From 559dd9946988cd35a7c26bcafe7d0f8c42dc547a Mon Sep 17 00:00:00 2001
From: Ekdohibs <nathanael.courant@laposte.net>
Date: Mon, 21 Mar 2016 12:58:52 +0100
Subject: Make node timers more efficient

---
 src/nodetimer.h | 77 +++++++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 61 insertions(+), 16 deletions(-)

(limited to 'src/nodetimer.h')

diff --git a/src/nodetimer.h b/src/nodetimer.h
index 9fb56edec..0fd43b2a8 100644
--- a/src/nodetimer.h
+++ b/src/nodetimer.h
@@ -23,6 +23,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "irr_v3d.h"
 #include <iostream>
 #include <map>
+#include <vector>
 
 /*
 	NodeTimer provides per-node timed callback functionality.
@@ -36,8 +37,10 @@ class NodeTimer
 {
 public:
 	NodeTimer(): timeout(0.), elapsed(0.) {}
-	NodeTimer(f32 timeout_, f32 elapsed_):
-		timeout(timeout_), elapsed(elapsed_) {}
+	NodeTimer(const v3s16 &position_):
+		timeout(0.), elapsed(0.), position(position_) {}
+	NodeTimer(f32 timeout_, f32 elapsed_, v3s16 position_):
+		timeout(timeout_), elapsed(elapsed_), position(position_) {}
 	~NodeTimer() {}
 	
 	void serialize(std::ostream &os) const;
@@ -45,6 +48,7 @@ public:
 	
 	f32 timeout;
 	f32 elapsed;
+	v3s16 position;
 };
 
 /*
@@ -54,37 +58,78 @@ public:
 class NodeTimerList
 {
 public:
-	NodeTimerList() {}
+	NodeTimerList(): m_next_trigger_time(-1.), m_time(0.) {}
 	~NodeTimerList() {}
 	
 	void serialize(std::ostream &os, u8 map_format_version) const;
 	void deSerialize(std::istream &is, u8 map_format_version);
 	
 	// Get timer
-	NodeTimer get(v3s16 p){
-		std::map<v3s16, NodeTimer>::iterator n = m_data.find(p);
-		if(n == m_data.end())
+	NodeTimer get(const v3s16 &p) {
+		std::map<v3s16, std::multimap<double, NodeTimer>::iterator>::iterator n =
+			m_iterators.find(p);
+		if (n == m_iterators.end())
 			return NodeTimer();
-		return n->second;
+		NodeTimer t = n->second->second;
+		t.elapsed = t.timeout - (n->second->first - m_time);
+		return t;
 	}
 	// Deletes timer
-	void remove(v3s16 p){
-		m_data.erase(p);
+	void remove(v3s16 p) {
+		std::map<v3s16, std::multimap<double, NodeTimer>::iterator>::iterator n =
+			m_iterators.find(p);
+		if(n != m_iterators.end()) {
+			double removed_time = n->second->first;
+			m_timers.erase(n->second);
+			m_iterators.erase(n);
+			// Yes, this is float equality, but it is not a problem
+			// since we only test equality of floats as an ordered type
+			// and thus we never lose precision
+			if (removed_time == m_next_trigger_time) {
+				if (m_timers.empty())
+					m_next_trigger_time = -1.;
+				else
+					m_next_trigger_time = m_timers.begin()->first;
+			}
+		}
+	}
+	// Undefined behaviour if there already is a timer
+	void insert(NodeTimer timer) {
+		v3s16 p = timer.position;
+		double trigger_time = m_time + (double)(timer.timeout - timer.elapsed);
+		std::multimap<double, NodeTimer>::iterator it =
+			m_timers.insert(std::pair<double, NodeTimer>(
+				trigger_time, timer
+			));
+		m_iterators.insert(
+			std::pair<v3s16, std::multimap<double, NodeTimer>::iterator>(p, it));
+		if (m_next_trigger_time == -1. || trigger_time < m_next_trigger_time)
+			m_next_trigger_time = trigger_time;
 	}
 	// Deletes old timer and sets a new one
-	void set(v3s16 p, NodeTimer t){
-		m_data[p] = t;
+	inline void set(const NodeTimer &timer) {
+		remove(timer.position);
+		insert(timer);
 	}
 	// Deletes all timers
-	void clear(){
-		m_data.clear();
+	void clear() {
+		m_timers.clear();
+		m_iterators.clear();
+		m_next_trigger_time = -1.;
+	}
+
+	inline double getNextTriggerTime() {
+		return m_next_trigger_time;
 	}
 
-	// A step in time. Returns map of elapsed timers.
-	std::map<v3s16, NodeTimer> step(float dtime);
+	// Move forward in time, returns elapsed timers
+	std::vector<NodeTimer> step(float dtime);
 
 private:
-	std::map<v3s16, NodeTimer> m_data;
+	std::multimap<double, NodeTimer> m_timers;
+	std::map<v3s16, std::multimap<double, NodeTimer>::iterator> m_iterators;
+	double m_next_trigger_time;
+	double m_time;
 };
 
 #endif
-- 
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