[base, thin_ls] factor out disk_units code

base/disk_units.h

@@ -0,0 +1,34 @@
+#ifndef BASE_DISK_UNITS_H
+#define BASE_DISK_UNITS_H
+
+#include <string>
+
+//----------------------------------------------------------------
+
+namespace base {
+	enum disk_unit {
+		UNIT_BYTE,
+		UNIT_SECTOR,
+
+		// decimal multipliers
+		UNIT_kB,
+		UNIT_MB,
+		UNIT_GB,
+		UNIT_TB,
+		UNIT_PB,
+
+		// binary multipliers
+		UNIT_KiB,
+		UNIT_MiB,
+		UNIT_GiB,
+		UNIT_TiB,
+		UNIT_PiB
+	};
+
+	unsigned long long disk_unit_multiplier(disk_unit u);
+	std::string format_disk_unit(unsigned long long numerator, disk_unit u);
+}
+
+//----------------------------------------------------------------
+
+#endif