Align IndexedDB metadata rollback on transaction abort to spec.

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

 /*
  * Copyright (C) 2012 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 15 matching lines @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef IDBMetadata_h
 #define IDBMetadata_h
 
 #include "modules/indexeddb/IDBKeyPath.h"
 #include "public/platform/modules/indexeddb/WebIDBMetadata.h"
 #include "wtf/Allocator.h"
 #include "wtf/HashMap.h"
+#include "wtf/RefCounted.h"
+#include "wtf/RefPtr.h"
 #include "wtf/text/StringHash.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
-struct IDBIndexMetadata {
-    DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
-    IDBIndexMetadata() { }
-    IDBIndexMetadata(const String& name, int64_t id, const IDBKeyPath& keyPath, bool unique, bool multiEntry)
-        : name(name)
-        , id(id)
-        , keyPath(keyPath)
-        , unique(unique)
-        , multiEntry(multiEntry) { }
+class IDBIndexMetadata : public RefCounted<IDBIndexMetadata> {
+    USING_FAST_MALLOC(IDBIndexMetadata);
+
+public:
+    IDBIndexMetadata();
+    IDBIndexMetadata(const String& name, int64_t id, const IDBKeyPath&, bool unique, bool multiEntry);
+
     String name;
     int64_t id;
     IDBKeyPath keyPath;
     bool unique;
     bool multiEntry;
 
     static const int64_t InvalidId = -1;
 };
 
-struct IDBObjectStoreMetadata {
-    DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
-    IDBObjectStoreMetadata() { }
-    IDBObjectStoreMetadata(const String& name, int64_t id, const IDBKeyPath& keyPath, bool autoIncrement, int64_t maxIndexId)
-        : name(name)
-        , id(id)
-        , keyPath(keyPath)
-        , autoIncrement(autoIncrement)
-        , maxIndexId(maxIndexId)
-    {
-    }
+struct IDBObjectStoreOwnMetadata {
+    DISALLOW_NEW();
+
+    IDBObjectStoreOwnMetadata();
+    IDBObjectStoreOwnMetadata(const String& name, int64_t id, const IDBKeyPath&, bool autoIncrement, int64_t maxIndexId);
+
+    IDBObjectStoreOwnMetadata(const IDBObjectStoreOwnMetadata&);
+    IDBObjectStoreOwnMetadata& operator =(const IDBObjectStoreOwnMetadata&);

[jsbell, 2016/09/16 18:17:28]

nit: we usually write: operator=

[pwnall, 2016/09/17 01:34:21]

Done.

+
     String name;
     int64_t id;
     IDBKeyPath keyPath;
     bool autoIncrement;
     int64_t maxIndexId;
+};
 
+class IDBObjectStoreMetadata : public RefCounted<IDBObjectStoreMetadata> {
+    USING_FAST_MALLOC(IDBObjectStoreMetadata);
+
+public:
+    IDBObjectStoreMetadata();
+    IDBObjectStoreMetadata(const String& name, int64_t id, const IDBKeyPath&, bool autoIncrement, int64_t maxIndexId);
+
+    // Creates a deep copy of the object metadata, which includes copies of index metadata items.
+    RefPtr<IDBObjectStoreMetadata> createCopy() const;
+
+    IDBObjectStoreOwnMetadata own;
     static const int64_t InvalidId = -1;
 
-    typedef HashMap<int64_t, IDBIndexMetadata> IndexMap;
+    using IndexMap = HashMap<int64_t, RefPtr<IDBIndexMetadata>>;
     IndexMap indexes;
 };
 
-struct IDBDatabaseMetadata {
+struct IDBDatabaseOwnMetadata {
     DISALLOW_NEW();
+
+    IDBDatabaseOwnMetadata();
+    IDBDatabaseOwnMetadata(const String& name, int64_t id, int64_t version, int64_t maxObjectStoreId);
+
+    // Copying is used to backup and restore metadata in versionchange transactions.
+    IDBDatabaseOwnMetadata(const IDBDatabaseOwnMetadata&);
+    IDBDatabaseOwnMetadata& operator =(const IDBDatabaseOwnMetadata&);
+
+    String name;
+    int64_t id;
+    int64_t version;
+    int64_t maxObjectStoreId;
+};
+
+struct MODULES_EXPORT IDBDatabaseMetadata {
+    DISALLOW_NEW();
+
+public:
     // FIXME: These can probably be collapsed into 0.
     enum {
         NoVersion = -1,
         DefaultVersion = 0
     };
 
-    typedef HashMap<int64_t, IDBObjectStoreMetadata> ObjectStoreMap;
-
-    IDBDatabaseMetadata()
-        : version(NoVersion)
-    {
-    }
-
-    IDBDatabaseMetadata(const String& name, int64_t id, int64_t version, int64_t maxObjectStoreId)
-        : name(name)
-        , id(id)
-        , version(version)
-        , maxObjectStoreId(maxObjectStoreId)
-    {
-    }
+    IDBDatabaseMetadata();
+    IDBDatabaseMetadata(const String& name, int64_t id, int64_t version, int64_t maxObjectStoreId);
 
     explicit IDBDatabaseMetadata(const WebIDBMetadata&);
 
-    String name;
-    int64_t id;
-    int64_t version;
-    int64_t maxObjectStoreId;
-
+    IDBDatabaseOwnMetadata own;
+    using ObjectStoreMap = HashMap<int64_t, RefPtr<IDBObjectStoreMetadata>>;
     ObjectStoreMap objectStores;
 };
 
 } // namespace blink
 
 #endif // IDBMetadata_h