[stable31] feat: Save a checksum for documents and use it to detect conflicts

composer/composer/autoload_classmap.php

@@ -61,6 +61,7 @@
     'OCA\\Text\\Migration\\Version030701Date20230207131313' => $baseDir . '/../lib/Migration/Version030701Date20230207131313.php',
     'OCA\\Text\\Migration\\Version030901Date20231114150437' => $baseDir . '/../lib/Migration/Version030901Date20231114150437.php',
     'OCA\\Text\\Migration\\Version040100Date20240611165300' => $baseDir . '/../lib/Migration/Version040100Date20240611165300.php',
+    'OCA\\Text\\Migration\\Version070000Date20250925110024' => $baseDir . '/../lib/Migration/Version070000Date20250925110024.php',
     'OCA\\Text\\Notification\\Notifier' => $baseDir . '/../lib/Notification/Notifier.php',
     'OCA\\Text\\Service\\ApiService' => $baseDir . '/../lib/Service/ApiService.php',
     'OCA\\Text\\Service\\AttachmentService' => $baseDir . '/../lib/Service/AttachmentService.php',

composer/composer/autoload_static.php

@@ -76,6 +76,7 @@ class ComposerStaticInitText
         'OCA\\Text\\Migration\\Version030701Date20230207131313' => __DIR__ . '/..' . '/../lib/Migration/Version030701Date20230207131313.php',
         'OCA\\Text\\Migration\\Version030901Date20231114150437' => __DIR__ . '/..' . '/../lib/Migration/Version030901Date20231114150437.php',
         'OCA\\Text\\Migration\\Version040100Date20240611165300' => __DIR__ . '/..' . '/../lib/Migration/Version040100Date20240611165300.php',
+        'OCA\\Text\\Migration\\Version070000Date20250925110024' => __DIR__ . '/..' . '/../lib/Migration/Version070000Date20250925110024.php',
         'OCA\\Text\\Notification\\Notifier' => __DIR__ . '/..' . '/../lib/Notification/Notifier.php',
         'OCA\\Text\\Service\\ApiService' => __DIR__ . '/..' . '/../lib/Service/ApiService.php',
         'OCA\\Text\\Service\\AttachmentService' => __DIR__ . '/..' . '/../lib/Service/AttachmentService.php',

cypress/e2e/conflict.spec.js

@@ -52,7 +52,7 @@ variants.forEach(function({ fixture, mime }) {
 		})
 
 		it(prefix + ': displays conflicts', function() {
-			createConflict(fileName, mime)
+			createConflict(fileName, 'edited-' + fileName, mime)
 
 			cy.openFile(fileName)
 
@@ -61,6 +61,9 @@ variants.forEach(function({ fixture, mime }) {
 			getWrapper()
 				.find('#read-only-editor')
 				.should('contain', 'Hello world')
+			getWrapper()
+				.find('#read-only-editor')
+				.should('not.contain', 'cruel conflicting')
 			getWrapper()
 				.find('.text-editor__main')
 				.should('contain', 'Hello world')
@@ -70,7 +73,7 @@ variants.forEach(function({ fixture, mime }) {
 		})
 
 		it(prefix + ': resolves conflict using current editing session', function() {
-			createConflict(fileName, mime)
+			createConflict(fileName, 'edited-' + fileName, mime)
 
 			cy.openFile(fileName)
 			cy.intercept({ method: 'POST', url: '**/session/*/push' })
@@ -81,12 +84,11 @@ variants.forEach(function({ fixture, mime }) {
 			getWrapper().should('not.exist')
 			cy.get('[data-cy="resolveThisVersion"]')
 				.should('not.exist')
-			cy.getContent().should('contain', 'Hello world')
 			cy.getContent().should('contain', 'cruel conflicting')
 		})
 
 		it(prefix + ': resolves conflict using server version', function() {
-			createConflict(fileName, mime)
+			createConflict(fileName, 'edited-' + fileName, mime)
 
 			cy.openFile(fileName)
 			cy.get('[data-cy="resolveServerVersion"]')
@@ -102,7 +104,7 @@ variants.forEach(function({ fixture, mime }) {
 		})
 
 		it(prefix + ': hides conflict in read only session', function() {
-			createConflict(fileName, mime)
+			createConflict(fileName, 'edited-' + fileName, mime)
 			cy.testName().then(testName => {
 				cy.shareFile(`/${testName}/${fileName}`)
 					.then((token) => {
@@ -114,6 +116,12 @@ variants.forEach(function({ fixture, mime }) {
 			getWrapper().should('not.exist')
 		})
 
