comparison vendor/guzzlehttp/psr7/src/LimitStream.php @ 0:4c8ae668cc8c

Initial import (non-working)
author Chris Cannam
date Wed, 29 Nov 2017 16:09:58 +0000
parents
children
comparison
equal deleted inserted replaced
-1:000000000000 0:4c8ae668cc8c
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 % 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 }