Merge branch 'main' into polish

2026-10-11 13:25:06 +02:00
parent 65f14b4380 54750e9742
commit c146d700e8
11 changed files with 1272 additions and 11 deletions
@@ -0,0 +1,478 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OCA\NgBackup\Tests\Unit\Backend;
+
+use OCA\NgBackup\Backend\BackendException;
+use OCA\NgBackup\Backend\SftpReadStream;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * SftpReadStream against a fake of the phpseclib connection: an SFTP server that answers READ
+ * requests from in-memory files, optionally capped. Every answer must be asked for by its request
+ * id, as phpseclib matches them: a server may answer out of order.
+ */
+class SftpReadStreamTest extends TestCase {
+	protected function setUp(): void {
+		SftpReadStream::reset();
+	}
+
+	public function testReadsAWholeFileWithSeveralRequestsInFlight(): void {
+		$data = random_bytes(5 * 1048576 + 12345);
+		$sftp = new FakeSftpConnection(['/home/repo/packs/ab/abcd' => $data]);
+		$fh = SftpReadStream::open(new FakeSftpStorage($sftp), 'repo/packs/ab/abcd');
+
+		$this->assertIsResource($fh);
+		$this->assertSame($data, stream_get_contents($fh));
+		$this->assertTrue(feof($fh));
+		fclose($fh);
+		$this->assertSame(SftpReadStream::DEPTH, $sftp->maxInFlight);
+		$this->assertSame(0, $sftp->pending(), 'nothing may be left on the connection after close');
+		$this->assertSame([], $sftp->openHandles);
+	}
+
+	public function testAServerThatCapsAReadStillGivesEveryByteInOrder(): void {
+		$data = random_bytes(3 * 1048576 + 7);
+		$sftp = new FakeSftpConnection(['/home/f' => $data], cap: 100000);
+		$fh = SftpReadStream::open(new FakeSftpStorage($sftp), 'f');
+
+		$this->assertSame($data, stream_get_contents($fh));
+		fclose($fh);
+		$this->assertSame(0, $sftp->pending());
+
+		// The cap is learned: a next stream asks for no more than the server gives.
+		$sftp->reads = [];
+		$fh = SftpReadStream::open(new FakeSftpStorage($sftp), 'f');
+		$this->assertSame($data, stream_get_contents($fh));
+		fclose($fh);
+		$this->assertSame([100000], array_values(array_unique($sftp->reads)));
+
+		// Only for that connection.
+		$other = new FakeSftpConnection(['/home/f' => $data]);
+		$fh = SftpReadStream::open(new FakeSftpStorage($other), 'f');
+		$this->assertSame($data, stream_get_contents($fh));
+		fclose($fh);
+		$this->assertSame(261120, max($other->reads));
+	}
+
+	public function testATinyAnswerDoesNotShrinkTheReadsBelowWhatEveryServerSupports(): void {
+		$data = random_bytes(1048576);
+		$sftp = new FakeSftpConnection(['/home/f' => $data], cap: 1000);
+		$fh = SftpReadStream::open(new FakeSftpStorage($sftp), 'f');
+		$this->assertSame($data, stream_get_contents($fh));
+		fclose($fh);
+		$this->assertSame(32768, min($sftp->reads));
+	}
+
+	public function testSeekingReadsFromTheNewOffset(): void {
+		$data = random_bytes(3 * 1048576);
+		$sftp = new FakeSftpConnection(['/home/f' => $data]);
+		$fh = SftpReadStream::open(new FakeSftpStorage($sftp), 'f');
+
+		$this->assertSame(0, fseek($fh, 2000000));
+		$this->assertSame(2000000, ftell($fh));
+		$this->assertSame(substr($data, 2000000, 1000), fread($fh, 1000));
+		$this->assertSame(0, fseek($fh, 10)); // backwards
+		$this->assertSame(substr($data, 10, 70000), $this->readExactly($fh, 70000));
+		$this->assertSame(0, fseek($fh, 100, SEEK_CUR)); // within what is already buffered
+		$this->assertSame(substr($data, 70110, 5000), $this->readExactly($fh, 5000));
+		fclose($fh);
+		$this->assertSame(0, $sftp->pending());
