fluo-notifications mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From ctubbsii <...@git.apache.org>
Subject [GitHub] incubator-fluo pull request #817: fixes #816 introduced better way to setup ...
Date Mon, 20 Mar 2017 22:38:20 GMT
Github user ctubbsii commented on a diff in the pull request:

    --- Diff: modules/api/src/main/java/org/apache/fluo/api/observer/ObserversFactory.java
    @@ -0,0 +1,119 @@
    + * 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
    + * 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
either express
    + * or implied. See the License for the specific language governing permissions and limitations
    + * the License.
    + */
    +package org.apache.fluo.api.observer;
    +import java.util.function.BiConsumer;
    +import org.apache.fluo.api.client.FluoClient;
    +import org.apache.fluo.api.config.FluoConfiguration;
    +import org.apache.fluo.api.config.SimpleConfiguration;
    +import org.apache.fluo.api.data.Bytes;
    +import org.apache.fluo.api.data.Column;
    +import org.apache.fluo.api.metrics.MetricsReporter;
    +import org.apache.fluo.api.observer.Observer.NotificationType;
    + * Fluo Workers use this class to create {@link Observer}s to process notifications.
    + * of this class should emit zero or more {@link Observer}s.
    + *
    + * <p>
    + * When Fluo is initialized {@link #getObservedColumns(Context, BiConsumer)} is called.
The columns
    + * it emits are stored in Zookeeper. Transactions will use the columns stored in Zookeeper
    + * determine when to set notifications. When Workers call
    + * {@link #createObservers(ObserverConsumer, Context)}, the columns emitted must be the
same as
    + * those emitted during initialization. If this is not the case, then the worker will
fail to start.
    + *
    + * @see FluoConfiguration#setObserversFactory(String)
    + * @since 1.1.0
    + */
    +public interface ObserversFactory {
    --- End diff --
    To me, `get` can have either connotation `retrieve existing` or `create and supply`. In
any case, there's no requirement for instances of this interface to construct new instances....
they could be supplying pre-existing (provided by user's implementation). From an API perspective,
we don't really care which is the case, and in my view, the semantics of `get` works with
    Unless you wanted to make it a `Consumer<Context>` (see previous comment, not recommended)
and force the use of the name `accept`, I think maybe `ObserverProvider` and `void provide(Context)`
might be worth considering. "Provider" comes with less baggage than "Factory", allowing more
flexibility to construct an API which doesn't necessarily fall directly into well-established
patterns and conventions. It's also literally what an instance of the class would be doing:
providing the observers to the framework.

If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.

View raw message