Ok, I seem to have found a workaround if anyone's interested:
Basically I add a read file callback that simply records in a map the
ReadResult for each file that is requested.
I then subclass the DatabasePager class to override the requestNodeFile
function so that it only calls the base class function for files that not been
recorded with a failed readresult.
Code:
class CustomDatabasePager : public osgDB::DatabasePager
{
public:
virtual void requestNodeFile(const std::string& fileName,osg::Group*
group,
float priority, const osg::FrameStamp*
framestamp,
osg::ref_ptr<osg::Referenced>&
databaseRequest,
const osg::Referenced* options)
{
osgDB::ReaderWriter::ReadResult::ReadStatus status;
if (CustomReadFileCallback::getCachedReadStatus(fileName, status))
{
if (status != osgDB::ReaderWriter::ReadResult::FILE_LOADED &&
status !=
osgDB::ReaderWriter::ReadResult::FILE_LOADED_FROM_CACHE)
{
// If we have requested this file and it failed, there is no
// point requesting it again, so bypassing normal request
// mechanism here.
return;
}
}
osgDB::DatabasePager::requestNodeFile(fileName, group, priority,
framestamp, databaseRequest, options);
}
};
chrisd wrote:
> I'm using the function:
> viewer->getDatabasePager()->getFileRequestListSize()
> to determine whether background processing of PagedLOD objects is complete.
> e.g I wait until it returns zero before performing screen grab.
> This normally works fine, but if there are any files referred to by the
> PagedLOD nodes are missing, then the files seem to keep getting added back to
> the database pager file request list by the cull visitor.
> This means (a) It is continuallly retrying to find each missing file, and (b)
> the file request queue is never empty and so I can't determine when the
> loading is as complete as it can get.
>
> My questions are:
> 1. Should this be happening?
> 2. How do I avoid it?
>
> I suppose I could check for file existence before constructing the PagedLOD
> object, but I wanted to avoid that because this check is relatively expensive
> over http, and would prefer that to be deferred to the db pager thread.
>
> Cheers,
> Chris
Code:
Code:
Code:
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=35404#35404
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