Caching.

alethzero/Main.ui

@@ -38,6 +38,13 @@
     </property>
     <item>
      <layout class="QHBoxLayout" name="horizontalLayout_7">
+      <item>
+       <widget class="QLabel" name="cacheUsage">
+        <property name="text">
+         <string>0 bytes used</string>
+        </property>
+       </widget>
+      </item>
       <item>
        <widget class="QLabel" name="balance">
         <property name="text">

alethzero/MainWin.cpp

@@ -141,6 +141,7 @@ Main::Main(QWidget *parent) :
 	ui->configDock->close();
 	on_verbosity_valueChanged();
 
+	statusBar()->addPermanentWidget(ui->cacheUsage);
 	statusBar()->addPermanentWidget(ui->balance);
 	statusBar()->addPermanentWidget(ui->peerCount);
 	statusBar()->addPermanentWidget(ui->mineStatus);
@@ -1144,6 +1145,12 @@ void Main::on_refresh_triggered()
 	refreshAll();
 }
 
+void Main::refreshCache()
+{
+	BlockChain::Statistics s = ethereum()->blockChain().usage();
+	ui->cacheUsage->setText(QString("%1 bytes used").arg(s.memTotal()));
+}
+
 void Main::timerEvent(QTimerEvent*)
 {
 	// 7/18, Alex: aggregating timers, prelude to better threading?
@@ -1172,6 +1179,7 @@ void Main::timerEvent(QTimerEvent*)
 		interval = 0;
 		refreshNetwork();
 		refreshWhispers();
+		refreshCache();
 		poll();
 	}
 	else

alethzero/MainWin.h

@@ -212,6 +212,7 @@ private:
 	void refreshNetwork();
 	void refreshMining();
 	void refreshWhispers();
+	void refreshCache();
 
 	void refreshAll();
 	void refreshPending();

libethereum/BlockChain.cpp

@@ -76,8 +76,33 @@ ldb::Slice dev::eth::toSlice(h256 _h, unsigned _sub)
 #endif
 }
 
+#if ETH_DEBUG
+static const chrono::system_clock::duration c_collectionDuration = chrono::seconds(15);
+static const unsigned c_collectionQueueSize = 2;
+static const unsigned c_maxCacheSize = 1024 * 1024 * 1;
+static const unsigned c_minCacheSize = 1;
+#else
+
+/// Duration between flushes.
+static const chrono::system_clock::duration c_collectionDuration = chrono::seconds(60);
+
+/// Length of death row (total time in cache is multiple of this and collection duration).
+static const unsigned c_collectionQueueSize = 20;
+
+/// Max size, above which we start forcing cache reduction.
+static const unsigned c_maxCacheSize = 1024 * 1024 * 64;
+
+/// Min size, below which we don't bother flushing it.
+static const unsigned c_minCacheSize = 1024 * 1024 * 32;
+
+#endif
+
 BlockChain::BlockChain(bytes const& _genesisBlock, std::string _path, bool _killExisting)
 {
+	// initialise deathrow.
+	m_cacheUsage.resize(c_collectionQueueSize);
+	m_lastCollection = chrono::system_clock::now();
+
 	// Initialise with the genesis as the last block on the longest chain.
 	m_genesisBlock = _genesisBlock;
 	m_genesisHash = sha3(RLP(m_genesisBlock)[0].data());
@@ -428,6 +453,103 @@ h256s BlockChain::treeRoute(h256 _from, h256 _to, h256* o_common, bool _pre, boo
 	return ret;
 }
 
