Merge pull request #61 from realm/tg/notifications

Add fine-grained notification stuff

Author: tgoyne

src/CMakeLists.txt

@@ -1,29 +1,40 @@
 set(SOURCES
+    collection_notifications.cpp
     index_set.cpp
     list.cpp
     object_schema.cpp
     object_store.cpp
     results.cpp
     schema.cpp
     shared_realm.cpp
-    impl/async_query.cpp
+    impl/collection_change_builder.cpp
+    impl/collection_notifier.cpp
+    impl/list_notifier.cpp
     impl/realm_coordinator.cpp
+    impl/results_notifier.cpp
     impl/transact_log_handler.cpp
     parser/parser.cpp
     parser/query_builder.cpp)
 
 set(HEADERS
+    collection_notifications.hpp
     index_set.hpp
     list.hpp
     object_schema.hpp
     object_store.hpp
+    property.hpp
     results.hpp
     schema.hpp
     shared_realm.hpp
-    impl/weak_realm_notifier.hpp
-    impl/weak_realm_notifier_base.hpp
+    impl/collection_change_builder.hpp
+    impl/collection_notifier.hpp
     impl/external_commit_helper.hpp
+    impl/list_notifier.hpp
+    impl/realm_coordinator.hpp
+    impl/results_notifier.hpp
     impl/transact_log_handler.hpp
+    impl/weak_realm_notifier.hpp
+    impl/weak_realm_notifier_base.hpp
     parser/parser.hpp
     parser/query_builder.hpp
     util/atomic_shared_ptr.hpp)

src/collection_notifications.cpp

@@ -0,0 +1,56 @@
+////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2016 Realm Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+////////////////////////////////////////////////////////////////////////////
+
+#include "collection_notifications.hpp"
+
+#include "impl/collection_notifier.hpp"
+
+using namespace realm;
+using namespace realm::_impl;
+
+NotificationToken::NotificationToken(std::shared_ptr<_impl::CollectionNotifier> notifier, size_t token)
+: m_notifier(std::move(notifier)), m_token(token)
+{
+}
+
+NotificationToken::~NotificationToken()
+{
+    // m_notifier itself (and not just the pointed-to thing) needs to be accessed
+    // atomically to ensure that there are no data races when the token is
+    // destroyed after being modified on a different thread.
+    // This is needed despite the token not being thread-safe in general as
+    // users find it very surprising for obj-c objects to care about what
+    // thread they are deallocated on.
+    if (auto notifier = m_notifier.exchange({})) {
+        notifier->remove_callback(m_token);
+    }
+}
+
+NotificationToken::NotificationToken(NotificationToken&& rgt) = default;
+
+NotificationToken& NotificationToken::operator=(realm::NotificationToken&& rgt)
+{
+    if (this != &rgt) {
+        if (auto notifier = m_notifier.exchange({})) {
+            notifier->remove_callback(m_token);
+        }
+        m_notifier = std::move(rgt.m_notifier);
+        m_token = rgt.m_token;
+    }
+    return *this;
+}

src/collection_notifications.hpp

@@ -0,0 +1,71 @@
+////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2016 Realm Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+////////////////////////////////////////////////////////////////////////////
+
+#ifndef REALM_COLLECTION_NOTIFICATIONS_HPP
+#define REALM_COLLECTION_NOTIFICATIONS_HPP
+
+#include "index_set.hpp"
+#include "util/atomic_shared_ptr.hpp"
+
+#include <exception>
+#include <functional>
+#include <memory>
+#include <vector>
+
+namespace realm {
+namespace _impl {
+    class CollectionNotifier;
+}
+
+// A token which keeps an asynchronous query alive
+struct NotificationToken {
+    NotificationToken() = default;
+    NotificationToken(std::shared_ptr<_impl::CollectionNotifier> notifier, size_t token);
+    ~NotificationToken();
+
+    NotificationToken(NotificationToken&&);
+    NotificationToken& operator=(NotificationToken&&);
+
+    NotificationToken(NotificationToken const&) = delete;
+    NotificationToken& operator=(NotificationToken const&) = delete;
+
+private:
+    util::AtomicSharedPtr<_impl::CollectionNotifier> m_notifier;
+    size_t m_token;
+};
+
+struct CollectionChangeSet {
+    struct Move {
+        size_t from;
+        size_t to;
+
+        bool operator==(Move m) const { return from == m.from && to == m.to; }
+    };
+
+    IndexSet deletions;
+    IndexSet insertions;
+    IndexSet modifications;
+    std::vector<Move> moves;
+
+    bool empty() const { return deletions.empty() && insertions.empty() && modifications.empty() && moves.empty(); }
+};
+
+using CollectionChangeCallback = std::function<void (CollectionChangeSet, std::exception_ptr)>;
+} // namespace realm
+
+#endif // REALM_COLLECTION_NOTIFICATIONS_HPP