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/*
This file is part of cpp-ethereum.
cpp-ethereum is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Foobar is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file Trie.h
* @author Gav Wood <i@gavwood.com>
* @date 2014
*/
#pragma once
#include <map>
#include <leveldb/db.h>
#include "RLP.h"
namespace ldb = leveldb;
namespace eth
{
bytes rlp256(StringMap const& _s);
h256 hash256(StringMap const& _s);
h256 hash256(u256Map const& _s);
std::string hexPrefixEncode(bytes const& _hexVector, bool _terminated = false, int _begin = 0, int _end = -1);
class TrieNode;
/**
* @brief Merkle Patricia Tree "Trie": a modifed base-16 Radix tree.
*/
class Trie
{
public:
Trie(): m_root(nullptr) {}
~Trie();
h256 hash256() const;
bytes rlp() const;
void debugPrint();
std::string const& at(std::string const& _key) const;
void insert(std::string const& _key, std::string const& _value);
void remove(std::string const& _key);
private:
TrieNode* m_root;
};
/**
* @brief Merkle Patricia Tree "Trie": a modifed base-16 Radix tree.
* This version uses an LDB backend - TODO: split off m_db & m_over into opaque key/value map layer and allow caching & testing without DB.
* TODO: Implement!
*/
class GenericTrieDB
{
public:
GenericTrieDB() {}
GenericTrieDB(ldb::DB* _db, std::map<h256, std::string>* _overlay = nullptr): GenericTrieDB() { open(_db, c_null, _overlay); }
GenericTrieDB(ldb::DB* _db, h256 _root, std::map<h256, std::string>* _overlay = nullptr): GenericTrieDB() { open(_db, _root, _overlay); }
~GenericTrieDB() {}
void open(ldb::DB* _db, h256 _root, std::map<h256, std::string>* _overlay = nullptr) { m_root = _root; m_db = _db; m_over = _overlay; }
void setRoot(h256 _root) { m_root = _root; }
h256 root() const { return m_root; }
void debugPrint() {}
std::string at(bytesConstRef _key) const { return std::string(); }
void insert(bytesConstRef _key, bytesConstRef _value) {}
void remove(bytesConstRef _key) {}
// TODO: iterators.
private:
std::string node(h256 _h) const { if (_h == c_null) return std::string(); if (m_over) { auto it = m_over->find(_h); if (it != m_over->end()) return it->second; } std::string ret; m_db->Get(m_readOptions, ldb::Slice((char const*)&m_root, 32), &ret); return ret; }
void insertNode(h256 _h, bytesConstRef _v) const {}
void killNode(h256 _h) const {} // only from overlay - no killing from DB proper.
static const h256 c_null;
h256 m_root = c_null;
ldb::DB* m_db = nullptr;
std::map<h256, std::string>* m_over = nullptr;
ldb::ReadOptions m_readOptions;
};
template <class KeyType>
class TrieDB: public GenericTrieDB
{
public:
TrieDB() {}
TrieDB(ldb::DB* _db, std::map<h256, std::string>* _overlay = nullptr): GenericTrieDB(_db, _overlay) {}
TrieDB(ldb::DB* _db, h256 _root, std::map<h256, std::string>* _overlay = nullptr): GenericTrieDB() { open(_db, _root, _overlay); }
std::string operator[](KeyType _k) const { return at(_k); }
std::string at(KeyType _k) const { return GenericTrieDB::at(bytesConstRef((byte const*)&_k, sizeof(KeyType))); }
void insert(KeyType _k, bytesConstRef _value) { GenericTrieDB::insert(bytesConstRef((byte const*)&_k, sizeof(KeyType)), _value); }
void insert(KeyType _k, bytes const& _value) { insert(_k, bytesConstRef(&_value)); }
void remove(KeyType _k) { GenericTrieDB::remove(bytesConstRef((byte const*)&_k, sizeof(KeyType))); }
};
}