* 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
* move common forks and parameters to common params
* port specs over to new format
* fix RPC tests
* parity-machine skeleton
* remove block type
* extract out ethereum-specific methods into EthereumMachine
* beginning to integrate Machine into engines. dealing with stale transitions in Ethash
* initial porting to machine
* move block reward back into engine
* abstract block reward logic
* move last hash and DAO HF logic into machine
* begin making engine function parameters generic
* abstract epoch verifier and ethash block reward logic
* instantiate special ethereummachine for ethash in spec
* optional full verification in verify_block_family
* re-instate tx_filter in a way that works for all engines
* fix warnings
* fix most tests, further generalize engine trait
* uncomment nullengine, get ethcore tests compiling
* fix warnings
* update a bunch of specs
* re-enable engine signer, validator set, and transition handler
* migrate basic_authority engine
* move last hashes into executedblock
* port tendermint
* make all ethcore tests pass
* json-tests compilation
* fix RPC tests: change in gas limit for new block changed PoW hash
* fix minor grumbles
* validate chainspecs
* fix broken import
* fix transaction verification for pre-homestead
