public Php::generate()
Generates a Universally Unique IDentifier (UUID).
Return value
A 16 byte integer represented as a hex string formatted with 4 hyphens.
Overrides UuidInterface::generate
File
- core/lib/Drupal/Component/Uuid/Php.php, line 18
Class
- Php
- Generates a UUID v4 (RFC 4122 section 4.4) using PHP code.
Namespace
Drupal\Component\Uuid
Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | public function generate() { // Obtain a random string of 32 hex characters. $hex = bin2hex(Crypt::randomBytes(16)); // The variable names $time_low, $time_mid, $time_hi_and_version, // $clock_seq_hi_and_reserved, $clock_seq_low, and $node correlate to // the fields defined in RFC 4122 section 4.1.2. // // Use characters 0-11 to generate 32-bit $time_low and 16-bit $time_mid. $time_low = substr($hex, 0, 8); $time_mid = substr($hex, 8, 4); // Use characters 12-15 to generate 16-bit $time_hi_and_version. // The 4 most significant bits are the version number (0100 == 0x4). // We simply skip character 12 from $hex, and concatenate the strings. $time_hi_and_version = '4' . substr($hex, 13, 3); // Use characters 16-17 to generate 8-bit $clock_seq_hi_and_reserved. // The 2 most significant bits are set to one and zero respectively. $clock_seq_hi_and_reserved = base_convert(substr($hex, 16, 2), 16, 10); $clock_seq_hi_and_reserved &= 0b00111111; $clock_seq_hi_and_reserved |= 0b10000000; // Use characters 18-19 to generate 8-bit $clock_seq_low. $clock_seq_low = substr($hex, 18, 2); // Use characters 20-31 to generate 48-bit $node. $node = substr($hex, 20); // Re-combine as a UUID. $clock_seq_hi_and_reserved is still an integer. $uuid = sprintf('%s-%s-%s-%02x%s-%s', $time_low, $time_mid, $time_hi_and_version, $clock_seq_hi_and_reserved, $clock_seq_low, $node ); return $uuid;} |
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