stockpack / vendor / guzzlehttp / psr7 / src / LimitStream.php

LimitStream.php in StockPack – Stock photos and AI images from Unsplash, Adobe Stock, Freepik and more 2.5.5, at vendor/guzzlehttp/psr7/src/LimitStream.php

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1	<?php
2	namespace GuzzleHttp\Psr7;
3
4	use Psr\Http\Message\StreamInterface;
5
6
7	/**
8	* Decorator used to return only a subset of a stream
9	*/
10	class LimitStream implements StreamInterface
11	{
12	use StreamDecoratorTrait;
13
14	/** @var int Offset to start reading from */
15	private $offset;
16
17	/** @var int Limit the number of bytes that can be read */
18	private $limit;
19
20	/**
21	* @param StreamInterface $stream Stream to wrap
22	* @param int $limit Total number of bytes to allow to be read
23	* from the stream. Pass -1 for no limit.
24	* @param int $offset Position to seek to before reading (only
25	* works on seekable streams).
26	*/
27	public function __construct(
28	StreamInterface $stream,
29	$limit = -1,
30	$offset = 0
31	) {
32	$this->stream = $stream;
33	$this->setLimit($limit);
34	$this->setOffset($offset);
35	}
36
37	public function eof()
38	{
39	// Always return true if the underlying stream is EOF
40	if ($this->stream->eof()) {
41	return true;
42	}
43
44	// No limit and the underlying stream is not at EOF
45	if ($this->limit == -1) {
46	return false;
47	}
48
49	return $this->stream->tell() >= $this->offset + $this->limit;
50	}
51
52	/**
53	* Returns the size of the limited subset of data
54	* {@inheritdoc}
55	*/
56	public function getSize()
57	{
58	if (null === ($length = $this->stream->getSize())) {
59	return null;
60	} elseif ($this->limit == -1) {
61	return $length - $this->offset;
62	} else {
63	return min($this->limit, $length - $this->offset);
64	}
65	}
66
67	/**
68	* Allow for a bounded seek on the read limited stream
69	* {@inheritdoc}
70	*/
71	public function seek($offset, $whence = SEEK_SET)
72	{
73	if ($whence !== SEEK_SET \|\| $offset < 0) {
74	throw new \RuntimeException(sprintf(
75	'Cannot seek to offset %s with whence %s',
76	$offset,
77	$whence
78	));
79	}
80
81	$offset += $this->offset;
82
83	if ($this->limit !== -1) {
84	if ($offset > $this->offset + $this->limit) {
85	$offset = $this->offset + $this->limit;
86	}
87	}
88
89	$this->stream->seek($offset);
90	}
91
92	/**
93	* Give a relative tell()
94	* {@inheritdoc}
95	*/
96	public function tell()
97	{
98	return $this->stream->tell() - $this->offset;
99	}
100
101	/**
102	* Set the offset to start limiting from
103	*
104	* @param int $offset Offset to seek to and begin byte limiting from
105	*
106	* @throws \RuntimeException if the stream cannot be seeked.
107	*/
108	public function setOffset($offset)
109	{
110	$current = $this->stream->tell();
111
112	if ($current !== $offset) {
113	// If the stream cannot seek to the offset position, then read to it
114	if ($this->stream->isSeekable()) {
115	$this->stream->seek($offset);
116	} elseif ($current > $offset) {
117	throw new \RuntimeException("Could not seek to stream offset $offset");
118	} else {
119	$this->stream->read($offset - $current);
120	}
121	}
122
123	$this->offset = $offset;
124	}
125
126	/**
127	* Set the limit of bytes that the decorator allows to be read from the
128	* stream.
129	*
130	* @param int $limit Number of bytes to allow to be read from the stream.
131	* Use -1 for no limit.
132	*/
133	public function setLimit($limit)
134	{
135	$this->limit = $limit;
136	}
137
138	public function read($length)
139	{
140	if ($this->limit == -1) {
141	return $this->stream->read($length);
142	}
143
144	// Check if the current position is less than the total allowed
145	// bytes + original offset
146	$remaining = ($this->offset + $this->limit) - $this->stream->tell();
147	if ($remaining > 0) {
148	// Only return the amount of requested data, ensuring that the byte
149	// limit is not exceeded
150	return $this->stream->read(min($remaining, $length));
151	}
152
153	return '';
154	}
155	}
156