Some cosmetic work on TrieDB.

libdevcore/TrieDB.h

@@ -66,7 +66,7 @@ class GenericTrieDB
 public:
 	using DB = _DB;
 
-	GenericTrieDB(DB* _db = nullptr): m_db(_db) {}
+	explicit GenericTrieDB(DB* _db = nullptr): m_db(_db) {}
 	GenericTrieDB(DB* _db, h256 const& _root, Verification _v = Verification::Normal) { open(_db, _root, _v); }
 	~GenericTrieDB() {}
 
@@ -96,11 +96,72 @@ public:
 	/// True if the trie is initialised but empty (i.e. that the DB contains the root node which is empty).
 	bool isEmpty() const { return m_root == c_shaNull && node(m_root).size(); }
 
-	h256 const& root() const { if (!node(m_root).size()) BOOST_THROW_EXCEPTION(BadRoot()); /*std::cout << "Returning root as " << ret << " (really " << m_root << ")" << std::endl;*/ return m_root; }	// patch the root in the case of the empty trie. TODO: handle this properly.
+	h256 const& root() const { if (node(m_root).empty()) BOOST_THROW_EXCEPTION(BadRoot()); /*std::cout << "Returning root as " << ret << " (really " << m_root << ")" << std::endl;*/ return m_root; }	// patch the root in the case of the empty trie. TODO: handle this properly.
+
+	std::string at(bytes const& _key) const { return at(&_key); }
+	std::string at(bytesConstRef _key) const;
+	void insert(bytes const& _key, bytes const& _value) { insert(&_key, &_value); }
+	void insert(bytesConstRef _key, bytes const& _value) { insert(_key, &_value); }
+	void insert(bytes const& _key, bytesConstRef _value) { insert(&_key, _value); }
+	void insert(bytesConstRef _key, bytesConstRef _value);
+	void remove(bytes const& _key) { remove(&_key); }
+	void remove(bytesConstRef _key);
+	bool contains(bytes const& _key) { return contains(&_key); }
+	bool contains(bytesConstRef _key) { return !at(_key).empty(); }
+
+	class iterator
+	{
+	public:
+		using value_type = std::pair<bytesConstRef, bytesConstRef>;
+
+		iterator() {}
+		explicit iterator(GenericTrieDB const* _db);
+		iterator(GenericTrieDB const* _db, bytesConstRef _key);
+
+		iterator& operator++() { next(); return *this; }
+
+		value_type operator*() const { return at(); }
+		value_type operator->() const { return at(); }
+
+		bool operator==(iterator const& _c) const { return _c.m_trail == m_trail; }
+		bool operator!=(iterator const& _c) const { return _c.m_trail != m_trail; }
+
+		value_type at() const;
+
+	private:
+		void next();
+		void next(NibbleSlice _key);
+
+		struct Node
+		{
+			std::string rlp;
+			std::string key;		// as hexPrefixEncoding.
+			byte child;				// 255 -> entering, 16 -> actually at the node, 17 -> exiting, 0-15 -> actual children.
+
+			// 255 -> 16 -> 0 -> 1 -> ... -> 15 -> 17
+
+			void setChild(unsigned _i) { child = _i; }
+			void setFirstChild() { child = 16; }
+			void incrementChild() { child = child == 16 ? 0 : child == 15 ? 17 : (child + 1); }
+
+			bool operator==(Node const& _c) const { return rlp == _c.rlp && key == _c.key && child == _c.child; }
+			bool operator!=(Node const& _c) const { return !operator==(_c); }
+		};
+
+	protected:
+		std::vector<Node> m_trail;
+		GenericTrieDB<DB> const* m_that;
+	};
+
+	iterator begin() const { return iterator(this); }
+	iterator end() const { return iterator(); }
+
+	iterator lower_bound(bytesConstRef _key) const { return iterator(this, _key); }
 
 	void debugPrint() {}
 
-	void descendKey(h256 _k, h256Hash& _keyMask, bool _wasExt, std::ostream* _out, int _indent = 0) const
+	/// Used for debugging, scans the whole trie.
+	void descendKey(h256 const& _k, h256Hash& _keyMask, bool _wasExt, std::ostream* _out, int _indent = 0) const
 	{
 		_keyMask.erase(_k);
 		if (_k == m_root && _k == c_shaNull)	// root allowed to be empty
@@ -108,6 +169,7 @@ public:
 		descendList(RLP(node(_k)), _keyMask, _wasExt, _out, _indent);	// if not, it must be a list
 	}
 
+	/// Used for debugging, scans the whole trie.
 	void descendEntry(RLP const& _r, h256Hash& _keyMask, bool _wasExt, std::ostream* _out, int _indent) const
 	{
 		if (_r.isData() && _r.size() == 32)
@@ -118,6 +180,7 @@ public:
 			BOOST_THROW_EXCEPTION(InvalidTrie());
 	}
 
+	/// Used for debugging, scans the whole trie.
 	void descendList(RLP const& _r, h256Hash& _keyMask, bool _wasExt, std::ostream* _out, int _indent) const
 	{
 		if (_r.isList() && _r.itemCount() == 2 && (!_wasExt || _out))
@@ -139,6 +202,7 @@ public:
 			BOOST_THROW_EXCEPTION(InvalidTrie());
 	}
 
+	/// Used for debugging, scans the whole trie.
 	h256Hash leftOvers(std::ostream* _out = nullptr) const
 	{
 		h256Hash k = m_db->keys();
@@ -146,11 +210,14 @@ public:
 		return k;
 	}
 
