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Diffstat (limited to 'accounts/abi/bind/backends/simulated.go')
| -rw-r--r-- | accounts/abi/bind/backends/simulated.go | 523 |
1 files changed, 523 insertions, 0 deletions
diff --git a/accounts/abi/bind/backends/simulated.go b/accounts/abi/bind/backends/simulated.go new file mode 100644 index 0000000..88610a4 --- /dev/null +++ b/accounts/abi/bind/backends/simulated.go @@ -0,0 +1,523 @@ +// 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 <http://www.gnu.org/licenses/>. + +package backends + +import ( + "context" + "errors" + "fmt" + "math/big" + "sync" + "time" + + "github.com/ava-labs/coreth/accounts/abi/bind" + "github.com/ava-labs/coreth/consensus/ethash" + "github.com/ava-labs/coreth/core" + "github.com/ava-labs/coreth/core/bloombits" + "github.com/ava-labs/coreth/core/rawdb" + "github.com/ava-labs/coreth/core/state" + "github.com/ava-labs/coreth/core/types" + "github.com/ava-labs/coreth/core/vm" + "github.com/ava-labs/coreth/params" + "github.com/ava-labs/coreth/rpc" + "github.com/ava-labs/go-ethereum" + "github.com/ava-labs/go-ethereum/common" + "github.com/ava-labs/go-ethereum/common/math" + "github.com/ava-labs/go-ethereum/eth/filters" + "github.com/ava-labs/go-ethereum/ethdb" + "github.com/ava-labs/go-ethereum/event" +) + +// This nil assignment ensures compile time that SimulatedBackend implements bind.ContractBackend. +var _ bind.ContractBackend = (*SimulatedBackend)(nil) + +var ( + errBlockNumberUnsupported = errors.New("simulatedBackend cannot access blocks other than the latest block") + errGasEstimationFailed = errors.New("gas required exceeds allowance or always failing transaction") +) + +// SimulatedBackend implements bind.ContractBackend, simulating a blockchain in +// the background. Its main purpose is to allow easily testing contract bindings. +type SimulatedBackend struct { + database ethdb.Database // In memory database to store our testing data + blockchain *core.BlockChain // Ethereum blockchain to handle the consensus + + mu sync.Mutex + pendingBlock *types.Block // Currently pending block that will be imported on request + pendingState *state.StateDB // Currently pending state that will be the active on on request + + events *filters.EventSystem // Event system for filtering log events live + + config *params.ChainConfig +} + +// NewSimulatedBackendWithDatabase creates a new binding backend based on the given database +// and uses a simulated blockchain for testing purposes. +func NewSimulatedBackendWithDatabase(database ethdb.Database, alloc core.GenesisAlloc, gasLimit uint64) *SimulatedBackend { + genesis := core.Genesis{Config: params.AllEthashProtocolChanges, GasLimit: gasLimit, Alloc: alloc} + genesis.MustCommit(database) + blockchain, _ := core.NewBlockChain(database, nil, genesis.Config, ethash.NewFaker(), vm.Config{}, nil) + + backend := &SimulatedBackend{ + database: database, + blockchain: blockchain, + config: genesis.Config, + events: filters.NewEventSystem(new(event.TypeMux), &filterBackend{database, blockchain}, false), + } + backend.rollback() + return backend +} + +// NewSimulatedBackend creates a new binding backend using a simulated blockchain +// for testing purposes. +func NewSimulatedBackend(alloc core.GenesisAlloc, gasLimit uint64) *SimulatedBackend { + return NewSimulatedBackendWithDatabase(rawdb.NewMemoryDatabase(), alloc, gasLimit) +} + +// Close terminates the underlying blockchain's update loop. +func (b *SimulatedBackend) Close() error { + b.blockchain.Stop() + return nil +} + +// Commit imports all the pending transactions as a single block and starts a +// fresh new state. +func (b *SimulatedBackend) Commit() { + b.mu.Lock() + defer b.mu.Unlock() + + if _, err := b.blockchain.InsertChain([]*types.Block{b.pendingBlock}); err != nil { + panic(err) // This cannot happen unless the simulator is wrong, fail in that case + } + b.rollback() +} + +// Rollback aborts all pending transactions, reverting to the last committed state. +func (b *SimulatedBackend) Rollback() { + b.mu.Lock() + defer b.mu.Unlock() + + b.rollback() +} + +func (b *SimulatedBackend) rollback() { + blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), ethash.NewFaker(), b.database, 1, func(int, *core.BlockGen) {}) + statedb, _ := b.blockchain.State() + + b.pendingBlock = blocks[0] + b.pendingState, _ = state.New(b.pendingBlock.Root(), statedb.Database()) +} + +// CodeAt returns the code associated with a