give
/
vendor
/
vendor-prefixed
/
stellarwp
/
licensing-api-client
/
src
/
Tracing
/
TraceParent.php
TraceParent.php
129 lines
| 1 | <?php declare(strict_types=1); |
| 2 | |
| 3 | namespace Give\Vendors\LiquidWeb\LicensingApiClient\Tracing; |
| 4 | |
| 5 | use InvalidArgumentException; |
| 6 | |
| 7 | /** |
| 8 | * Immutable W3C traceparent value object. |
| 9 | * |
| 10 | * @see https://www.w3.org/TR/trace-context/#traceparent-header |
| 11 | */ |
| 12 | final class TraceParent |
| 13 | { |
| 14 | private string $version; |
| 15 | |
| 16 | private string $traceId; |
| 17 | |
| 18 | private string $parentSpanId; |
| 19 | |
| 20 | private string $flags; |
| 21 | |
| 22 | private function __construct(string $version, string $traceId, string $parentSpanId, string $flags) { |
| 23 | $this->version = $version; |
| 24 | $this->traceId = $traceId; |
| 25 | $this->parentSpanId = $parentSpanId; |
| 26 | $this->flags = $flags; |
| 27 | } |
| 28 | |
| 29 | /** |
| 30 | * Parse and validate a W3C traceparent header value. |
| 31 | * |
| 32 | * @throws InvalidArgumentException |
| 33 | */ |
| 34 | public static function fromString(string $value): self { |
| 35 | $value = trim($value); |
| 36 | |
| 37 | if ($value === '') { |
| 38 | throw new InvalidArgumentException('traceparent cannot be empty.'); |
| 39 | } |
| 40 | |
| 41 | $parts = explode('-', strtolower($value)); |
| 42 | |
| 43 | if (count($parts) !== 4) { |
| 44 | throw new InvalidArgumentException('traceparent must have 4 dash-delimited parts.'); |
| 45 | } |
| 46 | |
| 47 | $version = $parts[0]; |
| 48 | $traceId = $parts[1]; |
| 49 | $parentSpanId = $parts[2]; |
| 50 | $flags = $parts[3]; |
| 51 | |
| 52 | if (!self::isHex($version, 2) || $version === 'ff') { |
| 53 | throw new InvalidArgumentException('traceparent version must be 2 hex characters and not ff.'); |
| 54 | } |
| 55 | |
| 56 | if (!self::isIdentifier($traceId, 32)) { |
| 57 | throw new InvalidArgumentException('traceparent trace-id must be 32 non-zero hex characters.'); |
| 58 | } |
| 59 | |
| 60 | if (!self::isIdentifier($parentSpanId, 16)) { |
| 61 | throw new InvalidArgumentException('traceparent parent-id must be 16 non-zero hex characters.'); |
| 62 | } |
| 63 | |
| 64 | if (!self::isHex($flags, 2)) { |
| 65 | throw new InvalidArgumentException('traceparent flags must be 2 hex characters.'); |
| 66 | } |
| 67 | |
| 68 | return new self($version, $traceId, $parentSpanId, $flags); |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * Generate a new root traceparent value. |
| 73 | */ |
| 74 | public static function generate(bool $sampled = true): self { |
| 75 | return new self( |
| 76 | '00', |
| 77 | bin2hex(random_bytes(16)), |
| 78 | bin2hex(random_bytes(8)), |
| 79 | $sampled ? '01' : '00' |
| 80 | ); |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * Return the normalized traceparent header string. |
| 85 | */ |
| 86 | public function header(): string { |
| 87 | return sprintf( |
| 88 | '%s-%s-%s-%s', |
| 89 | $this->version, |
| 90 | $this->traceId, |
| 91 | $this->parentSpanId, |
| 92 | $this->flags |
| 93 | ); |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * Return the trace-id segment. |
| 98 | */ |
| 99 | public function traceId(): string { |
| 100 | return $this->traceId; |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Return the parent span-id segment. |
| 105 | */ |
| 106 | public function parentSpanId(): string { |
| 107 | return $this->parentSpanId; |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * Return the trace-flags segment. |
| 112 | */ |
| 113 | public function flags(): string { |
| 114 | return $this->flags; |
| 115 | } |
| 116 | |
| 117 | public function __toString(): string { |
| 118 | return $this->header(); |
| 119 | } |
| 120 | |
| 121 | private static function isHex(string $value, int $length): bool { |
| 122 | return strlen($value) === $length && ctype_xdigit($value); |
| 123 | } |
| 124 | |
| 125 | private static function isIdentifier(string $value, int $length): bool { |
| 126 | return self::isHex($value, $length) && trim($value, '0') !== ''; |
| 127 | } |
| 128 | } |
| 129 |