backup / src / JetBackup / Web / File / FileChunk.php

FileChunk.php in JetBackup – Backup, Restore & Migrate 3.1.21.3, at src/JetBackup/Web/File/FileChunk.php

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1	<?php
2	/*
3	*
4	* JetBackup @ package
5	* Created By Idan Ben-Ezra
6	*
7	* Copyrights @ JetApps
8	* https://www.jetapps.com
9	*
10	**/
11	namespace JetBackup\Web\File;
12
13	use JetBackup\Exception\IOException;
14
15	defined( '__JETBACKUP__' ) or die( 'Restricted access' );
16
17	class FileChunk {
18
19	const CHUNK_SIZE = 5242880; // 5MB
20	const CHUNK_SIZE_PIECE = 1048576; // 1MB
21
22	private FileStream $_file;
23	private int $_chunk_start;
24	private int $_chunk_size;
25	private int $_readed;
26
27	/**
28	* Chunk constructor.
29	*
30	* @param FileStream $file
31	* @param int $chunk_size
32	*
33	* @throws IOException
34	*/
35	public function __construct(FileStream $file, int $chunk_size=self::CHUNK_SIZE) {
36	$this->_file = $file;
37	$this->_chunk_start = $this->getFile()->tell();
38	$this->_readed = 0;
39
40	$size = ($this->getFile()->getSize() - $this->_chunk_start);
41	if($size < 0) throw new IOException("Chunk size length is too small ($size bytes)");
42	$this->_chunk_size = min($size, $chunk_size);
43	}
44
45	/**
46	* @return void
47	*/
48	public function rewind():void {
49	$this->_readed = 0;
50	$this->getFile()->seek($this->_chunk_start);
51	}
52
53	/**
54	* @return int
55	*/
56	public function getSize():int {
57	return $this->_chunk_size;
58	}
59
60	/**
61	* @return FileStream
62	*/
63	public function getFile():FileStream {
64	return $this->_file;
65	}
66
67	/**
68	* @param int\|false $length
69	*
70	* @return false\|string
71	*/
72	public function readPiece($length=false) {
73	if(!$length \|\| $length > self::CHUNK_SIZE_PIECE) $length = self::CHUNK_SIZE_PIECE;
74	return $this->read($length);
75	}
76
77	/**
78	* @param int $length
79	*
80	* @return int
81	*/
82	public function length(int $length):int {
83	if($this->_readed + $length > $this->_chunk_size) $length = $this->_chunk_size - $this->_readed;
84	return $length;
85	}
86
87	/**
88	* @param int $length
89	*
90	* @return false\|string
91	*/
92	public function read(int $length) {
93	$length = $this->length($length);
94	if($length <= 0) return false;
95	$this->_readed += $length;
96	return $this->getFile()->read($length);
97	}
98
99	/**
100	* @return bool
101	*/
102	public function eof():bool {
103	return $this->getFile()->eof();
104	}
105
106	/**
107	* @param string $algorithm
108	*
109	* @return string
110	*/
111	public function getHash(string $algorithm, $binary=false):string {
112	$this->rewind();
113	$ctx = hash_init($algorithm);
114	while (($data = $this->read(self::CHUNK_SIZE_PIECE)) !== false) hash_update($ctx, $data);
115	$this->rewind();
116	return hash_final($ctx, $binary);
117	}
118
119	/**
120	* @return string
121	*/
122	public function __toString(): string {
123	return "Chunk -> " . json_encode([
124	'file' => $this->_file->getFile(),
125	'chunk_size' => $this->_chunk_size,
126	'chunk_start' => $this->_chunk_start,
127	'read' => $this->_readed,
128	]);
129	}
130	}