Merge pull request #11809 from annando/fetch-cache

Repeated fetch requests are now prohibited

database.sql

@@ -1,6 +1,6 @@
 -- ------------------------------------------
 -- Friendica 2022.09-dev (Giant Rhubarb)
--- DB_UPDATE_VERSION 1476
+-- DB_UPDATE_VERSION 1477
 -- ------------------------------------------
 
 
@@ -632,6 +632,21 @@ CREATE TABLE IF NOT EXISTS `fcontact` (
 	FOREIGN KEY (`uri-id`) REFERENCES `item-uri` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='Diaspora compatible contacts - used in the Diaspora implementation';
 
+--
+-- TABLE fetch-entry
+--
+CREATE TABLE IF NOT EXISTS `fetch-entry` (
+	`id` int unsigned NOT NULL auto_increment COMMENT 'sequential ID',
+	`url` varbinary(255) COMMENT 'url that awaiting to be fetched',
+	`created` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'Creation date of the fetch request',
+	`wid` int unsigned COMMENT 'Workerqueue id',
+	 PRIMARY KEY(`id`),
+	 UNIQUE INDEX `url` (`url`),
+	 INDEX `created` (`created`),
+	 INDEX `wid` (`wid`),
+	FOREIGN KEY (`wid`) REFERENCES `workerqueue` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE
+) DEFAULT COLLATE utf8mb4_general_ci COMMENT='';
+
 --
 -- TABLE fsuggest
 --

doc/database.md

@@ -24,6 +24,7 @@ Database Tables
 | [endpoint](help/database/db_endpoint) | ActivityPub endpoints - used in the ActivityPub implementation |
 | [event](help/database/db_event) | Events |
 | [fcontact](help/database/db_fcontact) | Diaspora compatible contacts - used in the Diaspora implementation |
+| [fetch-entry](help/database/db_fetch-entry) |  |
 | [fsuggest](help/database/db_fsuggest) | friend suggestion stuff |
 | [group](help/database/db_group) | privacy groups, group info |
 | [group_member](help/database/db_group_member) | privacy groups, member info |

doc/database/db_fetch-entry.md

@@ -0,0 +1,33 @@
+Table fetch-entry
+===========
+
+
+
+Fields
+------
+
+| Field   | Description                        | Type           | Null | Key | Default             | Extra          |
+| ------- | ---------------------------------- | -------------- | ---- | --- | ------------------- | -------------- |
+| id      | sequential ID                      | int unsigned   | NO   | PRI | NULL                | auto_increment |
+| url     | url that awaiting to be fetched    | varbinary(255) | YES  |     | NULL                |                |
+| created | Creation date of the fetch request | datetime       | NO   |     | 0001-01-01 00:00:00 |                |
+| wid     | Workerqueue id                     | int unsigned   | YES  |     | NULL                |                |
+
+Indexes
+------------
+
+| Name    | Fields      |
+| ------- | ----------- |
+| PRIMARY | id          |
+| url     | UNIQUE, url |
+| created | created     |
+| wid     | wid         |
+
+Foreign Keys
+------------
+
+| Field | Target Table | Target Field |
+|-------|--------------|--------------|
+| wid | [workerqueue](help/database/db_workerqueue) | id |
+
+Return to [database documentation](help/database)

src/Protocol/ActivityPub/Fetch.php

@@ -0,0 +1,83 @@
+<?php
+/**
+ * @copyright Copyright (C) 2010-2022, the Friendica project
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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 <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Protocol\ActivityPub;
+
+use Friendica\Core\Logger;
+use Friendica\Database\Database;
+use Friendica\Database\DBA;
+use Friendica\Util\DateTimeFormat;
+
+/**
+ * This class handles the fetching of posts
+ */
+class Fetch
+{
+	public static function add(string $url): int
+	{
+		DBA::insert('fetch-entry', ['url' => $url, 'created' => DateTimeFormat::utcNow()], Database::INSERT_IGNORE);
+
+		$fetch = DBA::selectFirst('fetch-entry', ['id'], ['url' => $url]);
+		Logger::debug('Added fetch entry', ['url' => $url, 'fetch' => $fetch]);
+		return $fetch['id'] ?? 0;
+	}
+
+	/**
+	 * Set the worker id for the queue entry
+	 *
+	 * @param array $activity
+	 * @param int   $wid
+	 * @return void
+	 */
+	public static function setWorkerId(string $url, int $wid)
+	{
+		if (empty($url) || empty($wid)) {
+			return;
+		}
+
+		DBA::update('fetch-entry', ['wid' => $wid], ['url' => $url]);
+		Logger::debug('Worker id set', ['url' => $url, 'wid' => $wid]);
+	}
+
+	/**
+	 * Check if there is an assigned worker task
+	 *
+	 * @param array $activity
+	 * @return bool
+	 */
+	public static function hasWorker(string $url): bool
+	{
+		$fetch = DBA::selectFirst('fetch-entry', ['id', 'wid'], ['url' => $url]);
+		if (empty($fetch['id'])) {
+			Logger::debug('No entry found for url', ['url' => $url]);
+			return false;
+		}
+
+		// We don't have a workerqueue id yet. So most likely is isn't assigned yet.
+		// To avoid the ramping up of another fetch request we simply claim that there is a waiting worker.
+		if (!empty($fetch['id']) && empty($fetch['wid'])) {
+			Logger::debug('Entry without worker found for url', ['url' => $url]);
+			return true;
+		}
+
+		return DBA::exists('workerqueue', ['id' => $fetch['wid'], 'done' => false]);
+	}
+}

