api/bind: add CallOpts.BlockHash to allow calling contracts at a specific block hash (#28084)

* api/bind: Add CallOpts.BlockHash to allow calling contracts at a specific block hash.

* ethclient: Add BalanceAtHash, NonceAtHash and StorageAtHash functions
This commit is contained in:
Adrian Sutton 2023-10-17 22:34:01 +10:00 committed by GitHub
parent f62502e123
commit b85c86022e
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GPG Key ID: 4AEE18F83AFDEB23
7 changed files with 253 additions and 1 deletions

@ -36,6 +36,10 @@ var (
// on a backend that doesn't implement PendingContractCaller.
ErrNoPendingState = errors.New("backend does not support pending state")
// ErrNoBlockHashState is raised when attempting to perform a block hash action
// on a backend that doesn't implement BlockHashContractCaller.
ErrNoBlockHashState = errors.New("backend does not support block hash state")
// ErrNoCodeAfterDeploy is returned by WaitDeployed if contract creation leaves
// an empty contract behind.
ErrNoCodeAfterDeploy = errors.New("no contract code after deployment")
@ -64,6 +68,17 @@ type PendingContractCaller interface {
PendingCallContract(ctx context.Context, call ethereum.CallMsg) ([]byte, error)
}
// BlockHashContractCaller defines methods to perform contract calls on a specific block hash.
// Call will try to discover this interface when access to a block by hash is requested.
// If the backend does not support the block hash state, Call returns ErrNoBlockHashState.
type BlockHashContractCaller interface {
// CodeAtHash returns the code of the given account in the state at the specified block hash.
CodeAtHash(ctx context.Context, contract common.Address, blockHash common.Hash) ([]byte, error)
// CallContractAtHash executes an Ethereum contract all against the state at the specified block hash.
CallContractAtHash(ctx context.Context, call ethereum.CallMsg, blockHash common.Hash) ([]byte, error)
}
// ContractTransactor defines the methods needed to allow operating with a contract
// on a write only basis. Besides the transacting method, the remainder are helpers
// used when the user does not provide some needed values, but rather leaves it up

@ -50,6 +50,7 @@ var _ bind.ContractBackend = (*SimulatedBackend)(nil)
var (
errBlockNumberUnsupported = errors.New("simulatedBackend cannot access blocks other than the latest block")
errBlockHashUnsupported = errors.New("simulatedBackend cannot access blocks by hash other than the latest block")
errBlockDoesNotExist = errors.New("block does not exist in blockchain")
errTransactionDoesNotExist = errors.New("transaction does not exist")
)
@ -202,6 +203,24 @@ func (b *SimulatedBackend) CodeAt(ctx context.Context, contract common.Address,
return stateDB.GetCode(contract), nil
}
// CodeAtHash returns the code associated with a certain account in the blockchain.
func (b *SimulatedBackend) CodeAtHash(ctx context.Context, contract common.Address, blockHash common.Hash) ([]byte, error) {
b.mu.Lock()
defer b.mu.Unlock()
header, err := b.headerByHash(blockHash)
if err != nil {
return nil, err
}
stateDB, err := b.blockchain.StateAt(header.Root)
if err != nil {
return nil, err
}
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()
@ -320,7 +339,11 @@ func (b *SimulatedBackend) blockByNumber(ctx context.Context, number *big.Int) (
func (b *SimulatedBackend) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error) {
b.mu.Lock()
defer b.mu.Unlock()
return b.headerByHash(hash)
}
// headerByHash retrieves a header from the database by hash without Lock.
func (b *SimulatedBackend) headerByHash(hash common.Hash) (*types.Header, error) {
if hash == b.pendingBlock.Hash() {
return b.pendingBlock.Header(), nil
}
@ -436,6 +459,22 @@ func (b *SimulatedBackend) CallContract(ctx context.Context, call ethereum.CallM
if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number) != 0 {
return nil, errBlockNumberUnsupported
}
return b.callContractAtHead(ctx, call)
}
// CallContractAtHash executes a contract call on a specific block hash.
func (b *SimulatedBackend) CallContractAtHash(ctx context.Context, call ethereum.CallMsg, blockHash common.Hash) ([]byte, error) {
b.mu.Lock()
defer b.mu.Unlock()
if blockHash != b.blockchain.CurrentBlock().Hash() {
return nil, errBlockHashUnsupported
}
return b.callContractAtHead(ctx, call)
}
// callContractAtHead executes a contract call against the latest block state.
func (b *SimulatedBackend) callContractAtHead(ctx context.Context, call ethereum.CallMsg) ([]byte, error) {
stateDB, err := b.blockchain.State()
if err != nil {
return nil, err

