ArrowPageSourceProvider.java

/*
 * Licensed 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 com.facebook.plugin.arrow;

import com.facebook.presto.spi.ColumnHandle;
import com.facebook.presto.spi.ConnectorPageSource;
import com.facebook.presto.spi.ConnectorSession;
import com.facebook.presto.spi.ConnectorSplit;
import com.facebook.presto.spi.SplitContext;
import com.facebook.presto.spi.connector.ConnectorPageSourceProvider;
import com.facebook.presto.spi.connector.ConnectorTransactionHandle;
import com.google.common.collect.ImmutableList;

import javax.inject.Inject;

import java.util.List;

import static java.util.Objects.requireNonNull;

public class ArrowPageSourceProvider
        implements ConnectorPageSourceProvider
{
    private final BaseArrowFlightClientHandler clientHandler;
    private final ArrowBlockBuilder arrowBlockBuilder;

    @Inject
    public ArrowPageSourceProvider(BaseArrowFlightClientHandler clientHandler, ArrowBlockBuilder arrowBlockBuilder)
    {
        this.clientHandler = requireNonNull(clientHandler, "clientHandler is null");
        this.arrowBlockBuilder = requireNonNull(arrowBlockBuilder, "arrowBlockBuilder is null");
    }

    @Override
    public ConnectorPageSource createPageSource(ConnectorTransactionHandle transactionHandle, ConnectorSession session, ConnectorSplit split, List<ColumnHandle> columns, SplitContext splitContext)
    {
        ImmutableList.Builder<ArrowColumnHandle> columnHandles = ImmutableList.builder();
        for (ColumnHandle handle : columns) {
            columnHandles.add((ArrowColumnHandle) handle);
        }
        ArrowSplit arrowSplit = (ArrowSplit) split;
        return new ArrowPageSource(arrowSplit, columnHandles.build(), clientHandler, session, arrowBlockBuilder);
    }
}