			APT::VersionSet::Version const &fallback, CacheSetHelper &helper,
+			bool const &onlyFromName = false);
+	static APT::VersionSet FromString(pkgCacheFile &Cache, std::string pkg,
+			APT::VersionSet::Version const &fallback) {
+		CacheSetHelper helper;
+		return APT::VersionSet::FromString(Cache, pkg, fallback, helper);
+	}
+	static APT::VersionSet FromString(pkgCacheFile &Cache, std::string pkg) {
+		return APT::VersionSet::FromString(Cache, pkg, CANDINST);
+	}
+
+	/** \brief returns all versions specified for the package
+
+	    \param Cache the package and versions are in
+	    \param P the package in question
+	    \param fallback the version(s) you want to get
+	    \param helper the helper used for display and error handling */
+	static APT::VersionSet FromPackage(pkgCacheFile &Cache, pkgCache::PkgIterator const &P,
+		VersionSet::Version const &fallback, CacheSetHelper &helper);
+	static APT::VersionSet FromPackage(pkgCacheFile &Cache, pkgCache::PkgIterator const &P,
+			APT::VersionSet::Version const &fallback) {
+		CacheSetHelper helper;
+		return APT::VersionSet::FromPackage(Cache, P, fallback, helper);
+	}
+	static APT::VersionSet FromPackage(pkgCacheFile &Cache, pkgCache::PkgIterator const &P) {
+		return APT::VersionSet::FromPackage(Cache, P, CANDINST);
+	}
+
+	struct Modifier {
+		enum Position { NONE, PREFIX, POSTFIX };
+		unsigned short ID;
+		const char * const Alias;
+		Position Pos;
+		VersionSet::Version SelectVersion;
+		Modifier (unsigned short const &id, const char * const alias, Position const &pos,
+			  VersionSet::Version const &select) : ID(id), Alias(alias), Pos(pos),
+			 SelectVersion(select) {};
+	};
+
+	static std::map<unsigned short, VersionSet> GroupedFromCommandLine(
+		pkgCacheFile &Cache, const char **cmdline,
+		std::list<VersionSet::Modifier> const &mods,
+		unsigned short const &fallback, CacheSetHelper &helper);
+	static std::map<unsigned short, VersionSet> GroupedFromCommandLine(
+		pkgCacheFile &Cache, const char **cmdline,
+		std::list<VersionSet::Modifier> const &mods,
+		unsigned short const &fallback) {
+		CacheSetHelper helper;
+		return APT::VersionSet::GroupedFromCommandLine(Cache, cmdline,
+				mods, fallback, helper);
+	}
+									/*}}}*/
+protected:								/*{{{*/
+
+	/** \brief returns the candidate version of the package
+
+	    \param Cache to be used to query for information
+	    \param Pkg we want the candidate version from this package */
+	static pkgCache::VerIterator getCandidateVer(pkgCacheFile &Cache,
+		pkgCache::PkgIterator const &Pkg, CacheSetHelper &helper);
+
+	/** \brief returns the installed version of the package
+
+	    \param Cache to be used to query for information
+	    \param Pkg we want the installed version from this package */
+	static pkgCache::VerIterator getInstalledVer(pkgCacheFile &Cache,
+		pkgCache::PkgIterator const &Pkg, CacheSetHelper &helper);
+									/*}}}*/
+};									/*}}}*/
+}
+#endif
diff --git a/apt-pkg/makefile b/apt-pkg/makefile
index e9e5651b0..4e5ec107f 100644
--- a/apt-pkg/makefile
+++ b/apt-pkg/makefile
@@ -35,7 +35,7 @@ SOURCE+= pkgcache.cc version.cc depcache.cc \
 	 srcrecords.cc cachefile.cc versionmatch.cc policy.cc \
 	 pkgsystem.cc indexfile.cc pkgcachegen.cc acquire-item.cc \
 	 indexrecords.cc vendor.cc vendorlist.cc cdrom.cc indexcopy.cc \
-	 aptconfiguration.cc cachefilter.cc
+	 aptconfiguration.cc cachefilter.cc cacheset.cc
 HEADERS+= algorithms.h depcache.h pkgcachegen.h cacheiterators.h \
 	  orderlist.h sourcelist.h packagemanager.h tagfile.h \
 	  init.h pkgcache.h version.h progress.h pkgrecords.h \
@@ -43,7 +43,7 @@ HEADERS+= algorithms.h depcache.h pkgcachegen.h cacheiterators.h \
 	  clean.h srcrecords.h cachefile.h versionmatch.h policy.h \
 	  pkgsystem.h indexfile.h metaindex.h indexrecords.h vendor.h \
 	  vendorlist.h cdrom.h indexcopy.h aptconfiguration.h \
-	  cachefilter.h
+	  cachefilter.h cacheset.h
 
 # Source code for the debian specific components
 # In theory the deb headers do not need to be exported..