Simplify Ethash

Author: chfast

libethcore/BlockHeader.h

@@ -86,7 +86,6 @@ class BlockHeader
 
 	void noteDirty() const { m_hashWithout = m_boundary = h256(); }
 
-	h256 const& seedHash() const;
 	uint64_t nonce() const { return m_nonce; }
 
 private:

libethcore/EthashAux.cpp

@@ -27,47 +27,42 @@ using namespace chrono;
 using namespace dev;
 using namespace eth;
 
-h256 const& BlockHeader::seedHash() const
-{
-	if (!m_seedHash)
-		m_seedHash = EthashAux::seedHash((unsigned)m_number);
-	return m_seedHash;
-}
-
-EthashAux* EthashAux::get()
+EthashAux& EthashAux::get()
 {
 	static EthashAux instance;
-	return &instance;
+	return instance;
 }
 
 h256 EthashAux::seedHash(unsigned _number)
 {
 	unsigned epoch = _number / ETHASH_EPOCH_LENGTH;
-	Guard l(get()->x_epochs);
-	if (epoch >= get()->m_seedHashes.size())
+	EthashAux& ethash = EthashAux::get();
+	Guard l(ethash.x_epochs);
+	if (epoch >= ethash.m_seedHashes.size())
 	{
 		h256 ret;
 		unsigned n = 0;
-		if (!get()->m_seedHashes.empty())
+		if (!ethash.m_seedHashes.empty())
 		{
-			ret = get()->m_seedHashes.back();
-			n = get()->m_seedHashes.size() - 1;
+			ret = ethash.m_seedHashes.back();
+			n = ethash.m_seedHashes.size() - 1;
 		}
-		get()->m_seedHashes.resize(epoch + 1);
+		ethash.m_seedHashes.resize(epoch + 1);
 		for (; n <= epoch; ++n, ret = sha3(ret))
-			get()->m_seedHashes[n] = ret;
+			ethash.m_seedHashes[n] = ret;
 	}
-	return get()->m_seedHashes[epoch];
+	return ethash.m_seedHashes[epoch];
 }
 
 uint64_t EthashAux::number(h256 const& _seedHash)
 {
-	Guard l(get()->x_epochs);
+	EthashAux& ethash = EthashAux::get();
+	Guard l(ethash.x_epochs);
 	unsigned epoch = 0;
-	auto epochIter = get()->m_epochs.find(_seedHash);
-	if (epochIter == get()->m_epochs.end())
+	auto epochIter = ethash.m_epochs.find(_seedHash);
+	if (epochIter == ethash.m_epochs.end())
 	{
-		for (h256 h; h != _seedHash && epoch < 2048; ++epoch, h = sha3(h), get()->m_epochs[h] = epoch) {}
+		for (h256 h; h != _seedHash && epoch < 2048; ++epoch, h = sha3(h), ethash.m_epochs[h] = epoch) {}
 		if (epoch == 2048)
 		{
 			std::ostringstream error;
@@ -82,10 +77,13 @@ uint64_t EthashAux::number(h256 const& _seedHash)
 
 EthashAux::LightType EthashAux::light(h256 const& _seedHash)
 {
-	Guard l(get()->x_lights);
-	if (get()->m_lights.count(_seedHash))
-		return get()->m_lights.at(_seedHash);
-	return (get()->m_lights[_seedHash] = make_shared<LightAllocation>(_seedHash));
+	// TODO: Use epoch number instead of seed hash?
+
+	EthashAux& ethash = EthashAux::get();
+	Guard l(ethash.x_lights);
+	if (ethash.m_lights.count(_seedHash))
+		return ethash.m_lights.at(_seedHash);
+	return (ethash.m_lights[_seedHash] = make_shared<LightAllocation>(_seedHash));
 }
 
 EthashAux::LightAllocation::LightAllocation(h256 const& _seedHash)
@@ -119,7 +117,7 @@ Result EthashAux::eval(h256 const& _seedHash, h256 const& _headerHash, uint64_t
 {
 	try
 	{
-		return EthashAux::get()->light(_seedHash)->compute(_headerHash, _nonce);
+		return get().light(_seedHash)->compute(_headerHash, _nonce);
 	}
 	catch(...)
 	{

libethcore/EthashAux.h

@@ -47,30 +47,9 @@ struct Result
 	h256 mixHash;
 };
 
-struct WorkPackage
-{
-	WorkPackage() = default;
-	WorkPackage(BlockHeader const& _bh) :
-		boundary(_bh.boundary()),
-		header(_bh.hashWithout()),
-		seed(_bh.seedHash())
-	{ }
-	void reset() { header = h256(); }
-	operator bool() const { return header != h256(); }
-
-	h256 boundary;
-	h256 header;	///< When h256() means "pause until notified a new work package is available".
-	h256 seed;
-
-	uint64_t startNonce = 0;
-	int exSizeBits = -1;
-};
-
 class EthashAux
 {
 public:
-	static EthashAux* get();
-
 	struct LightAllocation
 	{
 		LightAllocation(h256 const& _seedHash);
@@ -92,6 +71,7 @@ class EthashAux
 
 private:
 	EthashAux() = default;
+	static EthashAux& get();
 
 	Mutex x_lights;
 	std::unordered_map<h256, LightType> m_lights;
@@ -101,5 +81,24 @@ class EthashAux
 	h256s m_seedHashes;
 };
 
+struct WorkPackage
+{
+	WorkPackage() = default;
+	WorkPackage(BlockHeader const& _bh) :
+		boundary(_bh.boundary()),
+		header(_bh.hashWithout()),
+		seed(EthashAux::seedHash(static_cast<unsigned>(_bh.number())))
+	{ }
+	void reset() { header = h256(); }
+	operator bool() const { return header != h256(); }
+
+	h256 boundary;
+	h256 header;	///< When h256() means "pause until notified a new work package is available".
+	h256 seed;
+
+	uint64_t startNonce = 0;
+	int exSizeBits = -1;
+};
+
 }
 }