+	}
+
+	public function testASmallReadDoesNotFetchTheWholePipelineAhead(): void {
+		$sftp = new FakeSftpConnection(['/home/f' => random_bytes(10 * 1048576)]);
+		$fh = SftpReadStream::open(new FakeSftpStorage($sftp), 'f');
+		fread($fh, 100);
+		fclose($fh);
+		$this->assertCount(1, $sftp->reads, 'the first request goes alone, the pipeline grows while reading on');
+	}
+
+	public function testAnEmptyFileIsAtEndAtOnce(): void {
+		$sftp = new FakeSftpConnection(['/home/f' => '']);
+		$fh = SftpReadStream::open(new FakeSftpStorage($sftp), 'f');
+		$this->assertSame('', stream_get_contents($fh));
+		$this->assertTrue(feof($fh));
+		fclose($fh);
+	}
+
+	public function testAMissingFileCannotBeOpened(): void {
+		$sftp = new FakeSftpConnection([]);
+		$this->assertFalse(SftpReadStream::open(new FakeSftpStorage($sftp), 'nope'));
+		$this->assertSame(0, $sftp->pending());
+	}
+
+	public function testAServerErrorGoesOnWithTheStoragesOwnStreamFromTheSamePosition(): void {
+		$data = random_bytes(3 * 1048576);
+		$sftp = new FakeSftpConnection(['/home/f' => $data], failAt: 1048576);
+		$storage = new FakeSftpStorage($sftp);
+		$fh = SftpReadStream::open($storage, 'f');
+
+		$this->assertSame($data, $this->readAll($fh));
+		$this->assertSame(['f'], $storage->fopens);
+		$this->assertSame(strlen($data), ftell($fh));
+		fclose($fh);
+		$this->assertSame(0, $sftp->pending(), 'the connection is clean for the storage\'s own stream');
+		$this->assertSame([], $sftp->openHandles, 'the failed handle is closed');
+
+		// One failure is no reason to give up on the fast reads.
+		$fh = SftpReadStream::open($storage, 'f');
+		$this->assertIsResource($fh);
+		fclose($fh);
+	}
+
+	public function testOnlyFailuresInARowSwitchTheFastReadsOff(): void {
+		$data = random_bytes(2 * 1048576);
+		$failing = new FakeSftpStorage(new FakeSftpConnection(['/home/f' => $data], failAt: 1048576));
+		$working = new FakeSftpStorage(new FakeSftpConnection(['/home/f' => $data]));
+		for ($i = 1; $i < SftpReadStream::MAX_FAILURES; $i++) {
+			$fh = SftpReadStream::open($failing, 'f');
+			$this->assertSame($data, $this->readAll($fh));
+			fclose($fh);
+		}
+		$fh = SftpReadStream::open($working, 'f'); // a stream that works resets the count
+		$this->assertSame($data, $this->readAll($fh));
+		fclose($fh);
+		for ($i = 1; $i <= SftpReadStream::MAX_FAILURES; $i++) {
+			$fh = SftpReadStream::open($failing, 'f');
+			$this->assertIsResource($fh, "failure $i");
+			$this->assertSame($data, $this->readAll($fh));
+			fclose($fh);
+		}
+		$this->assertNull(SftpReadStream::open($working, 'f'));
+		$this->assertSame(SftpReadStream::MAX_FAILURES * 2 - 1, count($failing->fopens), 'every failed stream still gave all its data');
+	}
+
+	public function testAServerErrorAfterASeekGoesOnFromTheSeekedPosition(): void {
+		$data = random_bytes(3 * 1048576);
+		$sftp = new FakeSftpConnection(['/home/f' => $data], failAt: 2500000);
+		$storage = new FakeSftpStorage($sftp);
+		$fh = SftpReadStream::open($storage, 'f');
+		$this->assertSame(0, fseek($fh, 2400000));
+		$this->assertSame(substr($data, 2400000), $this->readAll($fh));
+		$this->assertSame(0, fseek($fh, 100)); // seeks go to the storage's stream now
+		$this->assertSame(substr($data, 100, 1000), $this->readExactly($fh, 1000));
+		fclose($fh);
+	}
+
+	public function testAConnectionErrorDoesNotFallBackOnTheSameConnection(): void {
+		// After an exception, answers may still be on their way; files_external's stream would
+		// take them for its own.
