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msd2/tracking/piwik/core/Concurrency/DistributedList.php

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+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+namespace Piwik\Concurrency;
+
+use Piwik\Common;
+use Piwik\Container\StaticContainer;
+use Piwik\Option;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Manages a simple distributed list stored in an Option. No locking occurs, so the list
+ * is not thread safe, and should only be used for use cases where atomicity is not
+ * important.
+ *
+ * The list of items is serialized and stored in an Option. Items are converted to string
+ * before being persisted, so it is not expected to unserialize objects.
+ */
+class DistributedList
+{
+    /**
+     * The name of the option to store the list in.
+     *
+     * @var string
+     */
+    private $optionName;
+
+    /**
+     * @var LoggerInterface
+     */
+    private $logger;
+
+    /**
+     * Constructor.
+     *
+     * @param string $optionName
+     */
+    public function __construct($optionName, LoggerInterface $logger = null)
+    {
+        $this->optionName = $optionName;
+        $this->logger = $logger ?: StaticContainer::get('Psr\Log\LoggerInterface');
+    }
+
+    /**
+     * Queries the option table and returns all items in this list.
+     *
+     * @return array
+     */
+    public function getAll()
+    {
+        $result = $this->getListOptionValue();
+
+        foreach ($result as $key => $item) {
+            // remove non-array items (unexpected state, though can happen when upgrading from an old Piwik)
+            if (is_array($item)) {
+                $this->logger->info("Found array item in DistributedList option value '{name}': {data}", array(
+                    'name' => $this->optionName,
+                    'data' => var_export($result, true)
+                ));
+
+                unset($result[$key]);
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * Sets the contents of the list in the option table.
+     *
+     * @param string[] $items
+     */
+    public function setAll($items)
+    {
+        foreach ($items as $key => &$item) {
+            if (is_array($item)) {
+                throw new \InvalidArgumentException("Array item encountered in DistributedList::setAll() [ key = $key ].");
+            } else {
+                $item = (string)$item;
+            }
+        }
+
+        Option::set($this->optionName, serialize($items));
+    }
+
+    /**
+     * Adds one or more items to the list in the option table.
+     *
+     * @param string|array $item
+     */
+    public function add($item)
+    {
+        $allItems = $this->getAll();
+        if (is_array($item)) {
+            $allItems = array_merge($allItems, $item);
+        } else {
+            $allItems[] = $item;
+        }
+
+        $this->setAll($allItems);
+    }
+
+    /**
+     * Removes one or more items by value from the list in the option table.
+     *
+     * Does not preserve array keys.
+     *
+     * @param string|array $items
+     */
+    public function remove($items)
+    {
+        if (!is_array($items)) {
+            $items = array($items);
+        }
+
+        $allItems = $this->getAll();
+
+        foreach ($items as $item) {
+            $existingIndex = array_search($item, $allItems);
+            if ($existingIndex === false) {
+                return;
+            }
+
+            unset($allItems[$existingIndex]);
+        }
+
+        $this->setAll(array_values($allItems));
+    }
+
+    /**
+     * Removes one or more items by index from the list in the option table.
+     *
+     * Does not preserve array keys.
+     *
+     * @param int[]|int $indices
+     */
+    public function removeByIndex($indices)
+    {
+        if (!is_array($indices)) {
+            $indices = array($indices);
+        }
+
+        $indices = array_unique($indices);
+
+        $allItems = $this->getAll();
+        foreach ($indices as $index) {
+            unset($allItems[$index]);
+        }
+
+        $this->setAll(array_values($allItems));
+    }
+
+    protected function getListOptionValue()
+    {
+        Option::clearCachedOption($this->optionName);
+        $array = Option::get($this->optionName);
+
+        $result = array();
+        if ($array
+            && ($array = Common::safe_unserialize($array))
+            && count($array)
+        ) {
+            $result = $array;
+        }
+        return $result;
+    }
+}