[IndexedDB] Propogating changes to observers : Renderer

third_party/WebKit/Source/modules/indexeddb/IDBObserver.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/IDBObserver.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/modules/v8/ToV8ForModules.h"
 #include "bindings/modules/v8/V8BindingForModules.h"
 #include "core/dom/ExceptionCode.h"
+#include "modules/IndexedDBNames.h"
 #include "modules/indexeddb/IDBDatabase.h"
 #include "modules/indexeddb/IDBObserverCallback.h"
+#include "modules/indexeddb/IDBObserverChanges.h"
 #include "modules/indexeddb/IDBObserverInit.h"
 #include "modules/indexeddb/IDBTransaction.h"
 #include "modules/indexeddb/WebIDBObserverImpl.h"
 
 namespace blink {
 
 IDBObserver* IDBObserver::create(IDBObserverCallback& callback, const IDBObserverInit& options)
 {
     return new IDBObserver(callback, options);
 }
 
 IDBObserver::IDBObserver(IDBObserverCallback& callback, const IDBObserverInit& options)
     : m_callback(&callback)
     , m_transaction(options.transaction())
     , m_values(options.values())
     , m_noRecords(options.noRecords())
 {
+    // TODO(palakj): Throw an exception if unknown operation type.
+    DCHECK_EQ(m_operationTypes.size(), WebIDBOperationTypeCount);
+    m_operationTypes.reset();
+    m_operationTypes[WebIDBAdd] = options.operationTypes().contains(IndexedDBNames::add);
+    m_operationTypes[WebIDBPut] = options.operationTypes().contains(IndexedDBNames::put);
+    m_operationTypes[WebIDBDelete] = options.operationTypes().contains(IndexedDBNames::kDelete);
+    m_operationTypes[WebIDBClear] = options.operationTypes().contains(IndexedDBNames::clear);
 }
 
 IDBObserver::~IDBObserver() {}
 
 void IDBObserver::observe(IDBDatabase* database, IDBTransaction* transaction, ExceptionState& exceptionState)
 {
     if (transaction->isFinished() || transaction->isFinishing()) {
         exceptionState.throwDOMException(TransactionInactiveError, IDBDatabase::transactionFinishedErrorMessage);
         return;
     }
     if (!transaction->isActive()) {
         exceptionState.throwDOMException(TransactionInactiveError, IDBDatabase::transactionInactiveErrorMessage);
         return;
     }
     if (!database->backend()) {
         exceptionState.throwDOMException(InvalidStateError, IDBDatabase::databaseClosedErrorMessage);
         return;
     }
 
     std::unique_ptr<WebIDBObserverImpl> observer = WebIDBObserverImpl::create(this);
     WebIDBObserverImpl* observerPtr = observer.get();
     int32_t observerId = database->backend()->addObserver(std::move(observer), transaction->id());
-    m_observerIds.insert(observerId);
+    m_observerIds.add(observerId, database);
     observerPtr->setId(observerId);
 }
 
 void IDBObserver::unobserve(IDBDatabase* database, ExceptionState& exceptionState)
 {
     if (!database->backend()) {
         exceptionState.throwDOMException(InvalidStateError, IDBDatabase::databaseClosedErrorMessage);
         return;
     }
-    auto it = m_observerIds.begin();
-    std::vector<int32_t> observerIdsToRemove;
-    while (it != m_observerIds.end()) {
-        if (database->backend()->containsObserverId(*it)) {
-            observerIdsToRemove.push_back(*it);
-            it = m_observerIds.erase(it);
-        } else {
-            it++;
-        }
+
+    HeapHashMap<int32_t, WeakMember<IDBDatabase>> observersToRetain;
+    Vector<int32_t> observerIdsToRemove;
+    for (const auto& it : m_observerIds) {
+        if (it.value == database)
+            observerIdsToRemove.append(it.key);
+        else
+            observersToRetain.add(it.key, it.value);
     }
-    if (!observerIdsToRemove.empty())
+    m_observerIds.swap(observersToRetain);

[haraken, 2016/07/20 16:22:12]

Can we use m_observerIds.removeAll() instead of building up another hash map?

[palakj1, 2016/07/20 18:22:11]

I believed swapping would be faster, since, removeAll needs to iterate over all
the elements to be removed.
But it is definitely cleaner. I can switch to that.

+
+    if (!observerIdsToRemove.isEmpty())
         database->backend()->removeObservers(observerIdsToRemove);
 }
 
 void IDBObserver::removeObserver(int32_t id)
 {
-    m_observerIds.erase(id);
+    m_observerIds.remove(id);
+}
+
+void IDBObserver::onChange(int32_t id, const WebVector<WebIDBObservation>& observations, const WebVector<int32_t>& observationIndex)
+{
+    auto it = m_observerIds.find(id);
+    DCHECK(it != m_observerIds.end());
+    m_callback->handleChanges(*IDBObserverChanges::create(it->value, observations, observationIndex), *this);
 }
 
 DEFINE_TRACE(IDBObserver)
 {
     visitor->trace(m_callback);
+    visitor->trace(m_observerIds);
 }
 
 } // namespace blink