org.apache.jena.fuseki.servlets.HttpAction Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.jena.fuseki.servlets;
import static org.apache.jena.query.ReadWrite.READ ;
import static org.apache.jena.query.ReadWrite.WRITE ;
import java.util.HashMap ;
import java.util.Map ;
import javax.servlet.http.HttpServletRequest ;
import javax.servlet.http.HttpServletResponse ;
import org.apache.jena.atlas.logging.Log ;
import org.apache.jena.atlas.web.MediaType ;
import org.apache.jena.fuseki.DEF ;
import org.apache.jena.fuseki.conneg.ConNeg ;
import org.apache.jena.fuseki.server.DatasetRef ;
import org.apache.jena.fuseki.server.ServiceRef ;
import org.apache.jena.query.ReadWrite ;
import org.apache.jena.sparql.SystemARQ ;
import org.apache.jena.sparql.core.* ;
/**
* HTTP action that represents the user request lifecycle. Its state is handled in the
* {@link SPARQL_ServletBase#executeLifecycle(HttpAction)} method.
*/
public class HttpAction
{
public final long id ;
public final boolean verbose ;
// Phase two items - set and valida after the datasetRef is known.
private DatasetGraph dsg ; // The data
public DatasetRef dsRef ;
public ServiceRef srvRef ;
private Transactional transactional ;
private boolean isTransactional;
private DatasetGraph activeDSG ; // Set when inside begin/end.
private ReadWrite activeMode ; // Set when inside begin/end.
private boolean startTimeIsSet = false ;
private boolean finishTimeIsSet = false ;
private long startTime = -2 ;
private long finishTime = -2 ;
// Incoming
//public final
// Outcome.
int statusCode = -1 ;
String message = null ;
int contentLength = -1 ;
String contentType = null ;
// Cleared to archive:
Map headers = new HashMap<>() ;
public HttpServletRequest request;
public HttpServletResponseTracker response ;
/**
* Creates a new HTTP Action, using the HTTP request and response, and a given ID.
*
* @param id given ID
* @param request HTTP request
* @param response HTTP response
* @param verbose verbose flag
*/
public HttpAction(long id, HttpServletRequest request, HttpServletResponse response, boolean verbose) {
this.id = id ;
this.request = request ;
this.response = new HttpServletResponseTracker(this, response) ;
// Should this be set when setDataset is called from the dataset context?
// Currently server-wide, e.g. from the command line.
this.verbose = verbose ;
}
/**
* Sets the action dataset. Setting a {@link DatasetRef} will replace any existing DatasetRef, as well as
* as the {@link DatasetGraph} of the current HTTP Action.
*
* Once it has updated its members, the HTTP Action will change its transactional state and
* {@link Transactional} instance according to its base dataset graph.
*
* @param desc {@link DatasetRef}
* @see Transactional
* @see DatasetGraphWrapper
*/
public void setDataset(DatasetRef desc) {
this.dsRef = desc ;
this.dsg = desc.dataset ;
setTransactionalPolicy(dsg) ;
}
private void setTransactionalPolicy(DatasetGraph dsg) {
if ( dsg.supportsTransactionAbort() ) {
// Use transactional if it looks safe - abort is necessary.
transactional = dsg ;
isTransactional = true ;
} else if ( dsg.supportsTransactions() ) {
// No abort - e.g. loading data needs buffering against syntax errors.
transactional = dsg ;
isTransactional = false ;
} else {
// Nothing to build on. Be safe.
transactional = new TransactionalMutex(dsg.getLock()) ;
isTransactional = false ;
}
}
/**
* A {@link DatasetGraph} may contain other wrapped DatasetGraph's. This method will return
* the first instance (including the argument to this method) that is not an instance of
* {@link DatasetGraphWrapper}.
