From ff0edf2d12b91e0e3240df9be502fc9dd88c37e5 Mon Sep 17 00:00:00 2001
From: Andrew Nicols <andrew@nicols.co.uk>
Date: Wed, 20 Dec 2017 11:31:28 +0800
Subject: [PATCH] MDL-61068 mod_forum: Round timed posts to nearest 60 seconds

This slightly reduces the effectiveness of the DB query cache, but gives
us correct results every time.
---
 mod/forum/lib.php    | 18 +++++++++---------
 mod/forum/rsslib.php |  2 +-
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/mod/forum/lib.php b/mod/forum/lib.php
index 37e94c0b29ab0..2c2135efaca25 100644
--- a/mod/forum/lib.php
+++ b/mod/forum/lib.php
@@ -2025,7 +2025,7 @@ function forum_search_posts($searchterms, $courseid=0, $limitfrom=0, $limitnum=5
         return false;
     }
 
-    $now = round(time(), -2); // db friendly
+    $now = floor(time() / 60) * 60; // DB Cache Friendly.
 
     $fullaccess = array();
     $where = array();
@@ -2467,7 +2467,7 @@ function forum_count_discussions($forum, $cm, $course) {
 
     static $cache = array();
 
-    $now = round(time(), -2); // db cache friendliness
+    $now = floor(time() / 60) * 60; // DB Cache Friendly.
 
     $params = array($course->id);
 
@@ -2567,7 +2567,7 @@ function forum_get_discussions($cm, $forumsort="", $fullpost=true, $unused=-1, $
 
     $timelimit = '';
 
-    $now = round(time(), -2);
+    $now = floor(time() / 60) * 60;
     $params = array($cm->instance);
 
     $modcontext = context_module::instance($cm->id);
@@ -2721,7 +2721,7 @@ function forum_get_discussion_neighbours($cm, $discussion, $forum) {
     }
 
     $neighbours = array('prev' => false, 'next' => false);
-    $now = round(time(), -2);
+    $now = floor(time() / 60) * 60;
     $params = array();
 
     $modcontext = context_module::instance($cm->id);
@@ -2889,7 +2889,7 @@ function forum_get_default_sort_order($desc = true, $compare = 'd.timemodified',
 function forum_get_discussions_unread($cm) {
     global $CFG, $DB, $USER;
 
-    $now = round(time(), -2);
+    $now = floor(time() / 60) * 60;
     $cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);
 
     $params = array();
@@ -2961,7 +2961,7 @@ function forum_get_discussions_unread($cm) {
 function forum_get_discussions_count($cm) {
     global $CFG, $DB, $USER;
 
-    $now = round(time(), -2);
+    $now = floor(time() / 60) * 60;
     $params = array($cm->instance);
     $groupmode    = groups_get_activity_groupmode($cm);
     $currentgroup = groups_get_activity_group($cm);
@@ -6376,7 +6376,7 @@ function forum_tp_is_post_old($post, $time=null) {
 function forum_tp_get_course_unread_posts($userid, $courseid) {
     global $CFG, $DB;
 
-    $now = round(time(), -2); // DB cache friendliness.
+    $now = floor(time() / 60) * 60; // DB cache friendliness.
     $cutoffdate = $now - ($CFG->forum_oldpostdays * 24 * 60 * 60);
     $params = array($userid, $userid, $courseid, $cutoffdate, $userid);
 
@@ -6475,7 +6475,7 @@ function forum_tp_count_forum_unread_posts($cm, $course, $resetreadcache = false
 
     list ($groups_sql, $groups_params) = $DB->get_in_or_equal($mygroups);
 
-    $now = round(time(), -2); // db cache friendliness
+    $now = floor(time() / 60) * 60; // DB Cache friendliness.
     $cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);
     $params = array($USER->id, $forumid, $cutoffdate);
 
@@ -7635,7 +7635,7 @@ function forum_get_posts_by_user($user, array $courses, $musthaveaccess = false,
     // Will record forums where the user can freely access everything
     $forumsearchfullaccess = array();
     // DB caching friendly
-    $now = round(time(), -2);
+    $now = floor(time() / 60) * 60;
     // For each course to search we want to find the forums the user has posted in
     // and providing the current user can access the forum create a search condition
     // for the forum to get the requested users posts.
diff --git a/mod/forum/rsslib.php b/mod/forum/rsslib.php
index 6c301b77da4c0..4f413976d93d0 100644
--- a/mod/forum/rsslib.php
+++ b/mod/forum/rsslib.php
@@ -146,7 +146,7 @@ function forum_rss_feed_discussions_sql($forum, $cm, $newsince=0) {
 
     $modcontext = null;
 
-    $now = round(time(), -2);
+    $now = floor(time() / 60) * 60; // DB Cache Friendly.
     $params = array();
 
     $modcontext = context_module::instance($cm->id);