Hi !
Le 09/03/2017 à 10:52, Bikash Srivastava a écrit :
> Hi Team,
>
> I am working on Apache DS, but having a hard time how to code flows and
> request gets process inside the server.
Actually, it depends on what you want to study. If you want to start
from the very moment a request is received by the server, thenn the
startng point is the LdapProtocolHandler.messageReceived() method. That
being said, if you are interested in one specific request (ie, a Search,
an Add, etc), then you have dedicated handler for each operation :
ADD : AddRequestHandler.handle()
DELETE : DeleteRequestHandler.handle()
SEARCH : SearchRequestHandler.handle()
...
But that is again a bit deep in the stack. Enough said that each of
those handler is passing the control to the DefaultCoreSession class,
which has one method per request type : add( AddRequest addRequest ),
delete( DeleteRequest deleteRequest ), search( SearchRequest
searchRequest )...
Those methods create a Context containing all the informations needed to
process the request, and then call the OperationManager instance, which
is stored in the DirectoryService. For instance :
public void add( AddRequest addRequest, LogChange log ) throws
LdapException
{
AddOperationContext addContext = new AddOperationContext( this,
addRequest );
addContext.setLogChange( log );
OperationManager operationManager =
directoryService.getOperationManager();
try
{
operationManager.add( addContext );
}
catch ( LdapException e )
{
addRequest.getResultResponse().addAllControls(
addContext.getResponseControls() );
throw e;
}
addRequest.getResultResponse().addAllControls(
addContext.getResponseControls() );
}
The OperationManager is now in charge. The code is in the
DefaultOperationManager class, where some pre-processing is done, before
we call the Interceptor chain. Interceptors are snippet of code dealing
with specific aspect of the processing. We have a bit more than 15
interceptors that can be executed, depending on the operations and the
context. They are all linked in a specific order, which is configured :
you don't have to care about it.
All in all, the first interceptor is the Head, the last one is the Nexus
(ie, the facade for the database in use - we may have many), and in the
middle, you have Authent, Authz, etc...
We call the first interceptor this way :
Interceptor head = directoryService.getInterceptor(
addContext.getNextInterceptor() );
head.add( addContext );
and in each interceptor, you can do some pre-processing, call the ext
interceptor, and do some post-processing :
public void add( AddOperationContext addContext ) throws LdapException
{
// Pre-processing
checkAuthenticated( addContext );
Entry entry = addContext.getEntry();
if ( !directoryService.isPwdPolicyEnabled() ||
addContext.isReplEvent() )
{
// Call the next interceptor, and retirn (no post-processing
in this case
next( addContext );
return;
}
...
Setting a Brekpoint in the OperationManager is the way to go.
I hope it helps. Do not hesitate to ask for more if needed !
--
Emmanuel Lecharny
Symas.com
directory.apache.org