+		it(prefix + ': no conflict when uploading same file content', function() {
+			createConflict(fileName, fileName, mime)
+			cy.openFile(fileName)
+			cy.getContent().should('contain', 'Hello world')
+			getWrapper().should('not.exist')
+		})
 	})
 })
 
@@ -129,7 +137,7 @@ describe('conflict dialog scroll behaviour', function() {
 		cy.login(user)
 		cy.createTestFolder()
 
-		createConflict(fileName, 'text/markdown')
+		createConflict(fileName, 'edited-' + fileName, 'text/markdown')
 
 		cy.openFile(fileName)
 
@@ -148,22 +156,29 @@ describe('conflict dialog scroll behaviour', function() {
 })
 
 /**
- * @param {string} fileName - filename
+ * @param {string} fileName1 - filename1
+ * @param {string} fileName2 - filename2
  * @param {string} mime - mimetype
  */
-function createConflict(fileName, mime) {
+function createConflict(fileName1, fileName2, mime) {
 	cy.testName().then(testName => {
-		cy.uploadFile(fileName, mime, `${testName}/${fileName}`)
+		cy.uploadFile(fileName1, mime, `${testName}/${fileName1}`)
 	})
 	cy.visitTestFolder()
-	cy.openFile(fileName)
+	cy.openFile(fileName1)
 	cy.log('Inspect editor')
 	cy.getEditor().find('.ProseMirror').should('have.attr', 'contenteditable', 'true')
+
 	cy.getContent()
 		.type('Hello you cruel conflicting world')
+
 	cy.testName().then(testName => {
-		cy.uploadFile(fileName, mime, testName + '/' + fileName)
+		cy.uploadFile(fileName2, mime, testName + '/' + fileName1)
 	})
+
+	cy.intercept('POST', '**/session/*/sync').as('sync')
+	cy.wait('@sync', { timeout: 10000 })
+
 	cy.get('#viewer .modal-header button.header-close').click()
 	cy.get('#viewer').should('not.exist')
 }

cypress/fixtures/edited-lines.txt

@@ -0,0 +1,9 @@
+This file contains multiple lines
+
+Hello world
+
+It's a text file so it should not be parsed as markdown
+
+But when it is these would turn into paragraphs.
+
+edited

