suyuan/vendor/maennchen/zipstream-php/guides/ContentLength.rst

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2023-10-14 13:36:39 +08:00
Adding Content-Length header
=============
Adding a ``Content-Length`` header for ``ZipStream`` is not trivial since the
size is not known beforehand.
The following workaround adds an approximated header:
.. code-block:: php
class Zip
{
/** @var string */
private $name;
private $files = [];
public function __construct($name)
{
$this->name = $name;
}
public function addFile($name, $data)
{
$this->files[] = ['type' => 'addFile', 'name' => $name, 'data' => $data];
}
public function addFileFromPath($name, $path)
{
$this->files[] = ['type' => 'addFileFromPath', 'name' => $name, 'path' => $path];
}
public function getEstimate()
{
$estimate = 22;
foreach ($this->files as $file) {
$estimate += 76 + 2 * strlen($file['name']);
if ($file['type'] === 'addFile') {
$estimate += strlen($file['data']);
}
if ($file['type'] === 'addFileFromPath') {
$estimate += filesize($file['path']);
}
}
return $estimate;
}
public function finish()
{
header('Content-Length: ' . $this->getEstimate());
$options = new \ZipStream\Option\Archive();
$options->setSendHttpHeaders(true);
$options->setEnableZip64(false);
$options->setDeflateLevel(-1);
$zip = new \ZipStream\ZipStream($this->name, $options);
$fileOptions = new \ZipStream\Option\File();
$fileOptions->setMethod(\ZipStream\Option\Method::STORE());
foreach ($this->files as $file) {
if ($file['type'] === 'addFile') {
$zip->addFile($file['name'], $file['data'], $fileOptions);
}
if ($file['type'] === 'addFileFromPath') {
$zip->addFileFromPath($file['name'], $file['path'], $fileOptions);
}
}
$zip->finish();
exit;
}
}
It only works with the following constraints:
- All file content is known beforehand.
- Content Deflation is disabled
Thanks to
`partiellkorrekt <https://github.com/maennchen/ZipStream-PHP/issues/89#issuecomment-1047949274>`_
for this workaround.