ObjectsController: try to control output buffering

...for REST API. Base requests on queries from new table objects

library/Director/Web/Controller/ObjectsController.php

@@ -2,10 +2,13 @@
 
 namespace Icinga\Module\Director\Web\Controller;
 
+use Icinga\Application\Benchmark;
+use Icinga\Application\Icinga;
 use Icinga\Data\Filter\FilterChain;
 use Icinga\Data\Filter\FilterExpression;
 use Icinga\Exception\NotFoundError;
 use Icinga\Data\Filter\Filter;
+use Icinga\Module\Director\Db\Cache\PrefetchCache;
 use Icinga\Module\Director\Forms\IcingaMultiEditForm;
 use Icinga\Module\Director\Objects\IcingaObject;
 use Icinga\Module\Director\Web\ActionBar\ObjectsActionBar;
@@ -13,11 +16,11 @@ use Icinga\Module\Director\Web\ActionBar\TemplateActionBar;
 use Icinga\Module\Director\Web\Table\ApplyRulesTable;
 use Icinga\Module\Director\Web\Table\ObjectSetTable;
 use Icinga\Module\Director\Web\Table\ObjectsTable;
-use Icinga\Module\Director\Web\Table\ServiceApplyRulesTable;
 use Icinga\Module\Director\Web\Table\TemplatesTable;
 use Icinga\Module\Director\Web\Tabs\ObjectsTabs;
 use Icinga\Module\Director\Web\Tree\TemplateTreeRenderer;
 use ipl\Html\Link;
+use Zend_Db_Select as ZfSelect;
 
 abstract class ObjectsController extends ActionController
 {
@@ -47,6 +50,15 @@ abstract class ObjectsController extends ActionController
 
     public function indexAction()
     {
+        if ($this->getRequest()->isApiRequest()) {
+            try {
+                $this->streamJsonResult();
+            } catch (\Exception $e) {
+                echo $e->getTraceAsString();
+                exit;
+            }
+            return;
+        }
         $type = $this->getType();
         $this
             ->addObjectsTabs()
@@ -58,9 +70,94 @@ abstract class ObjectsController extends ActionController
             $this->tabs()->activate('external');
         }
 
-        $this->table = ObjectsTable::create($type, $this->db())
+        // Hint: might be used in controllers extending this
-            ->setAuth($this->Auth())
+        $this->table = $this->getTable();
-            ->renderTo($this);
+        $this->table->renderTo($this);
+    }
+
+    protected function streamJsonResult()
+    {
+        $connection = $this->db();
+        Benchmark::measure('aha');
+        $db = $connection->getDbAdapter();
+        $query = $this->getTable()
+            ->getQuery()
+            ->reset(ZfSelect::COLUMNS)
+            ->columns('*')
+            ->reset(ZfSelect::LIMIT_COUNT)
+            ->reset(ZfSelect::LIMIT_OFFSET);
+
+        echo '{ "objects": [ ';
+        $cnt = 0;
+        $objects = [];
+
+        $dummy = IcingaObject::createByType($this->getType(), [], $connection);
+        $dummy->prefetchAllRelatedTypes();
+
+        Benchmark::measure('Prefetching');
+        PrefetchCache::initialize($this->db());
+        Benchmark::measure('Ready to query');
+        $stmt = $db->query($query);
+        $this->getResponse()->sendHeaders();
+        if (! ob_get_level()) {
+            ob_start();
+        }
+        $resolved = (bool) $this->params->get('resolved', false);
+        $first = true;
+        $flushes = 0;
+        while ($row = $stmt->fetch()) {
+            /** @var IcingaObject $object */
+            if ($first) {
+                Benchmark::measure('First row');
+            }
+            $object = $dummy::fromDbRow($row, $connection);
+            $objects[] = json_encode($object->toPlainObject($resolved, true), JSON_PRETTY_PRINT);
+            if ($first) {
+                Benchmark::measure('Got first row');
+                $first = false;
+            }
+            $cnt++;
+            if ($cnt === 100) {
+                if ($flushes > 0) {
+                    echo ', ';
+                }
+                echo implode(', ', $objects);
+                $cnt = 0;
+                $objects = [];
+                $flushes++;
+                ob_end_flush();
+                ob_start();
+            }
+        }
+
+        if ($cnt > 0) {
+            if ($flushes > 0) {
+                echo ', ';
+            }
+            echo implode(', ', $objects);
+        }
+
+        if ($this->params->get('benchmark')) {
+            echo "],\n";
+            Benchmark::measure('All done');
+            echo '"benchmark_string": ' . json_encode(Benchmark::renderToText());
+        } else {
+            echo '] ';
+        }
+
+        echo "}\n";
+        if (ob_get_level()) {
+            ob_end_flush();
+        }
+
+        // TODO: can we improve this?
+        exit;
+    }
+
+    protected function getTable()
+    {
+        return ObjectsTable::create($this->getType(), $this->db())
+            ->setAuth($this->getAuth());
     }
 
     public function editAction()