org.apache.druid.query.expression.TimestampParseExprMacro Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of druid-processing Show documentation
Show all versions of druid-processing Show documentation
A module that is everything required to understands Druid Segments
/*
* 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.druid.query.expression;
import org.apache.druid.java.util.common.DateTimes;
import org.apache.druid.math.expr.Expr;
import org.apache.druid.math.expr.ExprEval;
import org.apache.druid.math.expr.ExprMacroTable;
import org.apache.druid.math.expr.ExpressionType;
import org.joda.time.DateTimeZone;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;
import org.joda.time.format.DateTimeFormatterBuilder;
import org.joda.time.format.DateTimeParser;
import org.joda.time.format.ISODateTimeFormat;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.List;
public class TimestampParseExprMacro implements ExprMacroTable.ExprMacro
{
private static final String FN_NAME = "timestamp_parse";
@Override
public String name()
{
return FN_NAME;
}
@Override
public Expr apply(final List args)
{
validationHelperCheckArgumentRange(args, 1, 3);
final Expr arg = args.get(0);
final String formatString = args.size() > 1 ? (String) args.get(1).getLiteralValue() : null;
final DateTimeZone timeZone;
if (args.size() > 2 && args.get(2).getLiteralValue() != null) {
timeZone = DateTimes.inferTzFromString((String) args.get(2).getLiteralValue());
} else {
timeZone = DateTimeZone.UTC;
}
final DateTimes.UtcFormatter formatter =
formatString == null
? createDefaultParser(timeZone)
: DateTimes.wrapFormatter(DateTimeFormat.forPattern(formatString).withZone(timeZone));
class TimestampParseExpr extends ExprMacroTable.BaseScalarMacroFunctionExpr
{
private TimestampParseExpr(List args)
{
super(TimestampParseExprMacro.this, args);
}
@Nonnull
@Override
public ExprEval eval(final ObjectBinding bindings)
{
final String value = arg.eval(bindings).asString();
if (value == null) {
return ExprEval.of(null);
}
try {
return ExprEval.of(formatter.parse(value).getMillis());
}
catch (IllegalArgumentException e) {
// Catch exceptions potentially thrown by formatter.parseDateTime. Our docs say that unparseable timestamps
// are returned as nulls.
return ExprEval.of(null);
}
}
@Nullable
@Override
public ExpressionType getOutputType(InputBindingInspector inspector)
{
return ExpressionType.LONG;
}
}
return new TimestampParseExpr(args);
}
/**
* Default formatter that parses according to the docs for this method: "If the pattern is not provided, this parses
* time strings in either ISO8601 or SQL format."
*/
private static DateTimes.UtcFormatter createDefaultParser(final DateTimeZone timeZone)
{
final DateTimeFormatter offsetElement = new DateTimeFormatterBuilder()
.appendTimeZoneOffset("Z", true, 2, 4)
.toFormatter();
DateTimeParser timeOrOffset = new DateTimeFormatterBuilder()
.append(
null,
new DateTimeParser[]{
new DateTimeFormatterBuilder().appendLiteral('T').toParser(),
new DateTimeFormatterBuilder().appendLiteral(' ').toParser()
}
)
.appendOptional(ISODateTimeFormat.timeElementParser().getParser())
.appendOptional(offsetElement.getParser())
.toParser();
return DateTimes.wrapFormatter(
new DateTimeFormatterBuilder()
.append(ISODateTimeFormat.dateElementParser())
.appendOptional(timeOrOffset)
.toFormatter()
.withZone(timeZone)
);
}
}