1 files changed, 157 insertions, 0 deletions
diff --git a/vendor/open-telemetry/api/Trace/Propagation/TraceContextPropagator.php b/vendor/open-telemetry/api/Trace/Propagation/TraceContextPropagator.php
new file mode 100644
index 000000000..b70a15647
--- /dev/null
+++ b/vendor/open-telemetry/api/Trace/Propagation/TraceContextPropagator.php
@@ -0,0 +1,157 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\API\Trace\Propagation;
+
+use function count;
+use function explode;
+use function hexdec;
+use OpenTelemetry\API\Trace\Span;
+use OpenTelemetry\API\Trace\SpanContext;
+use OpenTelemetry\API\Trace\SpanContextInterface;
+use OpenTelemetry\API\Trace\SpanContextValidator;
+use OpenTelemetry\API\Trace\TraceFlags;
+use OpenTelemetry\API\Trace\TraceState;
+use OpenTelemetry\Context\Context;
+use OpenTelemetry\Context\ContextInterface;
+use OpenTelemetry\Context\Propagation\ArrayAccessGetterSetter;
+use OpenTelemetry\Context\Propagation\PropagationGetterInterface;
+use OpenTelemetry\Context\Propagation\PropagationSetterInterface;
+use OpenTelemetry\Context\Propagation\TextMapPropagatorInterface;
+
+/**
+ * TraceContext is a propagator that supports the W3C Trace Context format
+ * (https://www.w3.org/TR/trace-context/)
+ *
+ * This propagator will propagate the traceparent and tracestate headers to
+ * guarantee traces are not broken. It is up to the users of this propagator
+ * to choose if they want to participate in a trace by modifying the
+ * traceparent header and relevant parts of the tracestate header containing
+ * their proprietary information.
+ */
+final class TraceContextPropagator implements TextMapPropagatorInterface
+{
+    public const TRACEPARENT = 'traceparent';
+    public const TRACESTATE = 'tracestate';
+    private const VERSION = '00'; // Currently, only '00' is supported
+
+    public const FIELDS = [
+        self::TRACEPARENT,
+        self::TRACESTATE,
+    ];
+
+    private static ?self $instance = null;
+
+    public static function getInstance(): self
+    {
+        if (null === self::$instance) {
+            self::$instance = new self();
+        }
+
+        return self::$instance;
+    }
+
+    /** {@inheritdoc} */
+    public function fields(): array
+    {
+        return self::FIELDS;
+    }
+
+    /** {@inheritdoc} */
+    public function inject(&$carrier, PropagationSetterInterface $setter = null, ContextInterface $context = null): void
+    {
+        $setter ??= ArrayAccessGetterSetter::getInstance();
+        $context ??= Context::getCurrent();
+        $spanContext = Span::fromContext($context)->getContext();
+
+        if (!$spanContext->isValid()) {
+            return;
+        }
+
+        // Build and inject the traceparent header
+        $traceparent = self::VERSION . '-' . $spanContext->getTraceId() . '-' . $spanContext->getSpanId() . '-' . ($spanContext->isSampled() ? '01' : '00');
+        $setter->set($carrier, self::TRACEPARENT, $traceparent);
+
+        // Build and inject the tracestate header
+        // Spec says to avoid sending empty tracestate headers
+        if (($tracestate = (string) $spanContext->getTraceState()) !== '') {
+            $setter->set($carrier, self::TRACESTATE, $tracestate);
+        }
+    }
+
+    /** {@inheritdoc} */
+    public function extract($carrier, PropagationGetterInterface $getter = null, ContextInterface $context = null): ContextInterface
+    {
+        $getter ??= ArrayAccessGetterSetter::getInstance();
+        $context ??= Context::getCurrent();
+
+        $spanContext = self::extractImpl($carrier, $getter);
+        if (!$spanContext->isValid()) {
+            return $context;
+        }
+
+        return $context->withContextValue(Span::wrap($spanContext));
+    }
+
+    private static function extractImpl($carrier, PropagationGetterInterface $getter): SpanContextInterface
+    {
+        $traceparent = $getter->get($carrier, self::TRACEPARENT);
+        if ($traceparent === null) {
+            return SpanContext::getInvalid();
+        }
+
+        // traceParent = {version}-{trace-id}-{parent-id}-{trace-flags}
+        $pieces = explode('-', $traceparent);
+
+        // If the header does not have at least 4 pieces, it is invalid -- restart the trace.
+        if (count($pieces) < 4) {
+            return SpanContext::getInvalid();
+        }
+
+        [$version, $traceId, $spanId, $traceFlags] = $pieces;
+
+        /**
+         * Return invalid if:
+         * - Version is invalid (not 2 char hex or 'ff')
+         * - Trace version, trace ID, span ID or trace flag are invalid
+         */
+        if (!TraceContextValidator::isValidTraceVersion($version)
+            || !SpanContextValidator::isValidTraceId($traceId)
+            || !SpanContextValidator::isValidSpanId($spanId)
+            || !TraceContextValidator::isValidTraceFlag($traceFlags)
+        ) {
+            return SpanContext::getInvalid();
+        }
+
+        // Return invalid if the trace version is not a future version but still has > 4 pieces.
+        $versionIsFuture = hexdec($version) > hexdec(self::VERSION);
+        if (count($pieces) > 4 && !$versionIsFuture) {
+            return SpanContext::getInvalid();
+        }
+
+        // Only the sampled flag is extracted from the traceFlags (00000001)
+        $convertedTraceFlags = hexdec($traceFlags);
+        $isSampled = ($convertedTraceFlags & TraceFlags::SAMPLED) === TraceFlags::SAMPLED;
+
+        // Tracestate = 'Vendor1=Value1,...,VendorN=ValueN'
+        $rawTracestate = $getter->get($carrier, self::TRACESTATE);
+        if ($rawTracestate !== null) {
+            $tracestate = new TraceState($rawTracestate);
+
+            return SpanContext::createFromRemoteParent(
+                $traceId,
+                $spanId,
+                $isSampled ? TraceFlags::SAMPLED : TraceFlags::DEFAULT,
+                $tracestate
+            );
+        }
+
+        // Only traceparent header is extracted. No tracestate.
+        return SpanContext::createFromRemoteParent(
+            $traceId,
+            $spanId,
+            $isSampled ? TraceFlags::SAMPLED : TraceFlags::DEFAULT
+        );
+    }
+}