cypress/fixtures/edited-long.md

@@ -0,0 +1,23 @@
+# Hello world
+
+## First subheading
+
+Lorem ipsum dolor sit amet consectetur adipiscing elit. Quisque faucibus ex sapien vitae pellentesque sem placerat. In id cursus mi pretium tellus duis convallis. Tempus leo eu aenean sed diam urna tempor. Pulvinar vivamus fringilla lacus nec metus bibendum egestas. Iaculis massa nisl malesuada lacinia integer nunc posuere. Ut hendrerit semper vel class aptent taciti sociosqu. Ad litora torquent per conubia nostra inceptos himenaeos.
+
+Lorem ipsum dolor sit amet consectetur adipiscing elit. Quisque faucibus ex sapien vitae pellentesque sem placerat. In id cursus mi pretium tellus duis convallis. Tempus leo eu aenean sed diam urna tempor. Pulvinar vivamus fringilla lacus nec metus bibendum egestas. Iaculis massa nisl malesuada lacinia integer nunc posuere. Ut hendrerit semper vel class aptent taciti sociosqu. Ad litora torquent per conubia nostra inceptos himenaeos.
+
+Lorem ipsum dolor sit amet consectetur adipiscing elit. Quisque faucibus ex sapien vitae pellentesque sem placerat. In id cursus mi pretium tellus duis convallis. Tempus leo eu aenean sed diam urna tempor. Pulvinar vivamus fringilla lacus nec metus bibendum egestas. Iaculis massa nisl malesuada lacinia integer nunc posuere. Ut hendrerit semper vel class aptent taciti sociosqu. Ad litora torquent per conubia nostra inceptos himenaeos.
+
+## Second subheading
+
+Lorem ipsum dolor sit amet consectetur adipiscing elit. Quisque faucibus ex sapien vitae pellentesque sem placerat. In id cursus mi pretium tellus duis convallis. Tempus leo eu aenean sed diam urna tempor. Pulvinar vivamus fringilla lacus nec metus bibendum egestas. Iaculis massa nisl malesuada lacinia integer nunc posuere. Ut hendrerit semper vel class aptent taciti sociosqu. Ad litora torquent per conubia nostra inceptos himenaeos.
+
+Lorem ipsum dolor sit amet consectetur adipiscing elit. Quisque faucibus ex sapien vitae pellentesque sem placerat. In id cursus mi pretium tellus duis convallis. Tempus leo eu aenean sed diam urna tempor. Pulvinar vivamus fringilla lacus nec metus bibendum egestas. Iaculis massa nisl malesuada lacinia integer nunc posuere. Ut hendrerit semper vel class aptent taciti sociosqu. Ad litora torquent per conubia nostra inceptos himenaeos.
+
+Lorem ipsum dolor sit amet consectetur adipiscing elit. Quisque faucibus ex sapien vitae pellentesque sem placerat. In id cursus mi pretium tellus duis convallis. Tempus leo eu aenean sed diam urna tempor. Pulvinar vivamus fringilla lacus nec metus bibendum egestas. Iaculis massa nisl malesuada lacinia integer nunc posuere. Ut hendrerit semper vel class aptent taciti sociosqu. Ad litora torquent per conubia nostra inceptos himenaeos.
+
+## Third subheading
+
+Lorem ipsum dolor sit amet consectetur adipiscing elit. Quisque faucibus ex sapien vitae pellentesque sem placerat. In id cursus mi pretium tellus duis convallis. Tempus leo eu aenean sed diam urna tempor. Pulvinar vivamus fringilla lacus nec metus bibendum egestas. Iaculis massa nisl malesuada lacinia integer nunc posuere. Ut hendrerit semper vel class aptent taciti sociosqu. Ad litora torquent per conubia nostra inceptos himenaeos.
+
+edited

cypress/fixtures/edited-test.md

@@ -0,0 +1,2 @@
+## Hello world
+edited

lib/Db/Document.php

@@ -22,6 +22,8 @@
  * @method setLastSavedVersionEtag(string $etag): void
  * @method getBaseVersionEtag(): string
  * @method setBaseVersionEtag(string $etag): void
+ * @method getChecksum(): ?string
+ * @method setChecksum(?string $checksum): void
  */
 class Document extends Entity implements \JsonSerializable {
 	public $id = null;
@@ -32,13 +34,15 @@ class Document extends Entity implements \JsonSerializable {
 	protected int $lastSavedVersionTime = 0;
 	protected string $lastSavedVersionEtag = '';
 	protected string $baseVersionEtag = '';
+	protected ?string $checksum = null;
 
 	public function __construct() {
 		$this->addType('id', 'integer');
 		$this->addType('currentVersion', 'integer');
 		$this->addType('lastSavedVersion', 'integer');
 		$this->addType('lastSavedVersionTime', 'integer');
 		$this->addType('initialVersion', 'integer');
+		$this->addType('checksum', 'string');
 	}
 