+void BlockChain::noteUsed(h256 const& _h, unsigned _extra) const
+{
+	auto id = CacheID(_h, _extra);
+	Guard l(x_cacheUsage);
+	m_cacheUsage[0].insert(id);
+	if (m_cacheUsage[1].count(id))
+		m_cacheUsage[1].erase(id);
+	else
+		m_inUse.insert(id);
+}
+
+template <class T> static unsigned getHashSize(map<h256, T> const& _map)
+{
+	unsigned ret = 0;
+	for (auto const& i: _map)
+		ret += i.second.size + 64;
+	return ret;
+}
+
+void BlockChain::updateStats() const
+{
+	{
+		ReadGuard l1(x_blocks);
+		m_lastStats.memBlocks = 0;
+		for (auto const& i: m_blocks)
+			m_lastStats.memBlocks += i.second.size() + 64;
+	}
+	{
+		ReadGuard l2(x_details);
+		m_lastStats.memDetails = getHashSize(m_details);
+	}
+	{
+		ReadGuard l5(x_logBlooms);
+		m_lastStats.memLogBlooms = getHashSize(m_logBlooms);
+	}
+	{
+		ReadGuard l4(x_receipts);
+		m_lastStats.memReceipts = getHashSize(m_receipts);
+	}
+	{
+		ReadGuard l3(x_blockHashes);
+		m_lastStats.memBlockHashes = getHashSize(m_blockHashes);
+	}
+	{
+		ReadGuard l6(x_transactionAddresses);
+		m_lastStats.memTransactionAddresses = getHashSize(m_transactionAddresses);
+	}
+}
+
+void BlockChain::garbageCollect(bool _force)
+{
+	updateStats();
+
+	if (!_force && chrono::system_clock::now() < m_lastCollection + c_collectionDuration && m_lastStats.memTotal() < c_maxCacheSize)
+		return;
+	if (m_lastStats.memTotal() < c_minCacheSize)
+		return;
+
+	m_lastCollection = chrono::system_clock::now();
+
+	Guard l(x_cacheUsage);
+	WriteGuard l1(x_blocks);
+	WriteGuard l2(x_details);
+	WriteGuard l3(x_blockHashes);
+	WriteGuard l4(x_receipts);
+	WriteGuard l5(x_logBlooms);
+	WriteGuard l6(x_transactionAddresses);
+	for (CacheID const& id: m_cacheUsage.back())
+	{
+		m_inUse.erase(id);
+		// kill i from cache.
+		switch (id.second)
+		{
+		case (unsigned)-1:
+			m_blocks.erase(id.first);
+			break;
+		case ExtraDetails:
+			m_details.erase(id.first);
+			break;
+		case ExtraBlockHash:
+			m_blockHashes.erase(id.first);
+			break;
+		case ExtraReceipts:
+			m_receipts.erase(id.first);
+			break;
+		case ExtraLogBlooms:
+			m_logBlooms.erase(id.first);
+			break;
+		case ExtraTransactionAddress:
+			m_transactionAddresses.erase(id.first);
+			break;
+		}
+	}
+	m_cacheUsage.pop_back();
+	m_cacheUsage.push_front({});
+}
+
 void BlockChain::checkConsistency()
 {
 	{
@@ -511,5 +633,7 @@ bytes BlockChain::block(h256 _hash) const
 	m_blocks[_hash].resize(d.size());
 	memcpy(m_blocks[_hash].data(), d.data(), d.size());
 
+	noteUsed(_hash);
+
 	return m_blocks[_hash];
 }

libethereum/BlockChain.h

@@ -26,7 +26,7 @@
 #include <leveldb/db.h>
 #pragma warning(pop)
 
-#include <mutex>
+#include <chrono>
 #include <libdevcore/Log.h>
 #include <libdevcore/Exceptions.h>
 #include <libethcore/Common.h>
@@ -171,18 +171,20 @@ public:
 
 	struct Statistics
 	{
+		unsigned memBlocks;
 		unsigned memDetails;
 		unsigned memLogBlooms;
 		unsigned memReceipts;
 		unsigned memTransactionAddresses;
-		unsigned memCache;
+		unsigned memBlockHashes;
+		unsigned memTotal() const { return memBlocks + memDetails + memLogBlooms + memReceipts + memTransactionAddresses + memBlockHashes; }
 	};
 
 	/// @returns statistics about memory usage.
-	Statistics usage() const;
+	Statistics usage(bool _freshen = false) const { if (_freshen) updateStats(); return m_lastStats; }
 
 	/// Deallocate unused data.
-	void garbageCollect();
+	void garbageCollect(bool _force = false);
 
 private:
 	void open(std::string _path, bool _killExisting = false);
@@ -205,6 +207,8 @@ private:
 			return _n;
 		}
 
+		noteUsed(_h, N);
+
 		WriteGuard l(_x);
 		auto ret = _m.insert(std::make_pair(_h, T(RLP(s))));
 		return ret.first->second;
@@ -213,19 +217,29 @@ private:
 	void checkConsistency();
 
