org.apache.hive.service.cli.ColumnBasedSet.java Source code

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Here is the source code for org.apache.hive.service.cli.ColumnBasedSet.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.hive.service.cli;

import java.io.ByteArrayInputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.hadoop.hive.serde2.thrift.ColumnBuffer;
import org.apache.hive.service.rpc.thrift.TColumn;
import org.apache.hive.service.rpc.thrift.TRow;
import org.apache.hive.service.rpc.thrift.TRowSet;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TCompactProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TIOStreamTransport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * ColumnBasedSet.
 */
public class ColumnBasedSet implements RowSet {

    private long startOffset;

    private final TypeDescriptor[] descriptors; // non-null only for writing (server-side)
    private final List<ColumnBuffer> columns;
    private byte[] blob;
    private boolean isBlobBased = false;
    public static final Logger LOG = LoggerFactory.getLogger(ColumnBasedSet.class);

    public ColumnBasedSet(TableSchema schema) {
        descriptors = schema.toTypeDescriptors();
        columns = new ArrayList<ColumnBuffer>();
        for (ColumnDescriptor colDesc : schema.getColumnDescriptors()) {
            columns.add(new ColumnBuffer(colDesc.getType()));
        }
    }

    public ColumnBasedSet(TRowSet tRowSet) throws TException {
        descriptors = null;
        columns = new ArrayList<ColumnBuffer>();
        // Use TCompactProtocol to read serialized TColumns
        if (tRowSet.isSetBinaryColumns()) {
            TProtocol protocol = new TCompactProtocol(
                    new TIOStreamTransport(new ByteArrayInputStream(tRowSet.getBinaryColumns())));
            // Read from the stream using the protocol for each column in final schema
            for (int i = 0; i < tRowSet.getColumnCount(); i++) {
                TColumn tvalue = new TColumn();
                try {
                    tvalue.read(protocol);
                } catch (TException e) {
                    LOG.error(e.getMessage(), e);
                    throw new TException("Error reading column value from the row set blob", e);
                }
                columns.add(new ColumnBuffer(tvalue));
            }
        } else {
            if (tRowSet.getColumns() != null) {
                for (TColumn tvalue : tRowSet.getColumns()) {
                    columns.add(new ColumnBuffer(tvalue));
                }
            }
        }
        startOffset = tRowSet.getStartRowOffset();
    }

    private ColumnBasedSet(TypeDescriptor[] descriptors, List<ColumnBuffer> columns, long startOffset) {
        this.descriptors = descriptors;
        this.columns = columns;
        this.startOffset = startOffset;
    }

    public ColumnBasedSet(TableSchema schema, boolean isBlobBased) {
        this(schema);
        this.isBlobBased = isBlobBased;
    }

    @Override
    public ColumnBasedSet addRow(Object[] fields) {
        if (isBlobBased) {
            this.blob = (byte[]) fields[0];
        } else {
            for (int i = 0; i < fields.length; i++) {
                TypeDescriptor descriptor = descriptors[i];
                columns.get(i).addValue(descriptor.getType(), fields[i]);
            }
        }
        return this;
    }

    public List<ColumnBuffer> getColumns() {
        return columns;
    }

    @Override
    public int numColumns() {
        return columns.size();
    }

    @Override
    public int numRows() {
        return columns.isEmpty() ? 0 : columns.get(0).size();
    }

    @Override
    public ColumnBasedSet extractSubset(int maxRows) {
        int numRows = Math.min(numRows(), maxRows);

        List<ColumnBuffer> subset = new ArrayList<ColumnBuffer>();
        for (int i = 0; i < columns.size(); i++) {
            subset.add(columns.get(i).extractSubset(numRows));
        }
        ColumnBasedSet result = new ColumnBasedSet(descriptors, subset, startOffset);
        startOffset += numRows;
        return result;
    }

    @Override
    public long getStartOffset() {
        return startOffset;
    }

    @Override
    public void setStartOffset(long startOffset) {
        this.startOffset = startOffset;
    }

    public TRowSet toTRowSet() {
        TRowSet tRowSet = new TRowSet(startOffset, new ArrayList<TRow>());
        if (isBlobBased) {
            tRowSet.setColumns(null);
            tRowSet.setBinaryColumns(blob);
            tRowSet.setColumnCount(numColumns());
        } else {
            for (int i = 0; i < columns.size(); i++) {
                tRowSet.addToColumns(columns.get(i).toTColumn());
            }
        }
        return tRowSet;
    }

    @Override
    public Iterator<Object[]> iterator() {
        return new Iterator<Object[]>() {

            private int index;
            private final Object[] convey = new Object[numColumns()];

            @Override
            public boolean hasNext() {
                return index < numRows();
            }

            @Override
            public Object[] next() {
                for (int i = 0; i < columns.size(); i++) {
                    convey[i] = columns.get(i).get(index);
                }
                index++;
                return convey;
            }

            @Override
            public void remove() {
                throw new UnsupportedOperationException("remove");
            }
        };
    }

    public Object[] fill(int index, Object[] convey) {
        for (int i = 0; i < columns.size(); i++) {
            convey[i] = columns.get(i).get(index);
        }
        return convey;
    }
}