--salvage for backup:restore and backup:restore:full: restore what can be read from a damaged backup

A file whose data cannot be read or decrypted is left out and listed, and the command exits with code 2. When the database cannot be restored (its dump is damaged, or it does not fit this installation), backup:restore:full leaves the fresh database as it is and puts the data directory and config of the backup in ngb-salvage-<snapshot> in the data directory. Without --salvage a restore of damaged data stops as before and points at the option.
2026-11-04 04:08:20 +01:00
parent f0293e6d01
commit dfe1fe9aad
9 changed files with 369 additions and 78 deletions
@@ -0,0 +1,88 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OCA\NgBackup\Tests\Unit\Repository;
+
+use OCA\NgBackup\Backend\LocalBackend;
+use OCA\NgBackup\Crypto\KeyRing;
+use OCA\NgBackup\Repository\Repository;
+use OCA\NgBackup\Tests\Unit\TempDirTrait;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * --salvage: a file whose data is damaged on the location is left out and listed, the rest of the
+ * restore goes on. Without it, the restore stops at that file.
+ */
+class SalvageTest extends TestCase {
+	use TempDirTrait;
+
+	private string $root;
+	private KeyRing $keys;
+	private string $src;
+	private string $snapshot;
+
+	protected function setUp(): void {
+		$this->root = $this->tempDir();
+		$this->keys = KeyRing::generate();
+		$this->src = $this->tempDir();
+		mkdir("$this->src/docs");
+		// Incompressible, 2 MiB each: every file is a blob of its own in one pack
+		foreach (['a', 'b', 'c'] as $name) {
+			file_put_contents("$this->src/docs/$name.bin", random_bytes(2 * 1048576));
+		}
+		file_put_contents("$this->src/note.txt", "small\n");
+		$repo = Repository::initWithKey(new LocalBackend($this->root), $this->keys, $this->keys->wrap('pw'));
+		$this->snapshot = $repo->backupDirectory($this->src)['snapshot'];
+	}
+
+	/** Flip bytes in the middle of the (only) pack: inside one of the 2 MiB files. */
+	private function damagePack(): void {
+		$packs = glob($this->root . '/packs/*/*');
+		$this->assertCount(1, $packs);
+		$fh = fopen($packs[0], 'r+b');
+		$middle = intdiv(filesize($packs[0]), 2);
+		fseek($fh, $middle);
+		$bytes = fread($fh, 16);
+		fseek($fh, $middle);
+		fwrite($fh, ~$bytes);
+		fclose($fh);
+	}
+
+	public function testSalvageLeavesOutTheDamagedFileAndRestoresTheRest(): void {
+		$this->damagePack();
+		$target = $this->tempDir();
+		$skipped = [];
+
+		$restored = Repository::openWithKey(new LocalBackend($this->root), $this->keys)
+			->restore($this->snapshot, $target, '', false, null, $skipped);
+
+		$this->assertSame(3, $restored);
+		$this->assertCount(1, $skipped);
+		$damaged = array_key_first($skipped);
+		$this->assertMatchesRegularExpression('#^docs/[abc]\.bin$#', $damaged);
+		$this->assertFileDoesNotExist("$target/$damaged");
+		foreach (['docs/a.bin', 'docs/b.bin', 'docs/c.bin', 'note.txt'] as $file) {
+			if ($file !== $damaged) {
+				$this->assertFileEquals("$this->src/$file", "$target/$file");
+			}
+		}
+		$this->assertSame([], glob("$target/docs/*.ngb-restore-*"), 'no temporary left of the damaged file');
+	}
+
+	public function testWithoutSalvageTheRestoreStopsAtTheDamagedFile(): void {
+		$this->damagePack();
+
+		$this->expectException(\Exception::class);
+		Repository::openWithKey(new LocalBackend($this->root), $this->keys)->restore($this->snapshot, $this->tempDir());
+	}
+
+	public function testSalvageOfAnUndamagedSnapshotSkipsNothing(): void {
+		$target = $this->tempDir();
+		$skipped = [];
+
+		$this->assertSame(4, Repository::openWithKey(new LocalBackend($this->root), $this->keys)
+			->restore($this->snapshot, $target, '', false, null, $skipped));
+		$this->assertSame([], $skipped);
+	}
+}