Merge pull request #328 from silverstripe-terraformers/feature/stages…

…-differ-recursive

NEW: Stages differ recursive

_config/versionedownership.yml

@@ -4,6 +4,10 @@ Name: versionedownership
 SilverStripe\ORM\DataObject:
   extensions:
     RecursivePublishable: SilverStripe\Versioned\RecursivePublishable
+
+SilverStripe\Core\Injector\Injector:
+  SilverStripe\Versioned\RecursiveStagesInterface:
+    class: SilverStripe\Versioned\RecursiveStagesService
 ---
 Name: versionedownership-admin
 OnlyIf:

src/RecursivePublishable.php

@@ -12,7 +12,6 @@
 use SilverStripe\ORM\FieldType\DBDatetime;
 use SilverStripe\ORM\Queries\SQLUpdate;
 use SilverStripe\ORM\SS_List;
-use SilverStripe\ORM\Tests\MySQLDatabaseTest\Data;
 
 /**
  * Provides owns / owned_by and recursive publishing API for all objects.
@@ -448,4 +447,22 @@ public function onBeforeDuplicate($original, &$doWrite, &$relations)
         $owns = $this->owner->config()->get('owns');
         $relations = array_intersect($allowed ?? [], $owns);
     }
+
+    /**
+     * Make sure to flush cached data in case the data changes
+     * Extension point in @see DataObject::onAfterWrite()
+     */
+    public function onAfterWrite(): void
+    {
+        RecursiveStagesService::reset();
+    }
+
+    /**
+     * Make sure to flush cached data in case the data changes
+     * Extension point in @see DataObject::onAfterDelete()
+     */
+    public function onAfterDelete(): void
+    {
+        RecursiveStagesService::reset();
+    }
 }

src/RecursiveStagesInterface.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace SilverStripe\Versioned;
+
+use SilverStripe\ORM\DataObject;
+
+/**
+ * Interface RecursiveStagesInterface
+ *
+ * Interface for @see RecursiveStagesService to provide the capability to for "smart" dirty model state
+ * which can cover nested models
+ */
+interface RecursiveStagesInterface
+{
+    /**
+     * Determine if content differs on stages including nested objects
+     */
+    public function stagesDifferRecursive(DataObject $object): bool;
+}