certain account in the blockchain. +func (b *SimulatedBackend) CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error) { + b.mu.Lock() + defer b.mu.Unlock() + + if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 { + return nil, errBlockNumberUnsupported + } + statedb, _ := b.blockchain.State() + return statedb.GetCode(contract), nil +} + +// BalanceAt returns the wei balance of a certain account in the blockchain. +func (b *SimulatedBackend) BalanceAt(ctx context.Context, contract common.Address, blockNumber *big.Int) (*big.Int, error) { + b.mu.Lock() + defer b.mu.Unlock() + + if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 { + return nil, errBlockNumberUnsupported + } + statedb, _ := b.blockchain.State() + return statedb.GetBalance(contract), nil +} + +// NonceAt returns the nonce of a certain account in the blockchain. +func (b *SimulatedBackend) NonceAt(ctx context.Context, contract common.Address, blockNumber *big.Int) (uint64, error) { + b.mu.Lock() + defer b.mu.Unlock() + + if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 { + return 0, errBlockNumberUnsupported + } + statedb, _ := b.blockchain.State() + return statedb.GetNonce(contract), nil +} + +// StorageAt returns the value of key in the storage of an account in the blockchain. +func (b *SimulatedBackend) StorageAt(ctx context.Context, contract common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error) { + b.mu.Lock() + defer b.mu.Unlock() + + if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 { + return nil, errBlockNumberUnsupported + } + statedb, _ := b.blockchain.State() + val := statedb.GetState(contract, key) + return val[:], nil +} + +// TransactionReceipt returns the receipt of a transaction. +func (b *SimulatedBackend) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error) { + receipt, _, _, _ := rawdb.ReadReceipt(b.database, txHash, b.config) + return receipt, nil +} + +// TransactionByHash checks the pool of pending transactions in addition to the +// blockchain. The isPending return value indicates whether the transaction has been +// mined yet. Note that the transaction may not be part of the canonical chain even if +// it's not pending. +func (b *SimulatedBackend) TransactionByHash(ctx context.Context, txHash common.Hash) (*types.Transaction, bool, error) { + b.mu.Lock() + defer b.mu.Unlock() + + tx := b.pendingBlock.Transaction(txHash) + if tx != nil { + return tx, true, nil + } + tx, _, _, _ = rawdb.ReadTransaction(b.database, txHash) + if tx != nil { + return tx, false, nil + } + return nil, false, ethereum.NotFound +} + +// PendingCodeAt returns the code associated with an account in the pending state. +func (b *SimulatedBackend) PendingCodeAt(ctx context.Context, contract common.Address) ([]byte, error) { + b.mu.Lock() + defer b.mu.Unlock() + + return b.pendingState.GetCode(contract), nil +} + +// CallContract executes a contract call. +func (b *SimulatedBackend) CallContract(ctx context.Context, call ethereum.CallMsg, blockNumber *big.Int) ([]byte, error) { + b.mu.Lock() + defer b.mu.Unlock() + + if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 { + return nil, errBlockNumberUnsupported + } + state, err := b.blockchain.State() + if err != nil { + return nil, err + } + rval, _, _, err := b.callContract(ctx, call, b.blockchain.CurrentBlock(), state) + return rval, err +} + +// PendingCallContract executes a contract call on the pending state. +func (b *SimulatedBackend) PendingCallContract(ctx context.Context, call ethereum.CallMsg) ([]byte, error) { + b.mu.Lock() + defer b.mu.Unlock() + defer b.pendingState.RevertToSnapshot(b.pendingState.Snapshot()) + + rval, _, _, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState) + return rval, err +} + +// PendingNonceAt implements PendingStateReader.PendingNonceAt, retrieving +// the nonce currently pending for the account. +func (b *SimulatedBackend) PendingNonceAt(ctx context.Context, account common.Address) (uint64, error) { + b.mu.Lock() + defer b.mu.Unlock() + + return b.pendingState.GetOrNewStateObject(account).Nonce(), nil +} + +// SuggestGasPrice implements ContractTransactor.SuggestGasPrice. Since the simulated +// chain doesn't have miners, we just return a gas price of 1 for any call. +func (b *SimulatedBackend) SuggestGasPrice(ctx context.Context) (*big.Int, error) { + return big.NewInt(1), nil +} + +// EstimateGas executes the requested code against the currently pending block/state and +// returns the