# MariaDBWriteOperation.java

    package org.codefilarete.stalactite.sql.mariadb;

    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.SQLException;

    import org.codefilarete.stalactite.sql.ConnectionProvider;
    import org.codefilarete.tool.Retryer.RetryException;
    import org.codefilarete.tool.function.ThrowingBiFunction;
    import org.codefilarete.stalactite.sql.statement.SQLExecutionException;
    import org.codefilarete.stalactite.sql.statement.SQLStatement;
    import org.codefilarete.stalactite.sql.statement.WriteOperation;

    /**
     * MariaDB's implementation of {@link WriteOperation} to retry statement execution because MariaDB InnoDB has a poor behavior of insertion concurrency
     *
     * @author Guillaume Mary
     */
    public class MariaDBWriteOperation<ParamType> extends WriteOperation<ParamType> {

    	private final InnoDBLockRetryer retryer;

    	private final ThrowingBiFunction<Connection, String, PreparedStatement, SQLException> statementProvider;

    	public MariaDBWriteOperation(SQLStatement<ParamType> sqlGenerator, ConnectionProvider connectionProvider, RowCountListener rowCountListener,
    								 InnoDBLockRetryer retryer, ThrowingBiFunction<Connection, String, PreparedStatement, SQLException> statementProvider) {
    		super(sqlGenerator, connectionProvider, rowCountListener);
    		this.retryer = retryer;
    		this.statementProvider = statementProvider;
    	}

    	public MariaDBWriteOperation(SQLStatement<ParamType> sqlGenerator, ConnectionProvider connectionProvider, RowCountListener rowCountListener, InnoDBLockRetryer retryer) {
    		this(sqlGenerator, connectionProvider, rowCountListener, retryer, Connection::prepareStatement);
    	}

    	@Override
    	protected void prepareStatement(Connection connection) throws SQLException {
    		this.preparedStatement = statementProvider.apply(connection, getSQL());
    	}

    	/**
    	 * Overridden to :
    	 * - call executeUpdate() instead of executeLargeUpdate() because MariaDB client 1.3.4 doesn't support it
    	 * - call retryer to prevent exception due to key lock on insert
    	 */
    	@Override
    	protected long doExecuteUpdate() throws SQLException {
    		try {
    			return (long) retryer.execute(preparedStatement::executeUpdate, getSQL());
    		} catch (RetryException e) {
    			throw new SQLExecutionException(getSQL(), e);
    		}
    	}

    	/**
    	 * Overridden to :
    	 * - call executeBatch() instead of executeLargeBatch() because MariaDB client 1.3.4 doesn't support it
    	 * - call retryer to prevent exception due to key lock on insert
    	 */
    	@Override
    	protected long[] doExecuteBatch() throws SQLException {
    		int[] updatedRowCounts;
    		try {
    			updatedRowCounts = retryer.execute(preparedStatement::executeBatch, getSQL());
    		} catch (RetryException e) {
    			throw new SQLExecutionException(getSQL(), e);
    		}
    		long[] updatedRowCountsAsLong = new long[updatedRowCounts.length];
    		for (int i = 0; i < updatedRowCounts.length; i++) {
    			updatedRowCountsAsLong[i] = updatedRowCounts[i];
    		}
    		return updatedRowCountsAsLong;
    	}
    }