flink-connectors/flink-connector-files/src/main/java/org/apache/flink/connector/file/table/RowPartitionComputer.java

/*
 * 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.flink.connector.file.table;

import org.apache.flink.annotation.Internal;
import org.apache.flink.table.types.DataType;
import org.apache.flink.table.types.logical.LogicalType;
import org.apache.flink.table.types.logical.LogicalTypeRoot;
import org.apache.flink.types.Row;

import java.math.BigDecimal;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

/** {@link PartitionComputer} for {@link Row}. */
@Internal
public class RowPartitionComputer implements PartitionComputer<Row> {

    private static final long serialVersionUID = 1L;

    protected final String defaultPartValue;
    protected final String[] partitionColumns;
    private final int[] nonPartitionIndexes;
    protected final int[] partitionIndexes;

    public RowPartitionComputer(
            String defaultPartValue, String[] columnNames, String[] partitionColumns) {
        this.defaultPartValue = defaultPartValue;
        this.partitionColumns = partitionColumns;
        List<String> columnList = Arrays.asList(columnNames);
        this.partitionIndexes =
                Arrays.stream(partitionColumns).mapToInt(columnList::indexOf).toArray();
        List<Integer> partitionIndexList =
                Arrays.stream(partitionIndexes).boxed().collect(Collectors.toList());
        this.nonPartitionIndexes =
                IntStream.range(0, columnNames.length)
                        .filter(c -> !partitionIndexList.contains(c))
                        .toArray();
    }

    @Override
    public LinkedHashMap<String, String> generatePartValues(Row in) throws Exception {
        LinkedHashMap<String, String> partSpec = new LinkedHashMap<>();

        for (int i = 0; i < partitionIndexes.length; i++) {
            int index = partitionIndexes[i];
            Object field = in.getField(index);
            String partitionValue = field != null ? field.toString() : null;
            if (partitionValue == null || "".equals(partitionValue)) {
                partitionValue = defaultPartValue;
            }
            partSpec.put(partitionColumns[i], partitionValue);
        }
        return partSpec;
    }

    @Override
    public Row projectColumnsToWrite(Row in) {
        return partitionIndexes.length == 0 ? in : Row.project(in, nonPartitionIndexes);
    }

    public static Object restorePartValueFromType(String valStr, DataType type) {
        return restorePartValueFromType(valStr, type.getLogicalType());
    }

    /**
     * Restore partition value from string and type. This method is the opposite of method {@link
     * #generatePartValues}.
     *
     * @param valStr string partition value.
     * @param type type of partition field.
     * @return partition value.
     */
    public static Object restorePartValueFromType(String valStr, LogicalType type) {
        if (valStr == null) {
            return null;
        }

        LogicalTypeRoot typeRoot = type.getTypeRoot();
        switch (typeRoot) {
            case CHAR:
            case VARCHAR:
                return valStr;
            case BOOLEAN:
                return Boolean.parseBoolean(valStr);
            case TINYINT:
                return Integer.valueOf(valStr).byteValue();
            case SMALLINT:
                return Short.valueOf(valStr);
            case INTEGER:
                return Integer.valueOf(valStr);
            case BIGINT:
                return Long.valueOf(valStr);
            case FLOAT:
                return Float.valueOf(valStr);
            case DOUBLE:
                return Double.valueOf(valStr);
            case DATE:
                return LocalDate.parse(valStr);
            case TIMESTAMP_WITHOUT_TIME_ZONE:
                return LocalDateTime.parse(valStr);
            case DECIMAL:
                return new BigDecimal(valStr);
            default:
                throw new RuntimeException(
                        String.format(
                                "Can not convert %s to type %s for partition value", valStr, type));
        }
    }
}