@ -996,6 +996,43 @@ func TestCodeAt(t *testing.T) {
}
}
func TestCodeAtHash(t *testing.T) {
testAddr := crypto.PubkeyToAddress(testKey.PublicKey)
sim := simTestBackend(testAddr)
defer sim.Close()
bgCtx := context.Background()
code, err := sim.CodeAtHash(bgCtx, testAddr, sim.Blockchain().CurrentHeader().Hash())
if err != nil {
t.Errorf("could not get code at test addr: %v", err)
}
if len(code) != 0 {
t.Errorf("got code for account that does not have contract code")
}
parsed, err := abi.JSON(strings.NewReader(abiJSON))
if err != nil {
t.Errorf("could not get code at test addr: %v", err)
}
auth, _ := bind.NewKeyedTransactorWithChainID(testKey, big.NewInt(1337))
contractAddr, tx, contract, err := bind.DeployContract(auth, parsed, common.FromHex(abiBin), sim)
if err != nil {
t.Errorf("could not deploy contract: %v tx: %v contract: %v", err, tx, contract)
}
blockHash := sim.Commit()
code, err = sim.CodeAtHash(bgCtx, contractAddr, blockHash)
if err != nil {
t.Errorf("could not get code at test addr: %v", err)
}
if len(code) == 0 {
t.Errorf("did not get code for account that has contract code")
}
// ensure code received equals code deployed
if !bytes.Equal(code, common.FromHex(deployedCode)) {
t.Errorf("code received did not match expected deployed code:\n expected %v\n actual %v", common.FromHex(deployedCode), code)
}
}
// When receive("X") is called with sender 0x00... and value 1, it produces this tx receipt:
//
// receipt{status=1 cgas=23949 bloom=00000000004000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000040200000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 logs=[log: b6818c8064f645cd82d99b59a1a267d6d61117ef [75fd880d39c1daf53b6547ab6cb59451fc6452d27caa90e5b6649dd8293b9eed] 000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158 9ae378b6d4409eada347a5dc0c180f186cb62dc68fcc0f043425eb917335aa28 0 95d429d309bb9d753954195fe2d69bd140b4ae731b9b5b605c34323de162cf00 0]}
@ -1038,7 +1075,7 @@ func TestPendingAndCallContract(t *testing.T) {
t.Errorf("response from calling contract was expected to be 'hello world' instead received %v", string(res))
}
sim.Commit()
blockHash := sim.Commit()
// make sure you can call the contract
res, err = sim.CallContract(bgCtx, ethereum.CallMsg{
@ -1056,6 +1093,23 @@ func TestPendingAndCallContract(t *testing.T) {
if !bytes.Equal(res, expectedReturn) || !strings.Contains(string(res), "hello world") {
t.Errorf("response from calling contract was expected to be 'hello world' instead received %v", string(res))
}
// make sure you can call the contract by hash
res, err = sim.CallContractAtHash(bgCtx, ethereum.CallMsg{
From: testAddr,
To: &addr,
Data: input,
}, blockHash)
if err != nil {
t.Errorf("could not call receive method on contract: %v", err)
}
if len(res) == 0 {
t.Errorf("result of contract call was empty: %v", res)
}
if !bytes.Equal(res, expectedReturn) || !strings.Contains(string(res), "hello world") {
t.Errorf("response from calling contract was expected to be 'hello world' instead received %v", string(res))
}
}
// This test is based on the following contract:

@ -48,6 +48,7 @@ type CallOpts struct {
Pending bool // Whether to operate on the pending state or the last known one
From common.Address // Optional the sender address, otherwise the first account is used
BlockNumber *big.Int // Optional the block number on which the call should be performed
BlockHash common.Hash // Optional the block hash on which the call should be performed
Context context.Context // Network context to support cancellation and timeouts (nil = no timeout)
}
@ -189,6 +190,23 @@ func (c *BoundContract) Call(opts *CallOpts, results *[]interface{}, method stri
return ErrNoCode
}
}
} else if opts.BlockHash != (common.Hash{}) {
bh, ok := c.caller.(BlockHashContractCaller)
if !ok {
return ErrNoBlockHashState
}
output, err = bh.CallContractAtHash(ctx, msg, opts.BlockHash)
if err != nil {
return err
}
if len(output) == 0 {
// Make sure we have a contract to operate on, and bail out otherwise.
if code, err = bh.CodeAtHash(ctx, c.address, opts.BlockHash); err != nil {
return err
} else if len(code) == 0 {
return ErrNoCode
}
}
} else {
output, err = c.caller.CallContract(ctx, msg, opts.BlockNumber)
if err != nil {

