Extract the Engine trait (#10958)

* Add client-traits crate
Move the BlockInfo trait to new crate

* New crate `machine`
Contains code extracted from ethcore that defines `Machine`, `Externalities` and other execution related code.

* Use new machine and client-traits crates in ethcore

* Use new crates machine and client-traits instead of ethcore where appropriate

* Fix tests

* Don't re-export so many types from ethcore::client

* Fixing more fallout from removing re-export

* fix test

* More fallout from not re-exporting types

* Add some docs

* cleanup

* import the macro edition style

* Tweak docs

* Add missing import

* remove unused ethabi_derive imports

* Use latest ethabi-contract

* Move many traits from ethcore/client/traits to client-traits crate
Initial version of extracted Engine trait

* Move snapshot related traits to the engine crate (eew)

* Move a few snapshot related types to common_types
Cleanup Executed as exported from machine crate

* fix warning

* Gradually introduce new engine crate: snapshot

* ethcore typechecks with new engine crate

* Sort out types outside ethcore

* Add an EpochVerifier to ethash and use that in Engine.epoch_verifier()
Cleanup

* Document pub members

* Sort out tests
Sort out default impls for EpochVerifier

* Add test-helpers feature and move EngineSigner impl to the right place

* Sort out tests

* Sort out tests and refactor verification types

* Fix missing traits

* More missing traits
Fix Histogram

* Fix tests and cleanup

* cleanup

* Put back needed logger import

* Don't rexport common_types from ethcore/src/client
Don't export ethcore::client::*

* Remove files no longer used
Use types from the engine crate
Explicit exports from engine::engine

* Get rid of itertools

* Move a few more traits from ethcore to client-traits: BlockChainReset, ScheduleInfo, StateClient

* Move ProvingBlockChainClient to client-traits

* Don't re-export ForkChoice and Transition from ethcore

* Address grumbles: sort imports, remove commented out code

* Fix merge resolution error

* merge failure

ethcore/src/tests/client.rs

@@ -26,12 +26,13 @@ use types::{
 	ids::BlockId,
 	transaction::{PendingTransaction, Transaction, Action, Condition},
 	filter::Filter,
+	verification::Unverified,
 	view,
 	views::BlockView,
 };
 
-use client::{BlockChainClient, BlockChainReset, Client, ClientConfig, ChainInfo, PrepareOpenBlock, ImportSealedBlock, ImportBlock};
-use client_traits::BlockInfo;
+use client::{Client, ClientConfig, PrepareOpenBlock, ImportSealedBlock};
+use client_traits::{BlockInfo, BlockChainClient, BlockChainReset, ChainInfo, ImportBlock};
 use crate::spec;
 use machine::executive::{Executive, TransactOptions};
 use miner::{Miner, PendingOrdering, MinerService};
@@ -41,7 +42,6 @@ use test_helpers::{
 	generate_dummy_client, push_blocks_to_client, get_test_client_with_blocks, get_good_dummy_block_seq,
 	generate_dummy_client_with_data, get_good_dummy_block, get_bad_state_dummy_block
 };
-use verification::queue::kind::blocks::Unverified;
 
 #[test]
 fn imports_from_empty() {
@@ -210,7 +210,7 @@ fn can_generate_gas_price_histogram() {
 	let client = generate_dummy_client_with_data(20, 1, slice_into![6354,8593,6065,4842,7845,7002,689,4958,4250,6098,5804,4320,643,8895,2296,8589,7145,2000,2512,1408]);
 
 	let hist = client.gas_price_corpus(20).histogram(5).unwrap();
-	let correct_hist = ::stats::Histogram { bucket_bounds: vec_into![643, 2294, 3945, 5596, 7247, 8898], counts: vec![4,2,4,6,4] };
+	let correct_hist = stats::Histogram { bucket_bounds: vec_into![643, 2294, 3945, 5596, 7247, 8898], counts: vec![4,2,4,6,4] };
 	assert_eq!(hist, correct_hist);
 }
 
@@ -327,7 +327,7 @@ fn does_not_propagate_delayed_transactions() {
 
 #[test]
 fn transaction_proof() {
-	use ::client::ProvingBlockChainClient;
+	use client_traits::ProvingBlockChainClient;
 
 	let client = generate_dummy_client(0);
 	let address = Address::random();

ethcore/src/tests/trace.rs

@@ -22,21 +22,21 @@ use block::*;
 use ethereum_types::{U256, Address};
 use io::*;
 use crate::spec;
-use client::*;
 use test_helpers::get_temp_state_db;
-use client::{BlockChainClient, Client, ClientConfig};
+use client::{Client, ClientConfig};
+use client_traits::{BlockChainClient, ImportBlock};
 use std::sync::Arc;
 use std::str::FromStr;
 use miner::Miner;
 use trace::{RewardType, LocalizedTrace};
 use trace::trace::Action::Reward;
 use test_helpers;
-use verification::queue::kind::blocks::Unverified;
 use types::{
 	ids::BlockId,
 	transaction::{Action, Transaction},
 	trace_filter::Filter as TraceFilter,
 	header::Header,
+	verification::Unverified,
 	view,
 	views::BlockView,
 };