diff options
| -rw-r--r-- | accounts/abi/bind/backends/simulated.go | 28 | ||||
| -rw-r--r-- | accounts/abi/bind/bind_test.go | 51 | ||||
| -rw-r--r-- | internal/ethapi/api.go | 30 |
3 files changed, 100 insertions, 9 deletions
diff --git a/accounts/abi/bind/backends/simulated.go b/accounts/abi/bind/backends/simulated.go index c26662ea1..1c34ba0e7 100644 --- a/accounts/abi/bind/backends/simulated.go +++ b/accounts/abi/bind/backends/simulated.go @@ -201,10 +201,32 @@ func (b *SimulatedBackend) SuggestGasPrice(ctx context.Context) (*big.Int, error func (b *SimulatedBackend) EstimateGas(ctx context.Context, call ethereum.CallMsg) (*big.Int, error) { b.mu.Lock() defer b.mu.Unlock() - defer b.pendingState.RevertToSnapshot(b.pendingState.Snapshot()) - _, gas, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState) - return gas, err + // Binary search the gas requirement, as it may be higher than the amount used + var lo, hi uint64 + if call.Gas != nil { + hi = call.Gas.Uint64() + } else { + hi = b.pendingBlock.GasLimit().Uint64() + } + for lo+1 < hi { + // Take a guess at the gas, and check transaction validity + mid := (hi + lo) / 2 + call.Gas = new(big.Int).SetUint64(mid) + + snapshot := b.pendingState.Snapshot() + _, gas, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState) + b.pendingState.RevertToSnapshot(snapshot) + + // If the transaction became invalid or used all the gas (failed), raise the gas limit + if err != nil || gas.Cmp(call.Gas) == 0 { + lo = mid + continue + } + // Otherwise assume the transaction succeeded, lower the gas limit + hi = mid + } + return new(big.Int).SetUint64(hi), nil } // callContract implemens common code between normal and pending contract calls. diff --git a/accounts/abi/bind/bind_test.go b/accounts/abi/bind/bind_test.go index 6ebc8ea0a..eb46bc081 100644 --- a/accounts/abi/bind/bind_test.go +++ b/accounts/abi/bind/bind_test.go @@ -341,11 +341,11 @@ var bindTests = []struct { { `NonExistent`, ` - contract NonExistent { - function String() constant returns(string) { - return "I don't exist"; + contract NonExistent { + function String() constant returns(string) { + return "I don't exist"; + } } - } `, `6060604052609f8060106000396000f3606060405260e060020a6000350463f97a60058114601a575b005b600060605260c0604052600d60809081527f4920646f6e27742065786973740000000000000000000000000000000000000060a052602060c0908152600d60e081905281906101009060a09080838184600060046012f15050815172ffffffffffffffffffffffffffffffffffffff1916909152505060405161012081900392509050f3`, `[{"constant":true,"inputs":[],"name":"String","outputs":[{"name":"","type":"string"}],"type":"function"}]`, @@ -365,6 +365,49 @@ var bindTests = []struct { } `, }, + // Tests that gas estimation works for contracts with weird gas mechanics too. + { + `FunkyGasPattern`, + ` + contract FunkyGasPattern { + string public field; + + function SetField(string value) { + // This check will screw gas estimation! Good, good! + if (msg.gas < 100000) { + throw; + } + field = value; + } + } + `, + `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`, + `[{"constant":false,"inputs":[{"name":"value","type":"string"}],"name":"SetField","outputs":[],"type":"function"},{"constant":true,"inputs":[],"name":"field","outputs":[{"name":"","type":"string"}],"type":"function"}]`, + ` + // Generate a new random account and a funded simulator + key, _ := crypto.GenerateKey() + auth := bind.NewKeyedTransactor(key) + sim := backends.NewSimulatedBackend(core.GenesisAccount{Address: auth.From, Balance: big.NewInt(10000000000)}) + + // Deploy a funky gas pattern contract + _, _, limiter, err := DeployFunkyGasPattern(auth, sim) + if err != nil { + t.Fatalf("Failed to deploy funky contract: %v", err) + } + sim.Commit() + + // Set the field with automatic estimation and check that it succeeds + auth.GasLimit = nil + if _, err := limiter.SetField(auth, "automatic"); err != nil { + t.Fatalf("Failed to call automatically gased transaction: %v", err) + } + sim.Commit() + + if field, _ := limiter.Field(nil); field != "automatic" { + t.Fatalf("Field mismatch: have %v, want %v", field, "automatic") + } + `, + }, } // Tests that packages generated by the binder can be successfully compiled and diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go index 4359181c8..925f547b6 100644 --- a/internal/ethapi/api.go +++ b/internal/ethapi/api.go @@ -559,8 +559,34 @@ func (s *PublicBlockChainAPI) Call(ctx context.Context, args CallArgs, blockNr r // EstimateGas returns an estimate of the amount of gas needed to execute the given transaction. func (s *PublicBlockChainAPI) EstimateGas(ctx context.Context, args CallArgs) (*hexutil.Big, error) { - _, gas, err := s.doCall(ctx, args, rpc.PendingBlockNumber) - return (*hexutil.Big)(gas), err + // Binary search the gas requirement, as it may be higher than the amount used + var lo, hi uint64 + if (*big.Int)(&args.Gas).BitLen() > 0 { + hi = (*big.Int)(&args.Gas).Uint64() + } else { + // Retrieve the current pending block to act as the gas ceiling + block, err := s.b.BlockByNumber(ctx, rpc.PendingBlockNumber) + if err != nil { + return nil, err + } + hi = block.GasLimit().Uint64() + } + for lo+1 < hi { + // Take a guess at the gas, and check transaction validity + mid := (hi + lo) / 2 + (*big.Int)(&args.Gas).SetUint64(mid) + + _, gas, err := s.doCall(ctx, args, rpc.PendingBlockNumber) + + // If the transaction became invalid or used all the gas (failed), raise the gas limit + if err != nil || gas.Cmp((*big.Int)(&args.Gas)) == 0 { + lo = mid + continue + } + // Otherwise assume the transaction succeeded, lower the gas limit + hi = mid + } + return (*hexutil.Big)(new(big.Int).SetUint64(hi)), nil } // ExecutionResult groups all structured logs emitted by the EVM |