Wrap large IndexedDB values into Blobs before writing to LevelDB.

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 15 matching lines @@
 #ifndef IDBTransaction_h
 #define IDBTransaction_h
 
 #include "core/dom/ContextLifecycleObserver.h"
 #include "core/dom/DOMStringList.h"
 #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/IDBRequestQueue.h"
 #include "modules/indexeddb/IndexedDB.h"
 #include "platform/bindings/ActiveScriptWrappable.h"
 #include "platform/heap/Handle.h"
 #include "platform/wtf/HashSet.h"
 #include "platform/wtf/Vector.h"
 #include "public/platform/modules/indexeddb/WebIDBDatabase.h"
 #include "public/platform/modules/indexeddb/WebIDBTypes.h"
 
 namespace blink {
 
@@ skipping 52 matching lines @@
   const String& mode() const;
   DOMStringList* objectStoreNames() const;
   IDBDatabase* db() const { return database_.Get(); }
   DOMException* error() const { return error_; }
   IDBObjectStore* objectStore(const String& name, ExceptionState&);
   void abort(ExceptionState&);
 
   void RegisterRequest(IDBRequest*);
   void UnregisterRequest(IDBRequest*);
 
+  // True if this transaction has at least one request whose result is being
+  // post-processed.
+  //
+  // While this is true, new results must be queued using QueueResult().
+  inline bool HasQueuedResult() const { return !result_queue_.empty(); }
+  void EnqueueResult(IDBRequestQueueItem* result);
+  // Called when a result's post-processing has completed.
+  void OnResultReady();
+
   // 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 object_store_id, const String& name);
   void ObjectStoreRenamed(const String& old_name, const String& new_name);
   // Called when deleting an index whose IDBIndex had been created.
   void IndexDeleted(IDBIndex*);
@@ skipping 87 matching lines @@
   // because object stores cannot be renamed in non-versionchange
   // transactions.
   const HashSet<String> scope_;
 
   State state_ = kActive;
   bool has_pending_activity_ = true;
   Member<DOMException> error_;
 
   HeapListHashSet<Member<IDBRequest>> request_list_;
 
+  // The IDBRequest results whose events have not fired yet.
+  //
+  // When a result requires post-processing, such as large value unwrapping, all
+  // the results that arrive during the post-processing phase are queued up.
+  // This guarantees that result events are fired in the order in which the
+  // requests were performed, as prescribed by the IndexedDB specification.
+  IDBRequestQueue result_queue_;
+
 #if DCHECK_IS_ON()
   bool finish_called_ = false;
 #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.
   //
@@ skipping 31 matching lines @@
   // This does not include a snapshot of the database's object store / index
   // metadata.
   //
   // Only valid for versionchange transactions.
   IDBDatabaseMetadata old_database_metadata_;
 };
 
 }  // namespace blink
 
 #endif  // IDBTransaction_h