Lots of work on the btree_damage_visitor

unit-tests/btree_damage_visitor_t.cc

@@ -20,21 +20,21 @@ namespace {
 	block_address const SUPERBLOCK = 0;
 
 	struct thing {
-		thing(/* uint32_t x_ = 0, */ uint64_t y_ = 0)
-			: /* x(x_), */
+		thing(uint32_t x_ = 0, uint64_t y_ = 0)
+			: x(x_),
 			  y(y_) {
 		}
 
 		bool operator ==(thing const &rhs) const {
-			return /* (x == rhs.x) && */ (y == rhs.y);
+			return (x == rhs.x) && (y == rhs.y);
 		}
 
-		//uint32_t x;
+		uint32_t x;
 		uint64_t y;
 	};
 
 	struct thing_disk {
-		//le32 x;
+		le32 x;
 		le64 y;
 	};
 
@@ -44,16 +44,101 @@ namespace {
 		typedef persistent_data::no_op_ref_counter<value_type> ref_counter;
 
 		static void unpack(thing_disk const &disk, thing &value) {
-			//	value.x = to_cpu<uint32_t>(disk.x);
+			value.x = to_cpu<uint32_t>(disk.x);
 			value.y = to_cpu<uint64_t>(disk.y);
 		}
 
 		static void pack(thing const &value, thing_disk &disk) {
-			//	disk.x = to_disk<le32>(value.x);
+			disk.x = to_disk<le32>(value.x);
 			disk.y = to_disk<le64>(value.y);
 		}
 	};
 
+	template <uint32_t Levels, typename ValueTraits>
+	class btree_layout : public btree<Levels, ValueTraits>::visitor {
+	public:
+		struct node_info {
+			typedef boost::shared_ptr<node_info> ptr;
+
+			bool leaf;
+			unsigned depth;
+			unsigned level;
+			block_address b;
+			range<uint64_t> keys;
+		};
+
+		typedef btree_detail::node_location node_location;
+		typedef btree<Levels, ValueTraits> tree;
+		typedef boost::shared_ptr<btree_layout> ptr;
+
+		virtual bool visit_internal(node_location const &loc,
+					    typename tree::internal_node const &n) {
+			record_node(false, loc, n);
+			return true;
+		}
+
+		virtual bool visit_internal_leaf(node_location const &loc,
+						 typename tree::internal_node const &n) {
+			record_node(true, loc, n);
+			return true;
+		}
+
+
+		virtual bool visit_leaf(node_location const &loc,
+					typename tree::leaf_node const &n) {
+			record_node(true, loc, n);
+			return true;
+		}
+
+		virtual void visit_complete() {
+		}
+
+		vector<typename node_info::ptr> const &get_nodes() const {
+			return nodes_;
+		}
+
+		node_info const &random_node() const {
+			if (nodes_.empty())
+				throw runtime_error("no nodes in btree");
+
+			return *nodes_[::random() % nodes_.size()];
+		}
+
+	private:
+		// We rely on the visit order being depth first, lowest to highest.
+		template <typename N>
+		void record_node(bool leaf, node_location const &loc, N const &n) {
+			typename node_info::ptr ni(new node_info);
+
+			ni->leaf = leaf;
+			ni->depth = loc.depth;
+			ni->level = loc.level;
+			ni->b = n.get_location();
+
+			if (n.get_nr_entries())
+				ni->keys = range<uint64_t>(n.key_at(0));
+			else {
+				if (loc.key)
+					ni->keys = range<uint64_t>(*loc.key);
+				else
+					ni->keys = range<uint64_t>();
+			}
+
+			if (last_node_at_depth_.size() > loc.depth) {
+				typename node_info::ptr &last = last_node_at_depth_[loc.depth];
+
+				last->keys.end_ = ni->keys.begin_;
+				last_node_at_depth_[loc.depth] = ni;
+			} else
+				last_node_at_depth_.push_back(ni);
+
+			nodes_.push_back(ni);
+		}
+
+		vector<typename node_info::ptr> nodes_;
+		vector<typename node_info::ptr> last_node_at_depth_;
+	};
+
 	class value_visitor_mock {
 	public:
 		MOCK_METHOD1(visit, void(thing const &));
@@ -90,7 +175,7 @@ namespace {
 		void insert_values(unsigned nr) {
 			for (unsigned i = 0; i < nr; i++) {
 				uint64_t key[1] = {i};
-				thing value(i /*, i + 1234 */);
+				thing value(i, i + 1234);
 
 				tree_->insert(key, value);
 			}
@@ -100,13 +185,19 @@ namespace {
 			EXPECT_CALL(value_visitor_, visit(_)).Times(0);
 		}
 
+		void expect_value_range(uint64_t begin, uint64_t end) {
+			while (begin < end) {
+				EXPECT_CALL(value_visitor_, visit(Eq(thing(begin, begin + 1234)))).Times(1);
+				begin++;
+			}
+		}
+
 		void expect_nr_values(unsigned nr) {
-			for (unsigned i = 0; i < nr; i++)
-				EXPECT_CALL(value_visitor_, visit(Eq(thing(i /*, i + 1234 */)))).Times(1);
+			expect_value_range(0, nr);
 		}
 
 		void expect_value(unsigned n) {
-			EXPECT_CALL(value_visitor_, visit(Eq(thing(n /*, n + 1234 */)))).Times(1);
+			EXPECT_CALL(value_visitor_, visit(Eq(thing(n, n + 1234)))).Times(1);
 		}
 
 		void expect_no_damage() {
@@ -152,24 +243,62 @@ TEST_F(BTreeDamageVisitorTests, visiting_an_empty_tree)
 	run();
 }
 
-TEST_F(BTreeDamageVisitorTests, visiting_an_tree_with_a_trashed_root)
+TEST_F(BTreeDamageVisitorTests, visiting_a_tree_with_a_trashed_root)
 {
 	trash_block(tree_->get_root());
 
 	expect_no_values();
-	expect_damage(0, range<uint64_t>());
+	expect_damage(0, range<uint64_t>(0ull));
 
 	run();
 }
 
 TEST_F(BTreeDamageVisitorTests, visiting_a_populated_tree_with_no_damage)
 {
-	insert_values(1000);
+	insert_values(10000);
 
-	expect_nr_values(1000);
+	expect_nr_values(10000);
 	expect_no_damage();
 
 	run();
 }
 
+TEST_F(BTreeDamageVisitorTests, visiting_a_populated_tree_with_a_damaged_leaf_node)
+{
+	insert_values(10000);
+	commit();
+
+	btree_layout<1, thing_traits> layout;
+	tree_->visit_depth_first(layout);
+
+	typedef typename btree_layout<1, thing_traits>::node_info node_info;
+	vector<typename node_info::ptr> const &nodes = layout.get_nodes();
+
+	unsigned nr_leaf = 0;
+	for (unsigned i = 0; i < nodes.size(); i++)
+		if (nodes[i]->leaf)
+			nr_leaf++;
+
+	unsigned target = random() % nr_leaf;
+	unsigned i;
+	for (i = 0; i < nodes.size(); i++)
+		if (nodes[i]->leaf) {
+			if (!target)
+				break;
+			else
+				target--;
+		}
+
+	typename node_info::ptr n = nodes[i];
+
+	trash_block(n->b);
+	cerr << "trashed leaf node with keys " << n->keys << endl;
+
+	expect_value_range(0, *n->keys.begin_);
+	expect_value_range(*n->keys.end_, 10000);
+	expect_damage(0, n->keys);
+
+	run();
+}
+
 //----------------------------------------------------------------