From 21e12e1c4fc2f158e037999d293636cb18575a82 Mon Sep 17 00:00:00 2001
From: Vincent Petry <vincent@nextcloud.com>
Date: Wed, 5 Jan 2022 17:19:24 +0100
Subject: [PATCH] Remove inefficient fed share scanner

Remove scanAll which relies on the "shareinfo" endpoint that returns the
full cache tree.
The latter can become big for big shares and result in timeouts.
Furthermode, the full tree would be retrieved again for each and every
detected change which can become expensive quickly.

Signed-off-by: Vincent Petry <vincent@nextcloud.com>
---
 apps/files_sharing/lib/External/Scanner.php   | 70 -------------------
 .../tests/External/ScannerTest.php            | 12 ----
 2 files changed, 82 deletions(-)

diff --git a/apps/files_sharing/lib/External/Scanner.php b/apps/files_sharing/lib/External/Scanner.php
index 870ce6c2f3b64..e09ea3bf0f5de 100644
--- a/apps/files_sharing/lib/External/Scanner.php
+++ b/apps/files_sharing/lib/External/Scanner.php
@@ -31,29 +31,11 @@
 use OCP\Files\NotFoundException;
 use OCP\Files\StorageInvalidException;
 use OCP\Files\StorageNotAvailableException;
-use OCP\Http\Client\LocalServerException;
-use Psr\Log\LoggerInterface;
 
 class Scanner extends \OC\Files\Cache\Scanner {
 	/** @var \OCA\Files_Sharing\External\Storage */
 	protected $storage;
 
-	/** {@inheritDoc} */
-	public function scan($path, $recursive = self::SCAN_RECURSIVE, $reuse = -1, $lock = true) {
-		try {
-			if (!$this->storage->remoteIsOwnCloud()) {
-				return parent::scan($path, $recursive, $reuse, $lock);
-			}
-		} catch (LocalServerException $e) {
-			// Scanner doesn't have dependency injection
-			\OC::$server->get(LoggerInterface::class)
-				->warning('Trying to scan files inside invalid external storage: ' . $this->storage->getRemote() . ' for mountpoint ' . $this->storage->getMountPoint() . ' and id ' . $this->storage->getId());
-			return;
-		}
-
-		$this->scanAll();
-	}
-
 	/**
 	 * Scan a single file and store it in the cache.
 	 * If an exception happened while accessing the external storage,
@@ -83,56 +65,4 @@ public function scanFile($file, $reuseExisting = 0, $parentId = -1, $cacheData =
 			$this->storage->checkStorageAvailability();
 		}
 	}
-
-	/**
-	 * Checks the remote share for changes.
-	 * If changes are available, scan them and update
-	 * the cache.
-	 * @throws NotFoundException
-	 * @throws StorageInvalidException
-	 * @throws \Exception
-	 */
-	public function scanAll() {
-		try {
-			$data = $this->storage->getShareInfo();
-		} catch (\Exception $e) {
-			$this->storage->checkStorageAvailability();
-			throw new \Exception(
-				'Error while scanning remote share: "' .
-				$this->storage->getRemote() . '" ' .
-				$e->getMessage()
-			);
-		}
-		if ($data['status'] === 'success') {
-			$this->addResult($data['data'], '');
-		} else {
-			throw new \Exception(
-				'Error while scanning remote share: "' .
-				$this->storage->getRemote() . '"'
-			);
-		}
-	}
-
-	/**
-	 * @param array $data
-	 * @param string $path
-	 */
-	private function addResult($data, $path) {
-		$id = $this->cache->put($path, $data);
-		if (isset($data['children'])) {
-			$children = [];
-			foreach ($data['children'] as $child) {
-				$children[$child['name']] = true;
-				$this->addResult($child, ltrim($path . '/' . $child['name'], '/'));
-			}
-
-			$existingCache = $this->cache->getFolderContentsById($id);
-			foreach ($existingCache as $existingChild) {
-				// if an existing child is not in the new data, remove it
-				if (!isset($children[$existingChild['name']])) {
-					$this->cache->remove(ltrim($path . '/' . $existingChild['name'], '/'));
-				}
-			}
-		}
-	}
 }
diff --git a/apps/files_sharing/tests/External/ScannerTest.php b/apps/files_sharing/tests/External/ScannerTest.php
index 843f106af8102..ae05eca2b18bb 100644
--- a/apps/files_sharing/tests/External/ScannerTest.php
+++ b/apps/files_sharing/tests/External/ScannerTest.php
@@ -51,18 +51,6 @@ protected function setUp(): void {
 		$this->scanner = new Scanner($this->storage);
 	}
 
-	public function testScanAll() {
-		$this->storage->expects($this->any())
-			->method('getShareInfo')
-			->willReturn(['status' => 'success', 'data' => []]);
-
-		// FIXME add real tests, we are currently only checking for
-		// Declaration of OCA\Files_Sharing\External\Scanner::*() should be
-		// compatible with OC\Files\Cache\Scanner::*()
-		$this->scanner->scanAll();
-		$this->addToAssertionCount(1);
-	}
-
 	public function testScan() {
 		$this->storage->expects($this->any())
 			->method('getShareInfo')