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The core jetty server artifact.
//
// ========================================================================
// Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
// which is available at https://www.apache.org/licenses/LICENSE-2.0.
//
// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
// ========================================================================
//
package org.eclipse.jetty.server.handler;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayDeque;
import java.util.Queue;
import jakarta.servlet.ServletContext;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.eclipse.jetty.http.HttpMethod;
import org.eclipse.jetty.http.HttpStatus;
import org.eclipse.jetty.http.MimeTypes;
import org.eclipse.jetty.http.pathmap.PathSpecSet;
import org.eclipse.jetty.server.HttpChannel;
import org.eclipse.jetty.server.HttpOutput;
import org.eclipse.jetty.server.HttpOutput.Interceptor;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.Response;
import org.eclipse.jetty.util.BufferUtil;
import org.eclipse.jetty.util.Callback;
import org.eclipse.jetty.util.IncludeExclude;
import org.eclipse.jetty.util.IteratingCallback;
import org.eclipse.jetty.util.StringUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
* A Handler that can apply a {@link org.eclipse.jetty.server.HttpOutput.Interceptor}
* mechanism to buffer the entire response content until the output is closed.
* This allows the commit to be delayed until the response is complete and thus
* headers and response status can be changed while writing the body.
*
*
* Note that the decision to buffer is influenced by the headers and status at the
* first write, and thus subsequent changes to those headers will not influence the
* decision to buffer or not.
*
*
* Note also that there are no memory limits to the size of the buffer, thus
* this handler can represent an unbounded memory commitment if the content
* generated can also be unbounded.
*
*/
public class BufferedResponseHandler extends HandlerWrapper
{
private static final Logger LOG = LoggerFactory.getLogger(BufferedResponseHandler.class);
private final IncludeExclude _methods = new IncludeExclude<>();
private final IncludeExclude _paths = new IncludeExclude<>(PathSpecSet.class);
private final IncludeExclude _mimeTypes = new IncludeExclude<>();
public BufferedResponseHandler()
{
_methods.include(HttpMethod.GET.asString());
for (String type : MimeTypes.getKnownMimeTypes())
{
if (type.startsWith("image/") ||
type.startsWith("audio/") ||
type.startsWith("video/"))
_mimeTypes.exclude(type);
}
if (LOG.isDebugEnabled())
LOG.debug("{} mime types {}", this, _mimeTypes);
}
public IncludeExclude getMethodIncludeExclude()
{
return _methods;
}
public IncludeExclude getPathIncludeExclude()
{
return _paths;
}
public IncludeExclude getMimeIncludeExclude()
{
return _mimeTypes;
}
protected boolean isMimeTypeBufferable(String mimetype)
{
return _mimeTypes.test(mimetype);
}
protected boolean isPathBufferable(String requestURI)
{
if (requestURI == null)
return true;
return _paths.test(requestURI);
}
protected boolean shouldBuffer(HttpChannel channel, boolean last)
{
if (last)
return false;
Response response = channel.getResponse();
int status = response.getStatus();
if (HttpStatus.hasNoBody(status) || HttpStatus.isRedirection(status))
return false;
String ct = response.getContentType();
if (ct == null)
return true;
ct = MimeTypes.getContentTypeWithoutCharset(ct);
return isMimeTypeBufferable(StringUtil.asciiToLowerCase(ct));
}
@Override
public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
{
final ServletContext context = baseRequest.getServletContext();
final String path = baseRequest.getPathInContext();
if (LOG.isDebugEnabled())
LOG.debug("{} handle {} in {}", this, baseRequest, context);
// Are we already buffering?
HttpOutput out = baseRequest.getResponse().getHttpOutput();
HttpOutput.Interceptor interceptor = out.getInterceptor();
while (interceptor != null)
{
if (interceptor instanceof BufferedInterceptor)
{
if (LOG.isDebugEnabled())
LOG.debug("{} already intercepting {}", this, request);
_handler.handle(target, baseRequest, request, response);
return;
}
interceptor = interceptor.getNextInterceptor();
}
// If not a supported method this URI is always excluded.
if (!_methods.test(baseRequest.getMethod()))
{
if (LOG.isDebugEnabled())
LOG.debug("{} excluded by method {}", this, request);
_handler.handle(target, baseRequest, request, response);
return;
}
// If not a supported path this URI is always excluded.
if (!isPathBufferable(path))
{
if (LOG.isDebugEnabled())
LOG.debug("{} excluded by path {}", this, request);
_handler.handle(target, baseRequest, request, response);
return;
}
// If the mime type is known from the path then apply mime type filtering.
