media-cloud-sync / includes / sdk / s3 / GuzzleHttp / Psr7 / CachingStream.php

CachingStream.php in Media Cloud Sync 1.2.13, at includes/sdk/s3/GuzzleHttp/Psr7/CachingStream.php

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1	<?php
2
3	declare (strict_types=1);
4	namespace Dudlewebs\WPMCS\s3\GuzzleHttp\Psr7;
5
6	use Dudlewebs\WPMCS\s3\Psr\Http\Message\StreamInterface;
7	/**
8	* Stream decorator that can cache previously read bytes from a sequentially
9	* read stream.
10	*/
11	final class CachingStream implements StreamInterface
12	{
13	use StreamDecoratorTrait;
14	/** @var StreamInterface Stream being wrapped */
15	private $remoteStream;
16	/** @var int Number of bytes to skip reading due to a write on the buffer */
17	private $skipReadBytes = 0;
18	/**
19	* @var StreamInterface
20	*/
21	private $stream;
22	/**
23	* We will treat the buffer object as the body of the stream
24	*
25	* @param StreamInterface $stream Stream to cache. The cursor is assumed to be at the beginning of the stream.
26	* @param StreamInterface $target Optionally specify where data is cached
27	*/
28	public function __construct(StreamInterface $stream, ?StreamInterface $target = null)
29	{
30	$this->remoteStream = $stream;
31	$this->stream = $target ?: new Stream(Utils::tryFopen('php://temp', 'r+'));
32	}
33	public function getSize() : ?int
34	{
35	$remoteSize = $this->remoteStream->getSize();
36	if (null === $remoteSize) {
37	return null;
38	}
39	return \max($this->stream->getSize(), $remoteSize);
40	}
41	public function rewind() : void
42	{
43	$this->seek(0);
44	}
45	public function seek($offset, $whence = \SEEK_SET) : void
46	{
47	if ($whence === \SEEK_SET) {
48	$byte = $offset;
49	} elseif ($whence === \SEEK_CUR) {
50	$byte = $offset + $this->tell();
51	} elseif ($whence === \SEEK_END) {
52	$size = $this->remoteStream->getSize();
53	if ($size === null) {
54	$size = $this->cacheEntireStream();
55	}
56	$byte = $size + $offset;
57	} else {
58	throw new \InvalidArgumentException('Invalid whence');
59	}
60	$diff = $byte - $this->stream->getSize();
61	if ($diff > 0) {
62	// Read the remoteStream until we have read in at least the amount
63	// of bytes requested, or we reach the end of the file.
64	while ($diff > 0 && !$this->remoteStream->eof()) {
65	$this->read($diff);
66	$diff = $byte - $this->stream->getSize();
67	}
68	} else {
69	// We can just do a normal seek since we've already seen this byte.
70	$this->stream->seek($byte);
71	}
72	}
73	public function read($length) : string
74	{
75	// Perform a regular read on any previously read data from the buffer
76	$data = $this->stream->read($length);
77	$remaining = $length - \strlen($data);
78	// More data was requested so read from the remote stream
79	if ($remaining) {
80	// If data was written to the buffer in a position that would have
81	// been filled from the remote stream, then we must skip bytes on
82	// the remote stream to emulate overwriting bytes from that
83	// position. This mimics the behavior of other PHP stream wrappers.
84	$remoteData = $this->remoteStream->read($remaining + $this->skipReadBytes);
85	if ($this->skipReadBytes) {
86	$len = \strlen($remoteData);
87	$remoteData = \substr($remoteData, $this->skipReadBytes);
88	$this->skipReadBytes = \max(0, $this->skipReadBytes - $len);
89	}
90	$data .= $remoteData;
91	$this->stream->write($remoteData);
92	}
93	return $data;
94	}
95	public function write($string) : int
96	{
97	// When appending to the end of the currently read stream, you'll want
98	// to skip bytes from being read from the remote stream to emulate
99	// other stream wrappers. Basically replacing bytes of data of a fixed
100	// length.
101	$overflow = \strlen($string) + $this->tell() - $this->remoteStream->tell();
102	if ($overflow > 0) {
103	$this->skipReadBytes += $overflow;
104	}
105	return $this->stream->write($string);
106	}
107	public function eof() : bool
108	{
109	return $this->stream->eof() && $this->remoteStream->eof();
110	}
111	/**
112	* Close both the remote stream and buffer stream
113	*/
114	public function close() : void
115	{
116	$this->remoteStream->close();
117	$this->stream->close();
118	}
119	private function cacheEntireStream() : int
120	{
121	$target = new FnStream(['write' => 'strlen']);
122	Utils::copyToStream($this, $target);
123	return $this->tell();
124	}
125	}
126