Github user VladRodionov commented on a diff in the pull request:
https://github.com/apache/incubator-ratis/pull/4#discussion_r212153063
--- Diff:
ratis-logservice/src/main/java/org/apache/ratis/logservice/api/ArchivedLog.java
---
@@ -0,0 +1,43 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.
+ */
+package org.apache.ratis.logservice.api;
+
+/**
+ * A {@link LogStream} which has been archived in some external
+ * system. This interface is parameterized to allow for implementations
+ * to use their own class to encapsulate how to find the archived log.
+ *
+ * In the majority of cases, this should be transparent to end-users, as
+ * the {@link LogStream} should hide the fact that this even exists.
+ * TODO maybe that means this should be client-facing at all?
+ *
+ * @param <T> A referent to the log on the external system.
+ */
+public interface ArchivedLog<T> extends AutoCloseable {
+
+ /**
+ * Creates an asynchronous reader over this archived log.
+ */
+ AsyncLogReader createAsyncReader();
--- End diff --
It would be nice to have a clarification on all async stuff
(readers/writers).
1. Do they improve performance?
2. Do they improve latencies? and can we measure this improvement?
3. Do they simplify programming model?
My guess on all three is they don't. Async model (not based on OS kernel
support) is broken in Java.
---
