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

CachingStream.php in Media Cloud Sync 1.2.10, at includes/sdk/s3/GuzzleHttp/Psr7/CachingStream.php

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