Align IndexedDB metadata rollback on transaction abort to spec.

third_party/WebKit/Source/modules/indexeddb/IDBTransaction.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 22 matching lines @@
 #include "core/events/EventListener.h"
 #include "modules/EventModules.h"
 #include "modules/EventTargetModules.h"
 #include "modules/ModulesExport.h"
 #include "modules/indexeddb/IDBMetadata.h"
 #include "modules/indexeddb/IndexedDB.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/modules/indexeddb/WebIDBDatabase.h"
 #include "public/platform/modules/indexeddb/WebIDBTypes.h"
 #include "wtf/HashSet.h"
+#include "wtf/Vector.h"
 
 namespace blink {
 
 class DOMException;
 class ExceptionState;
 class IDBDatabase;
+class IDBIndex;
 class IDBObjectStore;
 class IDBOpenDBRequest;
 
 class MODULES_EXPORT IDBTransaction final : public EventTargetWithInlineData,
                                             public ActiveScriptWrappable,
                                             public ActiveDOMObject {
   USING_GARBAGE_COLLECTED_MIXIN(IDBTransaction);
   DEFINE_WRAPPERTYPEINFO();
 
  public:
@@ skipping 28 matching lines @@
   // Implement the IDBTransaction IDL
   const String& mode() const;
   DOMStringList* objectStoreNames() const;
   IDBDatabase* db() const { return m_database.get(); }
   DOMException* error() const { return m_error; }
   IDBObjectStore* objectStore(const String& name, ExceptionState&);
   void abort(ExceptionState&);
 
   void registerRequest(IDBRequest*);
   void unregisterRequest(IDBRequest*);
-  void objectStoreCreated(const String&, IDBObjectStore*);
-  void objectStoreDeleted(const String&);
+
+  // The methods below are called right before the changes are applied to the
+  // database's metadata. We use this unusual sequencing because some of the
+  // methods below need to access the metadata values before the change, and
+  // following the same lifecycle for all methods makes the code easier to
+  // reason about.
+  void objectStoreCreated(const String& name, IDBObjectStore*);
+  void objectStoreDeleted(const int64_t objectStoreId, const String& name);
   void objectStoreRenamed(const String& oldName, const String& newName);
+  // Called when deleting an index whose IDBIndex had been created.
+  void indexDeleted(IDBIndex*);
+
   void setActive(bool);
   void setError(DOMException*);
 
   DEFINE_ATTRIBUTE_EVENT_LISTENER(abort);
   DEFINE_ATTRIBUTE_EVENT_LISTENER(complete);
   DEFINE_ATTRIBUTE_EVENT_LISTENER(error);
 
   void onAbort(DOMException*);
   void onComplete();
 
   // EventTarget
   const AtomicString& interfaceName() const override;
   ExecutionContext* getExecutionContext() const override;
 
   // ScriptWrappable
   bool hasPendingActivity() const final;
 
   // ActiveDOMObject
   void contextDestroyed() override;
 
+  // Object store IDs are allocated sequentially, so we can tell if an object
+  // store was created in this transaction by comparing its ID against the
+  // database's maximum object store ID at the time when the transaction was
+  // started.
+  int64_t oldMaxObjectStoreId() const {
+    DCHECK(isVersionChange());
+    return m_oldDatabaseMetadata.maxObjectStoreId;
+  }
+
  protected:
   // EventTarget
   DispatchEventResult dispatchEventInternal(Event*) override;
 
  private:
+  using IDBObjectStoreMap = HeapHashMap<String, Member<IDBObjectStore>>;
+
   IDBTransaction(ScriptState*,
                  int64_t,
                  const HashSet<String>&,
                  WebIDBTransactionMode,
                  IDBDatabase*,
                  IDBOpenDBRequest*,
                  const IDBDatabaseMetadata&);
 
   void enqueueEvent(Event*);
 
@@ skipping 41 matching lines @@
 #endif  // DCHECK_IS_ON()
 
   // Caches the IDBObjectStore instances returned by the objectStore() method.
   //
   // The spec requires that a transaction's objectStore() returns the same
   // IDBObjectStore instance for a specific store, so this cache is necessary
   // for correctness.
   //
   // objectStore() throws for completed/aborted transactions, so this is not
   // used after a transaction is finished, and can be cleared.
-  using IDBObjectStoreMap = HeapHashMap<String, Member<IDBObjectStore>>;
   IDBObjectStoreMap m_objectStoreMap;
 
-  // Used to mark stores created in an aborted upgrade transaction as
-  // deleted.
-  HeapHashSet<Member<IDBObjectStore>> m_createdObjectStores;
+  // The metadata of object stores when they are opened by this transaction.
+  //
+  // Only valid for versionchange transactions.
+  HeapHashMap<Member<IDBObjectStore>, RefPtr<IDBObjectStoreMetadata>>
+      m_oldStoreMetadata;
 
-  // Used to notify object stores (which are no longer in m_objectStoreMap)
-  // when the transaction is finished.
-  HeapHashSet<Member<IDBObjectStore>> m_deletedObjectStores;
+  // The metadata of deleted object stores without IDBObjectStore instances.
+  //
+  // Only valid for versionchange transactions.
+  Vector<RefPtr<IDBObjectStoreMetadata>> m_deletedObjectStores;
 
-  // Holds stores created, deleted, or used during upgrade transactions to
-  // reset metadata in case of abort.
-  HeapHashMap<Member<IDBObjectStore>, IDBObjectStoreMetadata>
-      m_objectStoreCleanupMap;
+  // Tracks the indexes deleted by this transaction.
+  //
+  // This set only includes indexes that were created before this transaction,
+  // and were deleted during this transaction. Once marked for deletion, these
+  // indexes are removed from their object stores' index maps, so we need to
+  // stash them somewhere else in case the transaction gets aborted.
+  //
+  // This set does not include indexes created and deleted during this
+  // transaction, because we don't need to change their metadata when the
+  // transaction aborts, as they will still be marked for deletion.
+  //
+  // Only valid for versionchange transactions.
+  HeapVector<Member<IDBIndex>> m_deletedIndexes;
 
+  // Shallow snapshot of the database metadata when the transaction starts.
+  //
+  // This does not include a snapshot of the database's object store / index
+  // metadata.
+  //
+  // Only valid for versionchange transactions.
   IDBDatabaseMetadata m_oldDatabaseMetadata;
 };
 
 }  // namespace blink
 
 #endif  // IDBTransaction_h