Optimize Report\Xml\Facade for speed

Author: staabm

src/Report/Xml/Coverage.php

@@ -26,10 +26,8 @@ public function __construct(DOMElement $context, string $line)
         $this->line        = $line;
     }
 
-    public function finalize(array $tests): void
+    public function appendToWriter(XMLWriter $writer, array $tests): void
     {
-        $writer = new XMLWriter;
-        $writer->openMemory();
         $writer->startElementNs(null, $this->contextNode->nodeName, 'https://schema.phpunit.de/coverage/1.0');
         $writer->writeAttribute('nr', $this->line);
 
@@ -39,13 +37,5 @@ public function finalize(array $tests): void
             $writer->endElement();
         }
         $writer->endElement();
-
-        $fragment = $this->contextNode->ownerDocument->createDocumentFragment();
-        $fragment->appendXML($writer->outputMemory());
-
-        $this->contextNode->parentNode->replaceChild(
-            $fragment,
-            $this->contextNode,
-        );
     }
 }

src/Report/Xml/Facade.php

@@ -9,6 +9,7 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
+use XMLWriter;
 use const DIRECTORY_SEPARATOR;
 use function count;
 use function dirname;
@@ -159,15 +160,26 @@ private function processFile(FileNode $file, Directory $context): void
             $this->processFunction($function, $fileReport);
         }
 
+        $writer = new XMLWriter();
+        $writer->openMemory();
+        $coverageNode = $fileReport->lineCoverageNode();
         foreach ($file->lineCoverageData() as $line => $tests) {
             if (!is_array($tests) || count($tests) === 0) {
                 continue;
             }
 
-            $coverage = $fileReport->lineCoverage((string) $line);
-            $coverage->finalize($tests);
+            $coverage = new Coverage($coverageNode, (string) $line);
+            $coverage->appendToWriter($writer, $tests);
         }
 
+        $fragment = $coverageNode->ownerDocument->createDocumentFragment();
+        $fragment->appendXML($writer->outputMemory());
+
+        $coverageNode->parentNode->replaceChild(
+            $fragment,
+            $coverageNode,
+        );
+
         $fileReport->source()->setSourceCode(
             file_get_contents($file->pathAsString()),
         );

src/Report/Xml/File.php

@@ -45,7 +45,7 @@ public function totals(): Totals
         return new Totals($totalsContainer);
     }
 
-    public function lineCoverage(string $line): Coverage
+    public function lineCoverageNode(): DOMElement
     {
         $coverage = $this->contextNode->getElementsByTagNameNS(
             'https://schema.phpunit.de/coverage/1.0',
@@ -69,8 +69,7 @@ public function lineCoverage(string $line): Coverage
         );
 
         assert($lineNode instanceof DOMElement);
-
-        return new Coverage($lineNode, $line);
+        return $lineNode;
     }
 
     protected function contextNode(): DOMElement