$stream
$stream
Describes a data stream.
Typically, an instance will wrap a PHP stream; this interface provides a wrapper around the most common operations, including serialization of the entire stream to a string.
$options : \ZipStream\Option\File
__toString() : string
Reads all data from the stream into a string, from the beginning to end.
This method MUST attempt to seek to the beginning of the stream before reading data and read the stream until the end is reached.
Warning: This could attempt to load a large amount of data into memory.
This method MUST NOT raise an exception in order to conform with PHP's string casting operations.
seek(int $offset, int $whence = SEEK_SET) : void
Seek to a position in the stream.
| int | $offset | Stream offset |
| int | $whence | Specifies how the cursor position will be calculated
based on the seek offset. Valid values are identical to the built-in
PHP $whence values for |
on failure.
getMetadata(string $key = null) : array|mixed|null
Get stream metadata as an associative array or retrieve a specific key.
The keys returned are identical to the keys returned from PHP's stream_get_meta_data() function.
| string | $key | Specific metadata to retrieve. |
Returns an associative array if no key is provided. Returns a specific key value if a key is provided and the value is found, or null if the key is not found.
read(int $length) : string
Read data from the stream.
| int | $length | Read up to $length bytes from the object and return them. Fewer than $length bytes may be returned if underlying stream call returns fewer bytes. |
if an error occurs.
Returns the data read from the stream, or an empty string if no bytes are available.
<?php
declare(strict_types=1);
namespace ZipStream;
class DeflateStream extends Stream
{
protected $filter;
/**
* @var Option\File
*/
protected $options;
/**
* Rewind stream
*
* @return void
*/
public function rewind(): void
{
// deflate filter needs to be removed before rewind
if ($this->filter) {
$this->removeDeflateFilter();
$this->seek(0);
$this->addDeflateFilter($this->options);
} else {
rewind($this->stream);
}
}
/**
* Remove the deflate filter
*
* @return void
*/
public function removeDeflateFilter(): void
{
if (!$this->filter) {
return;
}
stream_filter_remove($this->filter);
$this->filter = null;
}
/**
* Add a deflate filter
*
* @param Option\File $options
* @return void
*/
public function addDeflateFilter(Option\File $options): void
{
$this->options = $options;
// parameter 4 for stream_filter_append expects array
// so we convert the option object in an array
$optionsArr = [
'comment' => $options->getComment(),
'method' => $options->getMethod(),
'deflateLevel' => $options->getDeflateLevel(),
'time' => $options->getTime()
];
$this->filter = stream_filter_append(
$this->stream,
'zlib.deflate',
STREAM_FILTER_READ,
$optionsArr
);
}
}