Align IndexedDB metadata rollback on transaction abort to spec.

third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.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 21 matching lines @@
 #include "modules/indexeddb/IDBIndex.h"
 #include "modules/indexeddb/IDBIndexParameters.h"
 #include "modules/indexeddb/IDBKey.h"
 #include "modules/indexeddb/IDBKeyRange.h"
 #include "modules/indexeddb/IDBMetadata.h"
 #include "modules/indexeddb/IDBRequest.h"
 #include "modules/indexeddb/IDBTransaction.h"
 #include "public/platform/modules/indexeddb/WebIDBCursor.h"
 #include "public/platform/modules/indexeddb/WebIDBDatabase.h"
 #include "public/platform/modules/indexeddb/WebIDBTypes.h"
-#include "wtf/PassRefPtr.h"
 #include "wtf/RefPtr.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class DOMStringList;
 class IDBAny;
 class ExceptionState;
 
 class IDBObjectStore final : public GarbageCollectedFinalized<IDBObjectStore>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static IDBObjectStore* create(const IDBObjectStoreMetadata& metadata, IDBTransaction* transaction)
+    static IDBObjectStore* create(RefPtr<IDBObjectStoreMetadata> metadata, IDBTransaction* transaction)
     {
-        return new IDBObjectStore(metadata, transaction);
+        return new IDBObjectStore(std::move(metadata), transaction);
     }
     ~IDBObjectStore() { }
     DECLARE_TRACE();
 
-    const IDBObjectStoreMetadata& metadata() const { return m_metadata; }
+    const IDBObjectStoreMetadata& metadata() const { return *m_metadata; }
     const IDBKeyPath& idbKeyPath() const { return metadata().keyPath; }
 
     // Implement the IDBObjectStore IDL
     int64_t id() const { return metadata().id; }
     const String& name() const { return metadata().name; }
     void setName(const String& name, ExceptionState&);
     ScriptValue keyPath(ScriptState*) const;
     DOMStringList* indexNames() const;
     IDBTransaction* transaction() const { return m_transaction.get(); }
     bool autoIncrement() const { return metadata().autoIncrement; }
@@ skipping 21 matching lines @@
     IDBRequest* count(ScriptState*, const ScriptValue& range, ExceptionState&);
 
     // Used by IDBCursor::update():
     IDBRequest* put(ScriptState*, WebIDBPutMode, IDBAny* source, const ScriptValue&, IDBKey*, ExceptionState&);
 
     // Used internally and by InspectorIndexedDBAgent:
     IDBRequest* openCursor(ScriptState*, IDBKeyRange*, WebIDBCursorDirection, WebIDBTaskType = WebIDBTaskTypeNormal);
 
     void markDeleted();
     bool isDeleted() const { return m_deleted; }
-    void abort();
-    void transactionFinished();
 
-    void setMetadata(const IDBObjectStoreMetadata& metadata) { m_metadata = metadata; }
+    // Clears the cache used to implement the index() method.
+    //
+    // This should be called when the store's transaction clears its reference
+    // to this IDBObjectStore instance, so the store can clear its references to
+    // IDBIndex instances. This way, Oilpan can garbage-collect the instances
+    // that are not referenced in JavaScript.
+    //
+    // For most stores, the condition above is met when the transaction
+    /// finishes. The exception is stores that are created and deleted in the

[jsbell, 2016/09/26 22:23:40]

Nit: extra /

[pwnall, 2016/09/27 00:12:19]

Done.

+    // same transaction. Those stores will remain marked for deletion even if
+    // the transaction aborts, so the transaction can forget about them (and
+    // clear their index caches) right when they are deleted.
+    void clearIndexCache();
+
+    // Sets the object store's metadata to a previous version.
+    //
+    // The reverting process includes reverting the metadata for the IDBIndex
+    // instances that are still tracked by the store. It does not revert the
+    // IDBIndex metadata for indexes that were deleted in this transaction.
+    //
+    // Used when a versionchange transaction is aborted.
+    void revertMetadata(RefPtr<IDBObjectStoreMetadata> previousMetadata);
+    // This relies on the changes made by revertMetadata().
+    void revertDeletedIndexMetadata(IDBIndex& deletedIndex);
 
     // Used by IDBIndex::setName:
     bool containsIndex(const String& name) const
     {
         return findIndexId(name) != IDBIndexMetadata::InvalidId;
     }
-    void indexRenamed(int64_t indexId, const String& newName);
+    void renameIndex(int64_t indexId, const String& newName);
 
     WebIDBDatabase* backendDB() const;
 
 private:
-    IDBObjectStore(const IDBObjectStoreMetadata&, IDBTransaction*);
+    IDBObjectStore(RefPtr<IDBObjectStoreMetadata>, IDBTransaction*);
 
     IDBIndex* createIndex(ScriptState*, const String& name, const IDBKeyPath&, const IDBIndexParameters&, ExceptionState&);
     IDBRequest* put(ScriptState*, WebIDBPutMode, IDBAny* source, const ScriptValue&, const ScriptValue& key, ExceptionState&);
 
     int64_t findIndexId(const String& name) const;
 
-    IDBObjectStoreMetadata m_metadata;
+    // The IDBObjectStoreMetadata is shared with the object store map in the
+    // database's metadata.
+    RefPtr<IDBObjectStoreMetadata> m_metadata;
     Member<IDBTransaction> m_transaction;
     bool m_deleted = false;
 
     // Caches the IDBIndex instances returned by the index() method.
+    //
     // The spec requires that an object store's index() returns the same
     // IDBIndex instance for a specific index, so this cache is necessary
     // for correctness.
     //
     // index() throws for completed/aborted transactions, so this is not used
     // after a transaction is finished, and can be cleared.
     using IDBIndexMap = HeapHashMap<String, Member<IDBIndex>>;
     IDBIndexMap m_indexMap;
 
-    // Used to mark indexes created in an aborted upgrade transaction as
-    // deleted.
-    HeapHashSet<Member<IDBIndex>> m_createdIndexes;
+#if DCHECK_IS_ON()
+    bool m_clearIndexCacheCalled = false;
+#endif // DCHECK_IS_ON()
 };
 
 } // namespace blink
 
 #endif // IDBObjectStore_h