+		$sftp = new FakeSftpConnection(['/home/f' => random_bytes(3 * 1048576)], throwAt: 1048576);
+		$storage = new FakeSftpStorage($sftp);
+		$fh = SftpReadStream::open($storage, 'f');
+		$this->assertLessThan(3 * 1048576, strlen($this->readAll($fh)));
+		fclose($fh);
+		$this->assertSame([], $storage->fopens);
+	}
+
+	public function testALostConnectionDoesNotFallBackEither(): void {
+		$sftp = new FakeSftpConnection(['/home/f' => random_bytes(3 * 1048576)], loseAt: 1048576);
+		$storage = new FakeSftpStorage($sftp);
+		$fh = SftpReadStream::open($storage, 'f');
+		$this->assertLessThan(3 * 1048576, strlen($this->readAll($fh)));
+		fclose($fh);
+		$this->assertSame([], $storage->fopens);
+	}
+
+	public function testWhenTheStoragesOwnStreamFailsTooTheReadFails(): void {
+		$sftp = new FakeSftpConnection(['/home/f' => random_bytes(3 * 1048576)], failAt: 1048576);
+		$storage = new FakeSftpStorage($sftp, fopenFails: true);
+		$fh = SftpReadStream::open($storage, 'f');
+		$this->assertLessThan(3 * 1048576, strlen($this->readAll($fh)));
+		fclose($fh);
+		$this->assertSame(['f'], $storage->fopens);
+	}
+
+	public function testAConnectionErrorWhileOpeningIsAnErrorNotAMissingFile(): void {
+		// The OPEN request went out: the storage's own stream must not be tried on this connection.
+		$storage = new FakeSftpStorage(new FakeSftpConnection(['/home/f' => 'x'], throwAt: -1));
+		try {
+			SftpReadStream::open($storage, 'f');
+			$this->fail('expected a BackendException');
+		} catch (BackendException $e) {
+			$this->assertStringContainsString('connection', $e->getMessage());
+		}
+		$lost = new FakeSftpStorage(new FakeSftpConnection(['/home/f' => 'x'], loseAt: -1));
+		$this->expectException(BackendException::class);
+		SftpReadStream::open($lost, 'f');
+	}
+
+	public function testAConnectionErrorWhileOpeningDoesNotStopTheNextFile(): void {
+		try {
+			SftpReadStream::open(new FakeSftpStorage(new FakeSftpConnection(['/home/f' => 'x'], throwAt: -1)), 'f');
+		} catch (BackendException) {
+		}
+		$fh = SftpReadStream::open(new FakeSftpStorage(new FakeSftpConnection(['/home/f' => 'x'])), 'f');
+		$this->assertSame('x', stream_get_contents($fh));
+		fclose($fh);
+	}
+
+	public function testAFailedCloseDoesNotFallBackOnTheSameConnection(): void {
+		$sftp = new FakeSftpConnection(['/home/f' => random_bytes(3 * 1048576)], failAt: 1048576, closeFails: true);
+		$storage = new FakeSftpStorage($sftp);
+		$fh = SftpReadStream::open($storage, 'f');
+		$this->assertLessThan(3 * 1048576, strlen($this->readAll($fh)));
+		fclose($fh);
+		$this->assertSame([], $storage->fopens);
+	}
+
+	public function testAStorageThatThrowsIsNotUsed(): void {
+		$storage = new class {
+			public function getRoot(): string {
+				return '/';
+			}
+
+			public function getConnection(): object {
+				throw new \RuntimeException('Login failed');
+			}
+		};
+		$this->assertNull(SftpReadStream::open($storage, 'f'));
+	}
+
+	public function testAConnectionWithoutTheNeededMethodsIsNotUsed(): void {
+		$storage = new class {
+			public function getRoot(): string {
+				return '/';
+			}
+
+			public function getConnection(): object {
+				return new \stdClass();
+			}
+		};
+		$this->assertNull(SftpReadStream::open($storage, 'f'));
+		$this->assertNull(SftpReadStream::open(new \stdClass(), 'f'));
+	}
+
+	public function testAPhpseclib3ConnectionIsNotUsed(): void {
+		// phpseclib 3 has no _-prefixed methods; its packet_type and packet methods are private.
