Cache all front page stats in APC if available

Use the APC cache to store all of the counts and the recently updated
package list in a cache, which cuts down on the number of database queries
needed. If the data isn't perfectly up to date we will survive.

This version of the patch will also cache the relevant counts for individual
logged-in users and is more careful about checking whether the value
actually exists in the cache by using the status reference to apc_fetch().

Signed-off-by: Dan McGee <dan@archlinux.org>
Signed-off-by: Loui Chang <louipc.ist@gmail.com>

1 files changed, 36 insertions, 17 deletions

diff --git a/web/lib/stats.inc b/web/lib/stats.inc
index 6fbc0334..e2b7f90f 100644
--- a/web/lib/stats.inc
+++ b/web/lib/stats.inc
@@ -2,10 +2,39 @@
 
 include_once('aur.inc');
 
+# Check if APC extension is loaded
+if (!defined('EXTENSION_LOADED_APC'))
+	define('EXTENSION_LOADED_APC', extension_loaded('apc'));
+$apc_prefix = 'aur:';
+
+# run a simple db query, retrieving and/or caching the value if APC
+# is available for use
+#
+function db_cache_value($dbq, $dbh, $key)
+{
+	if(!(EXTENSION_LOADED_APC && ($ret = apc_fetch($key)))) {
+		$result = db_query($dbq, $dbh);
+		$row = mysql_fetch_row($result);
+		$ret = $row[0];
+		# set the TTL here in seconds: 300 seconds = 5 minutes
+		apc_store($key, $ret, 300);
+	}
+	return $ret;
+}
+
 function updates_table($dbh)
 {
-	$q = 'SELECT * FROM Packages WHERE DummyPkg != 1 ORDER BY GREATEST(SubmittedTS,ModifiedTS) DESC LIMIT 0 , 10';
-	$newest_packages = db_query($q, $dbh);
+	$key = $apc_prefix . 'recent_updates';
+	if(!(EXTENSION_LOADED_APC && ($newest_packages = apc_fetch($key)))) {
+		$q = 'SELECT * FROM Packages WHERE DummyPkg != 1 ORDER BY GREATEST(SubmittedTS,ModifiedTS) DESC LIMIT 0 , 10';
+		$result = db_query($q, $dbh);
+
+		$newest_packages = new ArrayObject();
+		while ($row = mysql_fetch_assoc($result)) {
+			$newest_packages->append($row);
+		}
+		apc_store($key, $newest_packages, 300);
+	}
 	include('stats/updates_table.php');
 }
 
@@ -42,30 +71,20 @@ function general_stats_table($dbh)
 {
 	# AUR statistics
 	$q = "SELECT count(*) FROM Packages,PackageLocations WHERE Packages.LocationID = PackageLocations.ID AND PackageLocations.Location = 'unsupported'";
-	$result = db_query($q, $dbh);
-	$row = mysql_fetch_row($result);
-	$unsupported_count = $row[0];
+	$unsupported_count = db_cache_value($q, $dbh, $apc_prefix . 'unsupported_count');
 
 	$q = "SELECT count(*) FROM Packages,PackageLocations WHERE Packages.LocationID = PackageLocations.ID AND PackageLocations.Location = 'community'";
-	$result = db_query($q, $dbh);
-	$row = mysql_fetch_row($result);
-	$community_count = $row[0];
+	$community_count = db_cache_value($q, $dbh, $apc_prefix . 'community_count');
 
 	$q = "SELECT count(*) from Users";
-	$result = db_query($q, $dbh);
-	$row = mysql_fetch_row($result);
-	$user_count = $row[0];
+	$user_count = db_cache_value($q, $dbh, $apc_prefix . 'user_count');
 
 	$q = "SELECT count(*) from Users,AccountTypes WHERE Users.AccountTypeID = AccountTypes.ID AND AccountTypes.AccountType = 'Trusted User'";
-	$result = db_query($q, $dbh);
-	$row = mysql_fetch_row($result);
-	$tu_count = $row[0];
+	$tu_count = db_cache_value($q, $dbh, $apc_prefix . 'tu_count');
 
 	$targstamp = intval(strtotime("-7 days"));
 	$q = "SELECT count(*) from Packages WHERE (Packages.SubmittedTS >= $targstamp OR Packages.ModifiedTS >= $targstamp)";
-	$result = db_query($q, $dbh);
-	$row = mysql_fetch_row($result);
-	$update_count = $row[0];
+	$update_count = db_cache_value($q, $dbh, $apc_prefix . 'update_count');
 
 	include('stats/general_stats_table.php');
 }