diff options
Diffstat (limited to 'internal/ethapi/api.go')
| -rw-r--r-- | internal/ethapi/api.go | 30 |
1 files changed, 28 insertions, 2 deletions
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 |