+		$v3 = new class {
+			private int $packet_type = -1;
+
+			private function _send_sftp_packet(): bool {
+				return true;
+			}
+
+			private function _get_sftp_packet(): string {
+				return '';
+			}
+
+			public function _realpath(string $path): string {
+				return $path;
+			}
+
+			public function realpath(string $path): string {
+				return $path . (string)$this->packet_type . $this->_send_sftp_packet() . $this->_get_sftp_packet();
+			}
+		};
+		$storage = new class($v3) {
+			public function __construct(
+				private object $connection,
+			) {
+			}
+
+			public function getRoot(): string {
+				return '/';
+			}
+
+			public function getConnection(): object {
+				return $this->connection;
+			}
+		};
+		$this->assertNull(SftpReadStream::open($storage, 'f'));
+	}
+
+	public function testAPrivatePacketTypeIsNotUsed(): void {
+		$conn = new class {
+			private int $packet_type = -1;
+
+			public function _send_sftp_packet(): bool {
+				return true;
+			}
+
+			public function _get_sftp_packet(): string {
+				return (string)$this->packet_type;
+			}
+
+			public function _realpath(string $path): string {
+				return $path;
+			}
+		};
+		$storage = new class($conn) {
+			public function __construct(
+				private object $connection,
+			) {
+			}
+
+			public function getRoot(): string {
+				return '/';
+			}
+
+			public function getConnection(): object {
+				return $this->connection;
+			}
+		};
+		$this->assertNull(SftpReadStream::open($storage, 'f'));
+	}
+
+	/** @param resource $fh */
+	private function readAll($fh): string {
+		$data = '';
+		while (!feof($fh)) {
+			$chunk = fread($fh, 65536);
+			if ($chunk === false || $chunk === '') {
+				break;
+			}
+			$data .= $chunk;
+		}
+		return $data;
+	}
+
+	/** @param resource $fh */
+	private function readExactly($fh, int $length): string {
+		$data = '';
+		while (strlen($data) < $length && !feof($fh)) {
+			$data .= fread($fh, $length - strlen($data));
+		}
+		return $data;
+	}
+}
+
+final class FakeSftpStorage {
+	/** @var list<string> paths opened through the storage's own stream */
+	public array $fopens = [];
+
+	public function __construct(
+		private FakeSftpConnection $connection,
+		private bool $fopenFails = false,
+	) {
+	}
+
+	/** files_external's own read stream: here the file from memory, seekable. */
+	public function fopen(string $path, string $mode) {
+		$this->fopens[] = $path;
+		$data = $this->connection->file('/home/' . $path);
+		if ($this->fopenFails || $data === null) {
+			return false;
+		}
+		$fh = fopen('php://memory', 'r+');
+		fwrite($fh, $data);
+		rewind($fh);
+		return $fh;
+	}
+
+	public function getRoot(): string {
+		return '/home/';
+	}
+
+	public function getConnection(): FakeSftpConnection {
+		return $this->connection;
+	}
+}
+
+/** The part of phpseclib\Net\SFTP (2.x) that SftpReadStream uses. */
+final class FakeSftpConnection {
+	public int $packet_type = -1;
+	public int $maxInFlight = 0;
+	/** @var list<int> lengths asked for by READ requests */
+	public array $reads = [];
+	/** @var array<string, string> */
+	public array $openHandles = [];
+	/** @var array<int, array{int, string}> answers by request id, in the order the server sent them */
+	private array $answers = [];
+	private int $handles = 0;
+
+	/** @param array<string, string> $files */
+	public function __construct(
+		private array $files,
+		private int $cap = 261120,
+		private ?int $failAt = null,
+		/** READ at or past this offset throws; -1: OPEN throws */
+		private ?int $throwAt = null,
+		/** READ at or past this offset finds the connection gone (phpseclib returns false); -1: OPEN */
+		private ?int $loseAt = null,
+		private bool $closeFails = false,
+	) {
+	}
+
+	public function file(string $path): ?string {
+		return $this->files[$path] ?? null;
+	}
+
+	public function pending(): int {
+		return count($this->answers);
+	}
+
