| package org.apache.lucene.facet; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.io.IOException; |
| |
| import org.apache.lucene.index.AtomicReaderContext; |
| import org.apache.lucene.index.BinaryDocValues; |
| import org.apache.lucene.util.ArrayUtil; |
| import org.apache.lucene.util.BytesRef; |
| import org.apache.lucene.util.IntsRef; |
| |
| /** Decodes ordinals previously indexed into a BinaryDocValues field */ |
| |
| public class DocValuesOrdinalsReader extends OrdinalsReader { |
| private final String field; |
| |
| /** Default constructor. */ |
| public DocValuesOrdinalsReader() { |
| this(FacetsConfig.DEFAULT_INDEX_FIELD_NAME); |
| } |
| |
| /** Create this, with the specified indexed field name. */ |
| public DocValuesOrdinalsReader(String field) { |
| this.field = field; |
| } |
| |
| @Override |
| public OrdinalsSegmentReader getReader(AtomicReaderContext context) throws IOException { |
| BinaryDocValues values0 = context.reader().getBinaryDocValues(field); |
| if (values0 == null) { |
| values0 = BinaryDocValues.EMPTY; |
| } |
| |
| final BinaryDocValues values = values0; |
| |
| return new OrdinalsSegmentReader() { |
| private final BytesRef bytes = new BytesRef(32); |
| |
| @Override |
| public void get(int docID, IntsRef ordinals) throws IOException { |
| values.get(docID, bytes); |
| decode(bytes, ordinals); |
| } |
| }; |
| } |
| |
| @Override |
| public String getIndexFieldName() { |
| return field; |
| } |
| |
| /** Subclass & override if you change the encoding. */ |
| protected void decode(BytesRef buf, IntsRef ordinals) { |
| |
| // grow the buffer up front, even if by a large number of values (buf.length) |
| // that saves the need to check inside the loop for every decoded value if |
| // the buffer needs to grow. |
| if (ordinals.ints.length < buf.length) { |
| ordinals.ints = ArrayUtil.grow(ordinals.ints, buf.length); |
| } |
| |
| ordinals.offset = 0; |
| ordinals.length = 0; |
| |
| // it is better if the decoding is inlined like so, and not e.g. |
| // in a utility method |
| int upto = buf.offset + buf.length; |
| int value = 0; |
| int offset = buf.offset; |
| int prev = 0; |
| while (offset < upto) { |
| byte b = buf.bytes[offset++]; |
| if (b >= 0) { |
| ordinals.ints[ordinals.length] = ((value << 7) | b) + prev; |
| value = 0; |
| prev = ordinals.ints[ordinals.length]; |
| ordinals.length++; |
| } else { |
| value = (value << 7) | (b & 0x7F); |
| } |
| } |
| } |
| } |