org.graylog.plugins.pipelineprocessor.ast.expressions.VarRefExpression Maven / Gradle / Ivy
/**
* This file is part of Graylog.
*
* Graylog is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Graylog is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Graylog. If not, see .
*/
package org.graylog.plugins.pipelineprocessor.ast.expressions;
import org.antlr.v4.runtime.Token;
import org.graylog.plugins.pipelineprocessor.EvaluationContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Collections;
public class VarRefExpression extends BaseExpression {
private static final Logger log = LoggerFactory.getLogger(VarRefExpression.class);
private final String identifier;
private final Expression varExpr;
private Class type = Object.class;
public VarRefExpression(Token start, String identifier, Expression varExpr) {
super(start);
this.identifier = identifier;
this.varExpr = varExpr;
}
@Override
public boolean isConstant() {
return varExpr != null && varExpr.isConstant();
}
@Override
public Object evaluateUnsafe(EvaluationContext context) {
final EvaluationContext.TypedValue typedValue = context.get(identifier);
if (typedValue != null) {
return typedValue.getValue();
}
log.error("Unable to retrieve value for variable {}", identifier);
return null;
}
@Override
public Class getType() {
return type;
}
@Override
public String toString() {
return identifier;
}
public String varName() {
return identifier;
}
public Expression varExpr() { return varExpr; }
public void setType(Class type) {
this.type = type;
}
@Override
public Iterable children() {
return Collections.emptySet();
}
}