operations and tracer reset api

Author: nekufa

src/Metrics/Operations.php

@@ -43,4 +43,9 @@ public function count()
     {
         return count($this->data);
     }
+
+    public function reset()
+    {
+        $this->data = [];
+    }
 }

src/Tracing/Tracer.php

@@ -12,6 +12,13 @@ class Tracer
 
     public function __construct(SpanContext $context = null)
     {
+        $this->reset($context);
+    }
+
+    public function reset(SpanContext $context = null)
+    {
+        $this->spans = [];
+        $this->tail = [];
         $context = $context ?: SpanContext::generate();
         $this->active = $this->generateSpanInstance('tracer', $context);
     }

tests/Metrics/OperationsTest.php

@@ -32,5 +32,8 @@ public function testBasics(): void
 
         $this->assertSame(2, $registry->get('request_counter', [ 'hostname' => 1 ]));
         $this->assertSame(42 * 2, $registry->get('request_timing', [ 'hostname' => 1 ]));
+
+        $operations->reset();
+        $this->assertSame(0, $operations->count());
     }
 }

tests/Tracing/TracingTest.php

@@ -11,6 +11,25 @@
 
 class TracingTest extends TestCase
 {
+    public function testReset()
+    {
+        $tracer = new Tracer();
+        $this->assertCount(1, $tracer->getSpans());
+        $active = $tracer->getActiveSpan();
+
+        $tracer->createSpan('a');
+        $tracer->createSpan('b');
+        $this->assertCount(3, $tracer->getSpans());
+
+        $tracer->reset();
+        $this->assertCount(1, $tracer->getSpans());
+
+        $this->assertNotSame(
+            $active->getSpanContext()->getSpanId(),
+            $tracer->getActiveSpan()->getSpanContext()->getSpanId(),
+        );
+    }
+
     public function testContextGenerationAndRestore()
     {
         $spanContext = SpanContext::generate();