github.com/RobustRoundRobin/quorum@v20.10.0+incompatible/core/state/database.go

// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package state

import (
	"fmt"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/rawdb"
	"github.com/ethereum/go-ethereum/ethdb"
	"github.com/ethereum/go-ethereum/trie"
	lru "github.com/hashicorp/golang-lru"
)

const (
	// Number of codehash->size associations to keep.
	codeSizeCacheSize = 100000
)

// Database wraps access to tries and contract code.
type Database interface {
	// OpenTrie opens the main account trie.
	OpenTrie(root common.Hash) (Trie, error)

	// OpenStorageTrie opens the storage trie of an account.
	OpenStorageTrie(addrHash, root common.Hash) (Trie, error)

	// CopyTrie returns an independent copy of the given trie.
	CopyTrie(Trie) Trie

	// ContractCode retrieves a particular contract's code.
	ContractCode(addrHash, codeHash common.Hash) ([]byte, error)

	// ContractCodeSize retrieves a particular contracts code's size.
	ContractCodeSize(addrHash, codeHash common.Hash) (int, error)

	// TrieDB retrieves the low level trie database used for data storage.
	TrieDB() *trie.Database

	// Privacy metadata linker
	PrivacyMetadataLinker() rawdb.PrivacyMetadataLinker
}

// Trie is a Ethereum Merkle Patricia trie.
type Trie interface {
	// GetKey returns the sha3 preimage of a hashed key that was previously used
	// to store a value.
	//
	// TODO(fjl): remove this when SecureTrie is removed
	GetKey([]byte) []byte

	// TryGet returns the value for key stored in the trie. The value bytes must
	// not be modified by the caller. If a node was not found in the database, a
	// trie.MissingNodeError is returned.
	TryGet(key []byte) ([]byte, error)

	// TryUpdate associates key with value in the trie. If value has length zero, any
	// existing value is deleted from the trie. The value bytes must not be modified
	// by the caller while they are stored in the trie. If a node was not found in the
	// database, a trie.MissingNodeError is returned.
	TryUpdate(key, value []byte) error

	// TryDelete removes any existing value for key from the trie. If a node was not
	// found in the database, a trie.MissingNodeError is returned.
	TryDelete(key []byte) error

	// Hash returns the root hash of the trie. It does not write to the database and
	// can be used even if the trie doesn't have one.
	Hash() common.Hash

	// Commit writes all nodes to the trie's memory database, tracking the internal
	// and external (for account tries) references.
	Commit(onleaf trie.LeafCallback) (common.Hash, error)

	// NodeIterator returns an iterator that returns nodes of the trie. Iteration
	// starts at the key after the given start key.
	NodeIterator(startKey []byte) trie.NodeIterator

	// Prove constructs a Merkle proof for key. The result contains all encoded nodes
	// on the path to the value at key. The value itself is also included in the last
	// node and can be retrieved by verifying the proof.
	//
	// If the trie does not contain a value for key, the returned proof contains all
	// nodes of the longest existing prefix of the key (at least the root), ending
	// with the node that proves the absence of the key.
	Prove(key []byte, fromLevel uint, proofDb ethdb.KeyValueWriter) error
}

// NewDatabase creates a backing store for state. The returned database is safe for
// concurrent use, but does not retain any recent trie nodes in memory. To keep some
// historical state in memory, use the NewDatabaseWithCache constructor.
func NewDatabase(db ethdb.Database) Database {
	return NewDatabaseWithCache(db, 0)
}

// NewDatabaseWithCache creates a backing store for state. The returned database
// is safe for concurrent use and retains a lot of collapsed RLP trie nodes in a
// large memory cache.
func NewDatabaseWithCache(db ethdb.Database, cache int) Database {
	csc, _ := lru.New(codeSizeCacheSize)
	return &cachingDB{
		db: trie.NewDatabaseWithCache(db, cache),
		// Quorum - Privacy Enhancements
		privacyMetadataLinker: rawdb.NewPrivacyMetadataLinker(db),
		codeSizeCache:         csc,
	}
}

type cachingDB struct {
	db *trie.Database
	// Quorum:  Privacy enhacements introducing privacyMetadataLinker which maintains mapping between private state root and privacy metadata root. As this struct is the backing store for state, this gives the reference to the linker when needed.
	privacyMetadataLinker rawdb.PrivacyMetadataLinker
	codeSizeCache         *lru.Cache
}

// Quorum - Privacy Enhancements
func (db *cachingDB) PrivacyMetadataLinker() rawdb.PrivacyMetadataLinker {
	return db.privacyMetadataLinker
}

// OpenTrie opens the main account trie at a specific root hash.
func (db *cachingDB) OpenTrie(root common.Hash) (Trie, error) {
	return trie.NewSecure(root, db.db)
}

// OpenStorageTrie opens the storage trie of an account.
func (db *cachingDB) OpenStorageTrie(addrHash, root common.Hash) (Trie, error) {
	return trie.NewSecure(root, db.db)
}

// CopyTrie returns an independent copy of the given trie.
func (db *cachingDB) CopyTrie(t Trie) Trie {
	switch t := t.(type) {
	case *trie.SecureTrie:
		return t.Copy()
	default:
		panic(fmt.Errorf("unknown trie type %T", t))
	}
}

// ContractCode retrieves a particular contract's code.
func (db *cachingDB) ContractCode(addrHash, codeHash common.Hash) ([]byte, error) {
	code, err := db.db.Node(codeHash)
	if err == nil {
		db.codeSizeCache.Add(codeHash, len(code))
	}
	return code, err
}

// ContractCodeSize retrieves a particular contracts code's size.
func (db *cachingDB) ContractCodeSize(addrHash, codeHash common.Hash) (int, error) {
	if cached, ok := db.codeSizeCache.Get(codeHash); ok {
		return cached.(int), nil
	}
	code, err := db.ContractCode(addrHash, codeHash)
	return len(code), err
}

// TrieDB retrieves any intermediate trie-node caching layer.
func (db *cachingDB) TrieDB() *trie.Database {
	return db.db
}