accumulo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From scubafuchs <...@git.apache.org>
Subject [GitHub] accumulo pull request #244: Discuss ACCUMULO-3079: collapsing the iterator s...
Date Thu, 20 Apr 2017 18:41:16 GMT
Github user scubafuchs commented on a diff in the pull request:

    https://github.com/apache/accumulo/pull/244#discussion_r112530307
  
    --- Diff: core/src/main/java/org/apache/accumulo/core/iterators/ServerFilter.java ---
    @@ -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
    + *
    + *     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.accumulo.core.iterators;
    +
    +import java.io.IOException;
    +import java.util.Collection;
    +import java.util.Map;
    +
    +import org.apache.accumulo.core.data.ByteSequence;
    +import org.apache.accumulo.core.data.Key;
    +import org.apache.accumulo.core.data.Range;
    +import org.apache.accumulo.core.data.Value;
    +
    +/**
    + * A SortedKeyValueIterator that filters entries from its source iterator.
    + *
    + * Subclasses must implement an accept method: public boolean accept(Key k, Value v);
    + *
    + * Key/Value pairs for which the accept method returns true are said to match the filter.
By default, this class iterates over entries that match its filter.
    + * This iterator takes an optional "negate" boolean parameter that defaults to false.
If negate is set to true, this class instead omits entries that match its
    + * filter, thus iterating over entries that do not match its filter.
    + */
    +public abstract class ServerFilter extends ServerWrappingIterator {
    +
    +  public ServerFilter(SortedKeyValueIterator<Key,Value> source) {
    +    super(source);
    +  }
    +
    +  @Override
    +  public abstract SortedKeyValueIterator<Key,Value> deepCopy(IteratorEnvironment
env);
    +
    +  @Override
    +  public void next() throws IOException {
    +    source.next();
    +    findTop();
    +  }
    +
    +  @Override
    +  public void seek(Range range, Collection<ByteSequence> columnFamilies, boolean
inclusive) throws IOException {
    +    source.seek(range, columnFamilies, inclusive);
    +    findTop();
    +  }
    +
    +  /**
    +   * Iterates over the source until an acceptable key/value pair is found.
    +   */
    +  private void findTop() throws IOException {
    +    while (source.hasTop()) {
    +      Key top = source.getTopKey();
    +      if (top.isDeleted() || (accept(top, source.getTopValue()))) {
    --- End diff --
    
    Deletes need to pass through this filter. If we filter out a delete then we could end
up un-deleting records in a partial compaction. The break happens as an indication that a
top key is ready.


---
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.
---

Mime
View raw message