Light clippy(fy) (#9473)

* wasm tests

* `clippyfy` light-client

* Revert inefficient change `collect_ready()`

ethcore/light/src/cache.rs

@@ -31,7 +31,7 @@ use ethereum_types::{H256, U256};
 use memory_cache::MemoryLruCache;
 
 /// Configuration for how much data to cache.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub struct CacheSizes {
 	/// Maximum size, in bytes, of cached headers.
 	pub headers: usize,
@@ -83,33 +83,33 @@ impl Cache {
 			receipts: MemoryLruCache::new(sizes.receipts),
 			chain_score: MemoryLruCache::new(sizes.chain_score),
 			corpus: None,
-			corpus_expiration: corpus_expiration,
+			corpus_expiration,
 		}
 	}
 
 	/// Query header by hash.
 	pub fn block_header(&mut self, hash: &H256) -> Option<encoded::Header> {
-		self.headers.get_mut(hash).map(|x| x.clone())
+		self.headers.get_mut(hash).cloned()
 	}
 
 	/// Query hash by number.
-	pub fn block_hash(&mut self, num: &BlockNumber) -> Option<H256> {
-		self.canon_hashes.get_mut(num).map(|x| x.clone())
+	pub fn block_hash(&mut self, num: BlockNumber) -> Option<H256> {
+		self.canon_hashes.get_mut(&num).map(|h| *h)
 	}
 
 	/// Query block body by block hash.
 	pub fn block_body(&mut self, hash: &H256) -> Option<encoded::Body> {
-		self.bodies.get_mut(hash).map(|x| x.clone())
+		self.bodies.get_mut(hash).cloned()
 	}
 
 	/// Query block receipts by block hash.
 	pub fn block_receipts(&mut self, hash: &H256) -> Option<Vec<Receipt>> {
-		self.receipts.get_mut(hash).map(|x| x.clone())
+		self.receipts.get_mut(hash).cloned()
 	}
 
 	/// Query chain score by block hash.
 	pub fn chain_score(&mut self, hash: &H256) -> Option<U256> {
-		self.chain_score.get_mut(hash).map(|x| x.clone())
+		self.chain_score.get_mut(hash).map(|h| *h)
 	}
 
 	/// Cache the given header.