friendica/src/Core/StorageManager.php
2020-01-17 19:31:34 +01:00

289 lines
8 KiB
PHP

<?php
namespace Friendica\Core;
use Exception;
use Friendica\Core\Config\IConfiguration;
use Friendica\Core\L10n\L10n;
use Friendica\Database\Database;
use Friendica\Model\Storage;
use Psr\Log\LoggerInterface;
/**
* @brief Manage storage backends
*
* Core code uses this class to get and set current storage backend class.
* Addons use this class to register and unregister additional backends.
*/
class StorageManager
{
// Default tables to look for data
const TABLES = ['photo', 'attach'];
// Default storage backends
const DEFAULT_BACKENDS = [
Storage\Filesystem::NAME => Storage\Filesystem::class,
Storage\Database::NAME => Storage\Database::class,
];
private $backends = [];
/**
* @var Storage\IStorage[] A local cache for storage instances
*/
private $backendInstances = [];
/** @var Database */
private $dba;
/** @var IConfiguration */
private $config;
/** @var LoggerInterface */
private $logger;
/** @var L10n */
private $l10n;
/** @var Storage\IStorage */
private $currentBackend;
/**
* @param Database $dba
* @param IConfiguration $config
* @param LoggerInterface $logger
* @param L10n $l10n
*/
public function __construct(Database $dba, IConfiguration $config, LoggerInterface $logger, L10n $l10n)
{
$this->dba = $dba;
$this->config = $config;
$this->logger = $logger;
$this->l10n = $l10n;
$this->backends = $config->get('storage', 'backends', self::DEFAULT_BACKENDS);
$currentName = $this->config->get('storage', 'name', '');
// you can only use user backends as a "default" backend, so the second parameter is true
$this->currentBackend = $this->getByName($currentName, true);
}
/**
* @brief Return current storage backend class
*
* @return Storage\IStorage|null
*/
public function getBackend()
{
return $this->currentBackend;
}
/**
* @brief Return storage backend class by registered name
*
* @param string|null $name Backend name
* @param boolean $userBackend True, if just user specific instances should be returrned (e.g. not SystemResource)
*
* @return Storage\IStorage|null null if no backend registered at $name
*
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
public function getByName(string $name = null, $userBackend = false)
{
// If there's no cached instance create a new instance
if (!isset($this->backendInstances[$name])) {
// If the current name isn't a valid backend (or the SystemResource instance) create it
if ($this->isValidBackend($name, $userBackend)) {
switch ($name) {
// Try the filesystem backend
case Storage\Filesystem::getName():
$this->backendInstances[$name] = new Storage\Filesystem($this->config, $this->logger, $this->l10n);
break;
// try the database backend
case Storage\Database::getName():
$this->backendInstances[$name] = new Storage\Database($this->dba, $this->logger, $this->l10n);
break;
// at least, try if there's an addon for the backend
case Storage\SystemResource::getName():
$this->backendInstances[$name] = new Storage\SystemResource();
break;
default:
$data = [
'name' => $name,
'storage' => null,
];
Hook::callAll('storage_instance', $data);
if (($data['storage'] ?? null) instanceof Storage\IStorage) {
$this->backendInstances[$data['name'] ?? $name] = $data['storage'];
} else {
return null;
}
break;
}
} else {
return null;
}
}
return $this->backendInstances[$name];
}
/**
* Checks, if the storage is a valid backend
*
* @param string|null $name The name or class of the backend
* @param boolean $userBackend True, if just user backend should get returned (e.g. not SystemResource)
*
* @return boolean True, if the backend is a valid backend
*/
public function isValidBackend(string $name = null, bool $userBackend = false)
{
return array_key_exists($name, $this->backends) ||
(!$userBackend && $name === Storage\SystemResource::getName());
}
/**
* @brief Set current storage backend class
*
* @param string $name Backend class name
*
* @return boolean True, if the set was successful
*/
public function setBackend(string $name = null)
{
if (!$this->isValidBackend($name, false)) {
return false;
}
if ($this->config->set('storage', 'name', $name)) {
$this->currentBackend = $this->getByName($name, false);
return true;
} else {
return false;
}
}
/**
* @brief Get registered backends
*
* @return array
*/
public function listBackends()
{
return $this->backends;
}
/**
* Register a storage backend class
*
* You have to register the hook "storage_instance" as well to make this class work!
*
* @param string $class Backend class name
*
* @return boolean True, if the registration was successful
*/
public function register(string $class)
{
if (is_subclass_of($class, Storage\IStorage::class)) {
/** @var Storage\IStorage $class */
$backends = $this->backends;
$backends[$class::getName()] = $class;
if ($this->config->set('storage', 'backends', $backends)) {
$this->backends = $backends;
return true;
} else {
return false;
}
} else {
return false;
}
}
/**
* @brief Unregister a storage backend class
*
* @param string $class Backend class name
*
* @return boolean True, if unregistering was successful
*/
public function unregister(string $class)
{
if (is_subclass_of($class, Storage\IStorage::class)) {
/** @var Storage\IStorage $class */
unset($this->backends[$class::getName()]);
if ($this->currentBackend instanceof $class) {
$this->config->set('storage', 'name', null);
$this->currentBackend = null;
}
return $this->config->set('storage', 'backends', $this->backends);
} else {
return false;
}
}
/**
* @brief Move up to 5000 resources to storage $dest
*
* Copy existing data to destination storage and delete from source.
* This method cannot move to legacy in-table `data` field.
*
* @param Storage\IStorage $destination Destination storage class name
* @param array $tables Tables to look in for resources. Optional, defaults to ['photo', 'attach']
* @param int $limit Limit of the process batch size, defaults to 5000
*
* @return int Number of moved resources
* @throws Storage\StorageException
* @throws Exception
*/
public function move(Storage\IStorage $destination, array $tables = self::TABLES, int $limit = 5000)
{
if ($destination === null) {
throw new Storage\StorageException('Can\'t move to NULL storage backend');
}
$moved = 0;
foreach ($tables as $table) {
// Get the rows where backend class is not the destination backend class
$resources = $this->dba->select(
$table,
['id', 'data', 'backend-class', 'backend-ref'],
['`backend-class` IS NULL or `backend-class` != ?', $destination::getName()],
['limit' => $limit]
);
while ($resource = $this->dba->fetch($resources)) {
$id = $resource['id'];
$data = $resource['data'];
$source = $this->getByName($resource['backend-class']);
$sourceRef = $resource['backend-ref'];
if (!empty($source)) {
$this->logger->info('Get data from old backend.', ['oldBackend' => $source, 'oldReference' => $sourceRef]);
$data = $source->get($sourceRef);
}
$this->logger->info('Save data to new backend.', ['newBackend' => $destination]);
$destinationRef = $destination->put($data);
$this->logger->info('Saved data.', ['newReference' => $destinationRef]);
if ($destinationRef !== '') {
$this->logger->info('update row');
if ($this->dba->update($table, ['backend-class' => $destination, 'backend-ref' => $destinationRef, 'data' => ''], ['id' => $id])) {
if (!empty($source)) {
$this->logger->info('Delete data from old backend.', ['oldBackend' => $source, 'oldReference' => $sourceRef]);
$source->delete($sourceRef);
}
$moved++;
}
}
}
$this->dba->close($resources);
}
return $moved;
}
}