content-control / classes / Base / Stream.php

Stream.php in Content Control – The Ultimate Content Restriction Plugin! Restrict Content, Create Conditional Blocks & More 2.0.2, at classes/Base/Stream.php

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1	<?php
2	/**
3	* Plugin controller.
4	*
5	* @copyright (c) 2021, Code Atlantic LLC.
6	*
7	* @package ContentControl
8	*/
9
10	namespace ContentControl\Base;
11
12	defined( 'ABSPATH' ) \|\| exit;
13
14	/**
15	* HTTP Stream class.
16	*/
17	class Stream {
18
19	/**
20	* Stream name.
21	*
22	* @var string
23	*/
24	protected $stream_name;
25
26	/**
27	* Version.
28	*
29	* @var string
30	*/
31	const VERSION = '1.0.0';
32
33	/**
34	* Stream constructor.
35	*
36	* @param string $stream_name Stream name.
37	*/
38	public function __construct( $stream_name = 'stream' ) {
39	$this->stream_name = $stream_name;
40	}
41
42	/**
43	* Start SSE stream.
44	*
45	* @return void
46	*/
47	public function start() {
48	// Disable default disconnect checks.
49	ignore_user_abort( true );
50
51	// phpcs:disable WordPress.PHP.IniSet.Risky, WordPress.PHP.NoSilencedErrors.Discouraged
52	@ini_set( 'zlib.output_compression', 0 );
53	@ini_set( 'implicit_flush', 1 );
54	@ini_set( 'log_limit', 8096 );
55	@ob_end_clean();
56	set_time_limit( 0 );
57	// phpcs:enable WordPress.PHP.IniSet.Risky, WordPress.PHP.NoSilencedErrors.Discouraged
58
59	$this->send_headers();
60	}
61
62	/**
63	* Send SSE headers.
64	*
65	* @return void
66	*/
67	public function send_headers() {
68	header( 'Content-Type: text/event-stream' );
69	header( 'Stream-Name: ' . $this->stream_name );
70	header( 'Cache-Control: no-cache' );
71	header( 'Connection: keep-alive' );
72	// Nginx: unbuffered responses suitable for Comet and HTTP streaming applications.
73	header( 'X-Accel-Buffering: no' );
74	$this->flush_buffers();
75	}
76
77	/**
78	* Flush buffers.
79	*
80	* Uses a micro delay to prevent the stream from flushing too quickly.
81	*
82	* @return void
83	*/
84	protected function flush_buffers() {
85	// This is for the buffer achieve the minimum size in order to flush data.
86
87	// phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
88	echo str_repeat( ' ', 1024 * 8 ) . PHP_EOL;
89
90	flush(); // Unless both are called. Some browsers will still cache.
91
92	// Neccessary to prevent the stream from flushing too quickly.
93	usleep( 1000 );
94	}
95
96	/**
97	* Send general message/data to the client.
98	*
99	* @param mixed $data Data to send.
100	*
101	* @return void
102	*/
103	public function send_data( $data ) {
104	$data = is_string( $data ) ? $data : \wp_json_encode( $data );
105
106	// phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
107	echo "data: {$data}" . PHP_EOL;
108	echo PHP_EOL;
109
110	$this->flush_buffers();
111	}
112
113	/**
114	* Send an event to the client.
115	*
116	* @param string $event Event name.
117	* @param mixed $data Data to send.
118	*
119	* @return void
120	*/
121	public function send_event( $event, $data = '' ) {
122	$data = is_string( $data ) ? $data : \wp_json_encode( $data );
123
124	// phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
125	echo "event: {$event}" . PHP_EOL;
126	// phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
127	echo "data: {$data}" . PHP_EOL;
128	echo PHP_EOL;
129
130	$this->flush_buffers();
131	}
132
133	/**
134	* Send an error to the client.
135	*
136	* @param string $error Error message.
137	*
138	* @return void
139	*/
140	public function send_error( $error ) {
141	$this->send_event( 'error', $error );
142	}
143
144	/**
145	* Check if the connection should abort.
146	*
147	* @return bool
148	*/
149	public function should_abort() {
150	return connection_aborted();
151	}
152	}
153