 	/// The caches of the disk DB and their locks.
-	mutable boost::shared_mutex x_blocks;
+	mutable SharedMutex x_blocks;
 	mutable BlocksHash m_blocks;
-	mutable boost::shared_mutex x_details;
+	mutable SharedMutex x_details;
 	mutable BlockDetailsHash m_details;
-	mutable boost::shared_mutex x_logBlooms;
+	mutable SharedMutex x_logBlooms;
 	mutable BlockLogBloomsHash m_logBlooms;
-	mutable boost::shared_mutex x_receipts;
+	mutable SharedMutex x_receipts;
 	mutable BlockReceiptsHash m_receipts;
-	mutable boost::shared_mutex x_transactionAddresses;
+	mutable SharedMutex x_transactionAddresses;
 	mutable TransactionAddressHash m_transactionAddresses;
-	mutable boost::shared_mutex x_blockHashes;
+	mutable SharedMutex x_blockHashes;
 	mutable BlockHashHash m_blockHashes;
 
+	using CacheID = std::pair<h256, unsigned>;
+	mutable Mutex x_cacheUsage;
+	mutable std::deque<std::set<CacheID>> m_cacheUsage;
+	mutable std::set<CacheID> m_inUse;
+	void noteUsed(h256 const& _h, unsigned _extra = (unsigned)-1) const;
+	std::chrono::system_clock::time_point m_lastCollection;
+
+	void updateStats() const;
+	mutable Statistics m_lastStats;
+
 	/// The disk DBs. Thread-safe, so no need for locks.
 	ldb::DB* m_blocksDB;
 	ldb::DB* m_extrasDB;

libethereum/BlockDetails.cpp

@@ -32,9 +32,12 @@ BlockDetails::BlockDetails(RLP const& _r)
 	totalDifficulty = _r[1].toInt<u256>();
 	parent = _r[2].toHash<h256>();
 	children = _r[3].toVector<h256>();
+	size = _r.size();
 }
 
 bytes BlockDetails::rlp() const
 {
-	return rlpList(number, totalDifficulty, parent, children);
+	auto ret = rlpList(number, totalDifficulty, parent, children);
+	size = ret.size();
+	return ret;
 }

libethereum/BlockDetails.h

@@ -46,28 +46,32 @@ struct BlockDetails
 	bool isNull() const { return !totalDifficulty; }
 	explicit operator bool() const { return !isNull(); }
 
-	unsigned number;			// TODO: remove?
+	unsigned number;
 	u256 totalDifficulty;
 	h256 parent;
 	h256s children;
+
+	mutable unsigned size;
 };
 
 struct BlockLogBlooms
 {
 	BlockLogBlooms() {}
-	BlockLogBlooms(RLP const& _r) { blooms = _r.toVector<LogBloom>(); }
+	BlockLogBlooms(RLP const& _r) { blooms = _r.toVector<LogBloom>(); size = _r.data().size(); }
-	bytes rlp() const { RLPStream s; s << blooms; return s.out(); }
+	bytes rlp() const { RLPStream s; s << blooms; size = s.out().size(); return s.out(); }
 
 	LogBlooms blooms;
+	mutable unsigned size;
 };
 
 struct BlockReceipts
 {
 	BlockReceipts() {}
-	BlockReceipts(RLP const& _r) { for (auto const& i: _r) receipts.emplace_back(i.data()); }
+	BlockReceipts(RLP const& _r) { for (auto const& i: _r) receipts.emplace_back(i.data()); size = _r.data().size(); }
-	bytes rlp() const { RLPStream s(receipts.size()); for (TransactionReceipt const& i: receipts) i.streamRLP(s); return s.out(); }
+	bytes rlp() const { RLPStream s(receipts.size()); for (TransactionReceipt const& i: receipts) i.streamRLP(s); size = s.out().size(); return s.out(); }
 
 	TransactionReceipts receipts;
+	mutable unsigned size;
 };
 
 struct BlockHash
@@ -77,6 +81,7 @@ struct BlockHash
 	bytes rlp() const { return dev::rlp(value); }
 
 	h256 value;
+	static const unsigned size = 65;
 };
 
 struct TransactionAddress
@@ -89,6 +94,8 @@ struct TransactionAddress
 
 	h256 blockHash;
 	unsigned index = 0;
+
+	static const unsigned size = 67;
 };
 
 using BlockDetailsHash = std::map<h256, BlockDetails>;

libethereum/Client.cpp

@@ -635,6 +635,7 @@ void Client::doWork()
 			uninstallWatch(i);
 		m_lastGarbageCollection = chrono::system_clock::now();
 	}
+	m_bc.garbageCollect();
 }
 
 unsigned Client::numberOf(int _n) const