wp-staging / Backup / FileHeader / ExtraFieldCodec.php

ExtraFieldCodec.php in WP STAGING – WordPress Backups, Restore, Migration & Clone 4.12.0, at Backup/FileHeader/ExtraFieldCodec.php

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1	<?php
2
3	namespace WPStaging\Backup\FileHeader;
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27	final class ExtraFieldCodec
28	{
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33	const MAGIC = "\x57\x54";
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39	const MAX_VALUE_LENGTH = 65535;
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55	public function encode(array $entries): string
56	{
57	if (empty($entries)) {
58	return '';
59	}
60
61	$out = self::MAGIC;
62	foreach ($entries as $type => $value) {
63	if ($type === ExtraFieldType::LEGACY_RAW) {
64	continue;
65	}
66
67	if (!is_int($type) \|\| $type < 0 \|\| $type > 0xFF) {
68	throw new \UnexpectedValueException(sprintf('ExtraFieldCodec: type %s is out of the 0x00-0xFF range.', var_export($type, true)));
69	}
70
71	$length = strlen($value);
72	if ($length > self::MAX_VALUE_LENGTH) {
73	throw new \UnexpectedValueException(sprintf('ExtraFieldCodec: value for type 0x%02X is %d bytes, exceeding the %d-byte limit.', $type, $length, self::MAX_VALUE_LENGTH));
74	}
75
76	if (isset(ExtraFieldType::FIXED_WIRE_SIZES[$type]) && $length !== ExtraFieldType::FIXED_WIRE_SIZES[$type]) {
77	throw new \UnexpectedValueException(sprintf('ExtraFieldCodec: type 0x%02X requires exactly %d bytes, got %d.', $type, ExtraFieldType::FIXED_WIRE_SIZES[$type], $length));
78	}
79
80	$out .= chr($type) . pack('n', $length) . $value;
81	}
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83
84	if ($out === self::MAGIC) {
85	return '';
86	}
87
88	return $out;
89	}
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101	public function decode(string $bytes): array
102	{
103	if ($bytes === '') {
104	return [];
105	}
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107	if (substr($bytes, 0, 2) !== self::MAGIC) {
108	return [ExtraFieldType::LEGACY_RAW => $bytes];
109	}
110
111	$entries = [];
112	$offset = 2;
113	$total = strlen($bytes);
114
115	while ($offset < $total) {
116	if ($total - $offset < 3) {
117	throw new \UnexpectedValueException('ExtraFieldCodec: truncated entry header.');
118	}
119
120	$type = ord($bytes[$offset]);
121	$length = unpack('n', substr($bytes, $offset + 1, 2))[1];
122	$offset += 3;
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124	if ($type === ExtraFieldType::LEGACY_RAW) {
125	throw new \UnexpectedValueException(sprintf('ExtraFieldCodec: type 0x%02X is reserved as a parser-only sentinel and is not valid on the wire.', ExtraFieldType::LEGACY_RAW));
126	}
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128	if ($total - $offset < $length) {
129	throw new \UnexpectedValueException(sprintf('ExtraFieldCodec: declared length %d for type 0x%02X overruns end of input.', $length, $type));
130	}
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132	if (array_key_exists($type, $entries)) {
133	throw new \UnexpectedValueException(sprintf('ExtraFieldCodec: duplicate entry of type 0x%02X.', $type));
134	}
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136	$entries[$type] = substr($bytes, $offset, $length);
137	$offset += $length;
138	}
139
140	return $entries;
141	}
142	}
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