PluginDrivenExternalDatabase.java

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package org.apache.doris.datasource;

import org.apache.doris.connector.api.Connector;
import org.apache.doris.connector.api.ConnectorCapability;

/**
 * Generic {@link ExternalDatabase} for plugin-driven catalogs.
 *
 * <p>Provides minimal implementation that delegates table construction
 * to {@link PluginDrivenExternalTable}.</p>
 */
public class PluginDrivenExternalDatabase extends ExternalDatabase<PluginDrivenExternalTable> {

    /** No-arg constructor for GSON deserialization. */
    public PluginDrivenExternalDatabase() {
        super(null, 0, null, null, InitDatabaseLog.Type.PLUGIN);
    }

    public PluginDrivenExternalDatabase(ExternalCatalog extCatalog, long id,
            String name, String remoteName) {
        super(extCatalog, id, name, remoteName, InitDatabaseLog.Type.PLUGIN);
    }

    @Override
    protected PluginDrivenExternalTable buildTableInternal(String remoteTableName,
            String localTableName, long tblId, ExternalCatalog catalog, ExternalDatabase db) {
        // Capability gate: connectors that expose a point-in-time snapshot (e.g. Paimon) declare
        // SUPPORTS_MVCC_SNAPSHOT and get the MVCC/MTMV-capable subclass. The plain plugin connectors
        // (jdbc/es/max_compute/trino-connector) do NOT declare it and keep the base class, which has
        // no MTMV/MvccTable behavior. getConnector() forces init (makeSureInitialized) and returns the
        // built connector; the null check is a defensive fallback to the base class for a not-yet-built
        // or failed connector (post-init it is normally non-null ��� initLocalObjectsImpl throws on null).
        if (catalog instanceof PluginDrivenExternalCatalog) {
            Connector connector = ((PluginDrivenExternalCatalog) catalog).getConnector();
            if (connector != null
                    && connector.getCapabilities().contains(ConnectorCapability.SUPPORTS_MVCC_SNAPSHOT)) {
                return new PluginDrivenMvccExternalTable(tblId, localTableName, remoteTableName, catalog, db);
            }
        }
        return new PluginDrivenExternalTable(tblId, localTableName, remoteTableName, catalog, db);
    }
}