[IndexedDB] Propogating changes to observers : Renderer

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/indexeddb/IDBObserverChanges.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptState.h"
+#include "bindings/core/v8/V8Binding.h"
 #include "bindings/modules/v8/ToV8ForModules.h"
 #include "bindings/modules/v8/V8BindingForModules.h"
 #include "modules/indexeddb/IDBAny.h"
+#include "modules/indexeddb/IDBObservation.h"
+#include "public/platform/modules/indexeddb/WebIDBObservation.h"
+#include "public/platform/modules/indexeddb/WebIDBTypes.h"
 
 namespace blink {
 
 ScriptValue IDBObserverChanges::records(ScriptState* scriptState)
 {
-    return ScriptValue::from(scriptState, m_records);
+    v8::Local<v8::Context> context(scriptState->context());
+    v8::Isolate* isolate(scriptState->isolate());
+    v8::Local<v8::Map> map = v8::Map::New(isolate);
+    for (const auto& it : m_records) {
+        v8::Local<v8::String> key = v8String(isolate, m_database->getObjectStoreName(it.key));
+        v8::Local<v8::Value> value = toV8(it.value, context->Global(), isolate);
+        v8CallOrCrash(map->Set(context, key, value));
+    }
+    return ScriptValue::from(scriptState, map);
 }
 
-IDBObserverChanges* IDBObserverChanges::create(IDBDatabase* database, IDBTransaction* transaction, IDBAny* records)
+IDBObserverChanges* IDBObserverChanges::create(IDBDatabase* database, const std::vector<WebIDBObservation>& observations, const std::vector<int32_t>& observationIndex)
 {
-    return new IDBObserverChanges(database, transaction, records);
+    return new IDBObserverChanges(database, observations, observationIndex);
 }
 
-IDBObserverChanges::IDBObserverChanges(IDBDatabase* database, IDBTransaction* transaction, IDBAny* records)
+IDBObserverChanges::IDBObserverChanges(IDBDatabase* database, const std::vector<WebIDBObservation>& observations, const std::vector<int32_t>& observationIndex)
     : m_database(database)
-    , m_transaction(transaction)
-    , m_records(records)
 {
+    createMap(observations, observationIndex);
+}
+
+void IDBObserverChanges::createMap(const std::vector<WebIDBObservation>& observations, const std::vector<int32_t>& observationIndex)

[dmurph, 2016/07/13 23:29:13]

maybe extractChanges is a better name? I'm expecting createMap to give me back a
map.

[palakj1, 2016/07/14 17:52:06]

True. changed.

+{
+    for (const auto& idx : observationIndex) {
+        int64_t key = observations[idx].objectStoreId;
+        HeapVector<Member<IDBObservation>> result;

[dmurph, 2016/07/13 23:29:13]

Do you always have to get/set here? It's doing a lot of copying. Try grabbing a
reference instead.

So something like:

if (!m_records.contains(key)
  m_records.set(key, HeapVector<Member<IDBObservation>>());

HeapVector<Member<IDBObservation>>* changes = m_records.find(key).get();
changes->append(IDBObservation::create(observations[idx]));

[Marijn Kruisselbrink, 2016/07/13 23:34:39]

Or just something like (since add returns the existing entry rather than adding
a new one if an entry already existed):
m_records.add(key,
HeapVector<Member<IDBObservation>>()).storedValue->value.append(IDBObseravtion::create(observations[idx]));

[palakj1, 2016/07/14 17:52:06]

Wow! I was really looking for some suggestions here. But never thought it could
be a one liner. Thanks a lot.

+        if (m_records.contains(key))
+            result = m_records.get(key);
+        result.append(IDBObservation::create(observations[idx]));
+        m_records.set(key, result);
+    }
 }
 
 DEFINE_TRACE(IDBObserverChanges)
 {
     visitor->trace(m_database);
     visitor->trace(m_transaction);
     visitor->trace(m_records);
 }
 
 } // namespace blink