String mimeType = context == null ? MimeTypes.getDefaultMimeByExtension(path) : context.getMimeType(path);
if (mimeType != null)
{
mimeType = MimeTypes.getContentTypeWithoutCharset(mimeType);
if (!isMimeTypeBufferable(mimeType))
{
if (LOG.isDebugEnabled())
LOG.debug("{} excluded by path suffix mime type {}", this, request);
// handle normally without setting vary header
_handler.handle(target, baseRequest, request, response);
return;
}
}
// Install buffered interceptor and handle.
out.setInterceptor(newBufferedInterceptor(baseRequest.getHttpChannel(), out.getInterceptor()));
if (_handler != null)
_handler.handle(target, baseRequest, request, response);
}
protected BufferedInterceptor newBufferedInterceptor(HttpChannel httpChannel, Interceptor interceptor)
{
return new ArrayBufferedInterceptor(httpChannel, interceptor);
}
/**
* An {@link HttpOutput.Interceptor} which is created by {@link #newBufferedInterceptor(HttpChannel, Interceptor)}
* and is used by the implementation to buffer outgoing content.
*/
protected interface BufferedInterceptor extends HttpOutput.Interceptor
{
}
class ArrayBufferedInterceptor implements BufferedInterceptor
{
private final Interceptor _next;
private final HttpChannel _channel;
private final Queue _buffers = new ArrayDeque<>();
private Boolean _aggregating;
private ByteBuffer _aggregate;
public ArrayBufferedInterceptor(HttpChannel httpChannel, Interceptor interceptor)
{
_next = interceptor;
_channel = httpChannel;
}
@Override
public Interceptor getNextInterceptor()
{
return _next;
}
@Override
public void resetBuffer()
{
_buffers.clear();
_aggregating = null;
_aggregate = null;
BufferedInterceptor.super.resetBuffer();
}
@Override
public void write(ByteBuffer content, boolean last, Callback callback)
{
if (LOG.isDebugEnabled())
LOG.debug("{} write last={} {}", this, last, BufferUtil.toDetailString(content));
// If we are not committed, have to decide if we should aggregate or not.
if (_aggregating == null)
_aggregating = shouldBuffer(_channel, last);
// If we are not aggregating, then handle normally.
if (!_aggregating)
{
getNextInterceptor().write(content, last, callback);
return;
}
if (last)
{
// Add the current content to the buffer list without a copy.
if (BufferUtil.length(content) > 0)
_buffers.offer(content);
if (LOG.isDebugEnabled())
LOG.debug("{} committing {}", this, _buffers.size());
commit(callback);
}
else
{
if (LOG.isDebugEnabled())
LOG.debug("{} aggregating", this);
// Aggregate the content into buffer chain.
while (BufferUtil.hasContent(content))
{
// Do we need a new aggregate buffer.
if (BufferUtil.space(_aggregate) == 0)
{
// TODO: use a buffer pool always allocating with outputBufferSize to avoid polluting the ByteBufferPool.
int size = Math.max(_channel.getHttpConfiguration().getOutputBufferSize(), BufferUtil.length(content));
_aggregate = BufferUtil.allocate(size);
_buffers.offer(_aggregate);
}
BufferUtil.append(_aggregate, content);
}
callback.succeeded();
}
}
private void commit(Callback callback)
{
if (_buffers.size() == 0)
{
getNextInterceptor().write(BufferUtil.EMPTY_BUFFER, true, callback);
}
else if (_buffers.size() == 1)
{
getNextInterceptor().write(_buffers.poll(), true, callback);
}
else
{
// Create an iterating callback to do the writing.
IteratingCallback icb = new IteratingCallback()
{
@Override
protected Action process()
{
ByteBuffer buffer = _buffers.poll();
if (buffer == null)
return Action.SUCCEEDED;
getNextInterceptor().write(buffer, _buffers.isEmpty(), this);
return Action.SCHEDULED;
}
@Override
protected void onCompleteSuccess()
{
// Signal last callback.
callback.succeeded();
}
@Override
protected void onCompleteFailure(Throwable cause)
{
// Signal last callback.
callback.failed(cause);
}
};
icb.iterate();
}
}
}
}