move regex magic from apt-get to new FromRegEx method

4 files changed, 87 insertions, 3 deletions

diff --git a/apt-pkg/cacheiterators.h b/apt-pkg/cacheiterators.h
index 3d58f7ec0..ee852f594 100644
--- a/apt-pkg/cacheiterators.h
+++ b/apt-pkg/cacheiterators.h
@@ -66,7 +66,7 @@ template<typename Str, typename Itr> class pkgCache::Iterator :
 	inline operator Str const *() const {return S == OwnerPointer() ? 0 : S;};
 	inline Str &operator *() {return *S;};
 	inline Str const &operator *() const {return *S;};
-	inline pkgCache *Cache() {return Owner;};
+	inline pkgCache *Cache() const {return Owner;};
 
 	// Mixed stuff
 	inline void operator =(const Itr &B) {S = B.S; Owner = B.Owner;};
diff --git a/apt-pkg/makefile b/apt-pkg/makefile
index d4537859d..968275c5c 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
+	 aptconfiguration.cc packageset.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 \
diff --git a/apt-pkg/packageset.cc b/apt-pkg/packageset.cc
new file mode 100644
index 000000000..f452bc052
--- /dev/null
+++ b/apt-pkg/packageset.cc
@@ -0,0 +1,62 @@
+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+/* ######################################################################
+
+   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.
+
+   ##################################################################### */
+									/*}}}*/
+// Include Files							/*{{{*/
+#include <apt-pkg/error.h>
+#include <apt-pkg/packageset.h>
+#include <apt-pkg/strutl.h>
+
+#include <apti18n.h>
+
+#include <regex.h>
+									/*}}}*/
+namespace APT {
+// FromRegEx - Return all packages in the cache matching a pattern	/*{{{*/
+PackageSet PackageSet::FromRegEx(pkgCache &Cache, const char * const pattern, std::ostream &out) {
+	PackageSet pkgset;
+
+	const char * I;
+	for (I = pattern; *I != 0; I++)
+		if (*I == '.' || *I == '?' || *I == '+' || *I == '*' ||
+		    *I == '|' || *I == '[' || *I == '^' || *I == '$')
+			break;
+	if (*I == 0)
+		return pkgset;
+
+	regex_t Pattern;
+	int Res;
+	if ((Res = regcomp(&Pattern, pattern , REG_EXTENDED | REG_ICASE | REG_NOSUB)) != 0) {
+		char Error[300];
+		regerror(Res, &Pattern, Error, sizeof(Error));
+		_error->Error(_("Regex compilation error - %s"), Error);
+		return pkgset;
+	}
+
+	for (pkgCache::GrpIterator Grp = Cache.GrpBegin(); Grp.end() == false; ++Grp)
+	{
+		if (regexec(&Pattern, Grp.Name(), 0, 0, 0) != 0)
+			continue;
+		pkgCache::PkgIterator Pkg = Grp.FindPkg("native");
+		if (unlikely(Pkg.end() == true))
+			// FIXME: Fallback to different architectures here?
+			continue;
+
+		ioprintf(out, _("Note, selecting %s for regex '%s'\n"),
+			 Pkg.Name(), pattern);
+
+		pkgset.insert(Pkg);
+	}
+
+	regfree(&Pattern);
+
+	return pkgset;
+}
+									/*}}}*/
+}
diff --git a/apt-pkg/packageset.h b/apt-pkg/packageset.h
index d80536942..cd1430a2a 100644
--- a/apt-pkg/packageset.h
+++ b/apt-pkg/packageset.h
@@ -10,7 +10,11 @@
 #ifndef APT_PACKAGESET_H
 #define APT_PACKAGESET_H
 // Include Files							/*{{{*/
+#include <iostream>
+#include <fstream>
+#include <set>
 #include <string>
+
 #include <apt-pkg/pkgcache.h>
 									/*}}}*/
 namespace APT {
@@ -22,6 +26,8 @@ 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(); }
@@ -36,7 +42,8 @@ public:									/*{{{*/
 		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() {return (*this)->Cache();};
+		inline pkgCache *Cache() const { return (*this)->Cache(); };
+		inline unsigned long Index() const {return (*this)->Index();};
 
 		friend std::ostream& operator<<(std::ostream& out, const_iterator i) { return operator<<(out, (*i)); }
 
@@ -46,6 +53,21 @@ public:									/*{{{*/
 	};
 	// 103. set::iterator is required to be modifiable, but this allows modification of keys
 	typedef typename APT::PackageSet::const_iterator iterator;
+
+	/** \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 out stream to print the notice to */
+	static APT::PackageSet FromRegEx(pkgCache &Cache, const char *pattern, std::ostream &out);
+	static APT::PackageSet FromRegEx(pkgCache &Cache, const char *pattern) {
+		std::ostream out (std::ofstream("/dev/null").rdbuf());
+		return APT::PackageSet::FromRegEx(Cache, pattern, out);
+	}
+
 									/*}}}*/
 };
 									/*}}}*/