package org.apache.lucene.index;/** * 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 org.apache.lucene.util.ArrayUtil;import org.apache.lucene.search.Similarity;/** Taps into DocInverter, as an InvertedDocEndConsumer, *  which is called at the end of inverting each field.  We *  just look at the length for the field (docState.length) *  and record the norm. */final class NormsWriterPerField extends InvertedDocEndConsumerPerField implements Comparable {  final NormsWriterPerThread perThread;  final FieldInfo fieldInfo;  final DocumentsWriter.DocState docState;  // Holds all docID/norm pairs we've seen  int[] docIDs = new int[1];  byte[] norms = new byte[1];  int upto;  final DocInverter.FieldInvertState fieldState;  public void reset() {    // Shrink back if we are overallocated now:    docIDs = ArrayUtil.shrink(docIDs, upto);    norms = ArrayUtil.shrink(norms, upto);    upto = 0;  }  public NormsWriterPerField(final DocInverterPerField docInverterPerField, final NormsWriterPerThread perThread, final FieldInfo fieldInfo) {    this.perThread = perThread;    this.fieldInfo = fieldInfo;    docState = perThread.docState;    fieldState = docInverterPerField.fieldState;  }  void abort() {    upto = 0;  }  public int compareTo(Object other) {    return fieldInfo.name.compareTo(((NormsWriterPerField) other).fieldInfo.name);  }    void finish() {    assert docIDs.length == norms.length;    if (fieldInfo.isIndexed && !fieldInfo.omitNorms) {      if (docIDs.length <= upto) {        assert docIDs.length == upto;        docIDs = ArrayUtil.grow(docIDs, 1+upto);        norms = ArrayUtil.grow(norms, 1+upto);      }      final float norm = fieldState.boost * docState.similarity.lengthNorm(fieldInfo.name, fieldState.length);      norms[upto] = Similarity.encodeNorm(norm);      docIDs[upto] = docState.docID;      upto++;    }  }}