Merge pull request #11 from nenadstojanovikj/minor/update-propagator-…

…interface Update PropagatorInterface
nenad · Mar 28, 2019 · 4cea3aa · 4cea3aa
2 parents 4f76b19 + 1911445
commit 4cea3aa
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Showing 16 changed files with 193 additions and 120 deletions.
diff --git a/src/Core/Scope.php b/src/Core/Scope.php
@@ -58,7 +58,7 @@ public function __construct(callable $callback, $args = [])
     /**
      * Close and clean up the scope. Runs the initial callback provided.
      */
-    public function close()
+    public function close(): void
     {
         call_user_func_array($this->callback, $this->args);
     }

diff --git a/src/Trace/Integrations/Guzzle/EventSubscriber.php b/src/Trace/Integrations/Guzzle/EventSubscriber.php
@@ -18,6 +18,7 @@
 namespace OpenCensus\Trace\Integrations\Guzzle;
 
 use OpenCensus\Core\Scope;
+use OpenCensus\Trace\Propagator\ArrayHeaders;
 use OpenCensus\Trace\Span;
 use OpenCensus\Trace\Tracer;
 use OpenCensus\Trace\Propagator\HttpHeaderPropagator;
@@ -88,8 +89,9 @@ public function onBefore(BeforeEvent $event)
         $request = $event->getRequest();
         $context = Tracer::spanContext();
         if ($context->enabled()) {
+            $headers = new ArrayHeaders();
             $this->propagator->inject($context, $headers);
-            $request->setHeaders($headers);
+            $request->setHeaders($headers->toArray());
         }
 
         $span = Tracer::startSpan([

diff --git a/src/Trace/Integrations/Guzzle/Middleware.php b/src/Trace/Integrations/Guzzle/Middleware.php
@@ -17,6 +17,7 @@
 
 namespace OpenCensus\Trace\Integrations\Guzzle;
 
+use OpenCensus\Trace\Propagator\ArrayHeaders;
 use OpenCensus\Trace\Span;
 use OpenCensus\Trace\Tracer;
 use OpenCensus\Trace\Propagator\HttpHeaderPropagator;
@@ -70,8 +71,8 @@ public function __invoke(callable $handler)
         return function (RequestInterface $request, $options) use ($handler) {
             $context = Tracer::spanContext();
             if ($context->enabled()) {
+                $headers = new ArrayHeaders();
                 $this->propagator->inject($context, $headers) ;
-
                 foreach ($headers as $headerName => $headerValue) {
                     $request = $request->withHeader($headerName, $headerValue);
                 }

diff --git a/src/Trace/Propagator/ArrayHeaders.php b/src/Trace/Propagator/ArrayHeaders.php
@@ -0,0 +1,59 @@
+<?php declare(strict_types=1);
+
+namespace OpenCensus\Trace\Propagator;
+
+class ArrayHeaders implements HeaderSetter, HeaderGetter, \IteratorAggregate, \ArrayAccess
+{
+    /**
+     * @var string[]
+     */
+    private $headers;
+
+    /**
+     * @param string[] $headers An associative array with header name as key
+     */
+    public function __construct(array $headers = [])
+    {
+        $this->headers = $headers;
+    }
+
+    public function get(string $header): ?string
+    {
+        return $this->headers[$header] ?? null;
+    }
+
+    public function set(string $header, string $value): void
+    {
+        $this->headers[$header] = $value;
+    }
+
+    public function toArray(): array
+    {
+        return $this->headers;
+    }
+
+    public function getIterator()
+    {
+        return new \ArrayIterator($this->headers);
+    }
+
+    public function offsetExists($offset)
+    {
+        return isset($this->headers[$offset]);
+    }
+
+    public function offsetGet($offset)
+    {
+        return $this->get($offset);
+    }
+
+    public function offsetSet($offset, $value)
+    {
+        $this->set($offset, $value);
+    }
+
+    public function offsetUnset($offset)
+    {
+        unset($this->headers[$offset]);
+    }
+}
diff --git a/src/Trace/Propagator/B3HeadersPropagator.php b/src/Trace/Propagator/B3HeadersPropagator.php
@@ -14,12 +14,12 @@ class B3HeadersPropagator implements PropagatorInterface
     private const X_B3_SAMPLED = 'X-B3-Sampled';
     private const X_B3_FLAGS = 'X-B3-Flags';
 
