github.com/theQRL/go-zond@v0.1.1/les/state_accessor.go (about)

     1  // Copyright 2021 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package les
    18  
    19  import (
    20  	"context"
    21  	"errors"
    22  	"fmt"
    23  
    24  	"github.com/theQRL/go-zond/core"
    25  	"github.com/theQRL/go-zond/core/state"
    26  	"github.com/theQRL/go-zond/core/types"
    27  	"github.com/theQRL/go-zond/core/vm"
    28  	"github.com/theQRL/go-zond/zond/tracers"
    29  	"github.com/theQRL/go-zond/light"
    30  )
    31  
    32  // noopReleaser is returned in case there is no operation expected
    33  // for releasing state.
    34  var noopReleaser = tracers.StateReleaseFunc(func() {})
    35  
    36  // stateAtBlock retrieves the state database associated with a certain block.
    37  func (leth *LightEthereum) stateAtBlock(ctx context.Context, block *types.Block, reexec uint64) (*state.StateDB, tracers.StateReleaseFunc, error) {
    38  	return light.NewState(ctx, block.Header(), leth.odr), noopReleaser, nil
    39  }
    40  
    41  // stateAtTransaction returns the execution environment of a certain transaction.
    42  func (leth *LightEthereum) stateAtTransaction(ctx context.Context, block *types.Block, txIndex int, reexec uint64) (*core.Message, vm.BlockContext, *state.StateDB, tracers.StateReleaseFunc, error) {
    43  	// Short circuit if it's genesis block.
    44  	if block.NumberU64() == 0 {
    45  		return nil, vm.BlockContext{}, nil, nil, errors.New("no transaction in genesis")
    46  	}
    47  	// Create the parent state database
    48  	parent, err := leth.blockchain.GetBlock(ctx, block.ParentHash(), block.NumberU64()-1)
    49  	if err != nil {
    50  		return nil, vm.BlockContext{}, nil, nil, err
    51  	}
    52  	statedb, release, err := leth.stateAtBlock(ctx, parent, reexec)
    53  	if err != nil {
    54  		return nil, vm.BlockContext{}, nil, nil, err
    55  	}
    56  	if txIndex == 0 && len(block.Transactions()) == 0 {
    57  		return nil, vm.BlockContext{}, statedb, release, nil
    58  	}
    59  	// Recompute transactions up to the target index.
    60  	signer := types.MakeSigner(leth.blockchain.Config(), block.Number(), block.Time())
    61  	for idx, tx := range block.Transactions() {
    62  		// Assemble the transaction call message and return if the requested offset
    63  		msg, _ := core.TransactionToMessage(tx, signer, block.BaseFee())
    64  		txContext := core.NewEVMTxContext(msg)
    65  		context := core.NewEVMBlockContext(block.Header(), leth.blockchain, nil)
    66  		statedb.SetTxContext(tx.Hash(), idx)
    67  		if idx == txIndex {
    68  			return msg, context, statedb, release, nil
    69  		}
    70  		// Not yet the searched for transaction, execute on top of the current state
    71  		vmenv := vm.NewEVM(context, txContext, statedb, leth.blockchain.Config(), vm.Config{})
    72  		if _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas())); err != nil {
    73  			return nil, vm.BlockContext{}, nil, nil, fmt.Errorf("transaction %#x failed: %v", tx.Hash(), err)
    74  		}
    75  		// Ensure any modifications are committed to the state
    76  		// Only delete empty objects if EIP158/161 (a.k.a Spurious Dragon) is in effect
    77  		statedb.Finalise(vmenv.ChainConfig().IsEIP158(block.Number()))
    78  	}
    79  	return nil, vm.BlockContext{}, nil, nil, fmt.Errorf("transaction index %d out of range for block %#x", txIndex, block.Hash())
    80  }