From efd037cd34f4d174d936b3ad764b0ba9d71c6416 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20L=C3=BCck?= <christian@lueck.tv>
Date: Fri, 20 Apr 2018 22:21:59 +0200
Subject: [PATCH 1/2] Use sorted array to store timers and remove cancelled
 ones

---
 src/Timer/Timers.php | 68 +++++++++++++++-----------------------------
 1 file changed, 23 insertions(+), 45 deletions(-)

diff --git a/src/Timer/Timers.php b/src/Timer/Timers.php
index 17bbdac8..813072d4 100644
--- a/src/Timer/Timers.php
+++ b/src/Timer/Timers.php
@@ -3,8 +3,6 @@
 namespace React\EventLoop\Timer;
 
 use React\EventLoop\TimerInterface;
-use SplObjectStorage;
-use SplPriorityQueue;
 
 /**
  * A scheduler implementation that can hold multiple timer instances
@@ -17,14 +15,8 @@
 final class Timers
 {
     private $time;
-    private $timers;
-    private $scheduler;
-
-    public function __construct()
-    {
-        $this->timers = new SplObjectStorage();
-        $this->scheduler = new SplPriorityQueue();
-    }
+    private $timers = array();
+    private $schedule = array();
 
     public function updateTime()
     {
@@ -38,36 +30,26 @@ public function getTime()
 
     public function add(TimerInterface $timer)
     {
-        $interval = $timer->getInterval();
-        $scheduledAt = $interval + microtime(true);
-
-        $this->timers->attach($timer, $scheduledAt);
-        $this->scheduler->insert($timer, -$scheduledAt);
+        $id = spl_object_hash($timer);
+        $this->timers[$id] = $timer;
+        $this->schedule[$id] = $timer->getInterval() + microtime(true);
+        asort($this->schedule);
     }
 
     public function contains(TimerInterface $timer)
     {
-        return $this->timers->contains($timer);
+        return isset($this->timers[spl_oject_hash($timer)]);
     }
 
     public function cancel(TimerInterface $timer)
     {
-        $this->timers->detach($timer);
+        $id = spl_object_hash($timer);
+        unset($this->timers[$id], $this->schedule[$id]);
     }
 
     public function getFirst()
     {
-        while ($this->scheduler->count()) {
-            $timer = $this->scheduler->top();
-
-            if ($this->timers->contains($timer)) {
-                return $this->timers[$timer];
-            }
-
-            $this->scheduler->extract();
-        }
-
-        return null;
+        return reset($this->schedule);
     }
 
     public function isEmpty()
@@ -78,31 +60,27 @@ public function isEmpty()
     public function tick()
     {
         $time = $this->updateTime();
-        $timers = $this->timers;
-        $scheduler = $this->scheduler;
-
-        while (!$scheduler->isEmpty()) {
-            $timer = $scheduler->top();
 
-            if (!isset($timers[$timer])) {
-                $scheduler->extract();
-                $timers->detach($timer);
-
-                continue;
+        foreach ($this->schedule as $id => $scheduled) {
+            // schedule is ordered, so loop until first timer that is not scheduled for execution now
+            if ($scheduled >= $time) {
+                break;
             }
 
-            if ($timers[$timer] >= $time) {
-                break;
+            // skip any timers that are removed while we process the current schedule
+            if (!isset($this->schedule[$id]) || $this->schedule[$id] !== $scheduled) {
+                continue;
             }
 
-            $scheduler->extract();
+            $timer = $this->timers[$id];
             call_user_func($timer->getCallback(), $timer);
 
-            if ($timer->isPeriodic() && isset($timers[$timer])) {
-                $timers[$timer] = $scheduledAt = $timer->getInterval() + $time;
-                $scheduler->insert($timer, -$scheduledAt);
+            // re-schedule if this is a periodic timer and it has not been cancelled explicitly already
+            if ($timer->isPeriodic() && isset($this->timers[$id])) {
+                $this->schedule[$id] = $timer->getInterval() + $time;
+                asort($this->schedule);
             } else {
-                $timers->detach($timer);
+                unset($this->timers[$id], $this->schedule[$id]);
             }
         }
     }

From be70d8c65f9224ba1765e6761389bf593896114a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20L=C3=BCck?= <christian@lueck.tv>
Date: Sat, 21 Apr 2018 10:11:09 +0200
Subject: [PATCH 2/2] Improve performance by sorting timers only on demand

---
 src/Timer/Timers.php | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/Timer/Timers.php b/src/Timer/Timers.php
index 813072d4..7944b4c1 100644
--- a/src/Timer/Timers.php
+++ b/src/Timer/Timers.php
@@ -17,6 +17,7 @@ final class Timers
     private $time;
     private $timers = array();
     private $schedule = array();
+    private $sorted = true;
 
     public function updateTime()
     {
@@ -33,7 +34,7 @@ public function add(TimerInterface $timer)
         $id = spl_object_hash($timer);
         $this->timers[$id] = $timer;
         $this->schedule[$id] = $timer->getInterval() + microtime(true);
-        asort($this->schedule);
+        $this->sorted = false;
     }
 
     public function contains(TimerInterface $timer)
@@ -49,6 +50,12 @@ public function cancel(TimerInterface $timer)
 
     public function getFirst()
     {
+        // ensure timers are sorted to simply accessing next (first) one
+        if (!$this->sorted) {
+            $this->sorted = true;
+            asort($this->schedule);
+        }
+
         return reset($this->schedule);
     }
 
@@ -59,6 +66,12 @@ public function isEmpty()
 
     public function tick()
     {
+        // ensure timers are sorted so we can execute in order
+        if (!$this->sorted) {
+            $this->sorted = true;
+            asort($this->schedule);
+        }
+
         $time = $this->updateTime();
 
         foreach ($this->schedule as $id => $scheduled) {
@@ -78,7 +91,7 @@ public function tick()
             // re-schedule if this is a periodic timer and it has not been cancelled explicitly already
             if ($timer->isPeriodic() && isset($this->timers[$id])) {
                 $this->schedule[$id] = $timer->getInterval() + $time;
-                asort($this->schedule);
+                $this->sorted = false;
             } else {
                 unset($this->timers[$id], $this->schedule[$id]);
             }