[base] introduce a command type that gets registered with the app

caching/commands.h

@@ -2,15 +2,68 @@
 #define CACHING_COMMANDS_H
 
 #include "base/application.h"
+#include "boost/optional.hpp"
 
 //----------------------------------------------------------------
 
 namespace caching {
-	extern base::command cache_check_cmd;
-	extern base::command cache_dump_cmd;
-	extern base::command cache_metadata_size_cmd;
-	extern base::command cache_restore_cmd;
-	extern base::command cache_repair_cmd;
+	class cache_check_cmd : public base::command {
+	public:
+		cache_check_cmd();
+		virtual void usage(std::ostream &out) const;
+		virtual int run(int argc, char **argv);
+	};
+
+	class cache_dump_cmd : public base::command {
+	public:
+		cache_dump_cmd();
+		virtual void usage(std::ostream &out) const;
+		virtual int run(int argc, char **argv);
+	};
+
+	class cache_metadata_size_cmd : public base::command {
+	public:
+		cache_metadata_size_cmd();
+		virtual void usage(std::ostream &out) const;
+		virtual int run(int argc, char **argv);
+
+
+	private:
+		struct flags {
+			flags();
+
+			boost::optional<uint64_t> device_size;
+			boost::optional<uint32_t> block_size;
+			boost::optional<uint64_t> nr_blocks;
+			uint32_t max_hint_width;
+		};
+
+		enum parse_result {
+			FINISH,
+			CONTINUE
+		};
+
+		parse_result parse_command_line(std::string const &prog_name, int argc, char **argv, flags &fs);
+		uint64_t get_nr_blocks(flags &fs);
+		uint64_t meg(uint64_t n);
+		uint64_t calc_size(uint64_t nr_blocks, uint32_t max_hint_width);
+	};
+
+	class cache_repair_cmd : public base::command {
+	public:
+		cache_repair_cmd();
+		virtual void usage(std::ostream &out) const;
+		virtual int run(int argc, char **argv);
+	};
+
+	class cache_restore_cmd : public base::command {
+	public:
+		cache_restore_cmd();
+		virtual void usage(std::ostream &out) const;
+		virtual int run(int argc, char **argv);
+	};
+
+	void register_cache_commands(base::application &app);
 }
 
 //----------------------------------------------------------------