/**
* 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.drill.common.expression;
import java.io.IOException;
import org.antlr.runtime.ANTLRStringStream;
import org.antlr.runtime.CommonTokenStream;
import org.antlr.runtime.RecognitionException;
import org.apache.drill.common.config.DrillConfig;
import org.apache.drill.common.expression.parser.ExprLexer;
import org.apache.drill.common.expression.parser.ExprParser;
import org.apache.drill.common.expression.parser.ExprParser.parse_return;
import org.apache.drill.common.expression.visitors.ExprVisitor;
import org.apache.drill.common.types.TypeProtos.MajorType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
import com.fasterxml.jackson.databind.ser.std.StdSerializer;
//@JsonDeserialize(using = LogicalExpression.De.class) // Excluded as we need to register this with the DrillConfig.
@JsonSerialize(using = LogicalExpression.Se.class)
public interface LogicalExpression extends Iterable<LogicalExpression>{
static final Logger logger = LoggerFactory.getLogger(LogicalExpression.class);
public abstract MajorType getMajorType();
public <T, V, E extends Exception> T accept(ExprVisitor<T, V, E> visitor, V value) throws E;
public ExpressionPosition getPosition();
public static class De extends StdDeserializer<LogicalExpression> {
DrillConfig config;
public De(DrillConfig config) {
super(LogicalExpression.class);
this.config = config;
}
@Override
public LogicalExpression deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException,
JsonProcessingException {
String expr = jp.getText();
if (expr == null || expr.isEmpty())
return null;
try {
// logger.debug("Parsing expression string '{}'", expr);
ExprLexer lexer = new ExprLexer(new ANTLRStringStream(expr));
CommonTokenStream tokens = new CommonTokenStream(lexer);
ExprParser parser = new ExprParser(tokens);
//TODO: move functionregistry and error collector to injectables.
//ctxt.findInjectableValue(valueId, forProperty, beanInstance)
parser.setRegistry(new FunctionRegistry(config));
parse_return ret = parser.parse();
// ret.e.resolveAndValidate(expr, errorCollector);
return ret.e;
} catch (RecognitionException e) {
throw new RuntimeException(e);
}
}
}
public static class Se extends StdSerializer<LogicalExpression> {
protected Se() {
super(LogicalExpression.class);
}
@Override
public void serialize(LogicalExpression value, JsonGenerator jgen, SerializerProvider provider) throws IOException,
JsonGenerationException {
StringBuilder sb = new StringBuilder();
ExpressionStringBuilder esb = new ExpressionStringBuilder();
value.accept(esb, sb);
jgen.writeString(sb.toString());
}
}
}