Wrap large IndexedDB values into Blobs before writing to LevelDB.

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

 /*
  * 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 158 matching lines @@
   // during this destructor.
   DCHECK(state_ == kFinished || !GetExecutionContext());
   DCHECK(request_list_.IsEmpty() || !GetExecutionContext());
 }
 
 DEFINE_TRACE(IDBTransaction) {
   visitor->Trace(database_);
   visitor->Trace(open_db_request_);
   visitor->Trace(error_);
   visitor->Trace(request_list_);
+  visitor->Trace(result_queue_);
   visitor->Trace(object_store_map_);
   visitor->Trace(old_store_metadata_);
   visitor->Trace(deleted_indexes_);
   EventTargetWithInlineData::Trace(visitor);
   ContextLifecycleObserver::Trace(visitor);
 }
 
 void IDBTransaction::SetError(DOMException* error) {
   DCHECK_NE(state_, kFinished);
   DCHECK(error);
@@ skipping 181 matching lines @@
   if (BackendDB())
     BackendDB()->Abort(id_);
 }
 
 void IDBTransaction::RegisterRequest(IDBRequest* request) {
   DCHECK(request);
   DCHECK_EQ(state_, kActive);
   request_list_.insert(request);
 }
 
 void IDBTransaction::UnregisterRequest(IDBRequest* request) {

[jsbell, 2017/05/05 00:29:37]

Seems like we could have a DCHECK here that the request doesn't have a queued
result.

[pwnall, 2017/05/11 23:54:24]

Done.

   DCHECK(request);
   // If we aborted the request, it will already have been removed.
   request_list_.erase(request);
 }
 
+void IDBTransaction::EnqueueResult(IDBRequestQueueItem* result) {
+  DCHECK(result);
+  DCHECK(HasQueuedResult() || !result->IsReady());
+
+  result_queue_.push_back(result);
+}
+
+void IDBTransaction::OnResultReady() {
+  while (!result_queue_.empty()) {
+    IDBRequestQueueItem* result = result_queue_.front();
+    if (!result->IsReady())
+      break;
+
+    result->FireCallback();
+    result_queue_.pop_front();
+  }
+}
+
 void IDBTransaction::OnAbort(DOMException* error) {
   IDB_TRACE("IDBTransaction::onAbort");
   if (!GetExecutionContext()) {
     Finished();
     return;
   }
 
   DCHECK_NE(state_, kFinished);
   if (state_ != kFinishing) {
     // Abort was not triggered by front-end.
@@ skipping 218 matching lines @@
     IDBObjectStore* object_store = it.key;
     object_store->ClearIndexCache();
   }
   old_store_metadata_.clear();
 
   deleted_indexes_.clear();
   deleted_object_stores_.clear();
 }
 
 }  // namespace blink