Trace.java
/*
* Copyright 2013 Michael Mackenzie High
*
* 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 com.mackenziehigh.snowflake;
import java.io.PrintWriter;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
/**
* An instance of this class is the output of a tracer that records match-attempts.
*
* @author mackenzie
*/
public final class Trace
{
final List<TraceElement> elements = new LinkedList<TraceElement>();
final int total;
/**
* Sole Constructor.
*
* @param elements are records describing match-attempts.
* @param total is the total number of records that were created.
*/
public Trace(final List<TraceElement> elements, final int total)
{
Utils.checkNonNull(elements);
this.elements.addAll(elements);
this.total = total;
}
/**
* This method return records that describe the starts/failures/successes of match-attempts.
*
* @return a readonly list of immutable objects.
*/
public List<TraceElement> elements()
{
return Collections.unmodifiableList(elements);
}
/**
* This method returns the number of records that were created.
*
* <p>This count may be greater-than <code>elements().size()</code>.</p>
*
* @return the aforedescribed count.
*/
public int callCount()
{
return total;
}
/**
* This method prints the records herein contained to a writer.
*
* <p><b>Note:</b> The output format may change in the future.</p>
*
* @param out is the writer itself.
*/
public void print(final PrintWriter out)
{
out.print("Tracer Records (");
out.print(elements.size());
out.print(" of ");
out.print(total);
out.println(") (Most Recent Call Last):");
int i = 0;
for(TraceElement element : elements)
{
out.print(" ");
out.print('[');
out.print(i++);
out.print(']');
out.print(' ');
out.print(element.rule);
out.print(" => ");
out.print(element.reason.name());
out.print(" @ ");
out.print(element.position);
out.println();
}
}
}