@ -114,6 +114,26 @@ func (mc *mockPendingCaller) PendingCallContract(ctx context.Context, call ether
return mc.pendingCallContractBytes, mc.pendingCallContractErr
}
type mockBlockHashCaller struct {
*mockCaller
codeAtHashBytes []byte
codeAtHashErr error
codeAtHashCalled bool
callContractAtHashCalled bool
callContractAtHashBytes []byte
callContractAtHashErr error
}
func (mc *mockBlockHashCaller) CodeAtHash(ctx context.Context, contract common.Address, hash common.Hash) ([]byte, error) {
mc.codeAtHashCalled = true
return mc.codeAtHashBytes, mc.codeAtHashErr
}
func (mc *mockBlockHashCaller) CallContractAtHash(ctx context.Context, call ethereum.CallMsg, hash common.Hash) ([]byte, error) {
mc.callContractAtHashCalled = true
return mc.callContractAtHashBytes, mc.callContractAtHashErr
}
func TestPassingBlockNumber(t *testing.T) {
mc := &mockPendingCaller{
mockCaller: &mockCaller{
@ -400,6 +420,15 @@ func TestCall(t *testing.T) {
Pending: true,
},
method: method,
}, {
name: "ok hash",
mc: &mockBlockHashCaller{
codeAtHashBytes: []byte{0},
},
opts: &bind.CallOpts{
BlockHash: common.Hash{0xaa},
},
method: method,
}, {
name: "pack error, no method",
mc: new(mockCaller),
@ -413,6 +442,14 @@ func TestCall(t *testing.T) {
},
method: method,
wantErrExact: bind.ErrNoPendingState,
}, {
name: "interface error, blockHash but not a BlockHashContractCaller",
mc: new(mockCaller),
opts: &bind.CallOpts{
BlockHash: common.Hash{0xaa},
},
method: method,
wantErrExact: bind.ErrNoBlockHashState,
}, {
name: "pending call canceled",
mc: &mockPendingCaller{
@ -460,6 +497,34 @@ func TestCall(t *testing.T) {
mc: new(mockCaller),
method: method,
wantErrExact: bind.ErrNoCode,
}, {
name: "call contract at hash error",
mc: &mockBlockHashCaller{
callContractAtHashErr: context.DeadlineExceeded,
},
opts: &bind.CallOpts{
BlockHash: common.Hash{0xaa},
},
method: method,
wantErrExact: context.DeadlineExceeded,
}, {
name: "code at error",
mc: &mockBlockHashCaller{
codeAtHashErr: errors.New(""),
},
opts: &bind.CallOpts{
BlockHash: common.Hash{0xaa},
},
method: method,
wantErr: true,
}, {
name: "no code at hash",
mc: new(mockBlockHashCaller),
opts: &bind.CallOpts{
BlockHash: common.Hash{0xaa},
},
method: method,
wantErrExact: bind.ErrNoCode,
}, {
name: "unpack error missing arg",
mc: &mockCaller{