src/Protocol/ActivityPub/Processor.php

@@ -58,6 +58,7 @@ use Friendica\Worker\Delivery;
 class Processor
 {
 	const CACHEKEY_FETCH_ACTIVITY = 'processor:fetchMissingActivity:';
+	const CACHEKEY_JUST_FETCHED   = 'processor:isJustFetched:';
 	/**
 	 * Extracts the tag character (#, @, !) from mention links
 	 *
@@ -305,37 +306,52 @@ class Processor
 		}
 
 		if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
+			if (self::hasJustBeenFetched($activity['reply-to-id'])) {
+				Logger::notice('We just have tried to fetch this activity. We don\'t try it again.', ['parent' => $activity['reply-to-id']]);
+				$fetch_by_worker = false;
+				if (empty($conversation)) {
+					return [];
+				}
+			} else {
 				$recursion_depth = $activity['recursion-depth'] ?? 0;
 				Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 				if ($recursion_depth < DI::config()->get('system', 'max_recursion_depth')) {
 					$result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
+					$fetch_by_worker = empty($result);
 					if (empty($result) && self::isActivityGone($activity['reply-to-id'])) {
-					// Recursively delete this and all depending entries
 						if (!empty($activity['entry-id'])) {
 							Queue::deleteById($activity['entry-id']);
 						}
+						if (empty($conversation)) {
 							return [];
 						}
-				$fetch_by_worker = empty($result);
+					}
 				} else {
 					Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 					$fetch_by_worker = true;
 				}
+			}
 
 			if ($fetch_by_worker && Queue::hasWorker($activity)) {
 				Logger::notice('There is already a worker task to fetch the post.', ['id' => $activity['id'], 'parent' => $activity['reply-to-id']]);
 				$fetch_by_worker = false;
-				if (!empty($conversation)) {
+				if (empty($conversation)) {
 					return [];
 				}
 			}
 
-			if ($fetch_by_worker) {
+			if ($fetch_by_worker && DI::config()->get('system', 'fetch_by_worker')) {
 				Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 				$activity['recursion-depth'] = 0;
+				if (!Fetch::hasWorker($activity['reply-to-id'])) {
+					Fetch::add($activity['reply-to-id']);
 					$wid = Worker::add(PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
+					Fetch::setWorkerId($activity['reply-to-id'], $wid);
 					Queue::setWorkerId($activity, $wid);
-				if (!empty($conversation)) {
+				} else {
+					Logger::debug('Activity will already be fetched via a worker.', ['url' => $activity['reply-to-id']]);
+				}
+				if (empty($conversation)) {
 					return [];
 				}
 			} elseif (!empty($result)) {
@@ -466,6 +482,23 @@ class Processor
 		return $item;
 	}
 
+	/**
+	 * Check if a given activity has recently been fetched
+	 *
+	 * @param string $url
+	 * @return boolean
+	 */
+	private static function hasJustBeenFetched(string $url): bool
+	{
+		$cachekey = self::CACHEKEY_JUST_FETCHED . $url;
+		$time = DI::cache()->get($cachekey);
+		if (is_null($time)) {
+			DI::cache()->set($cachekey, time(), Duration::FIVE_MINUTES);
+			return false;
+		}
+		return ($time + 300) > time();
+	}
+
 	/**
 	 * Check if a given activity is no longer available
 	 *

static/dbstructure.config.php

@@ -55,7 +55,7 @@
 use Friendica\Database\DBA;
 
 if (!defined('DB_UPDATE_VERSION')) {
-	define('DB_UPDATE_VERSION', 1476);
+	define('DB_UPDATE_VERSION', 1477);
 }
 
 return [
@@ -692,6 +692,20 @@ return [
 			"uri-id" => ["UNIQUE", "uri-id"],
 		]
 	],
+	"fetch-entry" => [
+		"comment" => "",
+		"fields" => [
+			"id" => ["type" => "int unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "comment" => "sequential ID"],
+			"url" => ["type" => "varbinary(255)", "comment" => "url that awaiting to be fetched"],
+			"created" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => "Creation date of the fetch request"],
+			"wid" => ["type" => "int unsigned", "foreign" => ["workerqueue" => "id"], "comment" => "Workerqueue id"],		],
+		"indexes" => [
+			"PRIMARY" => ["id"],
+			"url" => ["UNIQUE", "url"],
+			"created" => ["created"],
+			"wid" => ["wid"],
+		]
+	],
 	"fsuggest" => [
 		"comment" => "friend suggestion stuff",
 		"fields" => [

static/defaults.config.php

@@ -282,6 +282,10 @@ return [
 		// Priority for the expirary notification 
 		'expire-notify-priority' => PRIORITY_LOW,
 
+		// fetch_by_worker (Boolean)
+		// Fetch missing posts via a background process
+		'fetch_by_worker' => false,
+
 		// free_crawls (Integer)
 		// Number of "free" searches when system => permit_crawling is enabled.
 		'free_crawls' => 10,
@@ -421,8 +425,8 @@ return [
 		'max_processes_frontend' => 20,
 
 		// max_recursion_depth (Integer)
-		// Maximum recursion depth when fetching posts until the job is delegated to a worker task.
-		'max_recursion_depth' => 10,
+		// Maximum recursion depth when fetching posts until the job is delegated to a worker task or finished.
+		'max_recursion_depth' => 50,
 
 		// maximagesize (Integer)
 		// Maximum size in bytes of an uploaded photo.