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
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
<?php
namespace Jaeger\Codec;
use Exception;
use Jaeger\SpanContext;
use const Jaeger\TRACE_ID_HEADER;
use const Jaeger\BAGGAGE_HEADER_PREFIX;
use const Jaeger\DEBUG_ID_HEADER_KEY;
class TextCodec implements CodecInterface
{
private $urlEncoding;
private $traceIdHeader;
private $baggagePrefix;
private $debugIdHeader;
private $prefixLength;
/**
* @param bool $urlEncoding
* @param string $traceIdHeader
* @param string $baggageHeaderPrefix
* @param string $debugIdHeader
*/
public function __construct(
bool $urlEncoding = false,
string $traceIdHeader = TRACE_ID_HEADER,
string $baggageHeaderPrefix = BAGGAGE_HEADER_PREFIX,
string $debugIdHeader = DEBUG_ID_HEADER_KEY
) {
$this->urlEncoding = $urlEncoding;
$this->traceIdHeader = str_replace('_', '-', strtolower($traceIdHeader));
$this->baggagePrefix = str_replace('_', '-', strtolower($baggageHeaderPrefix));
$this->debugIdHeader = str_replace('_', '-', strtolower($debugIdHeader));
$this->prefixLength = strlen($baggageHeaderPrefix);
}
/**
* {@inheritdoc}
*
* @see \Jaeger\Tracer::inject
*
* @param SpanContext $spanContext
* @param mixed $carrier
*
* @return void
*/
public function inject(SpanContext $spanContext, &$carrier)
{
$carrier[$this->traceIdHeader] = $this->spanContextToString(
$spanContext->getTraceId(),
$spanContext->getSpanId(),
$spanContext->getParentId(),
$spanContext->getFlags()
);
$baggage = $spanContext->getBaggage();
if (empty($baggage)) {
return;
}
foreach ($baggage as $key => $value) {
$encodedValue = $value;
if ($this->urlEncoding) {
$encodedValue = urlencode($value);
}
$carrier[$this->baggagePrefix . $key] = $encodedValue;
}
}
/**
* {@inheritdoc}
*
* @see \Jaeger\Tracer::extract
*
* @param mixed $carrier
* @return SpanContext|null
*
* @throws Exception
*/
public function extract($carrier)
{
$traceId = null;
$spanId = null;
$parentId = null;
$flags = null;
$baggage = null;
$debugId = null;
foreach ($carrier as $key => $value) {
$ucKey = strtolower($key);
if ($ucKey === $this->traceIdHeader) {
if ($this->urlEncoding) {
$value = urldecode($value);
}
list($traceId, $spanId, $parentId, $flags) =
$this->spanContextFromString($value);
} elseif ($this->startsWith($ucKey, $this->baggagePrefix)) {
if ($this->urlEncoding) {
$value = urldecode($value);
}
$attrKey = substr($key, $this->prefixLength);
if ($baggage === null) {
$baggage = [strtolower($attrKey) => $value];
} else {
$baggage[strtolower($attrKey)] = $value;
}
} elseif ($ucKey === $this->debugIdHeader) {
if ($this->urlEncoding) {
$value = urldecode($value);
}
$debugId = $value;
}
}
if ($traceId === null && $baggage !== null) {
throw new Exception('baggage without trace ctx');
}
if ($traceId === null) {
if ($debugId !== null) {
return new SpanContext(null, null, null, null, [], $debugId);
}
return null;
}
return new SpanContext($traceId, $spanId, $parentId, $flags, $baggage);
}
/**
* Store a span context to a string.
*
* @param int $traceId
* @param int $spanId
* @param int $parentId
* @param int $flags
* @return string
*/
private function spanContextToString($traceId, $spanId, $parentId, $flags)
{
$parentId = $parentId ?? 0;
return sprintf('%x:%x:%x:%x', $traceId, $spanId, $parentId, $flags);
}
/**
* Create a span context from a string.
*
* @param string $value
* @return array
*
* @throws Exception
*/
private function spanContextFromString($value): array
{
$parts = explode(':', $value);
if (count($parts) != 4) {
throw new Exception('Malformed tracer state string.');
}
return [
CodecUtility::hexToInt64($parts[0]),
CodecUtility::hexToInt64($parts[1]),
CodecUtility::hexToInt64($parts[2]),
$parts[3],
];
}
/**
* Checks that a string ($haystack) starts with a given prefix ($needle).
*
* @param string $haystack
* @param string $needle
* @return bool
*/
private function startsWith(string $haystack, string $needle): bool
{
return substr($haystack, 0, strlen($needle)) == $needle;
}
}
|
