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Trino - Delta Lake connector
/*
* 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 io.trino.plugin.deltalake.expression;
import com.google.common.annotations.VisibleForTesting;
import org.antlr.v4.runtime.ANTLRErrorListener;
import org.antlr.v4.runtime.BaseErrorListener;
import org.antlr.v4.runtime.CharStreams;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import org.antlr.v4.runtime.atn.PredictionMode;
import java.util.function.Function;
import static com.google.common.base.MoreObjects.firstNonNull;
public final class SparkExpressionParser
{
private static final ANTLRErrorListener ERROR_LISTENER = new BaseErrorListener()
{
@Override
public void syntaxError(Recognizer recognizer, Object offendingSymbol, int line, int charPositionInLine, String message, RecognitionException e)
{
throw new ParsingException(message, e);
}
};
private SparkExpressionParser() {}
public static String toTrinoExpression(String sparkExpression)
{
SparkExpression expression = createExpression(sparkExpression);
return SparkExpressionConverter.toTrinoExpression(expression);
}
@VisibleForTesting
static SparkExpression createExpression(String expression)
{
try {
return (SparkExpression) invokeParser(expression, SparkExpressionBaseParser::standaloneExpression);
}
catch (Exception e) {
throw new ParsingException("Cannot parse Spark expression [%s]: %s".formatted(expression, firstNonNull(e.getMessage(), e)), e);
}
}
private static Object invokeParser(String input, Function parseFunction)
{
try {
SparkExpressionBaseLexer lexer = new SparkExpressionBaseLexer(CharStreams.fromString(input));
CommonTokenStream tokenStream = new CommonTokenStream(lexer);
SparkExpressionBaseParser parser = new SparkExpressionBaseParser(tokenStream);
lexer.removeErrorListeners();
lexer.addErrorListener(ERROR_LISTENER);
parser.removeErrorListeners();
parser.addErrorListener(ERROR_LISTENER);
ParserRuleContext tree;
try {
// first, try parsing with potentially faster SLL mode
parser.getInterpreter().setPredictionMode(PredictionMode.SLL);
tree = parseFunction.apply(parser);
}
catch (ParsingException ex) {
// if we fail, parse with LL mode
tokenStream.seek(0); // rewind input stream
parser.reset();
parser.getInterpreter().setPredictionMode(PredictionMode.LL);
tree = parseFunction.apply(parser);
}
return new SparkExpressionBuilder().visit(tree);
}
catch (StackOverflowError e) {
throw new ParsingException("expression is too large (stack overflow while parsing)");
}
}
}