PluginDrivenQueryTableValueFunction.java

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package org.apache.doris.tablefunction;

import org.apache.doris.analysis.TupleDescriptor;
import org.apache.doris.catalog.Column;
import org.apache.doris.common.AnalysisException;
import org.apache.doris.connector.api.ConnectorMetadata;
import org.apache.doris.connector.api.ConnectorPassthroughSqlOps;
import org.apache.doris.connector.api.ConnectorSession;
import org.apache.doris.connector.api.ConnectorTableSchema;
import org.apache.doris.connector.api.handle.PassthroughQueryTableHandle;
import org.apache.doris.datasource.connector.converter.ConnectorColumnConverter;
import org.apache.doris.datasource.plugin.PluginDrivenExternalCatalog;
import org.apache.doris.datasource.plugin.PluginDrivenMetadata;
import org.apache.doris.datasource.scan.PluginDrivenScanNode;
import org.apache.doris.planner.PlanNodeId;
import org.apache.doris.planner.ScanContext;
import org.apache.doris.planner.ScanNode;
import org.apache.doris.qe.SessionVariable;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.util.List;
import java.util.Map;

/**
 * The {@code query()} TVF over a plugin-driven catalog: it passes the SQL string through to the connector,
 * which answers the column list and plans the scan.
 *
 * <p>It was called {@code JdbcQueryTableValueFunction} because jdbc is the only connector that declares the
 * passthrough capability today, but nothing here is jdbc-specific — {@link QueryTableValueFunction} routes
 * EVERY catalog declaring that capability to this one class, and it reaches the connector only through the
 * SPI. A second connector declaring it needs no new class and no change here.</p>
 */
public class PluginDrivenQueryTableValueFunction extends QueryTableValueFunction {
    public static final Logger LOG = LogManager.getLogger(PluginDrivenQueryTableValueFunction.class);

    public PluginDrivenQueryTableValueFunction(Map<String, String> params) throws AnalysisException {
        super(params);
    }

    @Override
    public List<Column> getTableColumns() throws AnalysisException {
        PluginDrivenExternalCatalog pluginCatalog = (PluginDrivenExternalCatalog) catalogIf;
        ConnectorSession session = pluginCatalog.buildConnectorSession();
        ConnectorMetadata metadata = PluginDrivenMetadata.get(session, pluginCatalog.getConnector());
        // The factory already refused a catalog whose metadata does not implement this.
        ConnectorTableSchema schema =
                ((ConnectorPassthroughSqlOps) metadata).getColumnsFromQuery(session, query);
        return ConnectorColumnConverter.convertColumns(schema.getColumns());
    }

    @Override
    public ScanNode getScanNode(PlanNodeId id, TupleDescriptor desc, SessionVariable sv) {
        PluginDrivenExternalCatalog pluginCatalog = (PluginDrivenExternalCatalog) catalogIf;
        ConnectorSession session = pluginCatalog.buildConnectorSession();
        PassthroughQueryTableHandle queryHandle = new PassthroughQueryTableHandle(query);
        return new PluginDrivenScanNode(id, desc, false, sv,
                ScanContext.builder().clusterName(sv.resolveCloudClusterName()).build(),
                pluginCatalog.getConnector(), session, queryHandle);
    }
}