*
* @param dsg a {@link DatasetGraph}
* @return the first found {@link DatasetGraph} that is not an instance of {@link DatasetGraphWrapper}
*/
// Unused currently.
private static DatasetGraph x_unwrap(DatasetGraph dsg) {
while (dsg instanceof DatasetGraphWrapper) {
dsg = ((DatasetGraphWrapper)dsg).getWrapped() ;
}
return dsg ;
}
/**
* Sets the {@link ServiceRef}.
*
* @param srvRef a {@link ServiceRef}
*/
public void setService(ServiceRef srvRef) {
this.srvRef = srvRef ;
}
/**
* Returns whether or not the underlying DatasetGraph is fully transactional (supports rollback).
* @return true if the underlying DatasetGraph is fully transactional (supports rollback),
* false otherwise.
*/
public boolean isTransactional() {
return isTransactional ;
}
public void beginRead() {
activeMode = READ ;
transactional.begin(READ) ;
activeDSG = dsg ;
dsRef.startTxn(READ) ;
}
public void endRead() {
dsRef.finishTxn(READ) ;
activeMode = null ;
transactional.end() ;
activeDSG = null ;
}
public void beginWrite() {
transactional.begin(WRITE) ;
activeMode = WRITE ;
activeDSG = dsg ;
dsRef.startTxn(WRITE) ;
}
public void commit() {
transactional.commit() ;
activeDSG = null ;
}
public void abort() {
try { transactional.abort() ; }
catch (Exception ex) {
// Some datasets claim to be transactional but
// don't provide a real abort. We tried to avoid
// them earlier but even if they sneek through,
// we try to continue server operation.
Log.warn(this, "Exception during abort (operation attempts to continue): "+ex.getMessage()) ;
}
activeDSG = null ;
}
public void endWrite() {
dsRef.finishTxn(WRITE) ;
activeMode = null ;
if ( transactional.isInTransaction() ) {
Log.warn(this, "Transaction still active in endWriter - no commit or abort seen (forced abort)") ;
try {
transactional.abort() ;
} catch (RuntimeException ex) {
Log.warn(this, "Exception in forced abort (trying to continue)", ex) ;
}
}
transactional.end() ;
activeDSG = null ;
}
public final DatasetGraph getActiveDSG() {
return activeDSG ;
}
public final DatasetRef getDatasetRef() {
return dsRef ;
}
/** Reduce to a size that can be kept around for sometime */
public void minimize() {
this.request = null ;
this.response = null ;
}
public void setStartTime() {
if ( startTimeIsSet )
Log.warn(this, "Start time reset") ;
startTimeIsSet = true ;
this.startTime = System.nanoTime() ;
}
public void setFinishTime() {
if ( finishTimeIsSet )
Log.warn(this, "Finish time reset") ;
finishTimeIsSet = true ;
this.finishTime = System.nanoTime() ;
}
public HttpServletRequest getRequest() { return request ; }
public HttpServletResponseTracker getResponse() { return response ; }
/** Return the recorded time taken in milliseconds.
* {@linkplain #setStartTime} and {@linkplain #setFinishTime}
* must have been called.
*/
public long getTime()
{
if ( ! startTimeIsSet )
Log.warn(this, "Start time not set") ;
if ( ! finishTimeIsSet )
Log.warn(this, "Finish time not set") ;
return (finishTime-startTime)/(1000*1000) ;
}
public void sync() {
SystemARQ.sync(dsg) ;
}
public static MediaType contentNegotationRDF(HttpAction action) {
MediaType mt = ConNeg.chooseContentType(action.request, DEF.rdfOffer, DEF.acceptRDFXML) ;
if ( mt == null )
return null ;
if ( mt.getContentType() != null )
action.response.setContentType(mt.getContentType()) ;
if ( mt.getCharset() != null )
action.response.setCharacterEncoding(mt.getCharset()) ;
return mt ;
}
public static MediaType contentNegotationQuads(HttpAction action) {
return ConNeg.chooseContentType(action.request, DEF.quadsOffer, DEF.acceptNQuads) ;
}
}