/*
* 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 com.facebook.presto.block.dictionary;
import com.facebook.presto.block.BlockBuilder;
import com.facebook.presto.tuple.Tuple;
import com.facebook.presto.tuple.TupleInfo;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import io.airlift.slice.Slice;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import static com.google.common.base.Preconditions.checkNotNull;
public class Dictionary
{
private final TupleInfo tupleInfo;
private final List<Slice> dictionary;
public Dictionary(TupleInfo tupleInfo, Slice... dictionary)
{
this(tupleInfo, ImmutableList.copyOf(dictionary));
}
public Dictionary(TupleInfo tupleInfo, Iterable<Slice> dictionary)
{
Preconditions.checkNotNull(tupleInfo, "tupleInfo is null");
Preconditions.checkNotNull(dictionary, "dictionary is null");
this.tupleInfo = tupleInfo;
this.dictionary = ImmutableList.copyOf(dictionary);
}
public TupleInfo getTupleInfo()
{
return tupleInfo;
}
public int size()
{
return dictionary.size();
}
public Tuple getTuple(int dictionaryKey)
{
return new Tuple(getTupleSlice(dictionaryKey), tupleInfo);
}
public boolean getBoolean(int dictionaryKey)
{
return tupleInfo.getBoolean(getTupleSlice(dictionaryKey));
}
public long getLong(int dictionaryKey)
{
return tupleInfo.getLong(getTupleSlice(dictionaryKey));
}
public double getDouble(int dictionaryKey)
{
return tupleInfo.getDouble(getTupleSlice(dictionaryKey));
}
public Slice getSlice(int dictionaryKey)
{
return tupleInfo.getSlice(getTupleSlice(dictionaryKey));
}
public boolean isNull(int dictionaryKey)
{
return tupleInfo.isNull(getTupleSlice(dictionaryKey));
}
public boolean tupleEquals(int dictionaryKey, Tuple value)
{
checkNotNull(value, "value is null");
return tupleInfo.equals(value.getTupleInfo()) && getTupleSlice(dictionaryKey).equals(value.getTupleSlice());
}
public Slice getTupleSlice(int dictionaryKey)
{
return dictionary.get(dictionaryKey);
}
public void appendTupleTo(int dictionaryKey, BlockBuilder blockBuilder)
{
Slice slice = dictionary.get(dictionaryKey);
blockBuilder.appendTuple(slice, 0, slice.length());
}
public static class DictionaryBuilder
{
private final TupleInfo tupleInfo;
private final Map<Slice, Integer> dictionary = new HashMap<>();
private int nextId = 0;
public DictionaryBuilder(TupleInfo tupleInfo)
{
this.tupleInfo = tupleInfo;
}
public long getId(Tuple tuple)
{
Preconditions.checkNotNull(tuple, "tuple is null");
Integer id = dictionary.get(tuple.getTupleSlice());
if (id == null) {
id = nextId;
nextId++;
dictionary.put(tuple.getTupleSlice(), id);
}
return id;
}
public Dictionary build()
{
// Convert ID map to compact dictionary array (should be contiguous)
Slice[] dictionary = new Slice[this.dictionary.size()];
for (Entry<Slice, Integer> entry : this.dictionary.entrySet()) {
dictionary[entry.getValue()] = entry.getKey();
}
return new Dictionary(tupleInfo, dictionary);
}
}
}