SimpleHttpCacheStorage.java
/*
* *********************************************************************************************************************
*
* blueMarine II: Semantic Media Centre
* http://tidalwave.it/projects/bluemarine2
*
* Copyright (C) 2015 - 2021 by Tidalwave s.a.s. (http://tidalwave.it)
*
* *********************************************************************************************************************
*
* 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.
*
* *********************************************************************************************************************
*
* git clone https://bitbucket.org/tidalwave/bluemarine2-src
* git clone https://github.com/tidalwave-it/bluemarine2-src
*
* *********************************************************************************************************************
*/
package it.tidalwave.bluemarine2.downloader.impl;
import javax.annotation.Nonnull;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.List;
import java.util.stream.Collectors;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.net.MalformedURLException;
import java.net.URL;
import it.tidalwave.util.annotation.VisibleForTesting;
import org.apache.http.Header;
import org.apache.http.HttpException;
import org.apache.http.HttpResponse;
import org.apache.http.client.cache.HttpCacheEntry;
import org.apache.http.client.cache.HttpCacheStorage;
import org.apache.http.client.cache.HttpCacheUpdateCallback;
import org.apache.http.client.cache.HttpCacheUpdateException;
import org.apache.http.client.cache.Resource;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicHttpResponse;
import org.apache.http.impl.client.cache.FileResource;
import org.apache.http.impl.io.DefaultHttpResponseParser;
import org.apache.http.impl.io.DefaultHttpResponseWriter;
import org.apache.http.impl.io.HttpTransportMetricsImpl;
import org.apache.http.impl.io.SessionInputBufferImpl;
import org.apache.http.impl.io.SessionOutputBufferImpl;
import lombok.Cleanup;
import lombok.Getter;
import lombok.Setter;
import lombok.extern.slf4j.Slf4j;
import static java.nio.file.Files.*;
import static java.nio.file.StandardCopyOption.*;
import static java.nio.file.StandardOpenOption.*;
/***********************************************************************************************************************
*
* @author Fabrizio Giudici
*
**********************************************************************************************************************/
@Slf4j
public class SimpleHttpCacheStorage implements HttpCacheStorage
{
private static final String PATH_CONTENT = "content";
private static final String PATH_HEADERS = "headers";
private static final Collection<String> NEVER_EXPIRING_HEADERS = List.of("Cache-Control", "Expires", "Pragma");
@Getter @Setter
private Path folderPath = Paths.get(System.getProperty("java.io.tmpdir"));
/** When this field is {@code true} the headers of items extracted from the cache are manipulated so it appears
* they never expire. */
@Getter @Setter
private boolean neverExpiring;
/*******************************************************************************************************************
*
* {@inheritDoc}
*
******************************************************************************************************************/
@Override
public void putEntry (@Nonnull final String key, @Nonnull final HttpCacheEntry entry)
throws IOException
{
try
{
log.debug("putEntry({}, {})", key, entry);
final Path cachePath = getCacheItemPath(new URL(key));
createDirectories(cachePath);
final Path cacheHeadersPath = cachePath.resolve(PATH_HEADERS);
final Path cacheContentPath = cachePath.resolve(PATH_CONTENT);
@Cleanup final OutputStream os = newOutputStream(cacheHeadersPath, CREATE);
final SessionOutputBufferImpl sob = sessionOutputBufferFrom(os);
final DefaultHttpResponseWriter writer = new DefaultHttpResponseWriter(sob);
writer.write(responseFrom(entry));
sob.flush();
if (entry.getResource().length() > 0)
{
copy(entry.getResource().getInputStream(), cacheContentPath, REPLACE_EXISTING);
}
}
catch (HttpException e)
{
throw new IOException(e);
}
}
/*******************************************************************************************************************
*
* {@inheritDoc}
*
******************************************************************************************************************/
@Override
public HttpCacheEntry getEntry (@Nonnull final String key)
throws IOException
{
log.debug("getEntry({})", key);
final Path cachePath = getCacheItemPath(new URL(key));
final Path cacheHeadersPath = cachePath.resolve(PATH_HEADERS);
final Path cacheContentPath = cachePath.resolve(PATH_CONTENT);
if (!exists(cacheHeadersPath))
{
log.trace(">>>> cache miss: {}", cacheHeadersPath);
return null;
}
try
{
@Cleanup final InputStream is = newInputStream(cacheHeadersPath);
