From 79b1169a9ff0b54ddf3b520a70a79c78ba5c988d Mon Sep 17 00:00:00 2001 From: Determinant Date: Mon, 21 Oct 2019 14:47:51 -0400 Subject: customize Blockchain code --- core/block_validator.go | 139 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 core/block_validator.go (limited to 'core/block_validator.go') diff --git a/core/block_validator.go b/core/block_validator.go new file mode 100644 index 0000000..ae6cd4d --- /dev/null +++ b/core/block_validator.go @@ -0,0 +1,139 @@ +// 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 core + +import ( + "fmt" + + "github.com/ava-labs/go-ethereum/consensus" + "github.com/ava-labs/go-ethereum/core/state" + "github.com/ava-labs/go-ethereum/core/types" + "github.com/ava-labs/go-ethereum/params" +) + +// BlockValidator is responsible for validating block headers, uncles and +// processed state. +// +// BlockValidator implements Validator. +type BlockValidator struct { + config *params.ChainConfig // Chain configuration options + bc *BlockChain // Canonical block chain + engine consensus.Engine // Consensus engine used for validating +} + +// NewBlockValidator returns a new block validator which is safe for re-use +func NewBlockValidator(config *params.ChainConfig, blockchain *BlockChain, engine consensus.Engine) *BlockValidator { + validator := &BlockValidator{ + config: config, + engine: engine, + bc: blockchain, + } + return validator +} + +// ValidateBody validates the given block's uncles and verifies the block +// header's transaction and uncle roots. The headers are assumed to be already +// validated at this point. +func (v *BlockValidator) ValidateBody(block *types.Block) error { + // Check whether the block's known, and if not, that it's linkable + if v.bc.HasBlockAndState(block.Hash(), block.NumberU64()) { + return ErrKnownBlock + } + // Header validity is known at this point, check the uncles and transactions + header := block.Header() + if err := v.engine.VerifyUncles(v.bc, block); err != nil { + return err + } + if hash := types.CalcUncleHash(block.Uncles()); hash != header.UncleHash { + return fmt.Errorf("uncle root hash mismatch: have %x, want %x", hash, header.UncleHash) + } + if hash := types.DeriveSha(block.Transactions()); hash != header.TxHash { + return fmt.Errorf("transaction root hash mismatch: have %x, want %x", hash, header.TxHash) + } + if !v.bc.HasBlockAndState(block.ParentHash(), block.NumberU64()-1) { + if !v.bc.HasBlock(block.ParentHash(), block.NumberU64()-1) { + return consensus.ErrUnknownAncestor + } + return consensus.ErrPrunedAncestor + } + return nil +} + +// ValidateState validates the various changes that happen after a state +// transition, such as amount of used gas, the receipt roots and the state root +// itself. ValidateState returns a database batch if the validation was a success +// otherwise nil and an error is returned. +func (v *BlockValidator) ValidateState(block *types.Block, statedb *state.StateDB, receipts types.Receipts, usedGas uint64) error { + header := block.Header() + if block.GasUsed() != usedGas { + return fmt.Errorf("invalid gas used (remote: %d local: %d)", block.GasUsed(), usedGas) + } + // Validate the received block's bloom with the one derived from the generated receipts. + // For valid blocks this should always validate to true. + rbloom := types.CreateBloom(receipts) + if rbloom != header.Bloom { + return fmt.Errorf("invalid bloom (remote: %x local: %x)", header.Bloom, rbloom) + } + // Tre receipt Trie's root (R = (Tr [[H1, R1], ... [Hn, R1]])) + receiptSha := types.DeriveSha(receipts) + if receiptSha != header.ReceiptHash { + return fmt.Errorf("invalid receipt root hash (remote: %x local: %x)", header.ReceiptHash, receiptSha) + } + // Validate the state root against the received state root and throw + // an error if they don't match. + if root := statedb.IntermediateRoot(v.config.IsEIP158(header.Number)); header.Root != root { + return fmt.Errorf("invalid merkle root (remote: %x local: %x)", header.Root, root) + } + return nil +} + +// CalcGasLimit computes the gas limit of the next block after parent. It aims +// to keep the baseline gas above the provided floor, and increase it towards the +// ceil if the blocks are full. If the ceil is exceeded, it will always decrease +// the gas allowance. +func CalcGasLimit(parent *types.Block, gasFloor, gasCeil uint64) uint64 { + // contrib = (parentGasUsed * 3 / 2) / 1024 + contrib := (parent.GasUsed() + parent.GasUsed()/2) / params.GasLimitBoundDivisor + + // decay = parentGasLimit / 1024 -1 + decay := parent.GasLimit()/params.GasLimitBoundDivisor - 1 + + /* + strategy: gasLimit of block-to-mine is set based on parent's + gasUsed value. if parentGasUsed > parentGasLimit * (2/3) then we + increase it, otherwise lower it (or leave it unchanged if it's right + at that usage) the amount increased/decreased depends on how far away + from parentGasLimit * (2/3) parentGasUsed is. + */ + limit := parent.GasLimit() - decay + contrib + if limit < params.MinGasLimit { + limit = params.MinGasLimit + } + // If we're outside our allowed gas range, we try to hone towards them + if limit < gasFloor { + limit = parent.GasLimit() + decay + if limit > gasFloor { + limit = gasFloor + } + } else if limit > gasCeil { + limit = parent.GasLimit() - decay + if limit < gasCeil { + limit = gasCeil + } + } + return limit +} -- cgit v1.2.3-70-g09d2