1 files changed, 90 insertions, 0 deletions
diff --git a/apt-pkg/aptconfiguration.cc b/apt-pkg/aptconfiguration.cc
new file mode 100644
index 000000000..45ae9bed5
--- /dev/null
+++ b/apt-pkg/aptconfiguration.cc
@@ -0,0 +1,90 @@
+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+/* ######################################################################
+
+   Provide access methods to various configuration settings,
+   setup defaults and returns validate settings.
+
+   ##################################################################### */
+									/*}}}*/
+// Include Files							/*{{{*/
+#include <apt-pkg/fileutl.h>
+#include <apt-pkg/aptconfiguration.h>
+#include <apt-pkg/configuration.h>
+
+#include <vector>
+#include <string>
+#include <algorithm>
+									/*}}}*/
+namespace APT {
+// getCompressionTypes - Return Vector of usbale compressiontypes	/*{{{*/
+// ---------------------------------------------------------------------
+/* return a vector of compression types in the prefered order. */
+std::vector<std::string>
+const Configuration::getCompressionTypes(bool const &Cached) {
+	static std::vector<std::string> types;
+	if (types.empty() == false) {
+		if (Cached == true)
+			return types;
+		else
+			types.clear();
+	}
+
+	// setup the defaults for the compressiontypes => method mapping
+	_config->CndSet("Acquire::CompressionTypes::bz2","bzip2");
+	_config->CndSet("Acquire::CompressionTypes::lzma","lzma");
+	_config->CndSet("Acquire::CompressionTypes::gz","gzip");
+
+	// Set default application paths to check for optional compression types
+	_config->CndSet("Dir::Bin::lzma", "/usr/bin/lzma");
+	_config->CndSet("Dir::Bin::bzip2", "/bin/bzip2");
+
+	// accept non-list order as override setting for config settings on commandline
+	std::string const overrideOrder = _config->Find("Acquire::CompressionTypes::Order","");
+	if (overrideOrder.empty() == false)
+		types.push_back(overrideOrder);
+
+	// load the order setting into our vector
+	std::vector<std::string> const order = _config->FindVector("Acquire::CompressionTypes::Order");
+	for (std::vector<std::string>::const_iterator o = order.begin();
+	     o != order.end(); o++) {
+		if ((*o).empty() == true)
+			continue;
+		// ignore types we have no method ready to use
+		if (_config->Exists(string("Acquire::CompressionTypes::").append(*o)) == false)
+			continue;
+		// ignore types we have no app ready to use
+		string const appsetting = string("Dir::Bin::").append(*o);
+		if (_config->Exists(appsetting) == true) {
+			std::string const app = _config->FindFile(appsetting.c_str(), "");
+			if (app.empty() == false && FileExists(app) == false)
+				continue;
+		}
+		types.push_back(*o);
+	}
+
+	// move again over the option tree to add all missing compression types
+	::Configuration::Item const *Types = _config->Tree("Acquire::CompressionTypes");
+	if (Types != 0)
+		Types = Types->Child;
+
+	for (; Types != 0; Types = Types->Next) {
+		if (Types->Tag == "Order" || Types->Tag.empty() == true)
+			continue;
+		// ignore types we already have in the vector
+		if (std::find(types.begin(),types.end(),Types->Tag) != types.end())
+			continue;
+		// ignore types we have no app ready to use
+		string const appsetting = string("Dir::Bin::").append(Types->Value);
+		if (appsetting.empty() == false && _config->Exists(appsetting) == true) {
+			std::string const app = _config->FindFile(appsetting.c_str(), "");
+			if (app.empty() == false && FileExists(app) == false)
+				continue;
+		}
+		types.push_back(Types->Tag);
+	}
+
+	return types;
+}
+									/*}}}*/
+}