accumulo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From scubafuchs <>
Subject [GitHub] accumulo pull request #244: Discuss ACCUMULO-3079: collapsing the iterator s...
Date Thu, 20 Apr 2017 18:53:58 GMT
Github user scubafuchs commented on a diff in the pull request:
    --- Diff: core/src/main/java/org/apache/accumulo/core/iterators/
    @@ -0,0 +1,80 @@
    + * 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
    + *
    + *
    + *
    + * 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.accumulo.core.iterators;
    +import java.util.Collection;
    +import java.util.Map;
    + * A convenience class for implementing iterators that select, but do not modify, entries
read from a source iterator. Default implementations exist for all
    + * methods, but {@link #deepCopy} will throw an <code>UnsupportedOperationException</code>.
    + *
    + * This iterator has some checks in place to enforce the iterator contract. Specifically,
it verifies that it has a source iterator and that {@link #seek} has
    + * been called before any data is read. If either of these conditions does not hold true,
an <code>IllegalStateException</code> will be thrown. In particular,
    + * this means that <code>getSource().seek</code> and <code></code>
no longer perform identical actions. Implementors should take note of this and if
    + * <code>seek</code> is overridden, ensure that <code></code>
is called before data is read.
    + */
    +public abstract class ServerWrappingIterator implements SortedKeyValueIterator<Key,Value>
    +  protected final SortedKeyValueIterator<Key,Value> source;
    +  public ServerWrappingIterator(SortedKeyValueIterator<Key,Value> source) {
    +    this.source = source;
    +  }
    +  @Override
    +  public SortedKeyValueIterator<Key,Value> deepCopy(IteratorEnvironment env) {
    +    throw new UnsupportedOperationException();
    --- End diff --
    At least at the time, I believe that a bunch of the extending classes would have implement
this method the same way, so it reduces the amount of code to have a common implementation
here. I think this is more of a question about whether deepCopy should really be common across
all uses of the SortedKeyValueIterator interface, or whether we should have organized it differently.
Interesting topic, but probably shouldn't hold up this project.

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 or file a JIRA ticket
with INFRA.

View raw message