create text map propagators from registry (#885)

* create text map propagators from registry removing undocumented dependency between sdk and extension by adding text map propagators to a registry as part of composer autoloading, similar to how exporters, transports etc are treated. * remove TextMapPropagatorFactory instances and register the singletons directly * rename FactoryRegistry to just Registry
open-telemetry · Dec 9, 2022 · 0073d6d · 0073d6d
1 parent 5a51249
commit 0073d6d
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Showing 21 changed files with 104 additions and 70 deletions.
diff --git a/composer.json b/composer.json
@@ -64,7 +64,9 @@
             "src/Contrib/Grpc/_register.php",
             "src/Contrib/Newrelic/_register.php",
             "src/Contrib/Zipkin/_register.php",
+            "src/Extension/Propagator/B3/_register.php",
             "src/SDK/Metrics/MetricExporter/_register.php",
+            "src/SDK/Propagation/_register.php",
             "src/SDK/Trace/SpanExporter/_register.php",
             "src/SDK/Common/Dev/Compatibility/_load.php",
             "src/SDK/Common/Util/functions.php",

diff --git a/examples/autoload_sdk.php b/examples/autoload_sdk.php
@@ -9,6 +9,7 @@
 putenv('OTEL_EXPORTER_OTLP_METRICS_PROTOCOL=grpc');
 putenv('OTEL_EXPORTER_OTLP_ENDPOINT=http://collector:4317');
 putenv('OTEL_PHP_TRACES_PROCESSOR=batch');
+putenv('OTEL_PROPAGATORS=b3,baggage,tracecontext');
 
 echo 'autoloading SDK example starting...' . PHP_EOL;
 

diff --git a/examples/autoload_sdk_with_custom_transport.php b/examples/autoload_sdk_with_custom_transport.php
@@ -40,7 +40,7 @@ public function forceFlush(?\OpenTelemetry\SDK\Common\Future\CancellationInterfa
     }
 };
 
-\OpenTelemetry\SDK\FactoryRegistry::registerTransportFactory('grpc', $factory, true);
+\OpenTelemetry\SDK\Registry::registerTransportFactory('grpc', $factory, true);
 
 $instrumentation = new \OpenTelemetry\API\Common\Instrumentation\CachedInstrumentation('demo');
 

diff --git a/src/Contrib/Grpc/_register.php b/src/Contrib/Grpc/_register.php
@@ -1,4 +1,4 @@
 <?php
 
 declare(strict_types=1);
-\OpenTelemetry\SDK\FactoryRegistry::registerTransportFactory('grpc', \OpenTelemetry\Contrib\Grpc\GrpcTransportFactory::class);
+\OpenTelemetry\SDK\Registry::registerTransportFactory('grpc', \OpenTelemetry\Contrib\Grpc\GrpcTransportFactory::class);
diff --git a/src/Contrib/Newrelic/_register.php b/src/Contrib/Newrelic/_register.php
@@ -2,4 +2,4 @@
 
 declare(strict_types=1);
 
-\OpenTelemetry\SDK\FactoryRegistry::registerSpanExporterFactory('newrelic', \OpenTelemetry\Contrib\Newrelic\SpanExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerSpanExporterFactory('newrelic', \OpenTelemetry\Contrib\Newrelic\SpanExporterFactory::class);
diff --git a/src/Contrib/Otlp/MetricExporterFactory.php b/src/Contrib/Otlp/MetricExporterFactory.php
@@ -9,9 +9,9 @@
 use OpenTelemetry\SDK\Common\Configuration\KnownValues;
 use OpenTelemetry\SDK\Common\Configuration\Variables;
 use OpenTelemetry\SDK\Common\Export\TransportInterface;
-use OpenTelemetry\SDK\FactoryRegistry;
 use OpenTelemetry\SDK\Metrics\MetricExporterFactoryInterface;
 use OpenTelemetry\SDK\Metrics\MetricExporterInterface;
+use OpenTelemetry\SDK\Registry;
 use UnexpectedValueException;
 
 class MetricExporterFactory implements MetricExporterFactoryInterface
@@ -44,7 +44,7 @@ private function buildTransport(string $protocol): TransportInterface
             : Configuration::getMap(Variables::OTEL_EXPORTER_OTLP_HEADERS);
         $headers += OtlpUtil::getUserAgentHeader();
 
