Requests

VFS_request instances will flow between nodes and have a particular lifespan. We don't want to leak memory, so special care is taken to ensure that requests are always deleted when their function has been performed.

This describes the lifespan of a request and notes about each stage of its life:

Function	Thread	Subclass-able	Call Base	Notes
VFS_node::createRequest()	0	Y	Y	origin is the creator of the request, who wants to receive a response
VFS_node::issueRequest()	0	N	N	on this thread and check global mutex for safety
VFS_node::subtreeRequest()	0->1	N	N	pass to another thread
VFS_node::find()	1	Y	maybe	traverse to node or fail
Fail and VFS_node::issueResponse()	1	Y	N	if the path is not found send an error
Succeed and VFS_node::executeRequest()	1	N	N	call an action using the payload in the VFS_request
VFS_node::ls()	1	Y	maybe	return the listing of container
VFS_node::rm()	1	Y	N	remove/delete an entry. Won't delete a container that has children.
VFS_node::read()	1	Y	N	Return the data contents of this node, or if it's a container call ls()
VFS_node::write()	1	Y	N	replace or create the contents/metadata of an entry
VFS_node::metadata()	1	Y	Y	read the metadata of entry
VFS_node::applyDiff()	1	Y	maybe	receive a diff... only call the base class if the subclass does not emit a diff on its own
VFS_node::submit()	1	Y	maybe	submit a diff to an entry
VFS_node::subscribe()	1	Y	Y	subscribe to an entry or container. This is tricky and not recommended for subclasses.
VFS_node::unsubscribe()	1	Y	Y	unsubscribe from an entry or container. This is tricky and not recommended for subclasses.
VFS_node::aclDefaults()	1	Y	maybe	return any VFS_acl default settings for this node. The ACL file has the option to override these.
VFS_node::report()	1	Y	Y	Report debugging information about the current state of this node.
VFS_node::requestLock()	1	Y	Y	Request a lock on this node.
VFS_node::releaseLock()	1	Y	Y	Release a lock on this node.
if NOT VFS_request::_isCallback	1	-na-	-na-	will be deleted when the callback completes
VFS_node::issueResponse()	1->0	N	N	finally we get back to the receiver
VFS_node::receiveResponse()	0	Y	Y	the request has completed here, but a bit of cleanup is left
VFS_request::execute()	0	Y	maybe	a VFS_request subclass can do something now with the satisfied request
if the request has a callback, VFS_request::copyCallback()	0	Y	N	copy the payload. This is the whole point of a request and in the case of a callback we want to transmit this.
VFS_node::issueResponse()	0	Y	Y	to the callback receiver
delete the VFS_request	0	-na-	Y	now all action is satisfied