openethereum/machine/src/lib.rs

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// Copyright 2015-2018 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity 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 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. If not, see <http://www.gnu.org/licenses/>.
//! Generalization of a state machine for a consensus engine.
//! This will define traits for the header, block, and state of a blockchain.
extern crate ethereum_types;
use ethereum_types::{H256, U256, Address};
/// A header. This contains important metadata about the block, as well as a
/// "seal" that indicates validity to a consensus engine.
pub trait Header {
/// Cryptographic hash of the header, excluding the seal.
fn bare_hash(&self) -> H256;
/// Cryptographic hash of the header, including the seal.
fn hash(&self) -> H256;
/// Get a reference to the seal fields.
fn seal(&self) -> &[Vec<u8>];
/// The author of the header.
fn author(&self) -> &Address;
/// The number of the header.
fn number(&self) -> u64;
}
Fork choice and metadata framework for Engine (#8401) * Add light client TODO item * Move existing total-difficulty-based fork choice check to Engine * Abstract total difficulty and block provider as Machine::BlockMetadata and Machine::BlockProvider * Decouple "generate_metadata" logic to Engine * Use fixed BlockMetadata and BlockProvider type for null and instantseal In this way they can use total difficulty fork choice check * Extend blockdetails with metadatas and finalized info * Extra data update: mark_finalized and update_metadatas * Check finalized block in Blockchain * Fix a test constructor in verification mod * Add total difficulty trait * Fix type import * Db migration to V13 with metadata column * Address grumbles * metadatas -> metadata * Use generic type for update_metadata to avoid passing HashMap all around * Remove metadata in blockdetails * [WIP] Implement a generic metadata architecture * [WIP] Metadata insertion logic in BlockChain * typo: Value -> Self::Value * [WIP] Temporarily remove Engine::is_new_best interface So that we don't have too many type errors. * [WIP] Fix more type errors * [WIP] ExtendedHeader::PartialEq * [WIP] Change metadata type Option<Vec<u8>> to Vec<u8> * [WIP] Remove Metadata Error * [WIP] Clean up error conversion * [WIP] finalized -> is_finalized * [WIP] Mark all fields in ExtrasInsert as pub * [WIP] Remove unused import * [WIP] Keep only local metadata info * Mark metadata as optional * [WIP] Revert metadata db change in BlockChain * [WIP] Put finalization in unclosed state * Use metadata interface in BlockDetail * [WIP] Fix current build failures * [WIP] Remove unused blockmetadata struct * Remove DB migration info * [WIP] Typo * Use ExtendedHeader to implement fork choice check * Implement is_new_best using Ancestry iterator * Use expect instead of panic * [WIP] Add ancestry Engine support via on_new_block * Fix tests * Emission of ancestry actions * use_short_version should take account of metadata * Engine::is_new_best -> Engine::fork_choice * Use proper expect format as defined in #1026 * panic -> expect * ancestry_header -> ancestry_with_metadata * Boxed iterator -> &mut iterator * Fix tests * is_new_best -> primitive_fork_choice * Document how fork_choice works * Engine::fork_choice -> Engine::primitive_fork_choice * comment: clarify types of finalization where Engine::primitive_fork_choice works * Expose FinalizationInfo to Engine * Fix tests due to merging * Remove TotalDifficulty trait * Do not pass FinalizationInfo to Engine If there's finalized blocks in from route, choose the old branch without calling `Engine::fork_choice`. * Fix compile * Fix unused import * Remove is_to_route_finalized When no block reorg passes a finalized block, this variable is always false. * Address format grumbles * Fix docs: mark_finalized returns None if block hash is not found `blockchain` mod does not yet have an Error type, so we still temporarily use None here. * Fix inaccurate tree_route None expect description
2018-05-16 08:58:01 +02:00
/// A header with an associated score (difficulty in PoW terms)
pub trait ScoredHeader: Header {
