Load and latency monitoring class.

This will allow us to assess our load level.

src/cpp/ripple/LoadMonitor.h

@@ -0,0 +1,76 @@
+#ifndef LOADMONITOR__H_
+#define LOADMONITOR__H_
+
+#include <string>
+
+#include <boost/thread/mutex.hpp>
+
+#include "types.h"
+
+// Monitors load levels and response times
+
+class LoadMonitor
+{
+protected:
+	std::string			mName;
+	uint64				mCounts;
+	uint64				mLatencyEvents;
+	uint64				mLatencyMS;
+	time_t				mLastUpdate;
+	boost::mutex		mLock;
+
+	void update();
+
+public:
+	LoadMonitor(const std::string& n) : mName(n), mCounts(0), mLatencyEvents(0), mLatencyMS(0)
+	{ mLastUpdate = time(NULL); }
+
+	void setName(const std::string& n)		{ mName = n; }
+
+	const std::string& getName() const		{ return mName; }
+
+	void addCount(int counts);
+	void addLatency(int latency);
+	void addCountAndLatency(int counts, int latency);
+
+	void getCountAndLatency(uint64& count, uint64& latency);
+};
+
+class LoadEvent
+{
+protected:
+	LoadMonitor&				mMonitor;
+	bool						mRunning;
+	int							mCount;
+	boost::posix_time::ptime	mStartTime;
+
+public:
+	LoadEvent(LoadMonitor& monitor, bool shouldStart, int count) : mMonitor(monitor), mRunning(false), mCount(count)
+	{
+		mStartTime = boost::posix_time::microsec_clock::universal_time();
+		if (shouldStart)
+			start();
+	}
+
+	~LoadEvent()
+	{
+		if (mRunning)
+			stop();
+	}
+
+	void start()
+	{ // okay to call if already started
+		mRunning = true;
+		mStartTime = boost::posix_time::microsec_clock::universal_time();
+	}
+
+	void stop()
+	{
+		assert(mRunning);
+		mRunning = false;
+		mMonitor.addCountAndLatency(mCount,
+			(boost::posix_time::microsec_clock::universal_time() - mStartTime).total_milliseconds());
+	}
+};
+
+#endif