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authorDeterminant <[email protected]>2020-06-28 14:47:41 -0400
committerDeterminant <[email protected]>2020-06-28 14:47:41 -0400
commitd235e2c6a5788ec4a6cff15a16f56b38a3876a0d (patch)
tree5f2727f7a50ee5840f889c82776d3a30a88dd59b /accounts/abi/bind/backends
parent13ebd8bd9468e9d769d598b0ca2afb72ba78cb97 (diff)
...
Diffstat (limited to 'accounts/abi/bind/backends')
-rw-r--r--accounts/abi/bind/backends/simulated.go523
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")
+}