Optimize the startup code so we don't have long periods of slowness on startup.

src/cpp/ripple/Ledger.cpp

@@ -529,6 +529,53 @@ Ledger::pointer Ledger::getSQL(const std::string& sql)
 	return ret;
 }
 
+uint256 Ledger::getHashByIndex(uint32 ledgerIndex)
+{
+	uint256 ret;
+
+	std::string sql="SELECT LedgerHash FROM Ledgers WHERE LedgerSeq='";
+	sql.append(boost::lexical_cast<std::string>(ledgerIndex));
+	sql.append("';");
+
+	std::string hash;
+	{
+		Database *db = theApp->getLedgerDB()->getDB();
+		ScopedLock sl(theApp->getLedgerDB()->getDBLock());
+		if (!db->executeSQL(sql) || !db->startIterRows())
+			return ret;
+		db->getStr("LedgerHash", hash);
+		db->endIterRows();
+	}
+
+	ret.SetHex(hash);
+	return ret;
+}
+
+bool Ledger::getHashesByIndex(uint32 ledgerIndex, uint256& ledgerHash, uint256& parentHash)
+{
+	std::string sql="SELECT LedgerHash,PrevHash FROM Ledgers WHERE LedgerSeq='";
+	sql.append(boost::lexical_cast<std::string>(ledgerIndex));
+	sql.append("';");
+
+	std::string hash, prevHash;
+	{
+		Database *db = theApp->getLedgerDB()->getDB();
+		ScopedLock sl(theApp->getLedgerDB()->getDBLock());
+		if (!db->executeSQL(sql) || !db->startIterRows())
+			return false;
+		db->getStr("LedgerHash", hash);
+		db->getStr("PrevHash", prevHash);
+		db->endIterRows();
+	}
+
+	ledgerHash.SetHex(hash);
+	parentHash.SetHex(prevHash);
+
+	assert(ledgerHash.isNonZero() && ((ledgerIndex == 0) || parentHash.isNonZero()));
+
+	return true;
+}
+
 Ledger::pointer Ledger::loadByIndex(uint32 ledgerIndex)
 { // This is a low-level function with no caching
 	std::string sql="SELECT * from Ledgers WHERE LedgerSeq='";

src/cpp/ripple/Ledger.h

@@ -178,9 +178,11 @@ public:
 	SLE::pointer getAccountRoot(const RippleAddress& naAccountID);
 	void updateSkipList();
 
-	// database functions
+	// database functions (low-level)
 	static Ledger::pointer loadByIndex(uint32 ledgerIndex);
 	static Ledger::pointer loadByHash(const uint256& ledgerHash);
+	static uint256 getHashByIndex(uint32 index);
+	static bool getHashesByIndex(uint32 index, uint256& ledgerHash, uint256& parentHash);
 	void pendSave(bool fromConsensus);
 
 	// next/prev function

src/cpp/ripple/LedgerMaster.cpp

@@ -134,19 +134,25 @@ bool LedgerMaster::haveLedgerRange(uint32 from, uint32 to)
 
 void LedgerMaster::asyncAccept(Ledger::pointer ledger)
 {
-	do
+	uint32 seq = ledger->getLedgerSeq();
+	uint256 prevHash = ledger->getParentHash();
+
+	while (seq > 0)
 	{
 		{
 			boost::recursive_mutex::scoped_lock ml(mLock);
-			mCompleteLedgers.setValue(ledger->getLedgerSeq());
+			mCompleteLedgers.setValue(seq);
-			if ((ledger->getLedgerSeq() == 0) || mCompleteLedgers.hasValue(ledger->getLedgerSeq() - 1))
+			--seq;
+			if (mCompleteLedgers.hasValue(seq))
 				break;
 		}
-		Ledger::pointer prevLedger = mLedgerHistory.getLedgerBySeq(ledger->getLedgerSeq() - 1); // FIXME
+
-		if (!prevLedger || (prevLedger->getHash() != ledger->getParentHash()))
+		uint256 tHash, pHash;
+		if (!Ledger::getHashesByIndex(seq, tHash, pHash) || (tHash != prevHash))
 			break;
-		ledger = prevLedger;
+		prevHash = pHash;
-	} while(1);
+	}
+
 	resumeAcquiring();
 }
 
@@ -156,7 +162,7 @@ bool LedgerMaster::acquireMissingLedger(const uint256& ledgerHash, uint32 ledger
 		return true;
 
 	Ledger::pointer ledger = mLedgerHistory.getLedgerBySeq(ledgerSeq);
-	if (ledger && (ledger->getHash() == ledgerHash))
+	if (Ledger::getHashByIndex(ledgerSeq) == ledgerHash)
 	{
 		cLog(lsDEBUG) << "Ledger hash found in database";
 		mTooFast = true;