-    public function extract($container): SpanContext
+    public function extract(HeaderGetter $headers): SpanContext
     {
-        $traceId = $container[self::X_B3_TRACE_ID] ?? null;
-        $spanId = $container[self::X_B3_SPAN_ID] ?? null;
-        $sampled = $container[self::X_B3_SAMPLED] ?? null;
-        $flags = $container[self::X_B3_FLAGS] ?? null;
+        $traceId = $headers->get(self::X_B3_TRACE_ID);
+        $spanId = $headers->get(self::X_B3_SPAN_ID);
+        $sampled = $headers->get(self::X_B3_SAMPLED);
+        $flags = $headers->get(self::X_B3_FLAGS);
 
         if (!$traceId || !$spanId) {
             return new SpanContext();
@@ -38,10 +38,10 @@ public function extract($container): SpanContext
         return new SpanContext($traceId, $spanId, $enabled, true);
     }
 
-    public function inject(SpanContext $context, &$container): void
+    public function inject(SpanContext $context, HeaderSetter $headers): void
     {
-        $container[self::X_B3_TRACE_ID] = $context->traceId();
-        $container[self::X_B3_SPAN_ID] = $context->spanId();
-        $container[self::X_B3_SAMPLED] = $context->enabled() ? 1 : 0;
+        $headers->set(self::X_B3_TRACE_ID, $context->traceId());
+        $headers->set(self::X_B3_SPAN_ID, $context->spanId());
+        $headers->set(self::X_B3_SAMPLED, $context->enabled() ? 1 : 0);
     }
 }
diff --git a/src/Trace/Propagator/GrpcMetadataPropagator.php b/src/Trace/Propagator/GrpcMetadataPropagator.php
@@ -26,7 +26,7 @@
  */
 class GrpcMetadataPropagator implements PropagatorInterface
 {
-    const DEFAULT_METADATA_KEY = 'grpc-trace-bin';
+    private const DEFAULT_METADATA_KEY = 'grpc-trace-bin';
 
     /**
      * @var FormatterInterface
@@ -43,25 +43,23 @@ class GrpcMetadataPropagator implements PropagatorInterface
      *
      * @param FormatterInterface $formatter [optional] The formatter used to serialize/deserialize SpanContext
      *        **Defaults to** a new BinaryFormatter.
-     * @param string $key [optional] The grpc metadata key to store/retrieve the encoded SpanContext.
-     *        **Defaults to** `grpc-trace-bin`
+     * @param string $key The grpc metadata key to store/retrieve the encoded SpanContext.
      */
-    public function __construct(FormatterInterface $formatter = null, $key = null)
+    public function __construct(FormatterInterface $formatter = null, string $key = self::DEFAULT_METADATA_KEY)
     {
         $this->formatter = $formatter ?: new BinaryFormatter();
-        $this->key = $key ?: self::DEFAULT_METADATA_KEY;
+        $this->key = $key;
     }
 
-    public function extract($metadata): SpanContext
+    public function extract(HeaderGetter $metadata): SpanContext
     {
-        if (array_key_exists($this->key, $metadata)) {
-            return $this->formatter->deserialize($metadata[$this->key]);
-        }
-        return new SpanContext();
+        $data = $metadata->get($this->key);
+
+        return $data ? $this->formatter->deserialize($data) : new SpanContext();
     }
 