-        $factory = FactoryRegistry::transportFactory($protocol);
+        $factory = Registry::transportFactory($protocol);
         switch ($protocol) {
             case KnownValues::VALUE_GRPC:
                 return $factory->create(

diff --git a/src/Contrib/Otlp/SpanExporterFactory.php b/src/Contrib/Otlp/SpanExporterFactory.php
@@ -12,7 +12,7 @@
 use OpenTelemetry\SDK\Common\Export\TransportFactoryInterface;
 use OpenTelemetry\SDK\Common\Export\TransportInterface;
 use OpenTelemetry\SDK\Common\Otlp\HttpEndpointResolver;
-use OpenTelemetry\SDK\FactoryRegistry;
+use OpenTelemetry\SDK\Registry;
 use OpenTelemetry\SDK\Trace\SpanExporter\SpanExporterFactoryInterface;
 use OpenTelemetry\SDK\Trace\SpanExporterInterface;
 
@@ -51,7 +51,7 @@ private function buildTransport(): TransportInterface
         $headers = $this->getHeaders();
         $compression = $this->getCompression();
 
-        $factoryClass = FactoryRegistry::transportFactory($protocol);
+        $factoryClass = Registry::transportFactory($protocol);
         $factory = $this->transportFactory ?: new $factoryClass();
 
         return $factory->create($endpoint, $contentType, $headers, $compression);

diff --git a/src/Contrib/Otlp/_register.php b/src/Contrib/Otlp/_register.php
@@ -1,7 +1,7 @@
 <?php
 
 declare(strict_types=1);
-\OpenTelemetry\SDK\FactoryRegistry::registerSpanExporterFactory('otlp', \OpenTelemetry\Contrib\Otlp\SpanExporterFactory::class);
-\OpenTelemetry\SDK\FactoryRegistry::registerMetricExporterFactory('otlp', \OpenTelemetry\Contrib\Otlp\MetricExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerSpanExporterFactory('otlp', \OpenTelemetry\Contrib\Otlp\SpanExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerMetricExporterFactory('otlp', \OpenTelemetry\Contrib\Otlp\MetricExporterFactory::class);
 
-\OpenTelemetry\SDK\FactoryRegistry::registerTransportFactory('http', \OpenTelemetry\Contrib\Otlp\OtlpHttpTransportFactory::class);
+\OpenTelemetry\SDK\Registry::registerTransportFactory('http', \OpenTelemetry\Contrib\Otlp\OtlpHttpTransportFactory::class);
diff --git a/src/Contrib/Zipkin/_register.php b/src/Contrib/Zipkin/_register.php
@@ -2,4 +2,4 @@
 
 declare(strict_types=1);
 
-\OpenTelemetry\SDK\FactoryRegistry::registerSpanExporterFactory('zipkin', \OpenTelemetry\Contrib\Zipkin\SpanExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerSpanExporterFactory('zipkin', \OpenTelemetry\Contrib\Zipkin\SpanExporterFactory::class);
diff --git a/src/Extension/Propagator/B3/_register.php b/src/Extension/Propagator/B3/_register.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+use OpenTelemetry\Extension\Propagator\B3\B3Propagator;
+use OpenTelemetry\SDK\Common\Configuration\KnownValues;
+use OpenTelemetry\SDK\Registry;
+
+Registry::registerTextMapPropagator(
+    KnownValues::VALUE_B3,
+    B3Propagator::getB3SingleHeaderInstance()
+);
+Registry::registerTextMapPropagator(
+    KnownValues::VALUE_B3_MULTI,
+    B3Propagator::getB3MultiHeaderInstance()
+);
diff --git a/src/Extension/Propagator/B3/composer.json b/src/Extension/Propagator/B3/composer.json
@@ -18,6 +18,9 @@
     "autoload": {
         "psr-4": {
             "OpenTelemetry\\Extension\\Propagator\\B3\\": "."
-        }
+        },
+        "files": [
+            "_register.php"
+        ]
     }
 }
diff --git a/src/SDK/Metrics/MeterProviderFactory.php b/src/SDK/Metrics/MeterProviderFactory.php
@@ -10,13 +10,13 @@
 use OpenTelemetry\SDK\Common\Configuration\KnownValues;
 use OpenTelemetry\SDK\Common\Configuration\Variables;
 use OpenTelemetry\SDK\Common\Time\ClockFactory;
-use OpenTelemetry\SDK\FactoryRegistry;
 use OpenTelemetry\SDK\Metrics\Exemplar\ExemplarFilter\AllExemplarFilter;
 use OpenTelemetry\SDK\Metrics\Exemplar\ExemplarFilter\NoneExemplarFilter;
 use OpenTelemetry\SDK\Metrics\Exemplar\ExemplarFilter\WithSampledTraceExemplarFilter;
 use OpenTelemetry\SDK\Metrics\Exemplar\ExemplarFilterInterface;
 use OpenTelemetry\SDK\Metrics\MetricExporter\NoopMetricExporter;
 use OpenTelemetry\SDK\Metrics\MetricReader\ExportingReader;
+use OpenTelemetry\SDK\Registry;
 use OpenTelemetry\SDK\Resource\ResourceInfoFactory;
 use OpenTelemetry\SDK\Sdk;
 
