org.apache.logging.log4j.core.pattern.VariablesNotEmptyReplacementConverter Maven / Gradle / Ivy
/*
* 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.logging.log4j.core.pattern;
import java.util.List;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.config.Configuration;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.layout.PatternLayout;
import org.apache.logging.log4j.util.PerformanceSensitive;
/**
* VariablesNotEmpty pattern converter.
*/
@Plugin(name = "notEmpty", category = PatternConverter.CATEGORY)
@ConverterKeys({
"notEmpty",
"varsNotEmpty",
"variablesNotEmpty",
})
@PerformanceSensitive("allocation")
public final class VariablesNotEmptyReplacementConverter extends LogEventPatternConverter {
private final List formatters;
/**
* Constructs the converter.
*
* @param formatters
* The PatternFormatters to generate the text to manipulate.
*/
private VariablesNotEmptyReplacementConverter(final List formatters) {
super("notEmpty", "notEmpty");
this.formatters = formatters;
}
/**
* Gets an instance of the class.
*
* @param config
* The current Configuration.
* @param options
* pattern options, may be null.
* @return instance of class.
*/
public static VariablesNotEmptyReplacementConverter newInstance(
final Configuration config, final String[] options) {
if (options.length != 1) {
LOGGER.error("Incorrect number of options on varsNotEmpty. Expected 1 received " + options.length);
return null;
}
if (options[0] == null) {
LOGGER.error("No pattern supplied on varsNotEmpty");
return null;
}
final PatternParser parser = PatternLayout.createPatternParser(config);
final List formatters = parser.parse(options[0]);
return new VariablesNotEmptyReplacementConverter(formatters);
}
/**
* {@inheritDoc}
*/
@Override
public void format(final LogEvent event, final StringBuilder toAppendTo) {
final int start = toAppendTo.length();
boolean allVarsEmpty = true;
boolean hasVars = false;
for (int i = 0; i < formatters.size(); i++) {
final PatternFormatter formatter = formatters.get(i);
final int formatterStart = toAppendTo.length();
formatter.format(event, toAppendTo);
final LogEventPatternConverter converter = formatter.getConverter();
if (converter.isVariable()) {
hasVars = true;
allVarsEmpty = allVarsEmpty
&& sequenceRegionMatches(toAppendTo, formatterStart, converter.emptyVariableOutput());
}
}
if (!hasVars || allVarsEmpty) {
toAppendTo.setLength(start); // remove formatter results
}
}
/**
* @param sequence1 the 1st sequence
* @param sequence1Offset the start index of the 1st sequence region
* @param sequence2 the 2nd sequence
* @return {@code true}, if the pointed region of the 1st sequence matches to the 2nd sequence; {@code false}, otherwise
*/
private static boolean sequenceRegionMatches(
final CharSequence sequence1, final int sequence1Offset, final CharSequence sequence2) {
final boolean lengthMatches = (sequence1.length() - sequence1Offset) == sequence2.length();
if (!lengthMatches) {
return false;
}
for (int i2 = 0; i2 < sequence2.length(); i2++) {
final char c2 = sequence2.charAt(i2);
final int i1 = i2 + sequence1Offset;
final char c1 = sequence1.charAt(i1);
if (c2 != c1) {
return false;
}
}
return true;
}
}