jaeger-client -> opentelemetry

vendor/open-telemetry/context/Propagation/MultiTextMapPropagator.php

@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Context\Propagation;
+
+use function array_map;
+use function array_merge;
+use function array_unique;
+use function array_values;
+use OpenTelemetry\Context\Context;
+use OpenTelemetry\Context\ContextInterface;
+
+final class MultiTextMapPropagator implements TextMapPropagatorInterface
+{
+    /**
+     * @readonly
+     *
+     * @var list<TextMapPropagatorInterface>
+     */
+    private array $propagators = [];
+
+    /**
+     * @readonly
+     *
+     * @var list<string>
+     */
+    private array $fields;
+
+    /**
+     * @no-named-arguments
+     *
+     * @param list<TextMapPropagatorInterface> $propagators
+     */
+    public function __construct(array $propagators)
+    {
+        $this->propagators = $propagators;
+        $this->fields = $this->extractFields($propagators);
+    }
+
+    public function fields(): array
+    {
+        return $this->fields;
+    }
+
+    public function inject(&$carrier, PropagationSetterInterface $setter = null, ContextInterface $context = null): void
+    {
+        foreach ($this->propagators as $propagator) {
+            $propagator->inject($carrier, $setter, $context);
+        }
+    }
+
+    public function extract($carrier, PropagationGetterInterface $getter = null, ContextInterface $context = null): ContextInterface
+    {
+        $context ??= Context::getCurrent();
+
+        foreach ($this->propagators as $propagator) {
+            $context = $propagator->extract($carrier, $getter, $context);
+        }
+
+        return $context;
+    }
+
+    /**
+     * @param list<TextMapPropagatorInterface> $propagators
+     * @return list<string>
+     */
+    private function extractFields(array $propagators): array
+    {
+        return array_values(
+            array_unique(
+                // Phan seems to struggle here with the variadic argument
+                // @phan-suppress-next-line PhanParamTooFewInternalUnpack
+                array_merge(
+                    ...array_map(
+                        static fn (TextMapPropagatorInterface $propagator) => $propagator->fields(),
+                        $propagators
+                    )
+                )
+            )
+        );
+    }
+}