From e61ed35aa06c633db93903d64244a3f82221586f Mon Sep 17 00:00:00 2001
From: Zankaria <zankaria.auxa@skiff.com>
Date: Fri, 16 Feb 2024 15:18:17 +0100
Subject: [PATCH] Refactor queue.php

---
 inc/functions.php |  12 ++++-
 inc/queue.php     | 121 ++++++++++++++++++++++++++++++++--------------
 2 files changed, 95 insertions(+), 38 deletions(-)

diff --git a/inc/functions.php b/inc/functions.php
index 50e0ca38..5890da8a 100755
--- a/inc/functions.php
+++ b/inc/functions.php
@@ -2918,8 +2918,16 @@ function generation_strategy($fun, $array=array()) { global $config;
 			return 'rebuild';
 		case 'defer':
 			// Ok, it gets interesting here :)
-			get_queue('generate')->push(serialize(array('build', $fun, $array, $action)));
-			return 'ignore';
+			$queue = Queues::get_queue($config, 'generate');
+			if ($queue === false) {
+				if ($config['syslog']) {
+					_syslog(LOG_ERR, "Could not initialize generate queue, falling back to immediate rebuild strategy");
+				}
+				return 'rebuild';
+			} else {
+				$queue->push(serialize(array('build', $fun, $array, $action)));
+				return 'ignore';
+			}
 		case 'build_on_load':
 			return 'delete';
 	}
diff --git a/inc/queue.php b/inc/queue.php
index 2801170e..0ecd1e3c 100644
--- a/inc/queue.php
+++ b/inc/queue.php
@@ -1,49 +1,98 @@
 <?php
 
-class Queue {
-	function __construct($key) { global $config;
-		if ($config['queue']['enabled'] == 'fs') {
-			$this->lock = Locks::get_lock($config, $key);
-			$key = str_replace('/', '::', $key);
-			$key = str_replace("\0", '', $key);
-			$this->key = "tmp/queue/$key/";
-		}
+class Queues {
+	private static $queues = array();
+
+
+	/**
+	 * This queue implementation isn't actually ordered, so it works more as a "bag".
+	 */
+	private static function filesystem(string $key, Lock $lock): Queue {
+		$key = str_replace('/', '::', $key);
+		$key = str_replace("\0", '', $key);
+		$key = "tmp/queue/$key/";
+
+		return new class($key, $lock) implements Queue {
+			private Lock $lock;
+			private string $key;
+
+
+			function __construct(string $key, Lock $lock) {
+				$this->lock = $lock;
+				$this->key = $key;
+			}
+
+			public function push(string $str): Queue {
+				$this->lock->get_ex();
+				file_put_contents($this->key . microtime(true), $str);
+				$this->lock->free();
+				return $this;
+			}
+
+			public function pop(int $n = 1): array {
+				$this->lock->get_ex();
+				$dir = opendir($this->key);
+				$paths = array();
+
+				while ($n > 0) {
+					$path = readdir($dir);
+					if ($path === false) {
+						break;
+					} elseif ($path == '.' || $path == '..') {
+						continue;
+					} else {
+						$paths[] = $path;
+						$n--;
+					}
+				}
+
+				$out = array();
+				foreach ($paths as $v) {
+					$out[] = file_get_contents($this->key . $v);
+					unlink($this->key . $v);
+				}
+
+				$this->lock->free();
+				return $out;
+			}
+		};
 	}
 
-	function push($str) { global $config;
-		if ($config['queue']['enabled'] == 'fs') {
-			$this->lock->get_ex();
-			file_put_contents($this->key.microtime(true), $str);
-			$this->lock->free();
-		}
-		return $this;
+	/**
+	 * No-op. Can be used for mocking.
+	 */
+	public static function none(): Queue {
+		return new class() implements Queue {
+			public function push(string $str): Queue {
+				return $this;
+			}
+
+			public function pop(int $n = 1): array {
+				return array();
+			}
+		};
 	}
 
-	function pop($n = 1) { global $config;
-		if ($config['queue']['enabled'] == 'fs') {
-			$this->lock->get_ex();
-			$dir = opendir($this->key);
-			$paths = array();
-			while ($n > 0) {
-				$path = readdir($dir);
-				if ($path === FALSE) break;
-				elseif ($path == '.' || $path == '..') continue;
-				else { $paths[] = $path; $n--; }
+	public static function get_queue(array $config, string $name): Queue|false {
+		if (!isset(self::$queues[$name])) {
+			if ($config['queue']['enabled'] == 'fs') {
+				$lock = Locks::get_lock($config, $name);
+				if ($lock === false) {
+					return false;
+				}
+				self::$queues[$name] = self::filesystem($name, $lock);
+			} else {
+				self::$queues[$name] = self::none();
 			}
-			$out = array();
-			foreach ($paths as $v) {
-				$out []= file_get_contents($this->key.$v);
-				unlink($this->key.$v);
-			}
-			$this->lock->free();
-			return $out;
 		}
+		return self::$queues[$name];
 	}
 }
 
-// Don't use the constructor. Use the get_queue function.
-$queues = array();
+interface Queue {
+	// Push a string in the queue.
+	public function push(string $str): Queue;
 
-function get_queue($name) { global $queues;
-	return $queues[$name] = isset ($queues[$name]) ? $queues[$name] : new Queue($name);
+	// Get a string from the queue.
+	public function pop(int $n = 1): array;
 }