"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, 46 insertions, 0 deletions

diff --git a/apt-pkg/aptconfiguration.h b/apt-pkg/aptconfiguration.h
new file mode 100644
index 000000000..6a123adce
--- /dev/null
+++ b/apt-pkg/aptconfiguration.h
@@ -0,0 +1,46 @@
+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+/** \class APT::Configuration
+ *  \brief Provide access methods to various configuration settings
+ *
+ *  This class and their methods providing a layer around the usual access
+ *  methods with _config to ensure that settings are correct and to be able
+ *  to set defaults without the need to recheck it in every method again.
+ */
+									/*}}}*/
+#ifndef APT_CONFIGURATION_H
+#define APT_CONFIGURATION_H
+// Include Files							/*{{{*/
+#include <string>
+#include <vector>
+									/*}}}*/
+namespace APT {
+class Configuration {							/*{{{*/
+public:									/*{{{*/
+	/** \brief Returns a vector of usable Compression Types
+	 *
+	 *  Files can be compressed in various ways to decrease the size of the
+	 *  download. Therefore the Acquiremethods support a few compression types
+	 *  and some archives provide also a few different types. This option
+	 *  group exists to give the user the choice to prefer one type over the
+	 *  other (some compression types are very resource intensive - great if you
+	 *  have a limited download, bad if you have a really lowpowered hardware.)
+	 *
+	 *  This method ensures that the defaults are set and checks at runtime
+	 *  if the type can be used. E.g. the current default is to prefer bzip2
+	 *  over lzma and gz - if the bzip2 binary is not available it has not much
+	 *  sense in downloading the bz2 file, therefore we will not return bz2 as
+	 *  a usable compression type. The availability is checked with the settings
+	 *  in the Dir::Bin group.
+	 *
+	 *  \param Cached saves the result so we need to calculated it only once
+	 *                this parameter should ony be used for testing purposes.
+	 *
+	 *  \return a vector of (all) Language Codes in the prefered usage order
+	 */
+	std::vector<std::string> static const getCompressionTypes(bool const &Cached = true);
+									/*}}}*/
+};
+									/*}}}*/
+}
+#endif