From f405a492a4524376294d92fe849c65173ad1fc02 Mon Sep 17 00:00:00 2001
From: JoelKatz <DavidJoelSchwartz@GMail.com>
Date: Sun, 7 Apr 2013 20:15:01 -0700
Subject: [PATCH] Avoid redundant exploration.

---
 src/cpp/ripple/Pathfinder.cpp | 45 +++++++++--------------------------
 src/cpp/ripple/Pathfinder.h   |  2 ++
 2 files changed, 13 insertions(+), 34 deletions(-)

diff --git a/src/cpp/ripple/Pathfinder.cpp b/src/cpp/ripple/Pathfinder.cpp
index 0a3a1b0400..f7193772cf 100644
--- a/src/cpp/ripple/Pathfinder.cpp
+++ b/src/cpp/ripple/Pathfinder.cpp
@@ -46,37 +46,6 @@ Test USD to EUR
 //    length of path
 //    width of path
 //    correct currency at the end
-#if 0
-bool sortPathOptions(PathOption::pointer first, PathOption::pointer second)
-{
-	if (first->mTotalCost<second->mTotalCost) return(true);
-	if (first->mTotalCost>second->mTotalCost) return(false);
-
-	if (first->mCorrectCurrency && !second->mCorrectCurrency) return(true);
-	if (!first->mCorrectCurrency && second->mCorrectCurrency) return(false);
-
-	if (first->mPath.size()<second->mPath.size()) return(true);
-	if (first->mPath.size()>second->mPath.size()) return(false);
-
-	if (first->mMinWidth<second->mMinWidth) return true;
-
-	return false;
-}
-
-PathOption::PathOption(uint160& srcAccount,uint160& srcCurrencyID,const uint160& dstCurrencyID)
-{
-	mCurrentAccount=srcAccount;
-	mCurrencyID=srcCurrencyID;
-	mCorrectCurrency=(srcCurrencyID==dstCurrencyID);
-	mQuality=0;
-	mMinWidth=STAmount(dstCurrencyID,99999,80);   // this will get lowered when we convert back to the correct currency
-}
-
-PathOption::PathOption(PathOption::pointer other)
-{
-	// TODO:
-}
-#endif
 
 // quality, length, liquidity, index
 typedef boost::tuple<uint64, int, STAmount, unsigned int> path_LQ_t;
@@ -395,7 +364,8 @@ bool Pathfinder::findPaths(const unsigned int iMaxSteps, const unsigned int iMax
 			{
 				// New end is an order book with the currency and issuer.
 
-				if (!spPath.hasSeen(ACCOUNT_XRP, book->getCurrencyOut(), book->getIssuerOut()))
+				if (!spPath.hasSeen(ACCOUNT_XRP, book->getCurrencyOut(), book->getIssuerOut()) &&
+					!matchesOrigin(book->getCurrencyOut(), book->getIssuerOut()))
 				{
 					// Not a order book already in path.
 					STPath			spNew(spPath);
@@ -456,7 +426,7 @@ bool Pathfinder::findPaths(const unsigned int iMaxSteps, const unsigned int iMax
 						// wrong currency
 						nothing();
 					}
-					else if (spPath.hasSeen(uPeerID, speEnd.mCurrencyID, uPeerID))
+					else if (spPath.hasSeen(uPeerID, speEnd.mCurrencyID, uPeerID) && (uPeerID != mSrcAccountID))
 					{
 						// Peer is in path already. Ignore it to avoid a loop.
 						cLog(lsTRACE) <<
@@ -513,7 +483,8 @@ bool Pathfinder::findPaths(const unsigned int iMaxSteps, const unsigned int iMax
 
 			BOOST_FOREACH(OrderBook::ref book, books)
 			{
-				if (!spPath.hasSeen(ACCOUNT_XRP, book->getCurrencyOut(), book->getIssuerOut()))
+				if (!spPath.hasSeen(ACCOUNT_XRP, book->getCurrencyOut(), book->getIssuerOut()) &&
+					!matchesOrigin(book->getCurrencyOut(), book->getIssuerOut()))
 				{
 					// A book we haven't seen before. Add it.
 					STPath			spNew(spPath);
@@ -812,4 +783,10 @@ boost::unordered_set<uint160> usAccountSourceCurrencies(const RippleAddress& raA
 
 	return usCurrencies;
 }
+
+bool Pathfinder::matchesOrigin(const uint160& currency, const uint160& issuer)
+{
+	return (currency == mSrcCurrencyID) && (issuer == mSrcIssuerID);
+}
+
 // vim:ts=4
diff --git a/src/cpp/ripple/Pathfinder.h b/src/cpp/ripple/Pathfinder.h
index 135bc3e2fe..87f3c95516 100644
--- a/src/cpp/ripple/Pathfinder.h
+++ b/src/cpp/ripple/Pathfinder.h
@@ -57,6 +57,8 @@ class Pathfinder
 
 //	void addPathOption(PathOption::pointer pathOption);
 
+	bool matchesOrigin(const uint160& currency, const uint160& issuer);
+
 public:
 	Pathfinder(Ledger::ref ledger,
 		const RippleAddress& srcAccountID, const RippleAddress& dstAccountID,