Add an untested non-Apple ExternalCommitHelper implementation

src/impl/generic/external_commit_helper.cpp

@@ -0,0 +1,46 @@
+////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2015 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 "external_commit_helper.hpp"
+
+#include "realm_coordinator.hpp"
+
+#include <realm/commit_log.hpp>
+#include <realm/replication.hpp>
+
+using namespace realm;
+using namespace realm::_impl;
+
+ExternalCommitHelper::ExternalCommitHelper(RealmCoordinator& parent)
+: m_parent(parent)
+, m_history(realm::make_client_history(parent.get_path(), parent.get_encryption_key().data()))
+, m_sg(*m_history, parent.is_in_memory() ? SharedGroup::durability_MemOnly : SharedGroup::durability_Full,
+       parent.get_encryption_key().data())
+, m_thread(std::async(std::launch::async, [=] {
+    while (m_sg.wait_for_change()) {
+        m_parent.on_change();
+    }
+}))
+{
+}
+
+ExternalCommitHelper::~ExternalCommitHelper()
+{
+    m_sg.wait_for_change_release();
+    m_thread.wait(); // Wait for the thread to exit
+}

src/impl/generic/external_commit_helper.hpp

@@ -0,0 +1,54 @@
+////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2015 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_EXTERNAL_COMMIT_HELPER_HPP
+#define REALM_EXTERNAL_COMMIT_HELPER_HPP
+
+#include <realm/group_shared.hpp>
+
+#include <future>
+
+namespace realm {
+class ClientHistory;
+
+namespace _impl {
+class RealmCoordinator;
+
+class ExternalCommitHelper {
+public:
+    ExternalCommitHelper(RealmCoordinator& parent);
+    ~ExternalCommitHelper();
+
+    // A no-op in this version, but needed for the Apple version
+    void notify_others() { }
+
+private:
+    RealmCoordinator& m_parent;
+
+    // The listener thread
+    std::future<void> m_thread;
+
+    // A shared group used to listen for changes
+    std::unique_ptr<ClientHistory> m_history;
+    SharedGroup m_sg;
+};
+
+} // namespace _impl
+} // namespace realm
+
+#endif /* REALM_EXTERNAL_COMMIT_HELPER_HPP */

src/impl/realm_coordinator.hpp

@@ -45,6 +45,8 @@ public:
     const Schema* get_schema() const noexcept;
     uint64_t get_schema_version() const noexcept { return m_config.schema_version; }
     const std::string& get_path() const noexcept { return m_config.path; }
+    const std::vector<char>& get_encryption_key() const noexcept { return m_config.encryption_key; }
+    bool is_in_memory() const noexcept { return m_config.in_memory; }
 
     // Asyncronously call notify() on every Realm instance for this coordinator's
     // path, including those in other processes