From f8005b88adfe93af477528bec748882da8fa9bea Mon Sep 17 00:00:00 2001
From: Joseph Henry <josephjah@gmail.com>
Date: Wed, 13 Jun 2018 14:50:37 -0700
Subject: [PATCH] Minor cleanup. More efficient push() operation for RingBuffer

---
 node/Path.hpp       | 7 -------
 node/Peer.hpp       | 4 ++--
 node/RingBuffer.hpp | 9 +++++++--
 3 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/node/Path.hpp b/node/Path.hpp
index e04263237..30655877c 100644
--- a/node/Path.hpp
+++ b/node/Path.hpp
@@ -161,11 +161,9 @@ public:
 	{
 		delete _throughputSamples;
 		delete _latencySamples;
-		delete _qualitySamples;
 		delete _packetValiditySamples;
 		_throughputSamples = NULL;
 		_latencySamples = NULL;
-		_qualitySamples = NULL;
 		_packetValiditySamples = NULL;
 	}
 
@@ -580,7 +578,6 @@ public:
 	 * @param now Current time
 	 */
 	inline void processBackgroundPathMeasurements(int64_t now, const int64_t peerId) {
-		// Compute path stability
 		if (now - _lastPathQualityComputeTime > ZT_PATH_QUALITY_COMPUTE_INTERVAL) {
 			Mutex::Lock _l(_statistics_m);
 			_lastPathQualityComputeTime = now;
@@ -606,8 +603,6 @@ public:
 			// Compute the quality product
 			_lastComputedStability = pdv_contrib + latency_contrib + throughput_disturbance_contrib;
 			_lastComputedStability *= 1 - _packetErrorRatio;
-			_qualitySamples->push(_lastComputedStability);
-
 			// Prevent QoS records from sticking around for too long
 			std::map<uint64_t,uint64_t>::iterator it = _outQoSRecords.begin();
 			while (it != _outQoSRecords.end()) {
@@ -650,7 +645,6 @@ public:
 	inline void prepareBuffers() {
 		_throughputSamples = new RingBuffer<uint64_t>(ZT_PATH_QUALITY_METRIC_WIN_SZ);
 		_latencySamples = new RingBuffer<uint32_t>(ZT_PATH_QUALITY_METRIC_WIN_SZ);
-		_qualitySamples = new RingBuffer<float>(ZT_PATH_QUALITY_METRIC_WIN_SZ);
 		_packetValiditySamples = new RingBuffer<bool>(ZT_PATH_QUALITY_METRIC_WIN_SZ);
 		memset(_ifname, 0, 16);
 		memset(_addrString, 0, sizeof(_addrString));
@@ -704,7 +698,6 @@ private:
 
 	RingBuffer<uint64_t> *_throughputSamples;
 	RingBuffer<uint32_t> *_latencySamples;
-	RingBuffer<float> *_qualitySamples;
 	RingBuffer<bool> *_packetValiditySamples;
 };
 
diff --git a/node/Peer.hpp b/node/Peer.hpp
index 21e8cbf26..9361f6654 100644
--- a/node/Peer.hpp
+++ b/node/Peer.hpp
@@ -678,8 +678,8 @@ private:
 	bool _linkIsRedundant;
 	bool _remotePeerMultipathEnabled;
 
-	uint64_t _lastAggregateStatsReport;
-	uint64_t _lastAggregateAllocation;
+	int64_t _lastAggregateStatsReport;
+	int64_t _lastAggregateAllocation;
 
 	char _interfaceListStr[256]; // 16 characters * 16 paths in a link
 };
diff --git a/node/RingBuffer.hpp b/node/RingBuffer.hpp
index 32ae037ca..e8d0d238b 100644
--- a/node/RingBuffer.hpp
+++ b/node/RingBuffer.hpp
@@ -37,7 +37,7 @@
 namespace ZeroTier {
 
 /**
- * A revolving (ring) buffer. 
+ * A circular buffer
  *
  * For fast handling of continuously-evolving variables (such as path quality metrics).
  * Using this, we can maintain longer sliding historical windows for important path 
@@ -169,7 +169,12 @@ public:
 		if (count() == size) {
 			consume(1);
 		}
-		write(&value, 1);
+		const size_t first_chunk = std::min((size_t)1, size - end);
+		*(buf + end) = value;
+		end = (end + first_chunk) % size;
+		if (begin == end) {
+			wrap = true;
+		}
 	}
 
 	/**