From f2e9469e1600bbb350ec170e6ac14ad6cd724d23 Mon Sep 17 00:00:00 2001
From: Evan Prodromou <evan@status.net>
Date: Wed, 13 Jan 2010 03:11:31 -0800
Subject: [PATCH] throttle subscriptions

---
 plugins/SubscriptionThrottlePlugin.php | 175 +++++++++++++++++++++++++
 1 file changed, 175 insertions(+)
 create mode 100644 plugins/SubscriptionThrottlePlugin.php

diff --git a/plugins/SubscriptionThrottlePlugin.php b/plugins/SubscriptionThrottlePlugin.php
new file mode 100644
index 0000000000..114113360e
--- /dev/null
+++ b/plugins/SubscriptionThrottlePlugin.php
@@ -0,0 +1,175 @@
+<?php
+/**
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * Plugin to throttle subscriptions by a user
+ *
+ * PHP version 5
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Throttle
+ * @package   StatusNet
+ * @author    Evan Prodromou <evan@status.net>
+ * @copyright 2010 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
+ * @link      http://status.net/
+ */
+
+if (!defined('STATUSNET')) {
+    // This check helps protect against security problems;
+    // your code file can't be executed directly from the web.
+    exit(1);
+}
+
+/**
+ * Subscription throttle
+ *
+ * @category  Throttle
+ * @package   StatusNet
+ * @author    Evan Prodromou <evan@status.net>
+ * @copyright 2010 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
+ * @link      http://status.net/
+ */
+
+class SubscriptionThrottlePlugin extends Plugin
+{
+    public $subLimits = array(86400 => 100,
+                              3600 => 50);
+
+    public $groupLimits = array(86400 => 50,
+                                3600 => 25);
+
+    /**
+     * Filter subscriptions to see if they're coming too fast.
+     *
+     * @param User $user  The user subscribing
+     * @param User $other The user being subscribed to
+     *
+     * @return boolean hook value
+     */
+
+    function onStartSubscribe($user, $other)
+    {
+        foreach ($this->subLimits as $seconds => $limit) {
+            $sub = $this->_getNthSub($user, $limit);
+
+            if (!empty($sub)) {
+                $subtime = strtotime($sub->created);
+                $now     = time();
+                if ($now - $subtime < $seconds) {
+                    throw new Exception(_("Too many subscriptions. Take a break and try again later."));
+                }
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Filter group joins to see if they're coming too fast.
+     *
+     * @param Group $group The group being joined
+     * @param User  $user  The user joining
+     *
+     * @return boolean hook value
+     */
+
+    function onStartJoinGroup($group, $user)
+    {
+        foreach ($this->groupLimits as $seconds => $limit) {
+            $mem = $this->_getNthMem($user, $limit);
+            if (!empty($mem)) {
+
+                $jointime = strtotime($mem->created);
+                $now      = time();
+                if ($now - $jointime < $seconds) {
+                    throw new Exception(_("Too many memberships. Take a break and try again later."));
+                }
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Get the Nth most recent subscription for this user
+     *
+     * @param User    $user The user to get subscriptions for
+     * @param integer $n    How far to count back
+     *
+     * @return Subscription a subscription or null
+     */
+
+    private function _getNthSub($user, $n)
+    {
+        $sub = new Subscription();
+
+        $sub->subscriber = $user->id;
+        $sub->orderBy('created DESC');
+        $sub->limit($n - 1, 1);
+
+        if ($sub->find(true)) {
+            return $sub;
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Get the Nth most recent group membership for this user
+     *
+     * @param User    $user The user to get memberships for
+     * @param integer $n    How far to count back
+     *
+     * @return Group_member a membership or null
+     */
+
+    private function _getNthMem($user, $n)
+    {
+        $mem = new Group_member();
+
+        $mem->profile_id = $user->id;
+        $mem->orderBy('created DESC');
+        $mem->limit($n - 1, 1);
+
+        if ($mem->find(true)) {
+            return $mem;
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Return plugin version data for display
+     *
+     * @param array &$versions Array of version arrays
+     *
+     * @return boolean hook value
+     */
+
+    function onPluginVersion(&$versions)
+    {
+        $versions[] = array('name' => 'SubscriptionThrottle',
+                            'version' => STATUSNET_VERSION,
+                            'author' => 'Evan Prodromou',
+                            'homepage' => 'http://status.net/wiki/Plugin:SubscriptionThrottle',
+                            'rawdescription' =>
+                            _m('Configurable limits for subscriptions and group memberships.'));
+        return true;
+    }
+}
+