IDBObserver: Lifetime Management: Adding Observer

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

Index: third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp b/third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp
index 219b81832bebfc898a2e679fa329c0a2b21d26c8..25a0fff96b6d826698421e82b75805d464f3537b 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp
@@ -7,8 +7,12 @@
 #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/indexeddb/IDBDatabase.h"
 #include "modules/indexeddb/IDBObserverCallback.h"
 #include "modules/indexeddb/IDBObserverInit.h"
+#include "modules/indexeddb/IDBTransaction.h"
+#include "modules/indexeddb/WebIDBObserverImpl.h"
 
 namespace blink {
 
@@ -25,9 +29,53 @@ IDBObserver::IDBObserver(IDBObserverCallback& callback, const IDBObserverInit& o
 {
 }
 
+IDBObserver::~IDBObserver() {}
+
 void IDBObserver::observe(IDBDatabase* database, IDBTransaction* transaction, ExceptionState& exceptionState)
 {
-    // TODO(palakj): Finish implementation.
+    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);
+    observerPtr->setId(observerId);

[haraken, 2016/07/01 01:55:02]

Would you help me understand why you need to introduce an ID system?

Can we probably just make WebIDBObserverImpl GarbageCollected and make
Backend::m_observers a hash set of WeakMembers?

[dmurph, 2016/07/01 19:01:57]

Do you mean in the browser process? It's because everything is across IPC, so we
need an ID for everything: connections, transactions, requests, callbacks, etc.

+}
+
+void IDBObserver::unobserve(IDBDatabase* database, ExceptionState& exceptionState)
+{
+    if (!database->backend()) {
+        exceptionState.throwDOMException(InvalidStateError, IDBDatabase::databaseClosedErrorMessage);
+        return;
+    }
+    std::set<int32_t>::iterator 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++;
+        }
+    }
+    if (!observerIdsToRemove.empty())
+        database->backend()->removeObservers(observerIdsToRemove);
+}
+
+void IDBObserver::removeObserver(int32_t id)
+{
+    m_observerIds.erase(id);
 }
 
 DEFINE_TRACE(IDBObserver)