openethereum/src/engine.rs

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use util::uint::*;
use util::hash::*;
use util::bytes::*;
use header::Header;
use std::collections::hash_map::*;
use util::error::*;
/// Definition of the cost schedule and other parameterisations for the EVM.
pub struct EvmSchedule {
pub exceptional_failed_code_deposit: bool,
pub have_delegate_call: bool,
pub stack_limit: U256,
pub tier_step_gas: [U256; 8],
pub exp_gas: U256,
pub exp_byte_gas: U256,
pub sha3_gas: U256,
pub sha3_word_gas: U256,
pub sload_gas: U256,
pub sstore_set_gas: U256,
pub sstore_reset_gas: U256,
pub sstore_refund_gas: U256,
pub jumpdest_gas: U256,
pub log_gas: U256,
pub log_data_gas: U256,
pub log_topic_gas: U256,
pub create_gas: U256,
pub call_gas: U256,
pub call_stipend: U256,
pub call_value_transfer_gas: U256,
pub call_new_account_gas: U256,
pub suicide_refund_gas: U256,
pub memory_gas: U256,
pub quad_coeff_div: U256,
pub create_data_gas: U256,
pub tx_gas: U256,
pub tx_create_gas: U256,
pub tx_data_zero_gas: U256,
pub tx_data_non_zero_gas: U256,
pub copy_gas: U256,
}
/// Definition of a contract whose implementation is built-in.
pub struct Builtin {
/// The gas cost of running this built-in for the given size of input data.
pub cost: Box<Fn(usize) -> U256>, // TODO: U256 should be bignum.
/// Run this built-in function with the input being the first argument and the output
/// being placed into the second.
pub execute: Box<Fn(&[u8], &mut [u8])>,
}
/// Parameters for a block chain; includes both those intrinsic to the design of the
/// chain and those to be interpreted by the active chain engine.
pub struct Params {
/*
TODO: std::unordered_map<Address, PrecompiledContract> precompiled;
*/
pub block_reward: U256,
pub maximum_extra_data_size: U256,
pub account_start_nonce: U256,
pub evm_schedule: EvmSchedule,
pub builtins: HashMap<Address, Builtin>,
pub misc: HashMap<String, String>,
}
// TODO: move to ethcore-util
/// A version value with strict meaning.
pub struct SemanticVersion {
/// Major version - API/feature removals & breaking changes.
pub major: u8,
/// Minor version - API/feature additions.
pub minor: u8,
/// Tiny version - bug fixes.
pub tiny: u8,
}
impl SemanticVersion {
/// Create a new object.
pub fn new(major: u8, minor: u8, tiny: u8) -> SemanticVersion { SemanticVersion{major: major, minor: minor, tiny: tiny} }
/// Convert to a `u32` representation.
pub fn as_u32(&self) -> u32 { ((self.major as u32) << 16u32) + ((self.minor as u32) << 8u32) + self.tiny as u32 }
}
// TODO: implement PartialOrdered for SemanticVersion.
/// A consensus mechanism for the chain. Generally either proof-of-work or proof-of-stake-based.
/// Provides hooks into each of the major parts of block import.
pub trait Engine {
/// The name of this engine.
fn name(&self) -> &str;
/// The version of this engine. Should be of the form
fn version(&self) -> SemanticVersion { SemanticVersion::new(0, 0 ,0) }
/// The number of additional header fields required for this engine.
fn seal_fields(&self) -> u32 { 0 }
/// Default values of the additional fields RLP-encoded in a raw (non-list) harness.
fn seal_rlp(&self) -> Bytes { vec![] }
/// Additional engine-specific information for the user/developer concerning `header`.
fn extra_info(&self, _header: &Header) -> HashMap<String, String> { HashMap::new() }
/// Verify that `header` is valid.
/// `parent` (the parent header) and `block` (the header's full block) may be provided for additional
/// checks. Returns either a null `Ok` or a general error detailing the problem with import.
fn verify(&self, _header: &Header, _parent: Option<&Header>, _block: Option<&[u8]>) -> Result<(), EthcoreError> { Ok(()) }
/*
virtual void verify(Strictness _s, BlockHeader const& _bi, BlockHeader const& _parent = BlockHeader(), bytesConstRef _block = bytesConstRef()) const;
/// Additional verification for transactions in blocks.
virtual void verifyTransaction(ImportRequirements::value _ir, TransactionBase const& _t, BlockHeader const& _bi) const;
/// Don't forget to call Super::populateFromParent when subclassing & overriding.
virtual void populateFromParent(BlockHeader& _bi, BlockHeader const& _parent) const;
*/
/// Get the general parameters of the chain.
fn params(&self) -> &Params;
/// Set the general parameters of the chain.
fn set_params(&mut self, p: Params);
}
/// An engine which does not provide any consensus mechanism.
pub struct NullEngine {
params: Params,
}
impl Engine for NullEngine {
fn name(&self) -> &str { "NullEngine" }
fn params(&self) -> &Params { &self.params }
fn set_params(&mut self, params: Params) { self.params = params; }
}