ParentFieldMapper.java

/*
 * Licensed to Elastic Search and Shay Banon under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Elastic Search 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.
 */

package org.elasticsearch.index.mapper.internal;

import org.apache.lucene.document.Field;
import org.apache.lucene.document.Fieldable;
import org.apache.lucene.index.FieldInfo.IndexOptions;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.ConstantScoreQuery;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.XTermsFilter;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.lucene.Lucene;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.index.mapper.*;
import org.elasticsearch.index.mapper.core.AbstractFieldMapper;
import org.elasticsearch.index.query.QueryParseContext;

import java.io.IOException;
import java.util.Map;

/**
 *
 */
public class ParentFieldMapper extends AbstractFieldMapper<Uid> implements InternalMapper, RootMapper {

    public static final String NAME = "_parent";

    public static final String CONTENT_TYPE = "_parent";

    public static class Defaults extends AbstractFieldMapper.Defaults {
        public static final String NAME = ParentFieldMapper.NAME;
        public static final Field.Index INDEX = Field.Index.NOT_ANALYZED;
        public static final boolean OMIT_NORMS = true;
        public static final IndexOptions INDEX_OPTIONS = IndexOptions.DOCS_ONLY;
    }

    public static class Builder extends Mapper.Builder<Builder, ParentFieldMapper> {

        protected String indexName;

        private String type;

        public Builder() {
            super(Defaults.NAME);
            this.indexName = name;
        }

        public Builder type(String type) {
            this.type = type;
            return builder;
        }

        @Override
        public ParentFieldMapper build(BuilderContext context) {
            if (type == null) {
                throw new MapperParsingException("Parent mapping must contain the parent type");
            }
            return new ParentFieldMapper(name, indexName, type);
        }
    }

    public static class TypeParser implements Mapper.TypeParser {
        @Override
        public Mapper.Builder parse(String name, Map<String, Object> node, ParserContext parserContext) throws MapperParsingException {
            ParentFieldMapper.Builder builder = new ParentFieldMapper.Builder();
            for (Map.Entry<String, Object> entry : node.entrySet()) {
                String fieldName = Strings.toUnderscoreCase(entry.getKey());
                Object fieldNode = entry.getValue();
                if (fieldName.equals("type")) {
                    builder.type(fieldNode.toString());
                }
            }
            return builder;
        }
    }

    private final String type;

    protected ParentFieldMapper(String name, String indexName, String type) {
        super(new Names(name, indexName, indexName, name), Defaults.INDEX, Field.Store.YES, Defaults.TERM_VECTOR, Defaults.BOOST,
                Defaults.OMIT_NORMS, Defaults.INDEX_OPTIONS, Lucene.KEYWORD_ANALYZER, Lucene.KEYWORD_ANALYZER);
        this.type = type;
    }

    public String type() {
        return type;
    }

    @Override
    public void preParse(ParseContext context) throws IOException {
    }

    @Override
    public void postParse(ParseContext context) throws IOException {
        parse(context);
    }

    @Override
    public void validate(ParseContext context) throws MapperParsingException {
    }

    @Override
    public boolean includeInObject() {
        return true;
    }

    @Override
    protected Field parseCreateField(ParseContext context) throws IOException {
        if (context.parser().currentName() != null && context.parser().currentName().equals(Defaults.NAME)) {
            // we are in the parsing of _parent phase
            String parentId = context.parser().text();
            context.sourceToParse().parent(parentId);
            return new Field(names.indexName(), Uid.createUid(context.stringBuilder(), type, parentId), store, index);
        }
        // otherwise, we are running it post processing of the xcontent
        String parsedParentId = context.doc().get(Defaults.NAME);
        if (context.sourceToParse().parent() != null) {
            String parentId = context.sourceToParse().parent();
            if (parsedParentId == null) {
                if (parentId == null) {
                    throw new MapperParsingException("No parent id provided, not within the document, and not externally");
                }
                // we did not add it in the parsing phase, add it now
                return new Field(names.indexName(), Uid.createUid(context.stringBuilder(), type, parentId), store, index);
            } else if (parentId != null && !parsedParentId.equals(Uid.createUid(context.stringBuilder(), type, parentId))) {
                throw new MapperParsingException("Parent id mismatch, document value is [" + Uid.createUid(parsedParentId).id() + "], while external value is [" + parentId + "]");
            }
        }
        // we have parent mapping, yet no value was set, ignore it...
        return null;
    }

    @Override
    public Uid value(Fieldable field) {
        return Uid.createUid(field.stringValue());
    }

    @Override
    public Uid valueFromString(String value) {
        return Uid.createUid(value);
    }

    @Override
    public String valueAsString(Fieldable field) {
        return field.stringValue();
    }

    @Override
    public Object valueForSearch(Fieldable field) {
        String fieldValue = field.stringValue();
        if (fieldValue == null) {
            return null;
        }
        int index = fieldValue.indexOf(Uid.DELIMITER);
        if (index == -1) {
            return fieldValue;
        }
        return fieldValue.substring(index + 1);
    }

    @Override
    public String indexedValue(String value) {
        if (value.indexOf(Uid.DELIMITER) == -1) {
            return Uid.createUid(type, value);
        }
        return value;
    }

    @Override
    public Query fieldQuery(String value, @Nullable QueryParseContext context) {
        if (context == null) {
            return super.fieldQuery(value, context);
        }
        return new ConstantScoreQuery(fieldFilter(value, context));
    }

    @Override
    public Filter fieldFilter(String value, @Nullable QueryParseContext context) {
        if (context == null) {
            return super.fieldFilter(value, context);
        }
        // we use all types, cause we don't know if its exact or not...
        Term[] typesTerms = new Term[context.mapperService().types().size()];
        int i = 0;
        for (String type : context.mapperService().types()) {
            typesTerms[i++] = names.createIndexNameTerm(Uid.createUid(type, value));
        }
        return new XTermsFilter(typesTerms);
    }

    /**
     * We don't need to analyzer the text, and we need to convert it to UID...
     */
    @Override
    public boolean useFieldQueryWithQueryString() {
        return true;
    }

    public Term term(String type, String id) {
        return term(Uid.createUid(type, id));
    }

    public Term term(String uid) {
        return names().createIndexNameTerm(uid);
    }

    @Override
    protected String contentType() {
        return CONTENT_TYPE;
    }

    @Override
    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
        builder.startObject(CONTENT_TYPE);
        builder.field("type", type);
        builder.endObject();
        return builder;
    }

    @Override
    public void merge(Mapper mergeWith, MergeContext mergeContext) throws MergeMappingException {
        // do nothing here, no merging, but also no exception
    }
}