[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/index_block_dumper.cc

@@ -0,0 +1,51 @@
+#include "dbg-lib/index_block_dumper.h"
+#include "dbg-lib/output_formatter.h"
+#include "dbg-lib/sm_show_traits.h"
+#include "persistent-data/space-maps/disk_structures.h"
+
+using namespace dbg;
+
+//----------------------------------------------------------------
+
+namespace {
+	using persistent_data::block_manager;
+
+	class index_block_dumper : public dbg::block_dumper {
+	public:
+		virtual void show(block_manager::read_ref &rr, std::ostream &out) {
+			sm_disk_detail::metadata_index const *mdi =
+				reinterpret_cast<sm_disk_detail::metadata_index const *>(rr.data());
+			show_metadata_index(mdi, sm_disk_detail::MAX_METADATA_BITMAPS, out);
+		}
+
+	private:
+		void show_metadata_index(sm_disk_detail::metadata_index const *mdi, unsigned nr_indexes, std::ostream &out) {
+			formatter::ptr f = create_xml_formatter();
+			field(*f, "csum", to_cpu<uint32_t>(mdi->csum_));
+			field(*f, "padding", to_cpu<uint32_t>(mdi->padding_));
+			field(*f, "blocknr", to_cpu<uint64_t>(mdi->blocknr_));
+
+			sm_disk_detail::index_entry ie;
+			for (unsigned i = 0; i < nr_indexes; i++) {
+				sm_disk_detail::index_entry_traits::unpack(*(mdi->index + i), ie);
+
+				if (!ie.blocknr_ && !ie.nr_free_ && !ie.none_free_before_)
+					continue;
+
+				formatter::ptr f2 = create_xml_formatter();
+				index_entry_show_traits::show(f2, "value", ie);
+				f->child(boost::lexical_cast<string>(i), f2);
+			}
+			f->output(out, 0);
+		}
+	};
+}
+
+//----------------------------------------------------------------
+
+block_dumper::ptr
+dbg::create_index_block_dumper() {
+	return block_dumper::ptr(new index_block_dumper());
+}
+
+//----------------------------------------------------------------