-    public function inject(SpanContext $context, &$metadata): void
+    public function inject(SpanContext $context, HeaderSetter $metadata): void
     {
-        $metadata[$this->key] = $this->formatter->serialize($context);
+        $metadata->set($this->key, $this->formatter->serialize($context));
     }
 }
diff --git a/src/Trace/Propagator/HeaderGetter.php b/src/Trace/Propagator/HeaderGetter.php
@@ -0,0 +1,12 @@
+<?php declare(strict_types=1);
+
+namespace OpenCensus\Trace\Propagator;
+
+interface HeaderGetter
+{
+    /**
+     * @param string $header Header name
+     * @return string|null
+     */
+    public function get(string $header): ?string;
+}
diff --git a/src/Trace/Propagator/HeaderSetter.php b/src/Trace/Propagator/HeaderSetter.php
@@ -0,0 +1,12 @@
+<?php declare(strict_types=1);
+
+namespace OpenCensus\Trace\Propagator;
+
+interface HeaderSetter
+{
+    /**
+     * @param string $header Header name
+     * @param string $value Header value
+     */
+    public function set(string $header, string $value): void;
+}
diff --git a/src/Trace/Propagator/HttpHeaderPropagator.php b/src/Trace/Propagator/HttpHeaderPropagator.php
@@ -25,7 +25,7 @@
  */
 class HttpHeaderPropagator implements PropagatorInterface
 {
-    const DEFAULT_HEADER = 'X-Cloud-Trace-Context';
+    private const DEFAULT_HEADER = 'X-Cloud-Trace-Context';
 
     /**
      * @var FormatterInterface
@@ -41,32 +41,29 @@ class HttpHeaderPropagator implements PropagatorInterface
      * Create a new HttpHeaderPropagator
      *
      * @param FormatterInterface $formatter The formatter used to serialize and
-     *        deserialize SpanContext. **Defaults to** a new
-     *        CloudTraceFormatter.
-     * @param string|null $header
+     *        deserialize SpanContext. **Defaults to** a new CloudTraceFormatter.
+     * @param string $header
      */
-    public function __construct(FormatterInterface $formatter = null, $header = null)
+    public function __construct(FormatterInterface $formatter = null, string $header = self::DEFAULT_HEADER)
     {
         $this->formatter = $formatter ?: new CloudTraceFormatter();
-        $this->header = $header ?: self::DEFAULT_HEADER;
+        $this->header = $header;
     }
 
-    public function extract($headers): SpanContext
+    public function extract(HeaderGetter $headers): SpanContext
     {
-        if (array_key_exists($this->header, $headers)) {
-            return $this->formatter->deserialize($headers[$this->header]);
-        }
-        return new SpanContext();
+        $data = $headers->get($this->header);
+
+        return $data ? $this->formatter->deserialize($data) : new SpanContext();
     }
 
-    public function inject(SpanContext $context, &$container): void
+    public function inject(SpanContext $context, HeaderSetter $setter): void
     {
-        $header = $this->header;
         $value = $this->formatter->serialize($context);
 
         if (!headers_sent()) {
-            header("$header: $value");
+            header("$this->header: $value");
         }
-        $container[$header] = $value;
+        $setter->set($this->header, $value);
     }
 }
diff --git a/src/Trace/Propagator/PropagatorInterface.php b/src/Trace/Propagator/PropagatorInterface.php
@@ -29,16 +29,16 @@ interface PropagatorInterface
     /**
      * Extract the SpanContext from some container
      *
-     * @param mixed $container
+     * @param HeaderGetter $getter
      * @return SpanContext
      */
-    public function extract($container): SpanContext;
+    public function extract(HeaderGetter $getter): SpanContext;
 
     /**
-     * Inject the SpanContext back into the response
+     * Inject the SpanContext back into the container
      *
      * @param SpanContext $context
-     * @param mixed $container An object in which the SpanContext data will be injected.
+     * @param HeaderSetter $setter
      */
-    public function inject(SpanContext $context, &$container): void;
+    public function inject(SpanContext $context, HeaderSetter $setter): void;
 }