io.druid.segment.column.SimpleDictionaryEncodedColumn.java Source code

Introduction

Here is the source code for io.druid.segment.column.SimpleDictionaryEncodedColumn.java

Source

/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group 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.
 */

package io.druid.segment.column;

import com.google.common.base.Strings;
import com.metamx.common.guava.CloseQuietly;
import io.druid.segment.data.CachingIndexed;
import io.druid.segment.data.IndexedInts;
import io.druid.segment.data.IndexedMultivalue;

import java.io.IOException;

/**
*/
public class SimpleDictionaryEncodedColumn implements DictionaryEncodedColumn {
    private final IndexedInts column;
    private final IndexedMultivalue<IndexedInts> multiValueColumn;
    private final CachingIndexed<String> cachedLookups;

    public SimpleDictionaryEncodedColumn(IndexedInts singleValueColumn,
            IndexedMultivalue<IndexedInts> multiValueColumn, CachingIndexed<String> cachedLookups) {
        this.column = singleValueColumn;
        this.multiValueColumn = multiValueColumn;
        this.cachedLookups = cachedLookups;
    }

    @Override
    public int length() {
        return hasMultipleValues() ? multiValueColumn.size() : column.size();
    }

    @Override
    public boolean hasMultipleValues() {
        return column == null;
    }

    @Override
    public int getSingleValueRow(int rowNum) {
        return column.get(rowNum);
    }

    @Override
    public IndexedInts getMultiValueRow(int rowNum) {
        return multiValueColumn.get(rowNum);
    }

    @Override
    public String lookupName(int id) {
        //Empty to Null will ensure that null and empty are equivalent for extraction function
        return Strings.emptyToNull(cachedLookups.get(id));
    }

    @Override
    public int lookupId(String name) {
        return cachedLookups.indexOf(name);
    }

    @Override
    public int getCardinality() {
        return cachedLookups.size();
    }

    @Override
    public void close() throws IOException {
        CloseQuietly.close(cachedLookups);

        if (column != null) {
            column.close();
        }
        if (multiValueColumn != null) {
            multiValueColumn.close();
        }
    }
}