Rust Cuckatoo for verifier and test-miner (#1558)

* cuck placeholder

* rustfmt

* cuckatoo, early days

* rustfmt

* data structures are in place, siphash key creation is consistent with @tromp

* solver in place, (not yet working)

* cuckatoo test solver working with test nonce

* rustfmt

* update solver to remove adjacency list removals

* verifier functioning

* rustfmt

* Proper error handing in Cuckatoo module, couple of tests

* modify cuckoo/cuckatoo solvers and verifiers to function identically, in advance of trait refactoring

* rustfmt

* refactor PoW context into trait, default to using cuckoo context

* rustfmt

* create macros for integer casting/unwraps

* don't instantiate structs when just verifying, add test validation vector for cuckatoo 29

* rustfmt

* don't init cuckoo structs if just validating

* test fix

* ensure BH hashing for POW is only done within miner/validators

servers/src/mining/stratumserver.rs

@@ -529,7 +529,7 @@ impl StratumServer {
 			);
 		} else {
 			// Do some validation but dont submit
-			if !pow::verify_size(&b.header, global::min_sizeshift()) {
+			if !pow::verify_size(&b.header, global::min_sizeshift()).is_ok() {
 				// Return error status
 				error!(
 					LOGGER,

servers/src/mining/test_miner.rs

@@ -26,7 +26,7 @@ use common::types::StratumServerConfig;
 use core::core::hash::{Hash, Hashed};
 use core::core::verifier_cache::VerifierCache;
 use core::core::{Block, BlockHeader};
-use core::pow::cuckoo;
+use core::pow::PoWContext;
 use core::{consensus, global};
 use mining::mine_block;
 use pool;
@@ -96,14 +96,16 @@ impl Miner {
 		let mut iter_count = 0;
 
 		while head.hash() == *latest_hash && Utc::now().timestamp() < deadline {
-			if let Ok(proof) = cuckoo::Miner::new(
-				&b.header,
-				consensus::EASINESS,
-				global::proofsize(),
+			let mut ctx = global::create_pow_context::<u32>(
 				global::min_sizeshift(),
-			).mine()
-			{
-				b.header.pow.proof = proof;
+				global::proofsize(),
+				consensus::EASINESS,
+				10,
+			).unwrap();
+			ctx.set_header_nonce(b.header.pre_pow(), None, true)
+				.unwrap();
+			if let Ok(proofs) = ctx.find_cycles() {
+				b.header.pow.proof = proofs[0].clone();
 				let proof_diff = b.header.pow.to_difficulty();
 				if proof_diff >= (b.header.total_difficulty() - head.total_difficulty()) {
 					return true;