@@ -37,7 +37,7 @@ public function create(): MeterProviderInterface
         $exporterName = $exporters[0];
 
         try {
-            $factory = FactoryRegistry::metricExporterFactory($exporterName);
+            $factory = Registry::metricExporterFactory($exporterName);
             $exporter = $factory->create();
         } catch (\Throwable $t) {
             self::logWarning(sprintf('Unable to create %s meter provider: %s', $exporterName, $t->getMessage()));

diff --git a/src/SDK/Metrics/MetricExporter/_register.php b/src/SDK/Metrics/MetricExporter/_register.php
@@ -2,5 +2,5 @@
 
 declare(strict_types=1);
 
-\OpenTelemetry\SDK\FactoryRegistry::registerMetricExporterFactory('memory', \OpenTelemetry\SDK\Metrics\MetricExporter\InMemoryExporterFactory::class);
-\OpenTelemetry\SDK\FactoryRegistry::registerMetricExporterFactory('none', \OpenTelemetry\SDK\Metrics\MetricExporter\NoopMetricExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerMetricExporterFactory('memory', \OpenTelemetry\SDK\Metrics\MetricExporter\InMemoryExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerMetricExporterFactory('none', \OpenTelemetry\SDK\Metrics\MetricExporter\NoopMetricExporterFactory::class);
diff --git a/src/SDK/Propagation/PropagatorFactory.php b/src/SDK/Propagation/PropagatorFactory.php
@@ -9,28 +9,21 @@
 use OpenTelemetry\Context\Propagation\TextMapPropagatorInterface;
 use OpenTelemetry\SDK\Behavior\LogsMessagesTrait;
 use OpenTelemetry\SDK\Common\Configuration\Configuration;
-use OpenTelemetry\SDK\Common\Configuration\KnownValues;
 use OpenTelemetry\SDK\Common\Configuration\Variables;
+use OpenTelemetry\SDK\Registry;
 
 class PropagatorFactory
 {
     use LogsMessagesTrait;
 
-    private const KNOWN_PROPAGATORS = [
-        KnownValues::VALUE_TRACECONTEXT => ['\OpenTelemetry\API\Trace\Propagation\TraceContextPropagator', 'getInstance'],
-        KnownValues::VALUE_BAGGAGE => ['\OpenTelemetry\API\Baggage\Propagation\BaggagePropagator', 'getInstance'],
-        KnownValues::VALUE_B3 => ['\OpenTelemetry\Extension\Propagator\B3\B3Propagator', 'getB3SingleHeaderInstance'],
-        KnownValues::VALUE_B3_MULTI => ['\OpenTelemetry\Extension\Propagator\B3\B3Propagator', 'getB3MultiHeaderInstance'],
-    ];
-
     public function create(): TextMapPropagatorInterface
     {
         $propagators = Configuration::getList(Variables::OTEL_PROPAGATORS);
         switch (count($propagators)) {
             case 0:
                 return new NoopTextMapPropagator();
             case 1:
-                return $this->buildPropagator($propagators[0]) ?? new NoopTextMapPropagator();
+                return $this->buildPropagator($propagators[0]);
             default:
                 return new MultiTextMapPropagator($this->buildPropagators($propagators));
         }
@@ -43,41 +36,20 @@ private function buildPropagators(array $names): array
     {
         $propagators = [];
         foreach ($names as $name) {
-            $propagator = $this->buildPropagator($name);
-            if ($propagator !== null) {
-                $propagators[] = $propagator;
-            }
+            $propagators[] = $this->buildPropagator($name);
         }
 
