From be4e327739853da881193cec8a7df85663b8fd04 Mon Sep 17 00:00:00 2001
From: Yonas Habteab <yonas.habteab@icinga.com>
Date: Mon, 17 Jul 2023 11:36:31 +0200
Subject: [PATCH] Add retryable connection

---
 src/RetryConnection.php | 87 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 src/RetryConnection.php

diff --git a/src/RetryConnection.php b/src/RetryConnection.php
new file mode 100644
index 0000000..3a7ea88
--- /dev/null
+++ b/src/RetryConnection.php
@@ -0,0 +1,87 @@
+<?php
+
+namespace ipl\Sql;
+
+use Exception;
+use PDOStatement;
+
+class RetryConnection extends Connection
+{
+    /** @var int Number of retries to be performed before giving up */
+    protected $retries;
+
+    /** @var string[] A list of PDO retryable errors */
+    protected static $retryableErrors = [
+        'server has gone away',
+        'no connection to the server',
+        'Lost connection',
+        'Connection was killed',
+        'Connection refused',
+        'Error while sending',
+        'is dead or not enabled',
+        'decryption failed or bad record mac',
+        'server closed the connection unexpectedly',
+        'SSL connection has been closed unexpectedly',
+        'Error writing data to the connection',
+        'Resource deadlock avoided',
+        'Transaction() on null',
+        'child connection forced to terminate due to client_idle_limit',
+        'query_wait_timeout',
+        'reset by peer',
+        'Physical connection is not usable',
+        'TCP Provider: Error code 0x68',
+        'ORA-03114',
+        'Packets out of order. Expected',
+        'Adaptive Server connection failed',
+        'Communication link failure',
+        'No such file or directory',
+    ];
+
+    public function __construct($config, int $numberRetries = 1)
+    {
+        parent::__construct($config);
+
+        $this->retries = $numberRetries;
+    }
+
+    public function prepexec($stmt, $values = null)
+    {
+        $retries = 0;
+        $retryHandler = function () use (&$retryHandler, &$retries, $stmt, $values): PDOStatement {
+            try {
+                return parent::prepexec($stmt, $values);
+            } catch (Exception $err) {
+                if ($retries < $this->retries && $this->isRetryable($err)) {
+                    $retries++;
+
+                    $this->disconnect();
+
+                    return $retryHandler();
+                }
+
+                throw $err;
+            }
+        };
+
+        return $retryHandler();
+    }
+
+    /**
+     * Get whether the given (PDO) exception can be fixed by reconnecting to the database.
+     *
+     * @param Exception $err
+     *
+     * @return bool
+     */
+    public static function isRetryable(Exception $err): bool
+    {
+        $message = $err->getMessage();
+        foreach (static::$retryableErrors as $error) {
+            if (strpos($message, $error) !== false) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+}