Fork choice and metadata framework for Engine (#8401) * Add light client TODO item * Move existing total-difficulty-based fork choice check to Engine * Abstract total difficulty and block provider as Machine::BlockMetadata and Machine::BlockProvider * Decouple "generate_metadata" logic to Engine * Use fixed BlockMetadata and BlockProvider type for null and instantseal In this way they can use total difficulty fork choice check * Extend blockdetails with metadatas and finalized info * Extra data update: mark_finalized and update_metadatas * Check finalized block in Blockchain * Fix a test constructor in verification mod * Add total difficulty trait * Fix type import * Db migration to V13 with metadata column * Address grumbles * metadatas -> metadata * Use generic type for update_metadata to avoid passing HashMap all around * Remove metadata in blockdetails * [WIP] Implement a generic metadata architecture * [WIP] Metadata insertion logic in BlockChain * typo: Value -> Self::Value * [WIP] Temporarily remove Engine::is_new_best interface So that we don't have too many type errors. * [WIP] Fix more type errors * [WIP] ExtendedHeader::PartialEq * [WIP] Change metadata type Option<Vec<u8>> to Vec<u8> * [WIP] Remove Metadata Error * [WIP] Clean up error conversion * [WIP] finalized -> is_finalized * [WIP] Mark all fields in ExtrasInsert as pub * [WIP] Remove unused import * [WIP] Keep only local metadata info * Mark metadata as optional * [WIP] Revert metadata db change in BlockChain * [WIP] Put finalization in unclosed state * Use metadata interface in BlockDetail * [WIP] Fix current build failures * [WIP] Remove unused blockmetadata struct * Remove DB migration info * [WIP] Typo * Use ExtendedHeader to implement fork choice check * Implement is_new_best using Ancestry iterator * Use expect instead of panic * [WIP] Add ancestry Engine support via on_new_block * Fix tests * Emission of ancestry actions * use_short_version should take account of metadata * Engine::is_new_best -> Engine::fork_choice * Use proper expect format as defined in #1026 * panic -> expect * ancestry_header -> ancestry_with_metadata * Boxed iterator -> &mut iterator * Fix tests * is_new_best -> primitive_fork_choice * Document how fork_choice works * Engine::fork_choice -> Engine::primitive_fork_choice * comment: clarify types of finalization where Engine::primitive_fork_choice works * Expose FinalizationInfo to Engine * Fix tests due to merging * Remove TotalDifficulty trait * Do not pass FinalizationInfo to Engine If there's finalized blocks in from route, choose the old branch without calling `Engine::fork_choice`. * Fix compile * Fix unused import * Remove is_to_route_finalized When no block reorg passes a finalized block, this variable is always false. * Address format grumbles * Fix docs: mark_finalized returns None if block hash is not found `blockchain` mod does not yet have an Error type, so we still temporarily use None here. * Fix inaccurate tree_route None expect description
2018-05-16 08:58:01 +02:00
type Value;
/// Get the score of this header.
Fork choice and metadata framework for Engine (#8401) * Add light client TODO item * Move existing total-difficulty-based fork choice check to Engine * Abstract total difficulty and block provider as Machine::BlockMetadata and Machine::BlockProvider * Decouple "generate_metadata" logic to Engine * Use fixed BlockMetadata and BlockProvider type for null and instantseal In this way they can use total difficulty fork choice check * Extend blockdetails with metadatas and finalized info * Extra data update: mark_finalized and update_metadatas * Check finalized block in Blockchain * Fix a test constructor in verification mod * Add total difficulty trait * Fix type import * Db migration to V13 with metadata column * Address grumbles * metadatas -> metadata * Use generic type for update_metadata to avoid passing HashMap all around * Remove metadata in blockdetails * [WIP] Implement a generic metadata architecture * [WIP] Metadata insertion logic in BlockChain * typo: Value -> Self::Value * [WIP] Temporarily remove Engine::is_new_best interface So that we don't have too many type errors. * [WIP] Fix more type errors * [WIP] ExtendedHeader::PartialEq * [WIP] Change metadata type Option<Vec<u8>> to Vec<u8> * [WIP] Remove Metadata Error * [WIP] Clean up error conversion * [WIP] finalized -> is_finalized * [WIP] Mark all fields in ExtrasInsert as pub * [WIP] Remove unused import * [WIP] Keep only local metadata info * Mark metadata as optional * [WIP] Revert metadata db change in BlockChain * [WIP] Put finalization in unclosed state * Use metadata interface in BlockDetail * [WIP] Fix current build failures * [WIP] Remove unused blockmetadata struct * Remove DB migration info * [WIP] Typo * Use ExtendedHeader to implement fork choice check * Implement is_new_best using Ancestry iterator * Use expect instead of panic * [WIP] Add ancestry Engine support via on_new_block * Fix tests * Emission of ancestry actions * use_short_version should take account of metadata * Engine::is_new_best -> Engine::fork_choice * Use proper expect format as defined in #1026 * panic -> expect * ancestry_header -> ancestry_with_metadata * Boxed iterator -> &mut iterator * Fix tests * is_new_best -> primitive_fork_choice * Document how fork_choice works * Engine::fork_choice -> Engine::primitive_fork_choice * comment: clarify types of finalization where Engine::primitive_fork_choice works * Expose FinalizationInfo to Engine * Fix tests due to merging * Remove TotalDifficulty trait * Do not pass FinalizationInfo to Engine If there's finalized blocks in from route, choose the old branch without calling `Engine::fork_choice`. * Fix compile * Fix unused import * Remove is_to_route_finalized When no block reorg passes a finalized block, this variable is always false. * Address format grumbles * Fix docs: mark_finalized returns None if block hash is not found `blockchain` mod does not yet have an Error type, so we still temporarily use None here. * Fix inaccurate tree_route None expect description
2018-05-16 08:58:01 +02:00
fn score(&self) -> &Self::Value;
/// Set the score of this header.
Fork choice and metadata framework for Engine (#8401) * Add light client TODO item * Move existing total-difficulty-based fork choice check to Engine * Abstract total difficulty and block provider as Machine::BlockMetadata and Machine::BlockProvider * Decouple "generate_metadata" logic to Engine * Use fixed BlockMetadata and BlockProvider type for null and instantseal In this way they can use total difficulty fork choice check * Extend blockdetails with metadatas and finalized info * Extra data update: mark_finalized and update_metadatas * Check finalized block in Blockchain * Fix a test constructor in verification mod * Add total difficulty trait * Fix type import * Db migration to V13 with metadata column * Address grumbles * metadatas -> metadata * Use generic type for update_metadata to avoid passing HashMap all around * Remove metadata in blockdetails * [WIP] Implement a generic metadata architecture * [WIP] Metadata insertion logic in BlockChain * typo: Value -> Self::Value * [WIP] Temporarily remove Engine::is_new_best interface So that we don't have too many type errors. * [WIP] Fix more type errors * [WIP] ExtendedHeader::PartialEq * [WIP] Change metadata type Option<Vec<u8>> to Vec<u8> * [WIP] Remove Metadata Error * [WIP] Clean up error conversion * [WIP] finalized -> is_finalized * [WIP] Mark all fields in ExtrasInsert as pub * [WIP] Remove unused import * [WIP] Keep only local metadata info * Mark metadata as optional * [WIP] Revert metadata db change in BlockChain * [WIP] Put finalization in unclosed state * Use metadata interface in BlockDetail * [WIP] Fix current build failures * [WIP] Remove unused blockmetadata struct * Remove DB migration info * [WIP] Typo * Use ExtendedHeader to implement fork choice check * Implement is_new_best using Ancestry iterator * Use expect instead of panic * [WIP] Add ancestry Engine support via on_new_block * Fix tests * Emission of ancestry actions * use_short_version should take account of metadata * Engine::is_new_best -> Engine::fork_choice * Use proper expect format as defined in #1026 * panic -> expect * ancestry_header -> ancestry_with_metadata * Boxed iterator -> &mut iterator * Fix tests * is_new_best -> primitive_fork_choice * Document how fork_choice works * Engine::fork_choice -> Engine::primitive_fork_choice * comment: clarify types of finalization where Engine::primitive_fork_choice works * Expose FinalizationInfo to Engine * Fix tests due to merging * Remove TotalDifficulty trait * Do not pass FinalizationInfo to Engine If there's finalized blocks in from route, choose the old branch without calling `Engine::fork_choice`. * Fix compile * Fix unused import * Remove is_to_route_finalized When no block reorg passes a finalized block, this variable is always false. * Address format grumbles * Fix docs: mark_finalized returns None if block hash is not found `blockchain` mod does not yet have an Error type, so we still temporarily use None here. * Fix inaccurate tree_route None expect description
2018-05-16 08:58:01 +02:00
fn set_score(&mut self, score: Self::Value);
}
/// A header with associated total score.
pub trait TotalScoredHeader: Header {
type Value;
/// Get the total score of this header.
fn total_score(&self) -> Self::Value;
}
/// A header with finalized information.
pub trait FinalizableHeader: Header {
/// Get whether this header is considered finalized, so that it will never be replaced in reorganization.
fn is_finalized(&self) -> bool;
}
/// A header with metadata information.
pub trait WithMetadataHeader: Header {
/// Get the current header metadata.
fn metadata(&self) -> Option<&[u8]>;
}
/// A "live" block is one which is in the process of the transition.
