From ca0dcc1af094a87f5d3c9dcf2a0cb1b06f725418 Mon Sep 17 00:00:00 2001
From: Tanguy Pruvot <tanguy.pruvot@gmail.com>
Date: Sat, 30 Oct 2010 20:54:42 +0200
Subject: [PATCH] implement frequency cache, actually only set in some cases :
 count recurrence or using lastOccurrence()

---
 blocks/SG_iCal_VEvent.php | 29 +++++++++++++++++++++++------
 demo/index.php            |  7 ++++---
 helpers/SG_iCal_Freq.php  | 36 ++++++++++++++++++++++++++++--------
 3 files changed, 55 insertions(+), 17 deletions(-)

diff --git a/blocks/SG_iCal_VEvent.php b/blocks/SG_iCal_VEvent.php
index 02e35ca..7b4fa69 100755
--- a/blocks/SG_iCal_VEvent.php
+++ b/blocks/SG_iCal_VEvent.php
@@ -15,7 +15,7 @@
  */
 class SG_iCal_VEvent {
 	const DEFAULT_CONFIRMED = true;
-	
+
 	protected $uid;
 	protected $start;
 	protected $end;
@@ -24,10 +24,12 @@ class SG_iCal_VEvent {
 	protected $summary;
 	protected $description;
 	protected $location;
-	
+
 	public $recurrence;
+	public $freq; //getFrequency()
+
 	public $data;
-	
+
 	/**
 	 * Constructs a new SG_iCal_VEvent. Needs the SG_iCalReader 
 	 * supplied so it can query for timezones.
@@ -35,6 +37,7 @@ class SG_iCal_VEvent {
 	 * @param SG_iCalReader $ical
 	 */
 	public function __construct($data, SG_iCal $ical) {
+		
 		$this->uid = $data['uid']->getData();
 		unset($data['uid']);
 
@@ -42,7 +45,7 @@ class SG_iCal_VEvent {
 			$this->recurrence = new SG_iCal_Recurrence($data['rrule']);
 			unset($data['rrule']);
 		}
-		
+
 		if( isset($data['dtstart']) ) {
 			$this->start = $this->getTimestamp($data['dtstart'], $ical);
 			unset($data['dtstart']);
@@ -67,8 +70,8 @@ class SG_iCal_VEvent {
 				//ok..
 			} elseif ($count) {
 				//if count is set, then figure out the last occurrence and set that as the end date
-				$freq = new SG_iCal_Freq($this->recurrence->rrule, $start);
-				$until = $freq->lastOccurrence($this->start);
+				$this->freq = new SG_iCal_Freq($this->recurrence->rrule, $start);
+				$until = $this->freq->lastOccurrence($this->start);
 			} else {
 				//forever... limit to 3 years
 				$this->recurrence->setUntil('+3 years');
@@ -94,6 +97,20 @@ class SG_iCal_VEvent {
 		$this->data = SG_iCal_Line::Remove_Line($data);
 	}
 	
+	
+	/**
+	 * Returns the Event Occurrences Iterator (if recurrence set)
+	 * @return SG_iCal_Freq
+	 */
+	public function getFrequency() {
+		if (! isset($this->freq)) {
+			if ( isset($this->recurrence) ) {
+				$this->freq = new SG_iCal_Freq($this->recurrence->rrule, $this->start);
+			}
+		}
+		return $this->freq;
+	}
+	
 	/**
 	 * Returns the UID of the event
 	 * @return string
diff --git a/demo/index.php b/demo/index.php
index 8551eb4..f6b4f0c 100644
--- a/demo/index.php
+++ b/demo/index.php
@@ -11,8 +11,8 @@ $ICS = "basic.ics";
 $ical = new SG_iCalReader($ICS);
 $query = new SG_iCal_Query();
 
-//$evts = $ical->getEvents();
-$evts = $query->Between($ical,strtotime('20100901'),strtotime('20101131'));
+$evts = $ical->getEvents();
+//$evts = $query->Between($ical,strtotime('20100901'),strtotime('20101131'));
 
 
 $data = array();
@@ -30,7 +30,8 @@ foreach($evts as $id => $ev) {
 	if (isset($ev->recurrence)) {
 		$count = 1;
 		$start = $ev->getStart();
-		$freq = new SG_iCal_Freq($ev->recurrence->rrule, $start);
+		//$freq = new SG_iCal_Freq($ev->recurrence->rrule, $start);
+		$freq = $ev->getFrequency();
 		while (($next = $freq->nextOccurrence($start)) > 0 ) {
 			if (!$next or $count >= 200) break;
 			$count++;
diff --git a/helpers/SG_iCal_Freq.php b/helpers/SG_iCal_Freq.php
index 4ad9c46..f02071e 100755
--- a/helpers/SG_iCal_Freq.php
+++ b/helpers/SG_iCal_Freq.php
@@ -31,11 +31,13 @@ class SG_iCal_Freq {
 	protected $rules = array('freq'=>'yearly', 'interval'=>1);
 	protected $start = 0;
 	protected $freq = '';
+	
+	public $cache;
 
 	/**
 	 * Constructs a new Freqency-rule
 	 * @param $rule string
-	 * @param $start int Unix-timestamp (important!)
+	 * @param $start int Unix-timestamp (important : Need to be the start of Event)
 	 */
 	public function __construct( $rule, $start ) {
 		$this->start = $start;
@@ -65,11 +67,14 @@ class SG_iCal_Freq {
 				$this->rules['bymonthday'] = date('d', $this->start);
 			}
 		}
-
+		
+		//set until, and cache
 		if( isset($this->rules['count']) ) {
 			$ts = $this->firstOccurrence();
+			$this->cache[0] = $ts;
 			for($i=1; $i<$this->rules['count']; $i++) {
 				$ts = $this->findNext($ts);
+				$this->cache[$i] = $ts;
 			}
 			$this->rules['until'] = $ts;
 		}
@@ -82,14 +87,24 @@ class SG_iCal_Freq {
 	 * @return int
 	 */
 	public function previousOccurrence( $offset ) {
-		$t1 = $this->start;
-		while( ($t2 = $this->findNext($t1)) < $offset) {
-			if( $t2 == false ){
-				break;
+		if (!empty($this->cache)) {
+			reset($this->cache);
+			while( ($t2 = next($this->cache)) < $offset) {
+				if( $t2 == false ){
+					break;
+				}
+				$ts = $t2;
+			}
+		} else {
+			$ts = $this->start;
+			while( ($t2 = $this->findNext($ts)) < $offset) {
+				if( $t2 == false ){
+					break;
+				}
+				$ts = $t2;
 			}
-			$t1 = $t2;
 		}
-		return $t1;
+		return $ts;
 	}
 
 	/**
@@ -116,9 +131,14 @@ class SG_iCal_Freq {
 	 * @return int timestamp
 	 */
 	public function lastOccurrence() {
+		if (!empty($this->cache)) {
+			return end($this->cache);
+		}
+		$i=0; $this->cache[0] = $this->start;
 		$ts = $next = $this->findNext($this->start);
 		while ($next) {
 			$ts = $next;
+			$i++; $this->cache[$i] = $ts;
 			$next = $this->findNext($ts);
 		}
 		return $ts;