Add Database storage backend

This storage store files data in a separate database table

config/dbstructure.config.php

@@ -34,7 +34,7 @@
 use Friendica\Database\DBA;
 
 if (!defined('DB_UPDATE_VERSION')) {
-	define('DB_UPDATE_VERSION', 1294);
+	define('DB_UPDATE_VERSION', 1295);
 }
 
 return [
@@ -1380,5 +1380,16 @@ return [
 			"done_priority_next_try" => ["done", "priority", "next_try"],
 			"done_next_try" => ["done", "next_try"]
 		]
+	],
+	"storage" => [
+		"comment" => "Data stored by Database storage backend",
+		"fields" => [
+			"id" => ["type" => "int unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "comment" => "Auto incremented image data id"],
+			"data" => ["type" => "longblob", "not null" => "1", "comment" => "file data"]
+		],
+		"indexes" => [
+			"PRIMARY" => ["id"]
+		]
 	]
 ];
+

database.sql

@@ -1,6 +1,6 @@
 -- ------------------------------------------
 -- Friendica 2019.03-dev (The Tazmans Flax-lily)
--- DB_UPDATE_VERSION 1294
+-- DB_UPDATE_VERSION 1295
 -- ------------------------------------------
 
 
@@ -1274,4 +1274,13 @@ CREATE TABLE IF NOT EXISTS `workerqueue` (
 	 INDEX `done_next_try` (`done`,`next_try`)
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='Background tasks queue entries';
 
+--
+-- TABLE storage
+--
+CREATE TABLE IF NOT EXISTS `storage` (
+	`id` int unsigned NOT NULL auto_increment COMMENT 'Auto incremented image data id',
+	`data` longblob NOT NULL COMMENT 'file data',
+	 PRIMARY KEY(`id`)
+) DEFAULT COLLATE utf8mb4_general_ci COMMENT='Data stored by Database storage backend';
+
 

src/Model/Storage/Database.php

@@ -0,0 +1,54 @@
+<?php
+/**
+ * @file src/Model/Storage/Filesystem.php
+ * @brief Storage backend system
+ */
+
+namespace Friendica\Model\Storage;
+
+use Friendica\Core\Logger;
+use Friendica\Core\L10n;
+use Friendica\Core\System;
+use Friendica\Database\DBA;
+
+/**
+ * @brief Database based storage system
+ *
+ * This class manage data stored in database table.
+ */
+class Database implements IStorage
+{
+	public static function get($ref)
+	{
+		$r = DBA::selectFirst('storage', ['data'], ['id' => $ref]);
+		if (!DBA::isResult($r)) {
+			return '';
+		}
+
+		return $r['data'];
+	}
+
+	public static function put($data, $ref = '')
+	{
+		if ($ref !== '') {
+			$r = DBA::update('storage', ['data' => $data], ['id' => $ref]);
+			if ($r === false) {
+				Logger::log('Failed to update data with id ' . $ref . ': ' . DBA::errorNo() . ' : ' . DBA::errorMessage());
+				throw new StorageException(L10n::t('Database storage failed to update %s', $ref));
+ 			}
+			return $ref;
+		} else {
+			$r = DBA::insert('storage', ['data' => $data]);
+			if ($r === false) {
+				Logger::log('Failed to insert data: ' . DBA::errorNo() . ' : ' . DBA::errorMessage());
+				throw new StorageException(L10n::t('Database storage failed to insert data'));
+			}
+			return DBA::lastInsertId();
+		}
+	}
+
+	public static function delete($ref)
+	{
+		return DBA::delete('storage', ['id' => $ref]);
+	}
+}