From df263f01da885e91f49f97deacb6aa890ddec309 Mon Sep 17 00:00:00 2001
From: Alec Smecher <alec@smecher.bc.ca>
Date: Thu, 16 Apr 2020 11:11:11 -0700
Subject: [PATCH] pkp/pkp-lib#3304 Switch caching implementation to Stash

---
 UsageStatsPlugin.inc.php | 40 ++++++++++++++--------------------------
 1 file changed, 14 insertions(+), 26 deletions(-)

diff --git a/UsageStatsPlugin.inc.php b/UsageStatsPlugin.inc.php
index 1fc1b03..b397966 100644
--- a/UsageStatsPlugin.inc.php
+++ b/UsageStatsPlugin.inc.php
@@ -774,12 +774,21 @@ function _hashIp($ip, $salt) {
 	 * @return array
 	 */
 	function _getDownloadStats($pubObjectId) {
-		$cache = CacheManager::getManager()->getCache('downloadStats', $pubObjectId, array($this, '_downloadStatsCacheMiss'));
-		if (time() - $cache->getCacheTime() > 60 * 60 * 24) {
-			// Cache is older than one day, erase it.
-			$cache->flush();
+		$pool = new Stash\Pool(Core::getStashDriver());
+		$item = $pool->getItem('downloadStats-' . md5($pubObjectId));
+		if ($item->isMiss()) {
+			$reportPlugin = $this->getReportPlugin();
+			$application = Application::get();
+			$item->set($application->getMetrics(
+				current($reportPlugin->getMetricTypes()),
+				[STATISTICS_DIMENSION_MONTH, STATISTICS_DIMENSION_REPRESENTATION_ID],
+				[STATISTICS_DIMENSION_SUBMISSION_ID => $pubObjectId, STATISTICS_DIMENSION_ASSOC_TYPE => ASSOC_TYPE_SUBMISSION_FILE],
+				[STATISTICS_DIMENSION_MONTH => STATISTICS_ORDER_ASC]
+			));
+			$item->expiresAfter(60 * 60 * 24); // Valid for one day
+			$pool->save($item);
 		}
-		$statsReports = $cache->get($pubObjectId);
+		$statsReports = $item->get();
 
 		$currentYear = date("Y");
 		$months = range(1, 12);
@@ -862,27 +871,6 @@ function getAllDownloadsStats($pubObjectId, $stats = array()) {
 		return $allDownloadStats;
 	}
 
-	/**
-	 * Callback to fill cache with data, if empty.
-	 * @param $cache FileCache
-	 * @param $pubObjectId int
-	 * @return array
-	 */
-	function _downloadStatsCacheMiss($cache, $pubObjectId) {
-		$filter = array(
-				STATISTICS_DIMENSION_SUBMISSION_ID => $pubObjectId,
-				STATISTICS_DIMENSION_ASSOC_TYPE => ASSOC_TYPE_SUBMISSION_FILE
-		);
-		$orderBy = array(STATISTICS_DIMENSION_MONTH => STATISTICS_ORDER_ASC);
-		$reportPlugin = $this->getReportPlugin();
-
-		$application = Application::get();
-
-		$statsReports = $application->getMetrics(current($reportPlugin->getMetricTypes()), array(STATISTICS_DIMENSION_MONTH, STATISTICS_DIMENSION_REPRESENTATION_ID), $filter, $orderBy);
-		$cache->setEntireCache(array($pubObjectId => $statsReports));
-		return $statsReports;
-	}
-
 	/**
 	 * Return a color RGB code to be used in the graph.
 	 * @private