         return $propagators;
     }
 
-    private function buildPropagator(string $name): ?TextMapPropagatorInterface
+    private function buildPropagator(string $name): TextMapPropagatorInterface
     {
-        switch ($name) {
-            case KnownValues::VALUE_NONE:
-                return null;
-            case KnownValues::VALUE_XRAY:
-            case KnownValues::VALUE_OTTRACE:
-                self::logWarning('Unimplemented propagator: ' . $name);
-
-                return null;
-            default:
-                if (!array_key_exists($name, self::KNOWN_PROPAGATORS)) {
-                    self::logWarning('Unknown propagator: ' . $name);
-
-                    return null;
-                }
-                $parts = self::KNOWN_PROPAGATORS[$name];
-
-                try {
-                    return call_user_func($parts);
-                } catch (\Throwable $e) {
-                    self::logError(sprintf('Unable to create %s propagator: %s', $name, $e->getMessage()));
-
-                    return null;
-                }
-
+        try {
+            return Registry::textMapPropagator($name);
+        } catch (\RuntimeException $e) {
+            self::logWarning($e->getMessage());
         }
+
+        return NoopTextMapPropagator::getInstance();
     }
 }
diff --git a/src/SDK/Propagation/_register.php b/src/SDK/Propagation/_register.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+\OpenTelemetry\SDK\Registry::registerTextMapPropagator(
+    \OpenTelemetry\SDK\Common\Configuration\KnownValues::VALUE_BAGGAGE,
+    \OpenTelemetry\API\Baggage\Propagation\BaggagePropagator::getInstance()
+);
+\OpenTelemetry\SDK\Registry::registerTextMapPropagator(
+    \OpenTelemetry\SDK\Common\Configuration\KnownValues::VALUE_TRACECONTEXT,
+    \OpenTelemetry\API\Trace\Propagation\TraceContextPropagator::getInstance()
+);
+\OpenTelemetry\SDK\Registry::registerTextMapPropagator(
+    \OpenTelemetry\SDK\Common\Configuration\KnownValues::VALUE_NONE,
+    \OpenTelemetry\Context\Propagation\NoopTextMapPropagator::getInstance()
+);
diff --git a/src/SDK/FactoryRegistry.php → src/SDK/Registry.php b/src/SDK/FactoryRegistry.php → src/SDK/Registry.php
@@ -4,16 +4,22 @@
 
 namespace OpenTelemetry\SDK;
 
+use OpenTelemetry\Context\Propagation\TextMapPropagatorInterface;
 use OpenTelemetry\SDK\Common\Export\TransportFactoryInterface;
 use OpenTelemetry\SDK\Metrics\MetricExporterFactoryInterface;
 use OpenTelemetry\SDK\Trace\SpanExporter\SpanExporterFactoryInterface;
 use RuntimeException;
 
-class FactoryRegistry
+/**
+ * A registry to enable central registration of components that the SDK requires but which may be provided
+ * by non-SDK modules, such as contrib and extension.
+ */
+class Registry
 {
     private static array $spanExporterFactories = [];
     private static array $transportFactories = [];
     private static array $metricExporterFactories = [];
+    private static array $textMapPropagators = [];
 
     /**
      * @param TransportFactoryInterface|class-string<TransportFactoryInterface> $factory
@@ -84,6 +90,14 @@ public static function registerMetricExporterFactory(string $exporter, $factory,
         self::$metricExporterFactories[$exporter] = $factory;
     }
 
+    public static function registerTextMapPropagator(string $name, TextMapPropagatorInterface $propagator, bool $clobber = false): void
+    {
+        if (!$clobber && array_key_exists($name, self::$textMapPropagators)) {
+            return;
+        }
+        self::$textMapPropagators[$name] = $propagator;
+    }
+
     public static function spanExporterFactory(string $exporter): SpanExporterFactoryInterface
     {
         if (!array_key_exists($exporter, self::$spanExporterFactories)) {
@@ -124,4 +138,13 @@ public static function metricExporterFactory(string $exporter): MetricExporterFa
 