+	public function _realpath(string $path): string {
+		return '/' . trim(preg_replace('#/+#', '/', $path), '/');
+	}
+
+	public function _send_sftp_packet(int $type, string $data, int $id = 1): bool {
+		switch ($type) {
+			case 3: // OPEN
+				if ($this->throwAt === -1) {
+					throw new \RuntimeException('Connection closed by server');
+				}
+				if ($this->loseAt === -1) {
+					return false;
+				}
+				$path = substr($data, 4, unpack('N', $data)[1]);
+				if (!isset($this->files[$path])) {
+					$this->answers[$id] = [101, pack('N', 2)];
+					break;
+				}
+				$handle = 'h' . ++$this->handles;
+				$this->openHandles[$handle] = $path;
+				$this->answers[$id] = [102, pack('Na*', strlen($handle), $handle)];
+				break;
+			case 4: // CLOSE
+				if ($this->closeFails) {
+					return false;
+				}
+				$handle = substr($data, 4, unpack('N', $data)[1]);
+				unset($this->openHandles[$handle]);
+				$this->answers[$id] = [101, pack('N', 0)];
+				break;
+			case 5: // READ
+				$len = unpack('N', $data)[1];
+				$handle = substr($data, 4, $len);
+				['hi' => $hi, 'lo' => $lo, 'n' => $n] = unpack('Nhi/Nlo/Nn', substr($data, 4 + $len));
+				$offset = $hi * 4294967296 + $lo;
+				$this->reads[] = $n;
+				if ($this->throwAt !== null && $this->throwAt >= 0 && $offset >= $this->throwAt) {
+					throw new \RuntimeException('Connection closed by server');
+				}
+				if ($this->loseAt !== null && $this->loseAt >= 0 && $offset >= $this->loseAt) {
+					$this->answers = [];
+					return false;
+				}
+				$file = $this->files[$this->openHandles[$handle]];
+				if ($this->failAt !== null && $offset >= $this->failAt) {
+					$this->answers[$id] = [101, pack('N', 4)]; // FX_FAILURE
+				} elseif ($offset >= strlen($file)) {
+					$this->answers[$id] = [101, pack('N', 1)]; // FX_EOF
+				} else {
+					$chunk = substr($file, $offset, min($n, $this->cap));
+					$this->answers[$id] = [103, pack('Na*', strlen($chunk), $chunk)];
+				}
+				$this->maxInFlight = max($this->maxInFlight, count($this->answers));
+				break;
+			default:
+				throw new \LogicException("unexpected packet type $type");
+		}
+		return true;
+	}
+
+	public function _get_sftp_packet(?int $id = null): string|false {
+		if ($this->answers === []) {
+			throw new \LogicException('waiting for an answer that will never come');
+		}
+		if ($id === null || !isset($this->answers[$id])) {
+			throw new \LogicException("no answer for request $id");
+		}
+		[$this->packet_type, $payload] = $this->answers[$id];
+		unset($this->answers[$id]);
+		return $payload;
+	}
+}
@@ -0,0 +1,172 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OCA\NgBackup\Tests\Unit\Repository;
+
+use OCA\NgBackup\Backend\IBackend;
+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;
+
+/** Restores and deep verifies read a pack as one stream instead of one request per blob. */
+class PackReadTest 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 = $this->tempDir();
+		for ($i = 0; $i < 200; $i++) {
+			file_put_contents(sprintf('%s/f%03d', $this->src, $i), random_bytes(20000));
+		}
+		$backend = new LocalBackend($this->root);
+		$repo = Repository::initWithKey($backend, $this->keys, $this->keys->wrap('pw'));
+		$this->snapshot = $repo->backupDirectory($this->src)['snapshot'];
+	}
+
+	private function open(PackOpenCountingBackend $backend): Repository {
+		return Repository::openWithKey($backend, $this->keys, null, null);
+	}
+
+	public function testFullRestoreOpensEachPackOnce(): void {
+		$backend = new PackOpenCountingBackend(new LocalBackend($this->root));
+		$target = $this->tempDir();
+
+		$this->assertSame(200, $this->open($backend)->restore($this->snapshot, $target));
+
+		for ($i = 0; $i < 200; $i++) {
+			$name = sprintf('f%03d', $i);
+			$this->assertSame(file_get_contents("$this->src/$name"), file_get_contents("$target/$name"));
+		}
+		// One pack: one stream instead of 200 requests.
