From d235e2c6a5788ec4a6cff15a16f56b38a3876a0d Mon Sep 17 00:00:00 2001 From: Determinant Date: Sun, 28 Jun 2020 14:47:41 -0400 Subject: ... --- core/state/iterator.go | 154 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 154 insertions(+) create mode 100644 core/state/iterator.go (limited to 'core/state/iterator.go') diff --git a/core/state/iterator.go b/core/state/iterator.go new file mode 100644 index 0000000..c6d2a48 --- /dev/null +++ b/core/state/iterator.go @@ -0,0 +1,154 @@ +// Copyright 2015 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 . + +package state + +import ( + "bytes" + "fmt" + + "github.com/ava-labs/go-ethereum/common" + "github.com/ava-labs/go-ethereum/rlp" + "github.com/ava-labs/go-ethereum/trie" +) + +// NodeIterator is an iterator to traverse the entire state trie post-order, +// including all of the contract code and contract state tries. +type NodeIterator struct { + state *StateDB // State being iterated + + stateIt trie.NodeIterator // Primary iterator for the global state trie + dataIt trie.NodeIterator // Secondary iterator for the data trie of a contract + + accountHash common.Hash // Hash of the node containing the account + codeHash common.Hash // Hash of the contract source code + code []byte // Source code associated with a contract + + Hash common.Hash // Hash of the current entry being iterated (nil if not standalone) + Parent common.Hash // Hash of the first full ancestor node (nil if current is the root) + + Error error // Failure set in case of an internal error in the iterator +} + +// NewNodeIterator creates an post-order state node iterator. +func NewNodeIterator(state *StateDB) *NodeIterator { + return &NodeIterator{ + state: state, + } +} + +// Next moves the iterator to the next node, returning whether there are any +// further nodes. In case of an internal error this method returns false and +// sets the Error field to the encountered failure. +func (it *NodeIterator) Next() bool { + // If the iterator failed previously, don't do anything + if it.Error != nil { + return false + } + // Otherwise step forward with the iterator and report any errors + if err := it.step(); err != nil { + it.Error = err + return false + } + return it.retrieve() +} + +// step moves the iterator to the next entry of the state trie. +func (it *NodeIterator) step() error { + // Abort if we reached the end of the iteration + if it.state == nil { + return nil + } + // Initialize the iterator if we've just started + if it.stateIt == nil { + it.stateIt = it.state.trie.NodeIterator(nil) + } + // If we had data nodes previously, we surely have at least state nodes + if it.dataIt != nil { + if cont := it.dataIt.Next(true); !cont { + if it.dataIt.Error() != nil { + return it.dataIt.Error() + } + it.dataIt = nil + } + return nil + } + // If we had source code previously, discard that + if it.code != nil { + it.code = nil + return nil + } + // Step to the next state trie node, terminating if we're out of nodes + if cont := it.stateIt.Next(true); !cont { + if it.stateIt.Error() != nil { + return it.stateIt.Error() + } + it.state, it.stateIt = nil, nil + return nil + } + // If the state trie node is an internal entry, leave as is + if !it.stateIt.Leaf() { + return nil + } + // Otherwise we've reached an account node, initiate data iteration + var account Account + if err := rlp.Decode(bytes.NewReader(it.stateIt.LeafBlob()), &account); err != nil { + return err + } + dataTrie, err := it.state.db.OpenStorageTrie(common.BytesToHash(it.stateIt.LeafKey()), account.Root) + if err != nil { + return err + } + it.dataIt = dataTrie.NodeIterator(nil) + if !it.dataIt.Next(true) { + it.dataIt = nil + } + if !bytes.Equal(account.CodeHash, emptyCodeHash) { + it.codeHash = common.BytesToHash(account.CodeHash) + addrHash := common.BytesToHash(it.stateIt.LeafKey()) + it.code, err = it.state.db.ContractCode(addrHash, common.BytesToHash(account.CodeHash)) + if err != nil { + return fmt.Errorf("code %x: %v", account.CodeHash, err) + } + } + it.accountHash = it.stateIt.Parent() + return nil +} + +// retrieve pulls and caches the current state entry the iterator is traversing. +// The method returns whether there are any more data left for inspection. +func (it *NodeIterator) retrieve() bool { + // Clear out any previously set values + it.Hash = common.Hash{} + + // If the iteration's done, return no available data + if it.state == nil { + return false + } + // Otherwise retrieve the current entry + switch { + case it.dataIt != nil: + it.Hash, it.Parent = it.dataIt.Hash(), it.dataIt.Parent() + if it.Parent == (common.Hash{}) { + it.Parent = it.accountHash + } + case it.code != nil: + it.Hash, it.Parent = it.codeHash, it.accountHash + case it.stateIt != nil: + it.Hash, it.Parent = it.stateIt.Hash(), it.stateIt.Parent() + } + return true +} -- cgit v1.2.3