MappingPhase.java

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package org.apache.doris.datasource.es;

import org.apache.doris.catalog.Column;

import java.util.stream.Collectors;

/**
 * Get index mapping from remote ES Cluster, and resolved `keyword` and `doc_values` field
 * Later we can use it to parse all relevant indexes
 */
public class MappingPhase implements SearchPhase {

    private EsRestClient client;

    // json response for `{index}/_mapping` API
    private String jsonMapping;

    public MappingPhase(EsRestClient client) {
        this.client = client;
    }

    @Override
    public void execute(SearchContext context) throws DorisEsException {
        jsonMapping = client.getMapping(context.sourceIndex());
    }

    @Override
    public void postProcess(SearchContext context) {
        resolveFields(context, jsonMapping);
    }

    /**
     * Parse the required field information from the json.
     *
     * @param searchContext the current associated column searchContext
     * @param indexMapping the return value of _mapping
     */
    public static void resolveFields(SearchContext searchContext, String indexMapping) throws DorisEsException {
        EsFieldContext fields = EsMappingUtils.resolveFieldContext(searchContext.columns().stream()
                .map(Column::getName).collect(Collectors.toList()), searchContext.sourceIndex(),
                indexMapping, searchContext.type());
        searchContext.setFieldContext(fields);
    }
}