From 4812d30c1695a2cc853d18cbbc2ccdaac106eb69 Mon Sep 17 00:00:00 2001
From: JoelKatz <DavidJoelSchwartz@GMail.com>
Date: Thu, 25 Apr 2013 19:11:18 -0700
Subject: [PATCH] Be smarter about when we grab fetch packs.

---
 src/cpp/ripple/LedgerMaster.cpp |  2 +-
 src/cpp/ripple/NetworkOPs.cpp   | 17 ++++++++++++-----
 src/cpp/ripple/NetworkOPs.h     |  5 +++--
 src/cpp/ripple/Peer.cpp         |  2 +-
 src/cpp/ripple/TaggedCache.h    |  7 +++++++
 5 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/cpp/ripple/LedgerMaster.cpp b/src/cpp/ripple/LedgerMaster.cpp
index 6d2cd820f1..377650973a 100644
--- a/src/cpp/ripple/LedgerMaster.cpp
+++ b/src/cpp/ripple/LedgerMaster.cpp
@@ -284,7 +284,7 @@ bool LedgerMaster::acquireMissingLedger(Ledger::ref origLedger, const uint256& l
 		}
 	}
 
-	if (theApp->getOPs().shouldFetchPack() && (ledgerSeq > 40000))
+	if (theApp->getOPs().shouldFetchPack(ledgerSeq) && (ledgerSeq > 40000))
 	{ // refill our fetch pack
 		Ledger::pointer nextLedger = mLedgerHistory.getLedgerBySeq(ledgerSeq + 1);
 		if (nextLedger)
diff --git a/src/cpp/ripple/NetworkOPs.cpp b/src/cpp/ripple/NetworkOPs.cpp
index 4d660cdc48..6df40d787b 100644
--- a/src/cpp/ripple/NetworkOPs.cpp
+++ b/src/cpp/ripple/NetworkOPs.cpp
@@ -36,7 +36,7 @@ NetworkOPs::NetworkOPs(boost::asio::io_service& io_service, LedgerMaster* pLedge
 	mMode(omDISCONNECTED), mNeedNetworkLedger(false), mProposing(false), mValidating(false),
 	mNetTimer(io_service), mLedgerMaster(pLedgerMaster), mCloseTimeOffset(0), mLastCloseProposers(0),
 	mLastCloseConvergeTime(1000 * LEDGER_IDLE_INTERVAL), mLastValidationTime(0),
-	mFetchPack("FetchPack", 2048, 30), mLastFetchPack(0),
+	mFetchPack("FetchPack", 2048, 30), mLastFetchPack(0), mFetchSeq(static_cast<uint32>(-1)),
 	mLastLoadBase(256), mLastLoadFactor(256)
 {
 }
@@ -2091,13 +2091,19 @@ bool NetworkOPs::getFetchPack(const uint256& hash, std::vector<unsigned char>& d
 	return true;
 }
 
-bool NetworkOPs::shouldFetchPack()
+bool NetworkOPs::shouldFetchPack(uint32 seq)
 {
 	uint32 now = getNetworkTimeNC();
 	if ((mLastFetchPack == now) || ((mLastFetchPack + 1) == now))
 		 return false;
-	mFetchPack.sweep();
-	if (mFetchPack.getCacheSize() > 384)
+	if (seq < mFetchSeq) // fetch pack has only data for ledgers ahead of where we are
+		mFetchPack.clear();
+	else
+		mFetchPack.sweep();
+	int size = mFetchPack.getCacheSize();
+	if (size == 0)
+		mFetchSeq = static_cast<uint32>(-1);
+	else if (mFetchPack.getCacheSize() > 384)
 		return false;
 	mLastFetchPack = now;
 	return true;
@@ -2108,9 +2114,10 @@ int NetworkOPs::getFetchSize()
 	return mFetchPack.getCacheSize();
 }
 
-void NetworkOPs::gotFetchPack(bool progress)
+void NetworkOPs::gotFetchPack(bool progress, uint32 seq)
 {
 	mLastFetchPack = 0;
+	mFetchSeq = seq;		// earliest pack we have data on
 	theApp->getJobQueue().addJob(jtLEDGER_DATA, "gotFetchPack",
 		boost::bind(&LedgerAcquireMaster::gotFetchPack, &theApp->getMasterLedgerAcquire(), _1));
 }
diff --git a/src/cpp/ripple/NetworkOPs.h b/src/cpp/ripple/NetworkOPs.h
index 095ef27a33..6469d8ff5e 100644
--- a/src/cpp/ripple/NetworkOPs.h
+++ b/src/cpp/ripple/NetworkOPs.h
@@ -130,6 +130,7 @@ protected:
 
 	TaggedCache< uint256, std::vector<unsigned char> >	mFetchPack;
 	uint32												mLastFetchPack;
+	uint32												mFetchSeq;
 
 	uint32												mLastLoadBase;
 	uint32												mLastLoadFactor;
@@ -262,8 +263,8 @@ public:
 	bool stillNeedTXSet(const uint256& hash);
 	void makeFetchPack(Job&, boost::weak_ptr<Peer> peer, boost::shared_ptr<ripple::TMGetObjectByHash> request,
 		Ledger::pointer wantLedger, Ledger::pointer haveLedger);
-	bool shouldFetchPack();
-	void gotFetchPack(bool progress);
+	bool shouldFetchPack(uint32 seq);
+	void gotFetchPack(bool progress, uint32 seq);
 	void addFetchPack(const uint256& hash, boost::shared_ptr< std::vector<unsigned char> >& data);
 	bool getFetchPack(const uint256& hash, std::vector<unsigned char>& data);
 	int getFetchSize();
diff --git a/src/cpp/ripple/Peer.cpp b/src/cpp/ripple/Peer.cpp
index c9a7a7d2a7..98c7cbd38e 100644
--- a/src/cpp/ripple/Peer.cpp
+++ b/src/cpp/ripple/Peer.cpp
@@ -1274,7 +1274,7 @@ void Peer::recvGetObjectByHash(const boost::shared_ptr<ripple::TMGetObjectByHash
 		}
 		tLog(pLDo && (pLSeq != 0), lsDEBUG) << "Received partial fetch pack for " << pLSeq;
 		if (packet.type() == ripple::TMGetObjectByHash::otFETCH_PACK)
-			theApp->getOPs().gotFetchPack(progress);
+			theApp->getOPs().gotFetchPack(progress, pLSeq);
 	}
 }
 
diff --git a/src/cpp/ripple/TaggedCache.h b/src/cpp/ripple/TaggedCache.h
index c7fb419028..03999099be 100644
--- a/src/cpp/ripple/TaggedCache.h
+++ b/src/cpp/ripple/TaggedCache.h
@@ -77,6 +77,7 @@ public:
 	void setTargetSize(int size);
 	void setTargetAge(int age);
 	void sweep();
+	void clear();
 
 	bool touch(const key_type& key);
 	bool del(const key_type& key, bool valid);
@@ -128,6 +129,12 @@ template<typename c_Key, typename c_Data> int TaggedCache<c_Key, c_Data>::getTra
 	return mCache.size();
 }
 
+template<typename c_Key, typename c_Data> void TaggedCache<c_Key, c_Data>::clear()
+{
+	mCache.clear();
+	mCacheCount = 0;
+}
+
 template<typename c_Key, typename c_Data> void TaggedCache<c_Key, c_Data>::sweep()
 {
 	boost::recursive_mutex::scoped_lock sl(mLock);