feat: Add experimental response propagator interface (#1712)

* Added experimental response propagator

* Added response propagator interface to Globals

* changed to experimental_response_propagator

* Update src/API/Globals.php

Co-authored-by: Brett McBride <[email protected]>

* Update src/Context/Propagation/ResponsePropagatorInterface.php

Co-authored-by: Brett McBride <[email protected]>

* Update src/Config/SDK/ComponentProvider/OpenTelemetrySdk.php

Co-authored-by: Tobias Bachert <[email protected]>

* Changed experimental_response_propagator to response_propagator/development

* Cleaned up the comment

* Bumped context and api version

* Bumped open-telemetry/sdk in open-telemetry/sdk-configuration

---------

Co-authored-by: Brett McBride <[email protected]>
Co-authored-by: Tobias Bachert <[email protected]>

Author: 3 people

Propagation/MultiResponsePropagator.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Context\Propagation;
+
+use OpenTelemetry\Context\ContextInterface;
+
+/**
+ * @experimental
+ */
+final class MultiResponsePropagator implements ResponsePropagatorInterface
+{
+    /**
+     * @no-named-arguments
+     *
+     * @param list<ResponsePropagatorInterface> $responsePropagators
+     */
+    public function __construct(
+        private readonly array $responsePropagators,
+    ) {
+    }
+
+    #[\Override]
+    public function inject(&$carrier, ?PropagationSetterInterface $setter = null, ?ContextInterface $context = null): void
+    {
+        foreach ($this->responsePropagators as $responsePropagator) {
+            $responsePropagator->inject($carrier, $setter, $context);
+        }
+    }
+}

Propagation/NoopResponsePropagator.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Context\Propagation;
+
+use OpenTelemetry\Context\ContextInterface;
+
+/**
+ * @experimental
+ */
+final class NoopResponsePropagator implements ResponsePropagatorInterface
+{
+    private static ?self $instance = null;
+
+    public static function getInstance(): self
+    {
+        if (null === self::$instance) {
+            self::$instance = new self();
+        }
+
+        return self::$instance;
+    }
+
+    #[\Override]
+    public function inject(&$carrier, ?PropagationSetterInterface $setter = null, ?ContextInterface $context = null): void
+    {
+    }
+}

Propagation/ResponsePropagatorInterface.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Context\Propagation;
+
+use OpenTelemetry\Context\ContextInterface;
+
+/**
+ * @experimental
+ */
+interface ResponsePropagatorInterface
+{
+    /**
+     * Injects specific values from the provided {@see ContextInterface} into the provided carrier
+     * via an {@see PropagationSetterInterface}.
+     *
+     * @see https://github.com/open-telemetry/opentelemetry-specification/blob/v1.48.0/specification/context/api-propagators.md#textmap-inject
+     * @experimental
+     */
+    public function inject(mixed &$carrier, ?PropagationSetterInterface $setter = null, ?ContextInterface $context = null): void;
+}