LimitStream.php — Booking for Appointments and Events Calendar – Amelia 1.2.20

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

ameliabooking / vendor / guzzlehttp / psr7 / src Last commit date

LimitStream.php

158 lines

1	<?php
2
3	namespace AmeliaGuzzleHttp\Psr7;
4
5	use AmeliaPsr\Http\Message\StreamInterface;
6
7	/**
8	* Decorator used to return only a subset of a stream.
9	*
10	* @final
11	*/
12	class LimitStream implements StreamInterface
13	{
14	use StreamDecoratorTrait;
15
16	/** @var int Offset to start reading from */
17	private $offset;
18
19	/** @var int Limit the number of bytes that can be read */
20	private $limit;
21
22	/**
23	* @param StreamInterface $stream Stream to wrap
24	* @param int $limit Total number of bytes to allow to be read
25	* from the stream. Pass -1 for no limit.
26	* @param int $offset Position to seek to before reading (only
27	* works on seekable streams).
28	*/
29	public function __construct(
30	StreamInterface $stream,
31	$limit = -1,
32	$offset = 0
33	) {
34	$this->stream = $stream;
35	$this->setLimit($limit);
36	$this->setOffset($offset);
37	}
38
39	public function eof()
40	{
41	// Always return true if the underlying stream is EOF
42	if ($this->stream->eof()) {
43	return true;
44	}
45
46	// No limit and the underlying stream is not at EOF
47	if ($this->limit == -1) {
48	return false;
49	}
50
51	return $this->stream->tell() >= $this->offset + $this->limit;
52	}
53
54	/**
55	* Returns the size of the limited subset of data
56	* {@inheritdoc}
57	*/
58	public function getSize()
59	{
60	if (null === ($length = $this->stream->getSize())) {
61	return null;
62	} elseif ($this->limit == -1) {
63	return $length - $this->offset;
64	} else {
65	return min($this->limit, $length - $this->offset);
66	}
67	}
68
69	/**
70	* Allow for a bounded seek on the read limited stream
71	* {@inheritdoc}
72	*/
73	public function seek($offset, $whence = SEEK_SET)
74	{
75	if ($whence !== SEEK_SET \|\| $offset < 0) {
76	throw new \RuntimeException(sprintf(
77	'Cannot seek to offset %s with whence %s',
78	$offset,
79	$whence
80	));
81	}
82
83	$offset += $this->offset;
84
85	if ($this->limit !== -1) {
86	if ($offset > $this->offset + $this->limit) {
87	$offset = $this->offset + $this->limit;
88	}
89	}
90
91	$this->stream->seek($offset);
92	}
93
94	/**
95	* Give a relative tell()
96	* {@inheritdoc}
97	*/
98	public function tell()
99	{
100	return $this->stream->tell() - $this->offset;
101	}
102
103	/**
104	* Set the offset to start limiting from
105	*
106	* @param int $offset Offset to seek to and begin byte limiting from
107	*
108	* @throws \RuntimeException if the stream cannot be seeked.
109	*/
110	public function setOffset($offset)
111	{
112	$current = $this->stream->tell();
113
114	if ($current !== $offset) {
115	// If the stream cannot seek to the offset position, then read to it
116	if ($this->stream->isSeekable()) {
117	$this->stream->seek($offset);
118	} elseif ($current > $offset) {
119	throw new \RuntimeException("Could not seek to stream offset $offset");
120	} else {
121	$this->stream->read($offset - $current);
122	}
123	}
124
125	$this->offset = $offset;
126	}
127
128	/**
129	* Set the limit of bytes that the decorator allows to be read from the
130	* stream.
131	*
132	* @param int $limit Number of bytes to allow to be read from the stream.
133	* Use -1 for no limit.
134	*/
135	public function setLimit($limit)
136	{
137	$this->limit = $limit;
138	}
139
140	public function read($length)
141	{
142	if ($this->limit == -1) {
143	return $this->stream->read($length);
144	}
145
146	// Check if the current position is less than the total allowed
147	// bytes + original offset
148	$remaining = ($this->offset + $this->limit) - $this->stream->tell();
149	if ($remaining > 0) {
150	// Only return the amount of requested data, ensuring that the byte
151	// limit is not exceeded
152	return $this->stream->read(min($remaining, $length));
153	}
154
155	return '';
156	}
157	}
158