From 02a3f24b92f70531c9bf761729d569b8ce5d307c Mon Sep 17 00:00:00 2001
From: Evan Prodromou <evan@controlyourself.ca>
Date: Sun, 28 Sep 2008 08:01:19 -0400
Subject: single function for important streams, with memcached support

I moved the 4 streams for a user (with friends, faves, replies,
personal) into functions on the User object. Added a helper function
in Notice for making notice streams. Also, will fetch notice streams
out of the memcached server, if possible. Made the API, RSS, and HTML
output all use the same streams (hopefully cached).

Added some code to Notice to blow the cache when a notice is posted.
Also, added code to favor and disfavor actions to blow the faves
cache, too.

darcs-hash:20080928120119-5ed1f-ead542348bcd3cf315be6f42934353154402eb16.gz
---
 classes/Notice.php | 164 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 163 insertions(+), 1 deletion(-)

(limited to 'classes/Notice.php')

diff --git a/classes/Notice.php b/classes/Notice.php
index b42a8726e..5bf8a2de8 100644
--- a/classes/Notice.php
+++ b/classes/Notice.php
@@ -24,6 +24,11 @@ if (!defined('LACONICA')) { exit(1); }
  */
 require_once INSTALLDIR.'/classes/Memcached_DataObject.php';
 
+/* We keep the first three 20-notice pages, plus one for pagination check,
+ * in the memcached cache. */
+
+define('NOTICE_CACHE_WINDOW', 61);
+
 class Notice extends Memcached_DataObject 
 {
     ###START_AUTOCODE
@@ -52,6 +57,12 @@ class Notice extends Memcached_DataObject
 		return Profile::staticGet($this->profile_id);
 	}
 
+	function delete() {
+		$this->blowCaches();
+		$this->blowFavesCache();
+		parent::delete();
+	}
+	
 	function saveTags() {
 		/* extract all #hastags */
 		$count = preg_match_all('/(?:^|\s)#([A-Za-z0-9_\-\.]{1,64})/', strtolower($this->content), $match);
@@ -118,11 +129,18 @@ class Notice extends Memcached_DataObject
 		# XXX: someone clever could prepend instead of clearing the cache
 		
 		if (common_config('memcached', 'enabled')) {
-			$notice->blowSubsCache();
+			$notice->blowCaches();
 		}
 		
 		return $notice;
 	}
+
+	function blowCaches() {
+		$this->blowSubsCache();
+		$this->blowNoticeCache();
+		$this->blowRepliesCache();
+		$this->blowPublicCache();
+	}
 	
 	function blowSubsCache() {
 		$cache = common_memcache();
@@ -141,4 +159,148 @@ class Notice extends Memcached_DataObject
 			unset($user);
 		}
 	}
+
+	function blowNoticeCache() {
+		if ($this->is_local) {
+			$cache = common_memcache();
+			if ($cache) {
+				$cache->delete(common_cache_key('user:notices:'.$this->profile_id));
+			}
+		}
+	}
+
+	function blowRepliesCache() {
+		$cache = common_memcache();
+		if ($cache) {
+			$reply = new Reply();
+			$reply->notice_id = $this->id;
+			if ($reply->find()) {
+				while ($reply->fetch()) {
+					$cache->delete(common_cache_key('user:replies:'.$reply->profile_id));
+				}
+			}
+			$reply->free();
+			unset($reply);
+		}
+	}
+
+	function blowPublicCache() {
+		if ($this->is_local) {
+			$cache = common_memcache();
+			if ($cache) {
+				$cache->delete(common_cache_key('public'));
+			}
+		}
+	}
+
+	function blowFavesCache() {
+		$cache = common_memcache();
+		if ($cache) {
+			$fave = new Fave();
+			$fave->notice_id = $this->id;
+			if ($fave->find()) {
+				while ($fave->fetch()) {
+					$cache->delete(common_cache_key('user:faves:'.$fave->user_id));
+				}
+			}
+			$fave->free();
+			unset($fave);
+		}
+	}
+	
+	static function getStream($qry, $cachekey, $offset=0, $limit=20) {
+		
+		if (common_config('memcached', 'enabled')) {
+			return Notice::getCachedStream($qry, $cachekey, $offset, $limit);
+		} else {
+			return Notice::getStreamDirect($qry, $offset, $limit);
+		}
+	
+	}
+
+	static function getStreamDirect($qry, $offset, $limit) {
+		
+		$qry .= 'ORDER BY notice.created DESC, notice.id DESC ';
+		
+		if(common_config('db','type')=='pgsql') {
+			$qry .= 'LIMIT ' . $limit . ' OFFSET ' . $offset;
+		} else {
+			$qry .= 'LIMIT ' . $offset . ', ' . $limit;
+		}
+
+		$notice = new Notice();
+
+		$notice->query($qry);
+		
+		return $notice;
+	}
+	
+	static function getCachedStream($qry, $cachekey, $offset, $limit) {
+
+		# If outside our cache window, just go to the DB
+		
+		if ($offset + $limit > NOTICE_CACHE_WINDOW) {
+			return Notice::getStreamDirect($qry, $offset, $limit);
+		}
+
+		# Get the cache; if we can't, just go to the DB
+		
+		$cache = common_memcache();
+		
+		if (!$cache) {
+			return Notice::getStreamDirect($qry, $offset, $limit);
+		}
+
+		# Get the notices out of the cache
+		
+		$notices = $cache->get(common_cache_key($cachekey));
+		
+		# On a cache hit, return a DB-object-like wrapper
+		
+		if ($notices) {
+			$wrapper = new NoticeWrapper(array_slice($notices, $offset, $limit));
+			return $wrapper;
+		}
+
+		# Otherwise, get the full cache window out of the DB
+
+		$notice = Notice::getStreamDirect($qry, 0, NOTICE_CACHE_WINDOW);
+		
+		# If there are no hits, just return the value
+		
+		if (!$notice) {
+			return $notice;
+		}
+
+		# Pack results into an array
+		
+		$notices = array();
+
+		while ($notice->fetch()) {
+			$notices[] = clone($notice);
+		}
+
+		# Store the array in the cache for next time
+		
+		$cache->set(common_cache_key($cachekey), $notices);
+
+		# return a wrapper of the array for use now
+		
+		$wrapper = new NoticeWrapper(array_slice($notices, $offset, $limit));
+		return $wrapper;
+	}
+	
+	function publicStream($page) {
+		
+		$qry = 'SELECT * FROM notice ';
+
+		if (common_config('public', 'localonly')) {
+			$qry .= ' WHERE is_local = 1 ';
+		}
+
+		return Notice::getStream($qry,
+								 'public',
+								 ($page-1)*NOTICES_PER_PAGE,
+								 NOTICES_PER_PAGE + 1);
+	}
 }
-- 
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