openethereum/crates/ethcore/src/engines/authority_round/block_gas_limit.rs

39 lines
1.6 KiB
Rust

// Copyright 2015-2019 Parity Technologies (UK) Ltd.
// This file is part of Parity Ethereum.
// Parity Ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity Ethereum 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 General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity Ethereum. If not, see <http://www.gnu.org/licenses/>.
//! A client interface for interacting with the block gas limit contract.
use client::{BlockChainClient, BlockId};
use types::header::Header;
use ethabi::FunctionOutputDecoder;
use ethabi_contract::use_contract;
use ethereum_types::{Address, U256};
use log::{debug, error};
use_contract!(contract, "res/contracts/block_gas_limit.json");
pub fn block_gas_limit(full_client: &dyn BlockChainClient, header: &Header, address: Address) -> Option<U256> {
let (data, decoder) = contract::functions::block_gas_limit::call();
let value = full_client.call_contract(BlockId::Hash(*header.parent_hash()), address, data).map_err(|err| {
error!(target: "block_gas_limit", "Contract call failed. Not changing the block gas limit. {:?}", err);
}).ok()?;
if value.is_empty() {
debug!(target: "block_gas_limit", "Contract call returned nothing. Not changing the block gas limit.");
None
} else {
decoder.decode(&value).ok()
}
}