"backport" the APT::Configuration class to apt-sid

We can use it to simplify the internal code to operate with
Acquire::CompressionTypes group. This also made it possible
to set this setting with the -o flag.

1 files changed, 78 insertions, 0 deletions

diff --git a/apt-pkg/aptconfiguration.cc b/apt-pkg/aptconfiguration.cc
new file mode 100644
index 000000000..1a8e8262f
--- /dev/null
+++ b/apt-pkg/aptconfiguration.cc
@@ -0,0 +1,78 @@
+// -*- 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>
+									/*}}}*/
+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();
+	}
+
+	// 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");
+
+	::Configuration::Item const *Opts = _config->Tree("Acquire::CompressionTypes");
+	if (Opts != 0)
+		Opts = Opts->Child;
+
+	// at first, move over the options to setup at least the default options
+	bool foundLzma=false, foundBzip2=false, foundGzip=false;
+	for (; Opts != 0; Opts = Opts->Next) {
+		if (Opts->Value == "lzma")
+			foundLzma = true;
+		else if (Opts->Value == "bz2")
+			foundBzip2 = true;
+		else if (Opts->Value == "gz")
+			foundGzip = true;
+	}
+
+	// setup the defaults now
+	if (!foundBzip2)
+		_config->Set("Acquire::CompressionTypes::bz2","bzip2");
+	if (!foundLzma)
+		_config->Set("Acquire::CompressionTypes::lzma","lzma");
+	if (!foundGzip)
+		_config->Set("Acquire::CompressionTypes::gz","gzip");
+
+	// move again over the option tree to finially calculate our result
+	::Configuration::Item const *Types = _config->Tree("Acquire::CompressionTypes");
+	if (Types != 0)
+		Types = Types->Child;
+
+	for (; Types != 0; Types = Types->Next) {
+		string const appsetting = string("Dir::Bin::").append(Types->Value);
+		// ignore compression types we have no app ready to use
+		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;
+}
+									/*}}}*/
+}