 	public function jsonSerialize(): array {
@@ -47,7 +51,8 @@ public function jsonSerialize(): array {
 			'lastSavedVersion' => $this->lastSavedVersion,
 			'lastSavedVersionTime' => $this->lastSavedVersionTime,
 			'baseVersionEtag' => $this->baseVersionEtag,
-			'initialVersion' => $this->initialVersion
+			'initialVersion' => $this->initialVersion,
+			'checksum' => $this->checksum
 		];
 	}
 }

lib/Migration/Version070000Date20250925110024.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Text\Migration;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\DB\Types;
+use OCP\Migration\Attributes\AddColumn;
+use OCP\Migration\Attributes\ColumnType;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+#[AddColumn(table: 'text_documents', name: 'checksum', type: ColumnType::STRING, description: 'CRC32 checksum of document content')]
+class Version070000Date20250925110024 extends SimpleMigrationStep {
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options) {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		$table = $schema->getTable('text_documents');
+		if (!$table->hasColumn('checksum')) {
+			$table->addColumn('checksum', Types::STRING, [
+				'notnull' => false,
+				'length' => 8,
+			]);
+			return $schema;
+		}
+
+		return null;
+	}
+}

lib/Service/DocumentService.php

@@ -143,6 +143,7 @@ public function createDocument(File $file): Document {
 		$document->setLastSavedVersionTime($file->getMTime());
 		$document->setLastSavedVersionEtag($file->getEtag());
 		$document->setBaseVersionEtag(uniqid());
+		$document->setChecksum($this->computeCheckSum($file->getContent()));
 		try {
 			/** @var Document $document */
 			$document = $this->documentMapper->insert($document);
@@ -310,25 +311,48 @@ public function getSteps(int $documentId, int $lastVersion): array {
 		return $this->stepMapper->find($documentId, $lastVersion);
 	}
 
+
+
 	/**
 	 * @throws DocumentSaveConflictException
 	 * @throws InvalidPathException
 	 * @throws NotFoundException
 	 */
 	public function assertNoOutsideConflict(Document $document, File $file, bool $force = false, ?string $shareToken = null): void {
 		$documentId = $document->getId();
-		$savedEtag = $file->getEtag();
 		$lastMTime = $document->getLastSavedVersionTime();
+		$lastEtag = $document->getLastSavedVersionEtag();
+
+		if ($lastMTime <= 0 || $force || $this->isReadOnly($file, $shareToken) || $this->cache->get('document-save-lock-' . $documentId)) {
+			return;
+		}
+
+		$fileMtime = $file->getMtime();
+		$fileEtag = $file->getEtag();
+
+		if ($lastEtag === $fileEtag && $lastMTime === $fileMtime) {
+			return;
+		}
+
+		$storedChecksum = $document->getChecksum();
+		$fileContent = $file->getContent();
+		$fileChecksum = $this->computeChecksum($fileContent);
 
-		if ($lastMTime > 0
-			&& $force === false
-			&& !$this->isReadOnly($file, $shareToken)
-			&& $savedEtag !== $document->getLastSavedVersionEtag()
-			&& $lastMTime !== $file->getMtime()
-			&& !$this->cache->get('document-save-lock-' . $documentId)
-		) {
+		if ($storedChecksum !== $fileChecksum) {
 			throw new DocumentSaveConflictException('File changed in the meantime from outside');
 		}
+
+		$document->setLastSavedVersionTime($fileMtime);
+		$document->setLastSavedVersionEtag($fileEtag);
+		$this->documentMapper->update($document);
+	}
+
+	/**
+	 * @param string $content
+	 * @return string
+	 */
+	private function computeCheckSum(string $content): string {
+		return hash('crc32', $content);
 	}
 
 	/**
@@ -414,6 +438,7 @@ public function autosave(Document $document, ?File $file, int $version, ?string
 			$document->setLastSavedVersion($version);
 			$document->setLastSavedVersionTime($file->getMTime());
 			$document->setLastSavedVersionEtag($file->getEtag());
+			$document->setChecksum($this->computeCheckSum($autoSaveDocument));
 			$this->documentMapper->update($document);
 		} catch (LockedException $e) {
 			// Ignore lock since it might occur when multiple people save at the same time