remove btree_checker, and add btree_counter

persistent-data/data-structures/btree_counter.h

@@ -0,0 +1,81 @@
+#ifndef PERSISTENT_DATA_DATA_STRUCTURES_BTREE_COUNTER_H
+#define PERSISTENT_DATA_DATA_STRUCTURES_BTREE_COUNTER_H
+
+#include "persistent-data/block_counter.h"
+
+//----------------------------------------------------------------
+
+namespace persistent_data {
+	namespace btree_count_detail {
+		template <unsigned Levels, typename ValueTraits, typename ValueCounter>
+		class counting_visitor : public btree<Levels, ValueTraits>::visitor {
+		public:
+			typedef btree<Levels, ValueTraits> tree;
+
+			counting_visitor(block_counter &bc, ValueCounter &vc)
+				: bc_(bc),
+				  vc_(vc) {
+			}
+
+			virtual bool visit_internal(node_location const &l,
+						    typename tree::internal_node const &n) {
+				return visit_node(n);
+			}
+
+			virtual bool visit_internal_leaf(node_location const &l,
+							 typename tree::internal_node const &n) {
+				return visit_node(n);
+			}
+
+			virtual bool visit_leaf(node_location const &l,
+						typename tree::leaf_node const &n) {
+				if (visit_node(n)) {
+					unsigned nr = n.get_nr_entries();
+
+					for (unsigned i = 0; i < nr; i++) {
+						// FIXME: confirm l2 is correct
+						node_location l2(l);
+						l2.push_key(i);
+						vc_.visit(l2, n.value_at(i));
+					}
+
+					return true;
+				}
+
+				return false;
+			}
+
+		private:
+			template <typename Node>
+			bool visit_node(Node const &n) {
+				block_address b = n.get_location();
+				bool seen = bc_.get_count(b);
+				bc_.inc(b);
+				return !seen;
+			}
+
+			block_counter &bc_;
+			ValueCounter &vc_;
+		};
+	}
+
+	template <typename T>
+	struct noop_value_counter {
+		void visit(btree_detail::node_location const &loc, T const &v) {
+		}
+	};
+
+	// Counts how many times each metadata block is referenced in the
+	// tree.  Blocks already referenced in the block counter are not
+	// walked.  This walk should only be done once you're sure the tree
+	// is not corrupt.
+	template <unsigned Levels, typename ValueTraits, typename ValueCounter>
+	void count_btree_blocks(btree<Levels, ValueTraits> const &tree, block_counter &bc, ValueCounter &vc) {
+		btree_count_detail::counting_visitor<Levels, ValueTraits, ValueCounter> v(bc, vc);
+		tree.visit_depth_first(v);
+	}
+}
+
+//----------------------------------------------------------------
+
+#endif