From 90fdf83ca7648418f899e28490f65de53fcd31d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Calvi=C3=B1o=20S=C3=A1nchez?= <danxuliu@gmail.com>
Date: Tue, 6 Feb 2018 14:03:50 +0100
Subject: [PATCH] Use zip32 only if there are less than 65536 files
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
A zip32 file can contain, at most, 65535 files (and folders), so take
that constraint into account.
Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>
---
lib/private/Streamer.php | 28 +++++++++++++++++++++++----
lib/private/legacy/files.php | 37 ++++++++++++++++++++++++++++++++----
2 files changed, 57 insertions(+), 8 deletions(-)
diff --git a/lib/private/Streamer.php b/lib/private/Streamer.php
index 3b033e265e7..51c2c923c23 100644
--- a/lib/private/Streamer.php
+++ b/lib/private/Streamer.php
@@ -40,14 +40,34 @@ class Streamer {
*
* @param IRequest $request
* @param int $size The size of the files in bytes
+ * @param int $numberOfFiles The number of files (and directories) that will
+ * be included in the streamed file
*/
- public function __construct(IRequest $request, int $size){
+ public function __construct(IRequest $request, int $size, int $numberOfFiles){
/**
- * If the size if below 4GB always use zip32
- * Use 4*1000*1000*1000 so we have a buffer for all the extra zip data
+ * zip32 constraints for a basic (without compression, volumes nor
+ * encryption) zip file according to the Zip specification:
+ * - No file size is larger than 4 bytes (file size < 4294967296); see
+ * 4.4.9 uncompressed size
+ * - The size of all files plus their local headers is not larger than
+ * 4 bytes; see 4.4.16 relative offset of local header and 4.4.24
+ * offset of start of central directory with respect to the starting
+ * disk number
+ * - The total number of entries (files and directories) in the zip file
+ * is not larger than 2 bytes (number of entries < 65536); see 4.4.22
+ * total number of entries in the central dir
+ * - The size of the central directory is not larger than 4 bytes; see
+ * 4.4.23 size of the central directory
+ *
+ * Due to all that, zip32 is used if the size is below 4GB and there are
+ * less than 65536 files; the margin between 4*1000^3 and 4*1024^3
+ * should give enough room for the extra zip metadata. Technically, it
+ * would still be possible to create an invalid zip32 file (for example,
+ * a zip file from files smaller than 4GB with a central directory
+ * larger than 4GiB), but it should not happen in the real world.
*/
- if ($size < 4 * 1000 * 1000 * 1000) {
+ if ($size < 4 * 1000 * 1000 * 1000 && $numberOfFiles < 65536) {
$this->streamerInstance = new ZipStreamer(['zip64' => false]);
} else if ($request->isUserAgent($this->preferTarFor)) {
$this->streamerInstance = new TarStreamer();
diff --git a/lib/private/legacy/files.php b/lib/private/legacy/files.php
index b7c99b7fef8..9281c1f7da4 100644
--- a/lib/private/legacy/files.php
+++ b/lib/private/legacy/files.php
@@ -146,17 +146,23 @@ class OC_Files {
self::lockFiles($view, $dir, $files);
- /* Calculate filesize */
+ /* Calculate filesize and number of files */
if ($getType === self::ZIP_FILES) {
+ $fileInfos = array();
$fileSize = 0;
foreach ($files as $file) {
- $fileSize += \OC\Files\Filesystem::getFileInfo($dir . '/' . $file)->getSize();
+ $fileInfo = \OC\Files\Filesystem::getFileInfo($dir . '/' . $file);
+ $fileSize += $fileInfo->getSize();
+ $fileInfos[] = $fileInfo;
}
+ $numberOfFiles = self::getNumberOfFiles($fileInfos);
} elseif ($getType === self::ZIP_DIR) {
- $fileSize = \OC\Files\Filesystem::getFileInfo($dir . '/' . $files)->getSize();
+ $fileInfo = \OC\Files\Filesystem::getFileInfo($dir . '/' . $files);
+ $fileSize = $fileInfo->getSize();
+ $numberOfFiles = self::getNumberOfFiles(array($fileInfo));
}
- $streamer = new Streamer(\OC::$server->getRequest(), $fileSize);
+ $streamer = new Streamer(\OC::$server->getRequest(), $fileSize, $numberOfFiles);
OC_Util::obEnd();
$streamer->sendHeaders($name);
@@ -324,6 +330,29 @@ class OC_Files {
}
}
+ /**
+ * Returns the total (recursive) number of files and folders in the given
+ * FileInfos.
+ *
+ * @param \OCP\Files\FileInfo[] $fileInfos the FileInfos to count
+ * @return int the total number of files and folders
+ */
+ private static function getNumberOfFiles($fileInfos) {
+ $numberOfFiles = 0;
+
+ $view = new View();
+
+ while ($fileInfo = array_pop($fileInfos)) {
+ $numberOfFiles++;
+
+ if ($fileInfo->getType() === \OCP\Files\FileInfo::TYPE_FOLDER) {
+ $fileInfos = array_merge($fileInfos, $view->getDirectoryContent($fileInfo->getPath()));
+ }
+ }
+
+ return $numberOfFiles;
+ }
+
/**
* @param View $view
* @param string $dir
--
GitLab