com.yelp.nrtsearch.server.luceneserver.doc.SegmentDocLookup Maven / Gradle / Ivy

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GRPC lucene server using near-real-time replication
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/*
 * Copyright 2020 Yelp 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 com.yelp.nrtsearch.server.luceneserver.doc;

import com.yelp.nrtsearch.server.luceneserver.IndexState;
import com.yelp.nrtsearch.server.luceneserver.field.FieldDef;
import com.yelp.nrtsearch.server.luceneserver.field.IndexableFieldDef;
import java.io.IOException;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import org.apache.lucene.index.LeafReaderContext;

/**
 * Class that provides a lookup interface for doc values in a single lucene segment. Values are
 * accessed through the Map interface, with each field name mapping to its {@link LoadedDocValues}.
 *
 * The {@link LoadedDocValues} for each field are cached and can be reused for all subsequent
 * documents in the segment.
 */
public class SegmentDocLookup implements Map> {

  private final IndexState indexState;
  private final LeafReaderContext context;
  private final Map> loaderCache = new HashMap<>();

  private int docId = -1;

  public SegmentDocLookup(IndexState indexState, LeafReaderContext context) {
    this.indexState = indexState;
    this.context = context;
  }

  /**
   * Set target document id. All retrieved {@link LoadedDocValues} after this call will contain the
   * doc values for this id.
   *
   * @param docId target document id
   */
  public void setDocId(int docId) {
    this.docId = docId;
  }

  @Override
  public int size() {
    throw new UnsupportedOperationException();
  }

  @Override
  public boolean isEmpty() {
    throw new UnsupportedOperationException();
  }

  /**
   * Check if a given field name is capable of having doc values. This does not mean there is data
   * present, just that there can be.
   *
   * @param key field name
   * @return if this field may have stored doc values
   */
  @Override
  public boolean containsKey(Object key) {
    if (key == null) {
      return false;
    }
    String fieldName = key.toString();
    try {
      FieldDef field = indexState.getField(fieldName);
      return field instanceof IndexableFieldDef && ((IndexableFieldDef) field).hasDocValues();
    } catch (Exception ignored) {
      return false;
    }
  }

  @Override
  public boolean containsValue(Object value) {
    throw new UnsupportedOperationException();
  }

  /**
   * Get the {@link LoadedDocValues} for a given field. Creates a new instance or uses one from the
   * cache. The data is loaded for the current set document id.
   *
   * @param key field name
   * @return {@link LoadedDocValues} implementation for the given field
   * @throws IllegalArgumentException if the field does not support doc values, if there is a
   *     problem setting the target doc id, or if the field does not exist in the index
   * @throws NullPointerException if key is null
   */
  @Override
  public LoadedDocValues get(Object key) {
    Objects.requireNonNull(key);
    String fieldName = key.toString();
    LoadedDocValues docValues = loaderCache.get(fieldName);
    if (docValues == null) {
      FieldDef fieldDef = indexState.getField(fieldName);
      if (fieldDef == null) {
        throw new IllegalArgumentException("Field does not exist: " + fieldName);
      }
      if (!(fieldDef instanceof IndexableFieldDef)) {
        throw new IllegalArgumentException("Field cannot have doc values: " + fieldName);
      }
      IndexableFieldDef indexableFieldDef = (IndexableFieldDef) fieldDef;
      try {
        docValues = indexableFieldDef.getDocValues(context);
      } catch (IOException e) {
        throw new IllegalArgumentException("Could not get doc values for field: " + fieldName, e);
      }
      loaderCache.put(fieldName, docValues);
    }
    try {
      docValues.setDocId(docId);
    } catch (IOException e) {
      throw new IllegalArgumentException(
          "Could not set doc: " + docId + ", field: " + fieldName, e);
    }
    return docValues;
  }

  @Override
  public LoadedDocValues put(String key, LoadedDocValues value) {
    throw new UnsupportedOperationException();
  }

  @Override
  public LoadedDocValues remove(Object key) {
    throw new UnsupportedOperationException();
  }

  @Override
  public void putAll(Map> m) {
    throw new UnsupportedOperationException();
  }

  @Override
  public void clear() {
    throw new UnsupportedOperationException();
  }

  @Override
  public Set keySet() {
    throw new UnsupportedOperationException();
  }

  @Override
  public Collection> values() {
    throw new UnsupportedOperationException();
  }

  @Override
  public Set>> entrySet() {
    throw new UnsupportedOperationException();
  }
}