BufferStream.php — ShareThis Dashboard for Google Analytics 3.3.0

googleanalytics / lib / analytics-admin / vendor / guzzlehttp / psr7 / src / BufferStream.php

googleanalytics / lib / analytics-admin / vendor / guzzlehttp / psr7 / src Last commit date

BufferStream.php

150 lines

1	<?php
2
3	declare(strict_types=1);
4
5	namespace GuzzleHttp\Psr7;
6
7	use Psr\Http\Message\StreamInterface;
8
9	/**
10	* Provides a buffer stream that can be written to to fill a buffer, and read
11	* from to remove bytes from the buffer.
12	*
13	* This stream returns a "hwm" metadata value that tells upstream consumers
14	* what the configured high water mark of the stream is, or the maximum
15	* preferred size of the buffer.
16	*/
17	final class BufferStream implements StreamInterface
18	{
19	/** @var int */
20	private $hwm;
21
22	/** @var string */
23	private $buffer = '';
24
25	/**
26	* @param int $hwm High water mark, representing the preferred maximum
27	* buffer size. If the size of the buffer exceeds the high
28	* water mark, then calls to write will continue to succeed
29	* but will return 0 to inform writers to slow down
30	* until the buffer has been drained by reading from it.
31	*/
32	public function __construct(int $hwm = 16384)
33	{
34	$this->hwm = $hwm;
35	}
36
37	public function __toString(): string
38	{
39	return $this->getContents();
40	}
41
42	public function getContents(): string
43	{
44	$buffer = $this->buffer;
45	$this->buffer = '';
46
47	return $buffer;
48	}
49
50	public function close(): void
51	{
52	$this->buffer = '';
53	}
54
55	public function detach()
56	{
57	$this->close();
58
59	return null;
60	}
61
62	public function getSize(): ?int
63	{
64	return strlen($this->buffer);
65	}
66
67	public function isReadable(): bool
68	{
69	return true;
70	}
71
72	public function isWritable(): bool
73	{
74	return true;
75	}
76
77	public function isSeekable(): bool
78	{
79	return false;
80	}
81
82	public function rewind(): void
83	{
84	$this->seek(0);
85	}
86
87	public function seek($offset, $whence = SEEK_SET): void
88	{
89	throw new \RuntimeException('Cannot seek a BufferStream');
90	}
91
92	public function eof(): bool
93	{
94	return strlen($this->buffer) === 0;
95	}
96
97	public function tell(): int
98	{
99	throw new \RuntimeException('Cannot determine the position of a BufferStream');
100	}
101
102	/**
103	* Reads data from the buffer.
104	*/
105	public function read($length): string
106	{
107	$currentLength = strlen($this->buffer);
108
109	if ($length >= $currentLength) {
110	// No need to slice the buffer because we don't have enough data.
111	$result = $this->buffer;
112	$this->buffer = '';
113	} else {
114	// Slice up the result to provide a subset of the buffer.
115	$result = substr($this->buffer, 0, $length);
116	$this->buffer = substr($this->buffer, $length);
117	}
118
119	return $result;
120	}
121
122	/**
123	* Writes data to the buffer.
124	*/
125	public function write($string): int
126	{
127	$this->buffer .= $string;
128
129	if (strlen($this->buffer) >= $this->hwm) {
130	return 0;
131	}
132
133	return strlen($string);
134	}
135
136	/**
137	* {@inheritdoc}
138	*
139	* @return mixed
140	*/
141	public function getMetadata($key = null)
142	{
143	if ($key === 'hwm') {
144	return $this->hwm;
145	}
146
147	return $key ? null : [];
148	}
149	}
150