used amount of gas. +func (b *SimulatedBackend) EstimateGas(ctx context.Context, call ethereum.CallMsg) (uint64, error) { + b.mu.Lock() + defer b.mu.Unlock() + + // Determine the lowest and highest possible gas limits to binary search in between + var ( + lo uint64 = params.TxGas - 1 + hi uint64 + cap uint64 + ) + if call.Gas >= params.TxGas { + hi = call.Gas + } else { + hi = b.pendingBlock.GasLimit() + } + cap = hi + + // Create a helper to check if a gas allowance results in an executable transaction + executable := func(gas uint64) bool { + call.Gas = gas + + snapshot := b.pendingState.Snapshot() + _, _, failed, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState) + b.pendingState.RevertToSnapshot(snapshot) + + if err != nil || failed { + return false + } + return true + } + // Execute the binary search and hone in on an executable gas limit + for lo+1 < hi { + mid := (hi + lo) / 2 + if !executable(mid) { + lo = mid + } else { + hi = mid + } + } + // Reject the transaction as invalid if it still fails at the highest allowance + if hi == cap { + if !executable(hi) { + return 0, errGasEstimationFailed + } + } + return hi, nil +} + +// callContract implements common code between normal and pending contract calls. +// state is modified during execution, make sure to copy it if necessary. +func (b *SimulatedBackend) callContract(ctx context.Context, call ethereum.CallMsg, block *types.Block, statedb *state.StateDB) ([]byte, uint64, bool, error) { + // Ensure message is initialized properly. + if call.GasPrice == nil { + call.GasPrice = big.NewInt(1) + } + if call.Gas == 0 { + call.Gas = 50000000 + } + if call.Value == nil { + call.Value = new(big.Int) + } + // Set infinite balance to the fake caller account. + from := statedb.GetOrNewStateObject(call.From) + from.SetBalance(math.MaxBig256) + // Execute the call. + msg := callmsg{call} + + evmContext := core.NewEVMContext(msg, block.Header(), b.blockchain, nil) + // Create a new environment which holds all relevant information + // about the transaction and calling mechanisms. + vmenv := vm.NewEVM(evmContext, statedb, b.config, vm.Config{}) + gaspool := new(core.GasPool).AddGas(math.MaxUint64) + + return core.NewStateTransition(vmenv, msg, gaspool).TransitionDb() +} + +// SendTransaction updates the pending block to include the given transaction. +// It panics if the transaction is invalid. +func (b *SimulatedBackend) SendTransaction(ctx context.Context, tx *types.Transaction) error { + b.mu.Lock() + defer b.mu.Unlock() + + sender, err := types.Sender(types.NewEIP155Signer(b.config.ChainID), tx) + if err != nil { + panic(fmt.Errorf("invalid transaction: %v", err)) + } + nonce := b.pendingState.GetNonce(sender) + if tx.Nonce() != nonce { + panic(fmt.Errorf("invalid transaction nonce: got %d, want %d", tx.Nonce(), nonce)) + } + + blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), ethash.NewFaker(), b.database, 1, func(number int, block *core.BlockGen) { + for _, tx := range b.pendingBlock.Transactions() { + block.AddTxWithChain(b.blockchain, tx) + } + block.AddTxWithChain(b.blockchain, tx) + }) + statedb, _ := b.blockchain.State() + + b.pendingBlock = blocks[0] + b.pendingState, _ = state.New(b.pendingBlock.Root(), statedb.Database()) + return nil +} + +// FilterLogs executes a log filter operation, blocking during execution and +// returning all the results in one batch. +// +// TODO(karalabe): Deprecate when the subscription one can return past data too. +func (b *SimulatedBackend) FilterLogs(ctx context.Context, query ethereum.FilterQuery) ([]types.Log, error) { + var filter *filters.Filter + if query.BlockHash != nil { + // Block filter requested, construct a single-shot filter + filter = filters.NewBlockFilter(&filterBackend{b.database, b.blockchain}, *query.BlockHash, query.Addresses, query.Topics) + } else { + // Initialize unset filter boundaried to run from genesis to chain head + from := int64(0) + if query.FromBlock != nil { + from = query.FromBlock.Int64() + } + to := int64(-1) + if query.ToBlock != nil { + to = query.ToBlock.Int64() + } + // Construct the range filter + filter = filters.NewRangeFilter(&filterBackend{b.database, b.blockchain}, from, to, query.Addresses, query.Topics) + } + // Run the filter and return all the logs + logs, err := filter.Logs(ctx) + if err != nil { + return nil, err + } + res := make([]types.Log, len(logs)) + for i, log := range logs { + res[i] = *log + } + return res, nil +} + +// SubscribeFilterLogs creates a background log filtering operation, returning a +// subscription immediately, which can be used to stream the found events. +func (b *SimulatedBackend) SubscribeFilterLogs(ctx context.Context, query ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error) { + // Subscribe to contract events + sink := make(chan []*types.Log) + + sub, err := b.events.SubscribeLogs(query, sink) + if err != nil { + return nil, err + } + // Since we're getting logs in batches, we need to flatten them into a plain stream + return event.NewSubscription(func(quit <-chan struct{}) error { + defer sub.Unsubscribe() + for { + select { + case logs := <-sink: + for _, log := range logs { + select { + case ch <- *log: + case err := <-sub.Err(): + return err + case <-quit: + return nil + } + } + case err := <-sub.Err(): + return err + case <-quit: + return nil + } + } + }), nil +} + +// AdjustTime adds a time shift to the simulated clock. +func (b *SimulatedBackend) AdjustTime(adjustment time.Duration) error { + b.mu.Lock() + defer b.mu.Unlock() + blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), ethash.NewFaker(), b.database, 1, func(number int, block *core.BlockGen) { + for _, tx := range b.pendingBlock.Transactions() { + block.AddTx(tx) + } + block.OffsetTime(int64(adjustment.Seconds())) + }) + statedb, _ := b.blockchain.State() + + b.pendingBlock = blocks[0] + b.pendingState, _ = state.New(b.pendingBlock.Root(), statedb.Database()) + + return nil +} + +// Blockchain returns the underlying blockchain. +func (b *SimulatedBackend) Blockchain() *core.BlockChain { + return b.blockchain +} + +// callmsg implements core.Message to allow passing it as a transaction simulator. +type callmsg struct { + ethereum.CallMsg +} + +func (m callmsg) From() common.Address { return m.CallMsg.From } +func (m callmsg) Nonce() uint64 { return 0 } +func (m callmsg) CheckNonce() bool { return false } +func (m callmsg) To() *common.Address { return m.CallMsg.To } +func (m callmsg) GasPrice() *big.Int { return m.CallMsg.GasPrice } +func (m callmsg) Gas() uint64 { return m.CallMsg.Gas } +func (m callmsg) Value() *big.Int { return m.CallMsg.Value } +func (m callmsg) Data() []byte { return m.CallMsg.Data } + +// filterBackend implements filters.Backend to support filtering for logs without +// taking bloom-bits acceleration structures into account. +type filterBackend struct { + db ethdb.Database + bc *core.BlockChain +} + +func (fb *filterBackend) ChainDb() ethdb.Database { return fb.db } +func (fb *filterBackend) EventMux() *event.TypeMux { panic("not supported") } + +func (fb *filterBackend) HeaderByNumber(ctx context.Context, block rpc.BlockNumber) (*types.Header, error) { + if block == rpc.LatestBlockNumber { + return fb.bc.CurrentHeader(), nil + } + return fb.bc.GetHeaderByNumber(uint64(block.Int64())), nil +} + +func (fb *filterBackend) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error) { + return fb.bc.GetHeaderByHash(hash), nil +} + +func (fb *filterBackend) GetReceipts(ctx context.Context, hash common.Hash) (types.Receipts, error) { + number := rawdb.ReadHeaderNumber(fb.db, hash) + if number == nil { + return nil, nil + } + return rawdb.ReadReceipts(fb.db, hash, *number, fb.bc.Config()), nil +} + +func (fb *filterBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error) { + number := rawdb.ReadHeaderNumber(fb.db, hash) + if number == nil { + return nil, nil + } + receipts := rawdb.ReadReceipts(fb.db, hash, *number, fb.bc.Config()) + if receipts == nil { + return nil, nil + } + logs := make([][]*types.Log, len(receipts)) + for i, receipt := range receipts { + logs[i] = receipt.Logs + } + return logs, nil +} + +func (fb *filterBackend) SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription { + return event.NewSubscription(func(quit <-chan struct{}) error { + <-quit + return nil + }) +} +func (fb *filterBackend) SubscribeChainEvent(ch chan<- core.ChainEvent) event.Subscription { + return fb.bc.SubscribeChainEvent(ch) +} +func (fb *filterBackend) SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription { + return fb.bc.SubscribeRemovedLogsEvent(ch) +} +func (fb *filterBackend) SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription { + return fb.bc.SubscribeLogsEvent(ch) +} + +func (fb *filterBackend) BloomStatus() (uint64, uint64) { return 4096, 0 } +func (fb *filterBackend) ServiceFilter(ctx context.Context, ms *bloombits.MatcherSession) { + panic("not supported") +} |