Don't wipe the order book while it's being used.

Fix OrderBookDB::getBooks so it can return something.
Fix some cases of the find/[] anti-pattern. (You don't need to search twice.)

src/cpp/ripple/OrderBookDB.cpp

@@ -64,17 +64,19 @@ void OrderBookDB::setup(Ledger::ref ledger)
 // return list of all orderbooks that want IssuerID
 std::vector<OrderBook::pointer>& OrderBookDB::getBooks(const uint160& issuerID)
 {
-	return mIssuerMap.find(issuerID) == mIssuerMap.end()
+	std::map< uint160, std::vector<OrderBook::pointer> >::iterator it = mIssuerMap.find(issuerID);
+	return (it == mIssuerMap.end())
 		? mEmptyVector
-		: mIssuerMap[issuerID];
+		: it->second;
 }
 
 // return list of all orderbooks that want this issuerID and currencyID
 void OrderBookDB::getBooks(const uint160& issuerID, const uint160& currencyID, std::vector<OrderBook::pointer>& bookRet)
 {
-	if (mIssuerMap.find(issuerID) == mIssuerMap.end())
+	std::map< uint160, std::vector<OrderBook::pointer> >::iterator it = mIssuerMap.find(issuerID);
+	if (it != mIssuerMap.end())
 	{
-		BOOST_FOREACH(OrderBook::ref book, mIssuerMap[issuerID])
+		BOOST_FOREACH(OrderBook::ref book, it->second)
 		{
 			if (book->getCurrencyIn() == currencyID)
 				bookRet.push_back(book);

src/cpp/ripple/Pathfinder.cpp

@@ -139,7 +139,7 @@ Pathfinder::Pathfinder(Ledger::ref ledger,
 		mLedger(ledger)
 {
 
-	theApp->getOrderBookDB().setup(mLedger); // TODO: have the orderbook update itself rather than rebuild it from scratch each time
+	mOrderBook.setup(mLedger); // TODO: have the orderbook update itself rather than rebuild it from scratch each time
 
 	mLoadMonitor = theApp->getJobQueue().getLoadEvent(jtPATH_FIND);
 
@@ -351,7 +351,7 @@ bool Pathfinder::findPaths(const unsigned int iMaxSteps, const unsigned int iMax
 		else if (!speEnd.mCurrencyID)
 		{
 			// Cursor is for XRP, continue with qualifying books: XRP -> non-XRP
-			BOOST_FOREACH(OrderBook::ref book, theApp->getOrderBookDB().getXRPInBooks())
+			BOOST_FOREACH(OrderBook::ref book, mOrderBook.getXRPInBooks())
 			{
 				// New end is an order book with the currency and issuer.
 
@@ -445,7 +445,7 @@ bool Pathfinder::findPaths(const unsigned int iMaxSteps, const unsigned int iMax
 			std::vector<OrderBook::pointer> books;
 
 
-			theApp->getOrderBookDB().getBooks(speEnd.mIssuerID, speEnd.mCurrencyID, books);
+			mOrderBook.getBooks(speEnd.mIssuerID, speEnd.mCurrencyID, books);
 
 			BOOST_FOREACH(OrderBook::ref book, books)
 			{
@@ -593,7 +593,7 @@ void Pathfinder::addOptions(PathOption::pointer tail)
 {
 	if (!tail->mCurrencyID)
 	{ // source XRP
-		BOOST_FOREACH(OrderBook::ref book, theApp->getOrderBookDB().getXRPInBooks())
+		BOOST_FOREACH(OrderBook::ref book, mOrderBook.getXRPInBooks())
 		{
 			PathOption::pointer pathOption(new PathOption(tail));
 
@@ -627,7 +627,7 @@ void Pathfinder::addOptions(PathOption::pointer tail)
 
 		// every offer that wants the source currency
 		std::vector<OrderBook::pointer> books;
-		theApp->getOrderBookDB().getBooks(tail->mCurrentAccount, tail->mCurrencyID, books);
+		mOrderBook.getBooks(tail->mCurrentAccount, tail->mCurrencyID, books);
 
 		BOOST_FOREACH(OrderBook::ref book,books)
 		{

src/cpp/ripple/Pathfinder.h

@@ -1,10 +1,12 @@
 #ifndef __PATHFINDER__
 #define __PATHFINDER__
 
+#include <boost/shared_ptr.hpp>
+
 #include "SerializedTypes.h"
 #include "RippleAddress.h"
 #include "RippleCalc.h"
-#include <boost/shared_ptr.hpp>
+#include "OrderBookDB.h"
 
 #if 0
 //
@@ -41,7 +43,7 @@ class Pathfinder
 	uint160				mSrcIssuerID;
 	STAmount			mSrcAmount;
 
-	//OrderBookDB			mOrderBook;
+	OrderBookDB			mOrderBook;
 	Ledger::pointer		mLedger;
 	PathState::pointer	mPsDefault;
 	LoadEvent::pointer	mLoadMonitor;