DataStaging::DataDeliveryComm Class Reference

This class provides an abstract interface for the Delivery layer. More...

#include <arc/data-staging/DataDeliveryComm.h>

Inheritance diagram for DataStaging::DataDeliveryComm:

Data Structures
struct	Status
	Plain C struct to pass information from executing process back to main thread. More...

Public Types
enum	CommStatusType {   CommInit, CommNoError, CommTimeout, CommClosed,   CommExited, CommFailed }
	Communication status with transfer. More...

Public Member Functions
virtual	~DataDeliveryComm ()
	Destroy object. This stops any ongoing transfer and cleans up resources.
Status	GetStatus () const
	Obtain status of transfer.
std::string	GetError () const
	Get explanation of error.
virtual	operator bool () const =0
	Returns true if transfer is currently active.
virtual bool	operator! () const =0
	Returns true if transfer is currently not active.

Static Public Member Functions
static DataDeliveryComm *	CreateInstance (DTR_ptr dtr, const TransferParameters &params)
	Factory method to get DataDeliveryComm instance.
static bool	CheckComm (DTR_ptr dtr, std::vector< std::string > &allowed_dirs)
	Check the delivery method is available. Calls CheckComm of the appropriate subclass. More...

Protected Member Functions
virtual void	PullStatus ()=0
	Check for new state and fill state accordingly. More...
	DataDeliveryComm (DTR_ptr dtr, const TransferParameters &params)
	Start transfer with parameters taken from DTR and supplied transfer limits. More...

Protected Attributes
Status	status_
	Current status of transfer.
Status	status_buf_
	Latest status of transfer is read into this buffer.
unsigned int	status_pos_
	Reading position of Status buffer.
Glib::Mutex	lock_
	Lock to protect access to status.
DataDeliveryCommHandler *	handler_
	Pointer to singleton handler of all DataDeliveryComm objects.
std::string	dtr_id
	ID of the DTR this object is handling. Used in log messages.
TransferParameters	transfer_params
	Transfer limits.
Arc::Time	start_
	Time transfer was started.
DTRLogger	logger_
	Logger object. Pointer to DTR's Logger.

Detailed Description

This class provides an abstract interface for the Delivery layer.

Different implementations provide different ways of providing Delivery functionality. DataDeliveryLocalComm launches a local process to perform the transfer and DataDeliveryRemoteComm contacts a remote service which performs the transfer. The implementation is chosen depending on what is set in the DTR, which the Scheduler should set based on various factors.

CreateInstance() should be used to get a pointer to the instantiated object. This also starts the transfer. Deleting this object stops the transfer and cleans up any used resources. A singleton instance of DataDeliveryCommHandler regularly polls all active transfers using PullStatus() and fills the Status object with current information, which can be obtained through GetStatus().

Member Enumeration Documentation

enum DataStaging::DataDeliveryComm::CommStatusType

Communication status with transfer.

Enumerator
CommInit	Initializing/starting transfer, rest of information not valid.
CommNoError	Communication going on smoothly.
CommTimeout	Communication experienced timeout.
CommClosed	Communication channel was closed.
CommExited	Transfer exited. Mostly same as CommClosed but exit detected before pipe closed.
CommFailed	Transfer failed. If we have CommFailed and no error code reported that normally means segfault or external kill.

Constructor & Destructor Documentation

DataStaging::DataDeliveryComm::DataDeliveryComm ( DTR_ptr  dtr, const TransferParameters &  params  )

protected

Start transfer with parameters taken from DTR and supplied transfer limits.

Constructor should not be used directly, CreateInstance() should be used instead.

Member Function Documentation

static bool DataStaging::DataDeliveryComm::CheckComm ( DTR_ptr  dtr, std::vector< std::string > &  allowed_dirs  )

static

Check the delivery method is available. Calls CheckComm of the appropriate subclass.

Parameters

dtr	DTR from which credentials are used
allowed_dirs	filled with list of dirs that this comm is allowed to read/write

Returns

true if selected delivery method is available

virtual void DataStaging::DataDeliveryComm::PullStatus ( )

protectedpure virtual

Check for new state and fill state accordingly.

This method is periodically called by the comm handler to obtain status info. It detects communication and delivery failures and delivery termination.

Implemented in DataStaging::DataDeliveryRemoteComm, and DataStaging::DataDeliveryLocalComm.

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The documentation for this class was generated from the following file:

• DataDeliveryComm.h