+	/// Used for debugging, scans the whole trie.
 	void debugStructure(std::ostream& _out) const
 	{
 		leftOvers(&_out);
 	}
 
+	/// Used for debugging, scans the whole trie.
+	/// @param _requireNoLeftOvers if true, requires that all keys are reachable.
 	bool check(bool _requireNoLeftOvers) const
 	{
 		try
@@ -164,66 +231,6 @@ public:
 		}
 	}
 
-	std::string at(bytes const& _key) const { return at(&_key); }
-	std::string at(bytesConstRef _key) const;
-	void insert(bytes const& _key, bytes const& _value) { insert(&_key, &_value); }
-	void insert(bytesConstRef _key, bytes const& _value) { insert(_key, &_value); }
-	void insert(bytes const& _key, bytesConstRef _value) { insert(&_key, _value); }
-	void insert(bytesConstRef _key, bytesConstRef _value);
-	void remove(bytes const& _key) { remove(&_key); }
-	void remove(bytesConstRef _key);
-	bool contains(bytes const& _key) { return contains(&_key); }
-	bool contains(bytesConstRef _key) { return !at(_key).empty(); }
-
-	class iterator
-	{
-	public:
-		using value_type = std::pair<bytesConstRef, bytesConstRef>;
-
-		iterator() {}
-		iterator(GenericTrieDB const* _db);
-		iterator(GenericTrieDB const* _db, bytesConstRef _key);
-
-		iterator& operator++() { next(); return *this; }
-
-		value_type operator*() const { return at(); }
-		value_type operator->() const { return at(); }
-
-		bool operator==(iterator const& _c) const { return _c.m_trail == m_trail; }
-		bool operator!=(iterator const& _c) const { return _c.m_trail != m_trail; }
-
-		value_type at() const;
-
-	private:
-		void next();
-		void next(NibbleSlice _key);
-
-		struct Node
-		{
-			std::string rlp;
-			std::string key;		// as hexPrefixEncoding.
-			byte child;				// 255 -> entering, 16 -> actually at the node, 17 -> exiting, 0-15 -> actual children.
-
-			// 255 -> 16 -> 0 -> 1 -> ... -> 15 -> 17
-
-			void setChild(unsigned _i) { child = _i; }
-			void setFirstChild() { child = 16; }
-			void incrementChild() { child = child == 16 ? 0 : child == 15 ? 17 : (child + 1); }
-
-			bool operator==(Node const& _c) const { return rlp == _c.rlp && key == _c.key && child == _c.child; }
-			bool operator!=(Node const& _c) const { return !operator==(_c); }
-		};
-
-	protected:
-		std::vector<Node> m_trail;
-		GenericTrieDB<DB> const* m_that;
-	};
-
-	iterator begin() const { return this; }
-	iterator end() const { return iterator(); }
-
-	iterator lower_bound(bytesConstRef _key) const { return iterator(this, _key); }
-
 protected:
 	DB* db() const { return m_db; }
 
@@ -279,12 +286,12 @@ private:
 	bool isTwoItemNode(RLP const& _n) const;
 	std::string deref(RLP const& _n) const;
 
-	std::string node(h256 _h) const { return m_db->lookup(_h); }
+	std::string node(h256 const& _h) const { return m_db->lookup(_h); }
 
 	// These are low-level node insertion functions that just go straight through into the DB.
 	h256 forceInsertNode(bytesConstRef _v) { auto h = sha3(_v); forceInsertNode(h, _v); return h; }
-	void forceInsertNode(h256 _h, bytesConstRef _v) { m_db->insert(_h, _v); }
+	void forceInsertNode(h256 const& _h, bytesConstRef _v) { m_db->insert(_h, _v); }
-	void forceKillNode(h256 _h) { m_db->kill(_h); }
+	void forceKillNode(h256 const& _h) { m_db->kill(_h); }
 
 	// This are semantically-aware node insertion functions that only kills when the node's
 	// data is < 32 bytes. It can safely be used when pruning the trie but won't work correctly
@@ -305,6 +312,9 @@ std::ostream& operator<<(std::ostream& _out, GenericTrieDB<DB> const& _db)
 	return _out;
 }
 
+/**
+ * Different view on a GenericTrieDB that can use different key types.
+ */
 template <class Generic, class _KeyType>
 class SpecificTrieDB: public Generic
 {
@@ -753,14 +763,14 @@ template <class DB> void GenericTrieDB<DB>::insert(bytesConstRef _key, bytesCons
 	tdebug << "Insert" << toHex(_key.cropped(0, 4)) << "=>" << toHex(_value);
 #endif
 
-	std::string rv = node(m_root);
+	std::string rootValue = node(m_root);
-	assert(rv.size());
+	assert(rootValue.size());
-	bytes b = mergeAt(RLP(rv), m_root, NibbleSlice(_key), _value);
+	bytes b = mergeAt(RLP(rootValue), m_root, NibbleSlice(_key), _value);
 
 	// mergeAt won't attempt to delete the node if it's less than 32 bytes
 	// However, we know it's the root node and thus always hashed.
 	// So, if it's less than 32 (and thus should have been deleted but wasn't) then we delete it here.
-	if (rv.size() < 32)
+	if (rootValue.size() < 32)
 		forceKillNode(m_root);
 	m_root = forceInsertNode(&b);
 }