/// The state of this block can be mutated by arbitrary rules of the
/// state transition function.
pub trait LiveBlock: 'static {
/// The block header type;
type Header: Header;
/// Get a reference to the header.
fn header(&self) -> &Self::Header;
/// Get a reference to the uncle headers. If the block type doesn't
/// support uncles, return the empty slice.
fn uncles(&self) -> &[Self::Header];
}
/// Trait for blocks which have a transaction type.
pub trait Transactions: LiveBlock {
/// The transaction type.
type Transaction;
/// Get a reference to the transactions in this block.
fn transactions(&self) -> &[Self::Transaction];
}
/// Generalization of types surrounding blockchain-suitable state machines.
pub trait Machine: for<'a> LocalizedMachine<'a> {
/// The block header type.
type Header: Header;
/// The live block type.
type LiveBlock: LiveBlock<Header=Self::Header>;
Fork choice and metadata framework for Engine (#8401) * Add light client TODO item * Move existing total-difficulty-based fork choice check to Engine * Abstract total difficulty and block provider as Machine::BlockMetadata and Machine::BlockProvider * Decouple "generate_metadata" logic to Engine * Use fixed BlockMetadata and BlockProvider type for null and instantseal In this way they can use total difficulty fork choice check * Extend blockdetails with metadatas and finalized info * Extra data update: mark_finalized and update_metadatas * Check finalized block in Blockchain * Fix a test constructor in verification mod * Add total difficulty trait * Fix type import * Db migration to V13 with metadata column * Address grumbles * metadatas -> metadata * Use generic type for update_metadata to avoid passing HashMap all around * Remove metadata in blockdetails * [WIP] Implement a generic metadata architecture * [WIP] Metadata insertion logic in BlockChain * typo: Value -> Self::Value * [WIP] Temporarily remove Engine::is_new_best interface So that we don't have too many type errors. * [WIP] Fix more type errors * [WIP] ExtendedHeader::PartialEq * [WIP] Change metadata type Option<Vec<u8>> to Vec<u8> * [WIP] Remove Metadata Error * [WIP] Clean up error conversion * [WIP] finalized -> is_finalized * [WIP] Mark all fields in ExtrasInsert as pub * [WIP] Remove unused import * [WIP] Keep only local metadata info * Mark metadata as optional * [WIP] Revert metadata db change in BlockChain * [WIP] Put finalization in unclosed state * Use metadata interface in BlockDetail * [WIP] Fix current build failures * [WIP] Remove unused blockmetadata struct * Remove DB migration info * [WIP] Typo * Use ExtendedHeader to implement fork choice check * Implement is_new_best using Ancestry iterator * Use expect instead of panic * [WIP] Add ancestry Engine support via on_new_block * Fix tests * Emission of ancestry actions * use_short_version should take account of metadata * Engine::is_new_best -> Engine::fork_choice * Use proper expect format as defined in #1026 * panic -> expect * ancestry_header -> ancestry_with_metadata * Boxed iterator -> &mut iterator * Fix tests * is_new_best -> primitive_fork_choice * Document how fork_choice works * Engine::fork_choice -> Engine::primitive_fork_choice * comment: clarify types of finalization where Engine::primitive_fork_choice works * Expose FinalizationInfo to Engine * Fix tests due to merging * Remove TotalDifficulty trait * Do not pass FinalizationInfo to Engine If there's finalized blocks in from route, choose the old branch without calling `Engine::fork_choice`. * Fix compile * Fix unused import * Remove is_to_route_finalized When no block reorg passes a finalized block, this variable is always false. * Address format grumbles * Fix docs: mark_finalized returns None if block hash is not found `blockchain` mod does not yet have an Error type, so we still temporarily use None here. * Fix inaccurate tree_route None expect description
2018-05-16 08:58:01 +02:00
/// Block header with metadata information.
