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package com.sun.grizzly.arp;
import com.sun.grizzly.http.ProcessorTask;
import com.sun.grizzly.tcp.Adapter;
import com.sun.grizzly.tcp.Response;
import com.sun.grizzly.tcp.http11.GrizzlyAdapter;
import com.sun.grizzly.util.ClassLoaderUtil;
import java.util.ArrayList;
import java.util.StringTokenizer;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* Default implementation of the {@link AsyncExecutor}. This class will
* execute a {@link ProcessorTask} asynchronously, by interrupting the
* process based on the logic defined in its associated {@link AsyncFilter}
* If no {@link AsyncFilter} are defined, the {@link ProcessorTask}
* will not be interrupted and executed synchronously.
*
* @author Jeanfrancois Arcand
*/
public class DefaultAsyncExecutor implements AsyncExecutor{
private final static String ASYNC_FILTER =
"com.sun.grizzly.asyncFilters";
/**
* The <code>AsyncFilter</code> to execute asynchronous operations on
* a <code>ProcessorTask</code>.
*/
private final static ArrayList<AsyncFilter> sharedAsyncFilters = loadFilters();
/**
* The {@link AsyncTask} used to wrap the
* {@link ProcessorTask}
*/
private AsyncTask asyncProcessorTask;
/**
* The associated {@link ProcessorTask}
*/
private ProcessorTask processorTask;
/**
* The {@link AsyncFilter} to execute asynchronous operations on
* a {@link ProcessorTask}.
*/
private final ArrayList<AsyncFilter> asyncFilters = new ArrayList<AsyncFilter>(sharedAsyncFilters);
/**
* The {@link AsyncHandler} associated with this object.
*/
private AsyncHandler asyncHandler;
/**
* Only one execution of every steps are allowed.
*/
private final AtomicBoolean parseHeaderPhase = new AtomicBoolean(false);
private final AtomicBoolean executeAdapterPhase = new AtomicBoolean(false);
private final AtomicBoolean commitResponsePhase = new AtomicBoolean(false);
// --------------------------------------------------------------------- //
public DefaultAsyncExecutor(){
}
// ------------------------------------------------Asynchrounous Execution --/
/**
* Pre-execute a {@link ProcessorTask} by parsing the request
* line.
*/
public boolean preExecute() throws Exception{
if (!parseHeaderPhase.getAndSet(true)){
processorTask.preProcess();
// True when there is an error or when the (@link FileCache} is enabled
if (processorTask.parseRequest()){
finishResponse();
return false;
}
return true;
}
return false;
}
/**
* Interrupt the {@link ProcessorTask} if {@link AsyncFilter}
* has been defined.
* @return true if the execution can continue, false if delayed.
*/
public boolean interrupt() throws Exception{
if (asyncFilters.isEmpty()) {
execute();
return false;
} else {
final AsyncFilter.Result result = invokeFilters();
if (result == AsyncFilter.Result.NEXT) {
return execute();
}
return result == AsyncFilter.Result.FINISH;
}
}
/**
* Execute the associated {@link Adapter} or {@link GrizzlyAdapter}
* @return true if the execution can continue, false if delayed.
*/
public boolean execute() throws Exception{
if (!executeAdapterPhase.getAndSet(true)){
processorTask.invokeAdapter();
return true;
}
return false;
}
/**
* Invoke the {@link AsyncFilter}s
*/
private AsyncFilter.Result invokeFilters(){
for (AsyncFilter asyncFilter : asyncFilters) {
final AsyncFilter.Result result = asyncFilter.doFilter(this);
if (result != AsyncFilter.Result.NEXT) {
return result;
}
}
return AsyncFilter.Result.NEXT;
}
/**
* Finish the {@link Response} and recycle {@link ProcessorTask}.
*/
private void finishResponse() throws Exception{
processorTask.postProcess();
processorTask.terminateProcess();
// De-reference so under stress we don't have a simili leak.
processorTask = null;
}
/**
* Resume the connection by commit the {@link Response} object.
*/
public boolean postExecute() throws Exception{
if (!commitResponsePhase.getAndSet(true)){
if (processorTask == null) return false;
processorTask.postResponse();
finishResponse();
return false;
}
return false;
}
/**
* Set the {@link AsyncTask}.
*/
public void setAsyncTask(AsyncTask asyncProcessorTask){
this.asyncProcessorTask = asyncProcessorTask;
}
/**
* Return {@link AsyncTask}.
*/
public AsyncTask getAsyncTask(){
return asyncProcessorTask;
}
// --------------------------------------------------------- Util --------//
/**
* Add an {@link AsyncFilter}
*/
public void addAsyncFilter(AsyncFilter asyncFilter) {
asyncFilters.add(asyncFilter);
}
/**
* Remove an {@link AsyncFilter}
*/
public boolean removeAsyncFilter(AsyncFilter asyncFilter) {
return asyncFilters.remove(asyncFilter);
}
/**
* Get the {@link AsyncHandler} who drive the asynchronous process.
*/
public AsyncHandler getAsyncHandler() {
return asyncHandler;
}
/**
* Set the {@link AsyncHandler} who drive the asynchronous process.
*/
public void setAsyncHandler(AsyncHandler asyncHandler) {
this.asyncHandler = asyncHandler;
}
/**
* Set the {@link ProcessorTask} used to execute the request processing.
* @param task a {@link ProcessorTask}
*/
public void setProcessorTask(ProcessorTask task) {
processorTask = task;
}
/**
* The {@link ProcessorTask} used to execute the request processing.
* @return {@link ProcessorTask} used to execute the request processing.
*/
public ProcessorTask getProcessorTask(){
return processorTask;
}
/**
* Load the list of <code>AsynchFilter</code>.
*/
protected static ArrayList<AsyncFilter> loadFilters(){
ArrayList<AsyncFilter> al = new ArrayList<AsyncFilter>();
if ( System.getProperty(ASYNC_FILTER) != null){
StringTokenizer st = new StringTokenizer(
System.getProperty(ASYNC_FILTER),",");
while (st.hasMoreTokens()){
AsyncFilter filter = (AsyncFilter)ClassLoaderUtil.load(st.nextToken());
if (filter != null) {
al.add(filter);
}
}
}
return al;
}
/**
* Reset
*/
void recycle(){
parseHeaderPhase.getAndSet(false);
executeAdapterPhase.getAndSet(false);
commitResponsePhase.getAndSet(false);
}
}