Java Code Examples for org.apache.flink.table.types.logical.LogicalType#copy()

/**
 * Returns the most common type of a set of types. It determines a type to which all given types
 * can be casted.
 *
 * <p>For example: {@code [INT, BIGINT, DECIMAL(2, 2)]} would lead to {@code DECIMAL(21, 2)}.
 */
public static Optional<LogicalType> findCommonType(List<LogicalType> types) {
	Preconditions.checkArgument(types.size() > 0, "List of types must not be empty.");

	// collect statistics first
	boolean hasAnyType = false;
	boolean hasNullType = false;
	boolean hasNullableTypes = false;
	for (LogicalType type : types) {
		final LogicalTypeRoot typeRoot = type.getTypeRoot();
		if (typeRoot == ANY) {
			hasAnyType = true;
		} else if (typeRoot == NULL) {
			hasNullType = true;
		}
		if (type.isNullable()) {
			hasNullableTypes = true;
		}
	}

	final List<LogicalType> normalizedTypes = types.stream()
		.map(t -> t.copy(true))
		.collect(Collectors.toList());

	LogicalType foundType = findCommonNullableType(normalizedTypes, hasAnyType, hasNullType);
	if (foundType == null) {
		foundType = findCommonCastableType(normalizedTypes);
	}

	if (foundType != null) {
		final LogicalType typeWithNullability = foundType.copy(hasNullableTypes);
		return Optional.of(typeWithNullability);
	}
	return Optional.empty();
}
 

/**
 * Returns the most common, more general {@link LogicalType} for a given set of types. If such
 * a type exists, all given types can be casted to this more general type.
 *
 * <p>For example: {@code [INT, BIGINT, DECIMAL(2, 2)]} would lead to {@code DECIMAL(21, 2)}.
 *
 * <p>This class aims to be compatible with the SQL standard. It is inspired by Apache Calcite's
 * {@code SqlTypeFactoryImpl#leastRestrictive} method.
 */
public static Optional<LogicalType> findCommonType(List<LogicalType> types) {
	Preconditions.checkArgument(types.size() > 0, "List of types must not be empty.");

	// collect statistics first
	boolean hasRawType = false;
	boolean hasNullType = false;
	boolean hasNullableTypes = false;
	for (LogicalType type : types) {
		final LogicalTypeRoot typeRoot = type.getTypeRoot();
		if (typeRoot == RAW) {
			hasRawType = true;
		} else if (typeRoot == NULL) {
			hasNullType = true;
		}
		if (type.isNullable()) {
			hasNullableTypes = true;
		}
	}

	final List<LogicalType> normalizedTypes = types.stream()
		.map(t -> t.copy(true))
		.collect(Collectors.toList());

	LogicalType foundType = findCommonNullableType(normalizedTypes, hasRawType, hasNullType);
	if (foundType == null) {
		foundType = findCommonCastableType(normalizedTypes);
	}

	if (foundType != null) {
		final LogicalType typeWithNullability = foundType.copy(hasNullableTypes);
		// NULL is reserved for untyped literals only
		if (hasRoot(typeWithNullability, NULL)) {
			return Optional.empty();
		}
		return Optional.of(typeWithNullability);
	}
	return Optional.empty();
}
 

@Override
protected LogicalType defaultMethod(LogicalType logicalType) {
	return logicalType.copy();
}
 

@Override
protected LogicalType defaultMethod(LogicalType logicalType) {
	return logicalType.copy();
}
 

/**
 * See {@code org.apache.flink.table.catalog.hive.util.HiveTypeUtil}.
 */
public static TypeDescription logicalTypeToOrcType(LogicalType type) {
	type = type.copy(true);
	switch (type.getTypeRoot()) {
		case CHAR:
			return TypeDescription.createChar().withMaxLength(((CharType) type).getLength());
		case VARCHAR:
			int len = ((VarCharType) type).getLength();
			if (len == VarCharType.MAX_LENGTH) {
				return TypeDescription.createString();
			} else {
				return TypeDescription.createVarchar().withMaxLength(len);
			}
		case BOOLEAN:
			return TypeDescription.createBoolean();
		case VARBINARY:
			if (type.equals(DataTypes.BYTES().getLogicalType())) {
				return TypeDescription.createBinary();
			} else {
				throw new UnsupportedOperationException(
						"Not support other binary type: " + type);
			}
		case DECIMAL:
			DecimalType decimalType = (DecimalType) type;
			return TypeDescription.createDecimal()
					.withScale(decimalType.getScale())
					.withPrecision(decimalType.getPrecision());
		case TINYINT:
			return TypeDescription.createByte();
		case SMALLINT:
			return TypeDescription.createShort();
		case INTEGER:
			return TypeDescription.createInt();
		case BIGINT:
			return TypeDescription.createLong();
		case FLOAT:
			return TypeDescription.createFloat();
		case DOUBLE:
			return TypeDescription.createDouble();
		case DATE:
			return TypeDescription.createDate();
		case TIMESTAMP_WITHOUT_TIME_ZONE:
			return TypeDescription.createTimestamp();
		case ARRAY:
			ArrayType arrayType = (ArrayType) type;
			return TypeDescription.createList(logicalTypeToOrcType(arrayType.getElementType()));
		case MAP:
			MapType mapType = (MapType) type;
			return TypeDescription.createMap(
					logicalTypeToOrcType(mapType.getKeyType()),
					logicalTypeToOrcType(mapType.getValueType()));
		case ROW:
			RowType rowType = (RowType) type;
			TypeDescription struct = TypeDescription.createStruct();
			for (int i = 0; i < rowType.getFieldCount(); i++) {
				struct.addField(
						rowType.getFieldNames().get(i),
						logicalTypeToOrcType(rowType.getChildren().get(i)));
			}
			return struct;
		default:
			throw new UnsupportedOperationException("Unsupported type: " + type);
	}
}
 

private static void testNullability(LogicalType nullableType) {
	final LogicalType notNullInstance = nullableType.copy(false);

	assertNotEquals(nullableType, notNullInstance);

	assertFalse(notNullInstance.isNullable());
}
 

private static void testNullability(LogicalType nullableType) {
	final LogicalType notNullInstance = nullableType.copy(false);

	assertNotEquals(nullableType, notNullInstance);

	assertFalse(notNullInstance.isNullable());
}