final SessionInputBufferImpl sib = sessionInputBufferFrom(is);
final DefaultHttpResponseParser parser = new DefaultHttpResponseParser(sib);
return entryFrom(cacheContentPath, parser.parse());
}
catch (HttpException e)
{
throw new IOException(e);
}
}
/*******************************************************************************************************************
*
* {@inheritDoc}
*
******************************************************************************************************************/
@Override
public void removeEntry (@Nonnull final String key)
throws IOException
{
log.debug("removeEntry({})", key);
// FIXME
}
/*******************************************************************************************************************
*
* {@inheritDoc}
*
******************************************************************************************************************/
@Override
public void updateEntry (@Nonnull final String key, @Nonnull final HttpCacheUpdateCallback callback)
throws IOException, HttpCacheUpdateException
{
log.debug("updateEntry({}, {})", key, callback);
// FIXME
}
/*******************************************************************************************************************
*
*
*
******************************************************************************************************************/
@VisibleForTesting boolean isCachedResourcePresent (@Nonnull final String key)
throws MalformedURLException
{
final Path cachePath = getCacheItemPath(new URL(key));
final Path cacheHeadersPath = cachePath.resolve(PATH_HEADERS);
final Path cacheContentPath = cachePath.resolve(PATH_CONTENT);
log.trace(">>>> probing cached entry at {}", cachePath);
return exists(cacheHeadersPath) && exists(cacheContentPath);
}
/*******************************************************************************************************************
*
*
*
******************************************************************************************************************/
@Nonnull
private Path getCacheItemPath (@Nonnull final URL url)
throws MalformedURLException
{
final int port = url.getPort();
final URL url2 = new URL(url.getProtocol(), url.getHost(), (port == 80) ? -1 : port, url.getFile());
final Path cachePath = Paths.get(url2.toString().replaceAll(":", ""));
return folderPath.resolve(cachePath);
}
/*******************************************************************************************************************
*
*
*
******************************************************************************************************************/
@Nonnull
private static SessionInputBufferImpl sessionInputBufferFrom (@Nonnull final InputStream is)
{
final HttpTransportMetricsImpl metrics = new HttpTransportMetricsImpl();
final SessionInputBufferImpl sib = new SessionInputBufferImpl(metrics, 100);
sib.bind(is);
return sib;
}
/*******************************************************************************************************************
*
*
*
******************************************************************************************************************/
@Nonnull
private static SessionOutputBufferImpl sessionOutputBufferFrom (@Nonnull final OutputStream os)
{
final HttpTransportMetricsImpl metrics = new HttpTransportMetricsImpl();
final SessionOutputBufferImpl sob = new SessionOutputBufferImpl(metrics, 100);
sob.bind(os);
return sob;
}
/*******************************************************************************************************************
*
*
*
******************************************************************************************************************/
@Nonnull
private static HttpResponse responseFrom (@Nonnull final HttpCacheEntry entry)
{
final BasicHttpResponse response = new BasicHttpResponse(entry.getStatusLine());
response.setHeaders(entry.getAllHeaders());
return response;
}
/*******************************************************************************************************************
*
*
*
******************************************************************************************************************/
@Nonnull
private HttpCacheEntry entryFrom (@Nonnull final Path cacheContentPath,
@Nonnull final HttpResponse response)
{
final Date date = new Date(); // FIXME: force hit?
// new Date(Files.getLastModifiedTime(cacheHeadersPath).toMillis());
final Resource resource = exists(cacheContentPath) ? new FileResource(cacheContentPath.toFile()) : null;
List<Header> headers = new ArrayList<>(List.of(response.getAllHeaders()));
if (neverExpiring)
{
headers = headers.stream().filter(header -> !NEVER_EXPIRING_HEADERS.contains(header.getName()))
.collect(Collectors.toList());
headers.add(new BasicHeader("Expires", "Mon, 31 Dec 2099 00:00:00 GMT"));
}
return new HttpCacheEntry(date, date, response.getStatusLine(), headers.toArray(new Header[0]), resource);
}
}