// Copyright 2006, 2007 The Apache Software Foundation
//
// 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 org.apache.tapestry.internal.services;
import org.apache.commons.logging.Log;
import org.apache.tapestry.MarkupWriter;
import org.apache.tapestry.ioc.util.Stack;
import org.apache.tapestry.runtime.RenderCommand;
import org.apache.tapestry.runtime.RenderQueue;
public class RenderQueueImpl implements RenderQueue
{
private static final int INITIAL_QUEUE_DEPTH = 100;
private final Stack<RenderCommand> _queue = new Stack<RenderCommand>(INITIAL_QUEUE_DEPTH);
private final Log _log;
public RenderQueueImpl(Log log)
{
_log = log;
}
public void push(RenderCommand command)
{
_queue.push(command);
}
public void run(MarkupWriter writer)
{
RenderCommand command = null;
// Seems to make sense to use one try/finally around the whole process, rather than
// around each call to render() since the end result (in a failure scenario) is the same.
try
{
while (!_queue.isEmpty())
{
command = _queue.pop();
if (_log.isDebugEnabled())
_log.debug(String.format("Executing: %s", command));
command.render(writer, this);
}
}
catch (RuntimeException ex)
{
// This will likely leave the page in a dirty state, and it will not go back into the
// page pool.
_log.error(ServicesMessages.renderQueueError(command, ex), ex);
throw ex;
}
}
}