type ExtendedHeader: Header;
/// A handle to a blockchain client for this machine.
type EngineClient: ?Sized;
/// A description of needed auxiliary data.
type AuxiliaryRequest;
Fork choice and metadata framework for Engine (#8401) * Add light client TODO item * Move existing total-difficulty-based fork choice check to Engine * Abstract total difficulty and block provider as Machine::BlockMetadata and Machine::BlockProvider * Decouple "generate_metadata" logic to Engine * Use fixed BlockMetadata and BlockProvider type for null and instantseal In this way they can use total difficulty fork choice check * Extend blockdetails with metadatas and finalized info * Extra data update: mark_finalized and update_metadatas * Check finalized block in Blockchain * Fix a test constructor in verification mod * Add total difficulty trait * Fix type import * Db migration to V13 with metadata column * Address grumbles * metadatas -> metadata * Use generic type for update_metadata to avoid passing HashMap all around * Remove metadata in blockdetails * [WIP] Implement a generic metadata architecture * [WIP] Metadata insertion logic in BlockChain * typo: Value -> Self::Value * [WIP] Temporarily remove Engine::is_new_best interface So that we don't have too many type errors. * [WIP] Fix more type errors * [WIP] ExtendedHeader::PartialEq * [WIP] Change metadata type Option<Vec<u8>> to Vec<u8> * [WIP] Remove Metadata Error * [WIP] Clean up error conversion * [WIP] finalized -> is_finalized * [WIP] Mark all fields in ExtrasInsert as pub * [WIP] Remove unused import * [WIP] Keep only local metadata info * Mark metadata as optional * [WIP] Revert metadata db change in BlockChain * [WIP] Put finalization in unclosed state * Use metadata interface in BlockDetail * [WIP] Fix current build failures * [WIP] Remove unused blockmetadata struct * Remove DB migration info * [WIP] Typo * Use ExtendedHeader to implement fork choice check * Implement is_new_best using Ancestry iterator * Use expect instead of panic * [WIP] Add ancestry Engine support via on_new_block * Fix tests * Emission of ancestry actions * use_short_version should take account of metadata * Engine::is_new_best -> Engine::fork_choice * Use proper expect format as defined in #1026 * panic -> expect * ancestry_header -> ancestry_with_metadata * Boxed iterator -> &mut iterator * Fix tests * is_new_best -> primitive_fork_choice * Document how fork_choice works * Engine::fork_choice -> Engine::primitive_fork_choice * comment: clarify types of finalization where Engine::primitive_fork_choice works * Expose FinalizationInfo to Engine * Fix tests due to merging * Remove TotalDifficulty trait * Do not pass FinalizationInfo to Engine If there's finalized blocks in from route, choose the old branch without calling `Engine::fork_choice`. * Fix compile * Fix unused import * Remove is_to_route_finalized When no block reorg passes a finalized block, this variable is always false. * Address format grumbles * Fix docs: mark_finalized returns None if block hash is not found `blockchain` mod does not yet have an Error type, so we still temporarily use None here. * Fix inaccurate tree_route None expect description
2018-05-16 08:58:01 +02:00
/// Actions taken on ancestry blocks when commiting a new block.
type AncestryAction;
/// Errors which can occur when querying or interacting with the machine.
type Error;
}
/// Machine-related types localized to a specific lifetime.
// TODO: this is a workaround for a lack of associated type constructors in the language.
pub trait LocalizedMachine<'a>: Sync + Send {
/// Definition of auxiliary data associated to a specific block.
type AuxiliaryData: 'a;
/// A context providing access to the state in a controlled capacity.
/// Generally also provides verifiable proofs.
type StateContext: ?Sized + 'a;
}
/// A state machine that uses balances.
pub trait WithBalances: Machine {
/// Get the balance, in base units, associated with an account.
/// Extracts data from the live block.
fn balance(&self, live: &Self::LiveBlock, address: &Address) -> Result<U256, Self::Error>;
/// Increment the balance of an account in the state of the live block.
fn add_balance(&self, live: &mut Self::LiveBlock, address: &Address, amount: &U256) -> Result<(), Self::Error>;
}