[contract-client] refactor (#7978)

* Refactor usage of registry contract

* remove unsed file

* Rename methods & fix comments

* refactor contract_client:

* Intoduced separate traits for asyncronous and syncronous contract clients
* Removed registrar from ethcore::client
* s/ContractClient/AsyncContractClient

* make the tests compile and pass

* omit changes in ethcore

* Use only one trait for ContractClient

* Use an associated type in the trait to determine syncronous or asyncronous communication
* Export the types from contract-client crate
* Document that "A" in the hash correspons to a DNS A Record A.K.A Address Record

* contract_client -> registrar

* address review feedback

dapps/src/tests/helpers/mod.rs

@@ -24,7 +24,7 @@ use jsonrpc_http_server::{self as http, Host, DomainsValidation};
 use parity_reactor::Remote;
 
 use devtools::http_client;
-use hash_fetch::urlhint::ContractClient;
+use registrar::{RegistrarClient, Asynchronous};
 use fetch::{Fetch, Client as FetchClient};
 use node_health::{NodeHealth, TimeChecker, CpuPool};
 
@@ -144,7 +144,7 @@ pub fn assert_security_headers_for_embed(headers: &[String]) {
 /// Webapps HTTP+RPC server build.
 pub struct ServerBuilder<T: Fetch = FetchClient> {
 	dapps_path: PathBuf,
-	registrar: Arc<ContractClient>,
+	registrar: Arc<RegistrarClient<Call=Asynchronous>>,
 	sync_status: Arc<SyncStatus>,
 	web_proxy_tokens: Arc<WebProxyTokens>,
 	signer_address: Option<(String, u16)>,
@@ -155,7 +155,7 @@ pub struct ServerBuilder<T: Fetch = FetchClient> {
 
 impl ServerBuilder {
 	/// Construct new dapps server
-	pub fn new<P: AsRef<Path>>(dapps_path: P, registrar: Arc<ContractClient>) -> Self {
+	pub fn new<P: AsRef<Path>>(dapps_path: P, registrar: Arc<RegistrarClient<Call=Asynchronous>>) -> Self {
 		ServerBuilder {
 			dapps_path: dapps_path.as_ref().to_owned(),
 			registrar: registrar,
@@ -227,7 +227,7 @@ impl Server {
 		signer_address: Option<(String, u16)>,
 		dapps_path: PathBuf,
 		extra_dapps: Vec<PathBuf>,
-		registrar: Arc<ContractClient>,
+		registrar: Arc<RegistrarClient<Call=Asynchronous>>,
 		sync_status: Arc<SyncStatus>,
 		web_proxy_tokens: Arc<WebProxyTokens>,
 		remote: Remote,

dapps/src/tests/helpers/registrar.rs

@@ -18,10 +18,9 @@ use std::str;
 use std::sync::Arc;
 use std::collections::HashMap;
 
-use futures::Future;
 use ethereum_types::{H256, Address};
 use bytes::{Bytes, ToPretty};
-use hash_fetch::urlhint::ContractClient;
+use registrar::{RegistrarClient, Asynchronous};
 use parking_lot::Mutex;
 use rustc_hex::FromHex;
 
@@ -62,12 +61,14 @@ impl FakeRegistrar {
 	}
 }
 
-impl ContractClient for FakeRegistrar {
-	fn registrar(&self) -> Result<Address, String> {
+impl RegistrarClient for FakeRegistrar {
+	type Call = Asynchronous;
+
+	fn registrar_address(&self) -> Result<Address, String> {
 		Ok(REGISTRAR.parse().unwrap())
 	}
 
-	fn call(&self, address: Address, data: Bytes) -> Box<Future<Item = Bytes, Error = String> + Send> {
+	fn call_contract(&self, address: Address, data: Bytes) -> Self::Call {
 		let call = (address.to_hex(), data.to_hex());
 		self.calls.lock().push(call.clone());
 		let res = self.responses.lock().get(&call).cloned().expect(&format!("No response for call: {:?}", call));