src/RecursiveStagesService.php

@@ -0,0 +1,188 @@
+<?php
+
+namespace SilverStripe\Versioned;
+
+use SilverStripe\Core\Injector\Injectable;
+use SilverStripe\Core\Injector\Injector;
+use SilverStripe\Core\Resettable;
+use SilverStripe\ORM\DataObject;
+
+/**
+ * Functionality for detecting the need of publishing nested objects owned by common parent / ancestor object
+ */
+class RecursiveStagesService implements RecursiveStagesInterface, Resettable
+{
+    use Injectable;
+
+    private array $stagesDifferCache = [];
+    private array $ownedObjectsCache = [];
+
+    public function flushCachedData(): void
+    {
+        $this->stagesDifferCache = [];
+        $this->ownedObjectsCache = [];
+    }
+
+    public static function reset(): void
+    {
+        /** @var RecursiveStagesInterface $service */
+        $service = Injector::inst()->get(RecursiveStagesInterface::class);
+
+        if (!$service instanceof RecursiveStagesService) {
+            // This covers the case where the service is overridden
+            return;
+        }
+
+        $service->flushCachedData();
+    }
+
+    /**
+     * Determine if content differs on stages including nested objects
+     * This method also supports non-versioned models to allow traversal of hierarchy
+     * which includes both versioned and non-versioned models
+     * In-memory cache is included and optimised for the most likely lookup profile:
+     * Non-shared models can have deep ownership hierarchy (i.e. content blocks)
+     * Shared models are unlikely to have deep ownership hierarchy (i.e Assets)
+     * This means that we provide in-memory cache only for top level models as we do not expect to query
+     * the nested models multiple times
+     */
+    public function stagesDifferRecursive(DataObject $object): bool
+    {
+        $cacheKey = $object->getUniqueKey();
+
+        if (!array_key_exists($cacheKey, $this->stagesDifferCache)) {
+            $this->stagesDifferCache[$cacheKey] = $this->determineStagesDifferRecursive($object);
+        }
+
+        return $this->stagesDifferCache[$cacheKey];
+    }
+
+    /**
+     * Execution ownership hierarchy traversal and inspect individual models
+     * This method use "stack based" recursive traversal as opposed to "true" recursive traversal
+     * for performance reasons (avoid memory spikes and long execution times due to deeper stack)
+     */
+    protected function determineStagesDifferRecursive(DataObject $object): bool
+    {
+        if (!$object->exists()) {
+            // Model hasn't been saved to DB, so we can just bail out as there is nothing to inspect
+            return false;
+        }
+
+        // Compare existing content (perform full ownership traversal)
+        $models = [$object];
+
+        // We will keep track of inspected models so we don;t inspect the same model multiple times
+        // This prevents some edge cases like infinite loops
+        $identifiers = [];
+
+        /** @var DataObject|Versioned $model */
+        while ($model = array_shift($models)) {
+            $identifier = $this->getObjectIdentifier($model);
+
+            if (in_array($identifier, $identifiers)) {
+                // We've already inspected this model, so we can skip processing it
+                // This is to prevent potential infinite loops
+                continue;
+            }
+
+            // Mark model as inspected
+            $identifiers[] = $identifier;
+
+            if ($model->hasExtension(Versioned::class) && $model->isModifiedOnDraft()) {
+                // Model is dirty,
+                // we can return here as there is no need to check the rest of the hierarchy
+                return true;
+            }
+
+            // Discover and add owned objects for inspection
+            $relatedObjects = $this->getOwnedObjects($model);
+            $models = array_merge($models, $relatedObjects);
+        }
+
+        // Compare deleted content,
+        // this wouldn't be covered in hierarchy traversal as deleted models are no longer present
+        $draftIdentifiers = $this->getOwnedIdentifiers($object, Versioned::DRAFT);
+        $liveIdentifiers = $this->getOwnedIdentifiers($object, Versioned::LIVE);
+
+        return $draftIdentifiers !== $liveIdentifiers;
+    }
+
+    /**
+     * Get unique identifiers for all owned objects, so we can easily compare them
+     */
+    protected function getOwnedIdentifiers(DataObject $object, string $stage): array
+    {
+        $identifiers = Versioned::withVersionedMode(function () use ($object, $stage): array {
+            Versioned::set_stage($stage);
+
+            /** @var DataObject $stagedObject */
+            $stagedObject = DataObject::get_by_id($object->ClassName, $object->ID);
+
+            if ($stagedObject === null) {
+                return [];
+            }
+
+            $models = [$stagedObject];
+            $identifiers = [];
+
+            while ($model = array_shift($models)) {
+                $identifier = $this->getObjectIdentifier($model);
+
+                if (in_array($identifier, $identifiers)) {
+                    // We've already inspected this model, so we can skip processing it
+                    // This is to prevent potential infinite loops
+                    continue;
+                }
+
+                $identifiers[] = $identifier;
+                $relatedObjects = $this->getOwnedObjects($model);
+                $models = array_merge($models, $relatedObjects);
+            }
+
+            return $identifiers;
+        });
+
+        sort($identifiers, SORT_STRING);
+
+        return array_values($identifiers);
+    }
+
+    /**
+     * This lookup will attempt to find "owned" objects
+     * This method uses the 'owns' relation, same as @see RecursivePublishable::publishRecursive()
+     */
+    protected function getOwnedObjects(DataObject $object): array
+    {
+        /** @var DataObject|Versioned $object */
+        if (!$object->hasExtension(RecursivePublishable::class)) {
+            return [];
+        }
+
+        // Add versioned stage to cache key to cover the case where non-versioned model owns versioned models
+        // In this situation the versioned models can have different cached state which we need to cover
+        $cacheKey = $object->getUniqueKey() . '-' . Versioned::get_stage();
+
+        if (!array_key_exists($cacheKey, $this->ownedObjectsCache)) {
+            $this->ownedObjectsCache[$cacheKey] = $object
+                // We intentionally avoid "true" recursive traversal here as it's not performant
+                // (often the cause of memory usage spikes and longer exeuction time due to deeper stack depth)
+                // Instead we use "stack based" recursive traversal approach for better performance
+                // which avoids the nested method calls
+                ->findOwned(false)
+                ->toArray();
+        }
+
+        return $this->ownedObjectsCache[$cacheKey];
+    }
+
+    /**
+     * This method covers cases where @see DataObject::getUniqueKey() can't be used
+     * For example when we want to compare models across stages we can't use getUniqueKey()
+     * as that one contains stage fragments which prevents us from making cross-stage comparison
+     */
+    private function getObjectIdentifier(DataObject $object): string
+    {
+        return $object->ClassName . '-' . $object->ID;
+    }
+}

src/Versioned.php

@@ -11,6 +11,7 @@
 use SilverStripe\Core\ClassInfo;
 use SilverStripe\Core\Config\Config;
 use SilverStripe\Core\Extension;
+use SilverStripe\Core\Injector\Injector;
 use SilverStripe\Core\Resettable;
 use SilverStripe\Forms\FieldList;
 use SilverStripe\ORM\ArrayList;
@@ -1997,6 +1998,18 @@ public function stagesDiffer()
         return (bool) $stagesDiffer;
     }
 
+    /**
+     * Determine if content differs on stages including nested objects
+     * 'owns' configuration drives the relationship traversal
+     */
+    public function stagesDifferRecursive(): bool
+    {
+        /** @var RecursiveStagesInterface $service */
+        $service = Injector::inst()->get(RecursiveStagesInterface::class);
+
+        return $service->stagesDifferRecursive($this->owner);
+    }
+
     /**
      * @param string $filter
      * @param string $sort