+		$this->assertSame(1, $backend->packOpens());
+	}
+
+	public function testDeepVerifyOpensEachPackOnce(): void {
+		$backend = new PackOpenCountingBackend(new LocalBackend($this->root));
+
+		$result = $this->open($backend)->verify($this->snapshot, deep: true);
+
+		$this->assertSame(200 * 20000, $result['bytesChecked']);
+		$this->assertSame(1, $backend->packOpens());
+	}
+
+	public function testReadingBackwardsOpensThePackAgain(): void {
+		$backend = new PackOpenCountingBackend(new LocalBackend($this->root));
+		$repo = $this->open($backend);
+
+		$this->assertSame(1, $repo->restore($this->snapshot, $this->tempDir(), 'f150'));
+		$this->assertSame(1, $repo->restore($this->snapshot, $this->tempDir(), 'f050'));
+
+		$this->assertSame(2, $backend->packOpens());
+	}
+
+	public function testThePackStreamIsClosedBeforeAnyOtherRequest(): void {
+		$backend = new PackOpenCountingBackend(new LocalBackend($this->root));
+		$repo = $this->open($backend);
+		$this->assertSame(1, $repo->restore($this->snapshot, $this->tempDir(), 'f010'));
+		$this->assertTrue($backend->packStreamOpen(), 'kept open for the next read');
+
+		$repo->putObject('objects/after-restore', 'data');
+
+		$this->assertSame([false], $backend->packStreamOpenAtPut);
+	}
+
+	public function testAPackStreamThatCannotSeekIsReadUpToTheOffset(): void {
+		$backend = new PackOpenCountingBackend(new LocalBackend($this->root), $this->root);
+		$target = $this->tempDir();
+
+		$this->assertSame(1, $this->open($backend)->restore($this->snapshot, $target, 'f150'));
+
+		$this->assertSame(file_get_contents("$this->src/f150"), file_get_contents("$target/f150"));
+	}
+
+	public function testDeepVerifyOfATruncatedPackStillChecksTheBlobsBeforeTheDamage(): void {
+		$packs = (new LocalBackend($this->root))->list('packs');
+		$this->assertCount(1, $packs);
+		$pack = $this->root . '/' . $packs[0];
+		$fh = fopen($pack, 'r+b');
+		ftruncate($fh, intdiv(filesize($pack), 2));
+		fclose($fh);
+
+		$result = $this->open(new PackOpenCountingBackend(new LocalBackend($this->root)))->verify($this->snapshot, deep: true);
+
+		$this->assertGreaterThan(80 * 20000, $result['bytesChecked']);
+		$this->assertNotSame([], $result['unreadable']);
+		$this->assertSame([], $result['failed']);
+	}
+}
+
+final class PackOpenCountingBackend implements IBackend {
+	/** @var list<string> */
+	public array $gets = [];
+	/** @var list<bool> */
+	public array $packStreamOpenAtPut = [];
+	/** @var resource|null */
+	private $lastPackStream = null;
+
+	/** @param ?string $pipeFrom serve packs as pipes (streams that cannot seek) from this local repository root */
+	public function __construct(
+		private IBackend $inner,
+		private ?string $pipeFrom = null,
+	) {
+	}
+
+	public function packStreamOpen(): bool {
+		return is_resource($this->lastPackStream);
+	}
+
+	public function put(string $path, $stream): void {
+		$this->packStreamOpenAtPut[] = $this->packStreamOpen();
+		$this->inner->put($path, $stream);
+	}
+
+	public function packOpens(): int {
+		return count(array_filter($this->gets, fn (string $p): bool => str_starts_with($p, 'packs/')));
+	}
+
+	public function get(string $path) {
+		$this->gets[] = $path;
+		if (!str_starts_with($path, 'packs/')) {
+			return $this->inner->get($path);
+		}
+		$fh = $this->pipeFrom !== null
+			? popen('cat ' . escapeshellarg($this->pipeFrom . '/' . $path), 'r')
+			: $this->inner->get($path);
+		$this->lastPackStream = $fh;
+		return $fh;
+	}
+
+	public function getRange(string $path, int $offset, int $length): string {
+		$this->gets[] = $path;
+		return $this->inner->getRange($path, $offset, $length);
+	}
+
+	public function exists(string $path): bool {
+		return $this->inner->exists($path);
+	}
+
+	public function move(string $from, string $to): void {
+		$this->inner->move($from, $to);
+	}
+
+	public function list(string $prefix): array {
+		return $this->inner->list($prefix);
+	}
+
+	public function listFiles(string $dir): array {
+		return $this->inner->listFiles($dir);
+	}
+
+	public function delete(string $path): void {
+		$this->inner->delete($path);
+	}
+}
@@ -129,7 +129,7 @@ class VerifyTest extends TestCase {
 	}
 }

-/** Delegates to a real backend, but getRange() throws for the first $failures calls. */
+/** Delegates to a real backend, but reading a pack throws for the first $failures reads. */
 final class FlakyRangeBackend implements IBackend {
 	public function __construct(
 		private IBackend $inner,
@@ -143,15 +143,22 @@ final class FlakyRangeBackend implements IBackend {
 	}

 	public function get(string $path) {
+		if (str_starts_with($path, 'packs/')) {
+			$this->fail();
+		}
 		return $this->inner->get($path);
 	}

 	public function getRange(string $path, int $offset, int $length): string {
+		$this->fail();
+		return $this->inner->getRange($path, $offset, $length);
+	}
+
+	private function fail(): void {
 		if ($this->failures > 0) {
 			$this->failures--;
 			throw $this->error ?? new BackendException('connection reset');
 		}
-		return $this->inner->getRange($path, $offset, $length);
 	}

 	public function exists(string $path): bool {