From 98b3c526ec8206f2091bff59dece85b278b7196d Mon Sep 17 00:00:00 2001
From: JoelKatz <DavidJoelSchwartz@GMail.com>
Date: Mon, 3 Dec 2012 16:16:50 -0800
Subject: [PATCH] Finish the load manager class.

---
 src/cpp/ripple/LoadManager.cpp | 105 +++++++++++++++++++++++++++++++++
 src/cpp/ripple/LoadManager.h   |  25 ++++----
 2 files changed, 118 insertions(+), 12 deletions(-)

diff --git a/src/cpp/ripple/LoadManager.cpp b/src/cpp/ripple/LoadManager.cpp
index 3e251c218..7ccb72060 100644
--- a/src/cpp/ripple/LoadManager.cpp
+++ b/src/cpp/ripple/LoadManager.cpp
@@ -1,2 +1,107 @@
 #include "LoadManager.h"
 
+int LoadManager::getCreditRate() const
+{
+	boost::mutex::scoped_lock sl(mLock);
+	return mCreditRate;
+}
+
+int LoadManager::getCreditLimit() const
+{
+	boost::mutex::scoped_lock sl(mLock);
+	return mCreditLimit;
+}
+
+int LoadManager::getDebitWarn() const
+{
+	boost::mutex::scoped_lock sl(mLock);
+	return mDebitWarn;
+}
+
+int LoadManager::getDebitLimit() const
+{
+	boost::mutex::scoped_lock sl(mLock);
+	return mDebitLimit;
+}
+
+void LoadManager::setCreditRate(int r)
+{
+	boost::mutex::scoped_lock sl(mLock);
+	mCreditRate = r;
+}
+
+void LoadManager::setCreditLimit(int r)
+{
+	boost::mutex::scoped_lock sl(mLock);
+	mCreditLimit = r;
+}
+
+void LoadManager::setDebitWarn(int r)
+{
+	boost::mutex::scoped_lock sl(mLock);
+	mDebitWarn = r;
+}
+
+void LoadManager::setDebitLimit(int r)
+{
+	boost::mutex::scoped_lock sl(mLock);
+	mDebitLimit = r;
+}
+
+void LoadManager::canonicalize(LoadSource& source, const time_t now) const
+{
+	if (source.mLastUpdate != now)
+	{
+		if (source.mLastUpdate < now)
+		{
+			source.mBalance += mCreditRate * (now - source.mLastUpdate);
+			if (source.mBalance > mCreditLimit)
+				source.mBalance = mCreditLimit;
+		}
+		source.mLastUpdate = now;
+	}
+}
+
+bool LoadManager::shouldWarn(LoadSource& source) const
+{
+	time_t now = time(NULL);
+	boost::mutex::scoped_lock sl(mLock);
+
+	canonicalize(source, now);
+	if (source.isPrivileged() || (source.mBalance < mDebitWarn) || (source.mLastWarning == now))
+		return false;
+	source.mLastWarning = now;
+	return true;
+}
+
+bool LoadManager::shouldCutoff(LoadSource& source) const
+{
+	time_t now = time(NULL);
+	boost::mutex::scoped_lock sl(mLock);
+
+	canonicalize(source, now);
+	return !source.isPrivileged() && (source.mBalance < mDebitLimit);
+}
+
+bool LoadManager::adjust(LoadSource& source, int credits) const
+{
+	time_t now = time(NULL);
+	boost::mutex::scoped_lock sl(mLock);
+
+	// We do it this way in case we want to add exponential decay later
+	canonicalize(source, now);
+	source.mBalance += credits;
+	if (source.mBalance > mCreditLimit)
+		source.mBalance = mCreditLimit;
+
+	if (source.isPrivileged()) // privileged sources never warn/cutoff
+		return false;
+
+	if (source.mBalance < mDebitLimit) // over-limit
+		return true;
+
+	if ((source.mBalance < mDebitWarn) && (source.mLastWarning != now)) // need to warn
+		return true;
+
+	return false;
+}
diff --git a/src/cpp/ripple/LoadManager.h b/src/cpp/ripple/LoadManager.h
index 11312ba31..5b9e2207b 100644
--- a/src/cpp/ripple/LoadManager.h
+++ b/src/cpp/ripple/LoadManager.h
@@ -19,8 +19,8 @@ protected:
 	time_t	mLastWarning;
 
 public:
-	LoadSource() : mBalance(0), mFlags(0), mLastUpdate(0), mLastWarning(0)
-									{ ; }
+	LoadSource() : mBalance(0), mFlags(0), mLastWarning(0)
+									{ mLastUpdate = time(NULL); }
 
 	bool	isPrivileged() const	{ return (mFlags & lsfPrivileged) != 0; }
 	void	setPrivileged()			{ mFlags |= lsfPrivileged; }
@@ -35,28 +35,29 @@ protected:
 	int mCreditRate;			// credits gained/lost per second
 	int mCreditLimit;			// the most credits a source can have
 	int	mDebitWarn;				// when a source drops below this, we warn
-	int mDebitLimit;			// when a source drops below this, we cut it off
+	int mDebitLimit;			// when a source drops below this, we cut it off (should be negative)
 
-	boost::mutex	mLock;
+	mutable boost::mutex mLock;
+
+	void canonicalize(LoadSource&, const time_t now) const;
 
 public:
 
 	LoadManager(int creditRate, int creditLimit, int debitWarn, int debitLimit) :
 		mCreditRate(creditRate), mCreditLimit(creditLimit), mDebitWarn(debitWarn), mDebitLimit(debitLimit) { ; }
 
-	int getCreditRate();
-	int getCreditLimit();
-	int getDebitWarn();
-	int getDebitLimit();
+	int getCreditRate() const;
+	int getCreditLimit() const;
+	int getDebitWarn() const;
+	int getDebitLimit() const;
 	void setCreditRate(int);
 	void setCreditLimit(int);
 	void setDebitWarn(int);
 	void setDebitLimit(int);
 
-	bool shouldWarn(const LoadSource&);
-	bool shouldCutoff(const LoadSource&);
-	void credit(LoadSource&, int credits);
-	bool debit(LoadSource&, int credits);	// return value: false = balance okay, true = warn/cutoff
+	bool shouldWarn(LoadSource&) const;
+	bool shouldCutoff(LoadSource&) const;
+	bool adjust(LoadSource&, int credits) const;	// return value: false = balance okay, true = warn/cutoff
 };
 
 #endif