/**
*
* Copyright 2009-2011 Rickard Öberg AB
*
* 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.qi4j.library.rest.client;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.restlet.Request;
import org.restlet.Response;
import org.restlet.data.Method;
import org.restlet.data.Reference;
import org.restlet.data.Tag;
/**
* Cache for the ContextResourceClient. This is primarily used to keep track of ETags and lastmodified timestamps for now.
*/
public class ClientCache
{
Map<String, CacheInfo> identityToTimestamp = new HashMap<String, CacheInfo>( );
Map<String, String> pathToIdentity = new HashMap<String, String>( );
public void updateCache( Response response)
{
if (response.getRequest().getMethod().equals( Method.DELETE ))
{
String path = getIdentityPath( response.getRequest().getResourceRef() );
String id = pathToIdentity.get( path );
if (id != null)
{
// Clear anything related to this id from cache
identityToTimestamp.remove( id );
Iterator<Map.Entry<String, String>> paths = pathToIdentity.entrySet().iterator();
while (paths.hasNext())
{
Map.Entry<String, String> entry = paths.next();
if (entry.getValue().equals( id ))
paths.remove();
}
}
} else if (response.getRequest().getMethod().equals( Method.PUT ) || response.getRequest().getMethod().equals( Method.POST ))
{
Tag tag = response.getEntity().getTag();
if (tag != null)
{
Reference ref = response.getRequest().getResourceRef().clone();
CacheInfo value = new CacheInfo( response.getEntity().getModificationDate(), tag, ref );
identityToTimestamp.put( value.getEntity(), value );
String path = getIdentityPath( ref );
pathToIdentity.put( path, value.getEntity() );
// LoggerFactory.getLogger( ClientCache.class ).info( "Update:"+value.getEntity()+" ("+ref.toString()+") -> "+value.getLastModified() );
}
} else
{
// TODO GET caching goes here
}
}
public void updateQueryConditions( Request request)
{
String identity = pathToIdentity.get( getIdentityPath( request.getResourceRef() ));
if (identity != null)
{
CacheInfo cacheInfo = identityToTimestamp.get( identity );
if (cacheInfo != null)
{
// LoggerFactory.getLogger( ClientCache.class ).info( "Send: "+cacheInfo.getEntity()+" ("+request.getMethod().getName()+":"+request.getResourceRef()+") -> "+cacheInfo.getLastModified() );
request.getConditions().setModifiedSince( cacheInfo.getLastModified() );
}
}
}
public void updateCommandConditions( Request request)
{
String identity = pathToIdentity.get( getIdentityPath( request.getResourceRef() ));
if (identity != null)
{
CacheInfo cacheInfo = identityToTimestamp.get( identity );
if (cacheInfo != null)
{
// LoggerFactory.getLogger( ClientCache.class ).info( "Send: "+cacheInfo.getEntity()+" ("+request.getMethod().getName()+":"+request.getResourceRef()+") -> "+cacheInfo.getLastModified() );
request.getConditions().setUnmodifiedSince( cacheInfo.getLastModified() );
}
}
}
private String getIdentityPath( Reference ref )
{
String path = ref.getPath();
if (!path.endsWith( "/" ))
path = path.substring( 0, path.lastIndexOf('/' )+1);
return path;
}
static class CacheInfo
{
private Reference ref;
private Date lastModified;
private Tag tag;
private String entity;
CacheInfo( Date lastModified, Tag tag, Reference ref )
{
this.lastModified = lastModified;
this.tag = tag;
this.ref = ref;
entity = tag.getName().split( "/" )[0];
}
public Reference getRef()
{
return ref;
}
public Date getLastModified()
{
return lastModified;
}
public Tag getTag()
{
return tag;
}
public String getEntity()
{
return entity;
}
}
}