Cleanup of the state-machine crate (#3524)

* Start refactoring state-machine crate

* More improvement to state-machine

* Fix tests compilation on master and remove warnings

* Fix compilation

* Apply suggestions from code review

Co-Authored-By: Sergei Pepyakin <sergei@parity.io>

* Update core/state-machine/src/basic.rs

Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com>

* Line width

* Update core/primitives/src/storage.rs

Co-Authored-By: Benjamin Kampmann <ben.kampmann@googlemail.com>

* Update core/state-machine/src/error.rs

Co-Authored-By: Benjamin Kampmann <ben.kampmann@googlemail.com>

* Review feedback

substrate/core/executor/src/error.rs

@@ -16,7 +16,6 @@
 
 //! Rust executor possible errors.
 
-use state_machine;
 use serializer;
 use wasmi;
 
@@ -92,8 +91,6 @@ impl std::error::Error for Error {
 	}
 }
 
-impl state_machine::Error for Error {}
-
 impl wasmi::HostError for Error {}
 
 impl From<String> for Error {

substrate/core/executor/src/lib.rs

@@ -43,11 +43,10 @@ pub use wasmi;
 pub use wasm_executor::WasmExecutor;
 pub use native_executor::{with_native_environment, NativeExecutor, NativeExecutionDispatch};
 pub use wasm_runtimes_cache::RuntimesCache;
-pub use state_machine::Externalities;
 pub use runtime_version::{RuntimeVersion, NativeVersion};
 pub use codec::Codec;
 #[doc(hidden)]
-pub use primitives::Blake2Hasher;
+pub use primitives::{Blake2Hasher, traits::Externalities};
 #[doc(hidden)]
 pub use wasm_interface;
 

substrate/core/executor/src/native_executor.rs

@@ -16,12 +16,11 @@
 
 use std::{result, cell::RefCell, panic::UnwindSafe};
 use crate::error::{Error, Result};
-use state_machine::{CodeExecutor, Externalities};
 use crate::wasm_executor::WasmExecutor;
 use runtime_version::{NativeVersion, RuntimeVersion};
 use codec::{Decode, Encode};
 use crate::RuntimeInfo;
-use primitives::{Blake2Hasher, NativeOrEncoded};
+use primitives::{Blake2Hasher, NativeOrEncoded, traits::{CodeExecutor, Externalities}};
 use log::{trace, warn};
 
 use crate::RuntimesCache;
@@ -35,7 +34,7 @@ fn safe_call<F, U>(f: F) -> Result<U>
 {
 	// Substrate uses custom panic hook that terminates process on panic. Disable termination for the native call.
 	let _guard = panic_handler::AbortGuard::force_unwind();
-	::std::panic::catch_unwind(f).map_err(|_| Error::Runtime)
+	std::panic::catch_unwind(f).map_err(|_| Error::Runtime)
 }
 
 /// Set up the externalities and safe calling environment to execute calls to a native runtime.
@@ -44,7 +43,7 @@ fn safe_call<F, U>(f: F) -> Result<U>
 pub fn with_native_environment<F, U>(ext: &mut dyn Externalities<Blake2Hasher>, f: F) -> Result<U>
 	where F: UnwindSafe + FnOnce() -> U
 {
-	::runtime_io::with_externalities(ext, move || safe_call(f))
+	runtime_io::with_externalities(ext, move || safe_call(f))
 }
 
 /// Delegate for dispatching a CodeExecutor call.

substrate/core/executor/src/wasm_executor.rs

@@ -27,12 +27,12 @@ use wasmi::{
 	Module, ModuleInstance, MemoryInstance, MemoryRef, TableRef, ImportsBuilder, ModuleRef,
 	memory_units::Pages, RuntimeValue::{I32, I64, self},
 };
-use state_machine::Externalities;
 use crate::error::{Error, Result};
 use codec::{Encode, Decode};
 use primitives::{
 	blake2_128, blake2_256, twox_64, twox_128, twox_256, ed25519, sr25519, Pair, crypto::KeyTypeId,
-	offchain, hexdisplay::HexDisplay, sandbox as sandbox_primitives, Blake2Hasher,
+	offchain, hexdisplay::HexDisplay, sandbox as sandbox_primitives, H256, Blake2Hasher,
+	traits::Externalities, child_storage_key::ChildStorageKey,
 };
 use trie::{TrieConfiguration, trie_types::Layout};
 use crate::sandbox;

substrate/core/executor/src/wasm_runtimes_cache.rs

@@ -21,13 +21,9 @@ use crate::wasm_executor::WasmExecutor;
 use log::{trace, warn};
 use codec::Decode;
 use parity_wasm::elements::{deserialize_buffer, DataSegment, Instruction, Module as RawModule};
-use primitives::storage::well_known_keys;
-use primitives::Blake2Hasher;
+use primitives::{storage::well_known_keys, Blake2Hasher, traits::Externalities};
 use runtime_version::RuntimeVersion;
-use state_machine::Externalities;
-use std::collections::hash_map::{Entry, HashMap};
-use std::mem;
-use std::rc::Rc;
+use std::{collections::hash_map::{Entry, HashMap}, mem, rc::Rc};
 use wasmi::{Module as WasmModule, ModuleRef as WasmModuleInstanceRef, RuntimeValue};
 
 #[derive(Debug)]