[dbg] Pull out common code into dbg-lib

- Modularize common routines
- Extract the block_dumper interface for displaying blocks
- Remove inheritance from show_traits

dbg-lib/array_block_dumper.h

@@ -0,0 +1,53 @@
+#include "dbg-lib/block_dumper.h"
+#include "dbg-lib/output_formatter.h"
+#include "persistent-data/data-structures/array_block.h"
+
+//----------------------------------------------------------------
+
+namespace dbg {
+	using persistent_data::block_manager;
+	using persistent_data::array_block;
+
+	template <typename ShowTraits>
+	class array_block_dumper : public block_dumper {
+	public:
+		array_block_dumper(typename ShowTraits::value_trait::ref_counter rc)
+			: rc_(rc) {
+		}
+
+		virtual void show(block_manager::read_ref &rr, std::ostream &out) {
+			rblock b(rr, rc_);
+			show_array_entries(b, out);
+		}
+
+	private:
+		typedef array_block<typename ShowTraits::value_trait, block_manager::read_ref> rblock;
+
+		void show_array_entries(rblock const& b, std::ostream &out) {
+			formatter::ptr f = create_xml_formatter();
+			uint32_t nr_entries = b.nr_entries();
+
+			field(*f, "max_entries", b.max_entries());
+			field(*f, "nr_entries", nr_entries);
+			field(*f, "value_size", b.value_size());
+
+			for (unsigned i = 0; i < nr_entries; i++) {
+				formatter::ptr f2 = create_xml_formatter();
+				ShowTraits::show(f2, "value", b.get(i));
+				f->child(boost::lexical_cast<std::string>(i), f2);
+			}
+
+			f->output(out, 0);
+		}
+
+		typename ShowTraits::value_trait::ref_counter rc_;
+	};
+
+	template <typename ShowTraits>
+	block_dumper::ptr
+	create_array_block_dumper(typename ShowTraits::value_trait::ref_counter rc) {
+		return block_dumper::ptr(new array_block_dumper<ShowTraits>(rc));
+	}
+}
+
+//----------------------------------------------------------------