         return $factory;
     }
+
+    public static function textMapPropagator(string $name): TextMapPropagatorInterface
+    {
+        if (!array_key_exists($name, self::$textMapPropagators)) {
+            throw new RuntimeException('Text map propagator not registered for: ' . $name);
+        }
+
+        return self::$textMapPropagators[$name];
+    }
 }
diff --git a/src/SDK/Trace/ExporterFactory.php b/src/SDK/Trace/ExporterFactory.php
@@ -7,7 +7,7 @@
 use InvalidArgumentException;
 use OpenTelemetry\SDK\Common\Configuration\Configuration;
 use OpenTelemetry\SDK\Common\Configuration\Variables;
-use OpenTelemetry\SDK\FactoryRegistry;
+use OpenTelemetry\SDK\Registry;
 use RuntimeException;
 
 class ExporterFactory
@@ -26,7 +26,7 @@ public function create(): ?SpanExporterInterface
         if ($exporter === 'none') {
             return null;
         }
-        $factory = FactoryRegistry::spanExporterFactory($exporter);
+        $factory = Registry::spanExporterFactory($exporter);
 
         return $factory->create();
     }

diff --git a/src/SDK/Trace/SpanExporter/ConsoleSpanExporterFactory.php b/src/SDK/Trace/SpanExporter/ConsoleSpanExporterFactory.php
@@ -4,14 +4,14 @@
 
 namespace OpenTelemetry\SDK\Trace\SpanExporter;
 
-use OpenTelemetry\SDK\FactoryRegistry;
+use OpenTelemetry\SDK\Registry;
 use OpenTelemetry\SDK\Trace\SpanExporterInterface;
 
 class ConsoleSpanExporterFactory implements SpanExporterFactoryInterface
 {
     public function create(): SpanExporterInterface
     {
-        $transport = FactoryRegistry::transportFactory('stream')->create('php://stdout', 'application/json');
+        $transport = Registry::transportFactory('stream')->create('php://stdout', 'application/json');
 
         return new ConsoleSpanExporter($transport);
     }

diff --git a/src/SDK/Trace/SpanExporter/_register.php b/src/SDK/Trace/SpanExporter/_register.php
@@ -1,7 +1,7 @@
 <?php
 
 declare(strict_types=1);
-\OpenTelemetry\SDK\FactoryRegistry::registerSpanExporterFactory('console', \OpenTelemetry\SDK\Trace\SpanExporter\ConsoleSpanExporterFactory::class);
-\OpenTelemetry\SDK\FactoryRegistry::registerSpanExporterFactory('memory', \OpenTelemetry\SDK\Trace\SpanExporter\InMemorySpanExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerSpanExporterFactory('console', \OpenTelemetry\SDK\Trace\SpanExporter\ConsoleSpanExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerSpanExporterFactory('memory', \OpenTelemetry\SDK\Trace\SpanExporter\InMemorySpanExporterFactory::class);
 
-\OpenTelemetry\SDK\FactoryRegistry::registerTransportFactory('stream', \OpenTelemetry\SDK\Common\Export\Stream\StreamTransportFactory::class);
+\OpenTelemetry\SDK\Registry::registerTransportFactory('stream', \OpenTelemetry\SDK\Common\Export\Stream\StreamTransportFactory::class);
diff --git a/src/SDK/composer.json b/src/SDK/composer.json
@@ -32,6 +32,7 @@
         "files": [
             "Common/Util/functions.php",
             "Metrics/MetricExporter/_register.php",
+            "Propagation/_register.php",
             "Trace/SpanExporter/_register.php",
             "_autoload.php"
         ]
-Original file line number
+Diff line change
@@ Expand Up @@
         }
     };
-    \OpenTelemetry\SDK\FactoryRegistry::registerTransportFactory('grpc', $factory, true);
+    \OpenTelemetry\SDK\Registry::registerTransportFactory('grpc', $factory, true);
     $instrumentation = new \OpenTelemetry\API\Common\Instrumentation\CachedInstrumentation('demo');
@@ Expand Down @@
Original file line number	Diff line number	Diff line change
Expand Up		@@ -2,4 +2,4 @@

		declare(strict_types=1);

		\OpenTelemetry\SDK\FactoryRegistry::registerSpanExporterFactory('newrelic', \OpenTelemetry\Contrib\Newrelic\SpanExporterFactory::class);
		\OpenTelemetry\SDK\Registry::registerSpanExporterFactory('newrelic', \OpenTelemetry\Contrib\Newrelic\SpanExporterFactory::class);