@ -370,6 +370,13 @@ func (ec *Client) BalanceAt(ctx context.Context, account common.Address, blockNu
return (*big.Int)(&result), err
}
// BalanceAtHash returns the wei balance of the given account.
func (ec *Client) BalanceAtHash(ctx context.Context, account common.Address, blockHash common.Hash) (*big.Int, error) {
var result hexutil.Big
err := ec.c.CallContext(ctx, &result, "eth_getBalance", account, rpc.BlockNumberOrHashWithHash(blockHash, false))
return (*big.Int)(&result), err
}
// StorageAt returns the value of key in the contract storage of the given account.
// The block number can be nil, in which case the value is taken from the latest known block.
func (ec *Client) StorageAt(ctx context.Context, account common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error) {
@ -378,6 +385,13 @@ func (ec *Client) StorageAt(ctx context.Context, account common.Address, key com
return result, err
}
// StorageAtHash returns the value of key in the contract storage of the given account.
func (ec *Client) StorageAtHash(ctx context.Context, account common.Address, key common.Hash, blockHash common.Hash) ([]byte, error) {
var result hexutil.Bytes
err := ec.c.CallContext(ctx, &result, "eth_getStorageAt", account, key, rpc.BlockNumberOrHashWithHash(blockHash, false))
return result, err
}
// CodeAt returns the contract code of the given account.
// The block number can be nil, in which case the code is taken from the latest known block.
func (ec *Client) CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error) {
@ -386,6 +400,13 @@ func (ec *Client) CodeAt(ctx context.Context, account common.Address, blockNumbe
return result, err
}
// CodeAtHash returns the contract code of the given account.
func (ec *Client) CodeAtHash(ctx context.Context, account common.Address, blockHash common.Hash) ([]byte, error) {
var result hexutil.Bytes
err := ec.c.CallContext(ctx, &result, "eth_getCode", account, rpc.BlockNumberOrHashWithHash(blockHash, false))
return result, err
}
// NonceAt returns the account nonce of the given account.
// The block number can be nil, in which case the nonce is taken from the latest known block.
func (ec *Client) NonceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (uint64, error) {
@ -394,6 +415,13 @@ func (ec *Client) NonceAt(ctx context.Context, account common.Address, blockNumb
return uint64(result), err
}
// NonceAtHash returns the account nonce of the given account.
func (ec *Client) NonceAtHash(ctx context.Context, account common.Address, blockHash common.Hash) (uint64, error) {
var result hexutil.Uint64
err := ec.c.CallContext(ctx, &result, "eth_getTransactionCount", account, rpc.BlockNumberOrHashWithHash(blockHash, false))
return uint64(result), err
}
// Filters
// FilterLogs executes a filter query.

@ -584,6 +584,11 @@ func testCallContract(t *testing.T, client *rpc.Client) {
func testAtFunctions(t *testing.T, client *rpc.Client) {
ec := NewClient(client)
block, err := ec.HeaderByNumber(context.Background(), big.NewInt(1))
if err != nil {
t.Fatalf("BlockByNumber error: %v", err)
}
// send a transaction for some interesting pending status
sendTransaction(ec)
time.Sleep(100 * time.Millisecond)
@ -601,6 +606,13 @@ func testAtFunctions(t *testing.T, client *rpc.Client) {
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
hashBalance, err := ec.BalanceAtHash(context.Background(), testAddr, block.Hash())
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
if balance.Cmp(hashBalance) == 0 {
t.Fatalf("unexpected balance at hash: %v %v", balance, hashBalance)
}
penBalance, err := ec.PendingBalanceAt(context.Background(), testAddr)
if err != nil {
t.Fatalf("unexpected error: %v", err)
@ -613,6 +625,13 @@ func testAtFunctions(t *testing.T, client *rpc.Client) {
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
hashNonce, err := ec.NonceAtHash(context.Background(), testAddr, block.Hash())
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
if hashNonce == nonce {
t.Fatalf("unexpected nonce at hash: %v %v", nonce, hashNonce)
}
penNonce, err := ec.PendingNonceAt(context.Background(), testAddr)
if err != nil {
t.Fatalf("unexpected error: %v", err)
@ -625,6 +644,13 @@ func testAtFunctions(t *testing.T, client *rpc.Client) {
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
hashStorage, err := ec.StorageAtHash(context.Background(), testAddr, common.Hash{}, block.Hash())
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
if !bytes.Equal(storage, hashStorage) {
t.Fatalf("unexpected storage at hash: %v %v", storage, hashStorage)
}
penStorage, err := ec.PendingStorageAt(context.Background(), testAddr, common.Hash{})
if err != nil {
t.Fatalf("unexpected error: %v", err)
@ -637,6 +663,13 @@ func testAtFunctions(t *testing.T, client *rpc.Client) {
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
hashCode, err := ec.CodeAtHash(context.Background(), common.Address{}, block.Hash())
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
if !bytes.Equal(code, hashCode) {
t.Fatalf("unexpected code at hash: %v %v", code, hashCode)
}
penCode, err := ec.PendingCodeAt(context.Background(), testAddr)
if err != nil {
t.Fatalf("unexpected error: %v", err)