Rustify core/src/core (#1122)

Small refactoring of one folder, if it makes sense I could extend the scope.
* Remove some cloning (real and just verbosity in the code)
* Naming conventions like to/into*
* Some Clippy's suggestions

I found that we don't use field init shorthand syntax, so I didn't touch this part, was it discussed before?

servers/src/mining/mine_block.rs

@@ -181,15 +181,14 @@ fn build_block(
 	b.header.nonce = rng.gen();
 	b.header.timestamp = time::at_utc(time::Timespec::new(now_sec, 0));
 
-	let b_difficulty =
-		(b.header.total_difficulty.clone() - head.total_difficulty.clone()).into_num();
+	let b_difficulty = (b.header.total_difficulty.clone() - head.total_difficulty.clone()).to_num();
 	debug!(
 		LOGGER,
 		"Built new block with {} inputs and {} outputs, network difficulty: {}, cumulative difficulty {}",
 		b.inputs.len(),
 		b.outputs.len(),
 		b_difficulty,
-		b.header.clone().total_difficulty.clone().into_num(),
+		b.header.clone().total_difficulty.to_num(),
 	);
 
 	let roots_result = chain.set_txhashset_roots(&mut b, false);

servers/src/mining/stratumserver.rs

@@ -446,7 +446,6 @@ impl StratumServer {
 			// Reconstruct the block header with this nonce and pow added
 			b = self.current_block.clone();
 			b.header.nonce = submit_params.nonce;
-			b.header.pow.proof_size = submit_params.pow.len();
 			b.header.pow.nonces = submit_params.pow;
 			let res = self.chain.process_block(b.clone(), chain::Options::MINE);
 			if let Err(e) = res {
@@ -644,7 +643,7 @@ impl StratumServer {
 				self.current_block = new_block;
 				self.current_difficulty = (self.current_block.header.total_difficulty.clone()
 					- head.total_difficulty.clone())
-					.into_num();
+					.to_num();
 				self.current_key_id = block_fees.key_id();
 				current_hash = latest_hash;
 				// set a new deadline for rebuilding with fresh transactions

servers/src/mining/test_miner.rs

@@ -17,23 +17,23 @@
 //! header with its proof-of-work.  Any valid mined blocks are submitted to the
 //! network.
 
-use std::sync::{Arc, RwLock};
 use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, RwLock};
 use time;
 
 use common::adapters::PoolToChainAdapter;
+use common::types::StratumServerConfig;
 use core::consensus;
 use core::core::Proof;
-use core::core::{Block, BlockHeader};
 use core::core::hash::{Hash, Hashed};
+use core::core::{Block, BlockHeader};
 use core::pow::cuckoo;
-use common::types::StratumServerConfig;
 use util::LOGGER;
 
 use chain;
-use pool;
-use mining::mine_block;
 use core::global;
+use mining::mine_block;
+use pool;
 
 // Max number of transactions this miner will assemble in a block
 const MAX_TX: u32 = 5000;
@@ -108,7 +108,7 @@ impl Miner {
 				global::sizeshift(),
 			).mine()
 			{
-				let proof_diff = proof.clone().to_difficulty();
+				let proof_diff = proof.to_difficulty();
 				if proof_diff >= (b.header.total_difficulty.clone() - head.total_difficulty.clone())
 				{
 					sol = Some(proof);