Protocol

This module defines the base class for implementing a transfer protocol, along with some of the default methods for LFN2PFN translations.

RSEProtocol(protocol_attr, rse_settings, logger=logging.log)

This class is virtual and acts as a base to inherit new protocols from. It further provides some common functionality which applies for the majority of the protocols.

Initializes the object with information about the referred RSE.

Parameters:

Name	Type	Description	Default
protocol_attr		Properties of the requested protocol.	required
rse_settting		The RSE settings.	required
logger		Optional decorated logger that can be passed from the calling daemons or servers.	log

lfns2pfns(lfns)

Returns a fully qualified PFN for the file referred by path.

Parameters:

Name	Type	Description	Default
path		The path to the file.	required

Returns:

Type	Description
	Fully qualified PFN.

__lfns2pfns_client(lfns)

Provides the path of a replica for non-deterministic sites. Will be assigned to get path by the init method if necessary.

Parameters:

Name	Type	Description	Default
scope		list of DIDs	required

Returns:

Type	Description
	dict with scope:name as keys and PFN as value (in case of errors the Rucio exception si assigned to the key)

_get_path(scope, name)

Transforms the logical file name into a PFN. Suitable for sites implementing the RUCIO naming convention. This implementation is only invoked if the RSE is deterministic.

Parameters:

Name	Type	Description	Default
scope		scope	required
name		filename	required

Returns:

Type	Description
	RSE specific URI of the physical file

_get_path_nondeterministic_server(scope, name)

Provides the path of a replica for non-deterministic sites. Will be assigned to get path by the init method if necessary.

parse_pfns(pfns)

Splits the given PFN into the parts known by the protocol. It is also checked if the provided protocol supports the given PFNs.

Parameters:

Name	Type	Description	Default
pfns		a list of a fully qualified PFNs	required

Returns:

Type	Description
	dic with PFN as key and a dict with path and name as value

Raises:

Type	Description
RSEFileNameNotSupported	if the provided PFN doesn't match with the protocol settings

exists(path) abstractmethod

Checks if the requested file is known by the referred RSE.

Parameters:

Name	Type	Description	Default
path		Physical file name	required

Returns:

Type	Description
	True if the file exists, False if it doesn't

Raises:

Type	Description
SourceNotFound	if the source file was not found on the referred storage.

connect() abstractmethod

Establishes the actual connection to the referred RSE.

Raises:

Type	Description
RSEAccessDenied	if no connection could be established.

close() abstractmethod

Closes the connection to RSE.

get(path, dest, transfer_timeout=None) abstractmethod

Provides access to files stored inside connected the RSE.

Parameters:

Name	Type	Description	Default
path		Physical file name of requested file	required
dest		Name and path of the files when stored at the client	required
transfer_timeout		Transfer timeout (in seconds)	None

Raises:

Type	Description
DestinationNotAccessible	if the destination storage was not accessible.
ServiceUnavailable	if some generic error occurred in the library.
SourceNotFound	if the source file was not found on the referred storage.

put(source, target, source_dir, transfer_timeout=None) abstractmethod

Allows to store files inside the referred RSE.

Parameters:

Name	Type	Description	Default
source		path to the source file on the client file system	required
target		path to the destination file on the storage	required
source_dir		Path where the to be transferred files are stored in the local file system	required
transfer_timeout		Transfer timeout (in seconds)	None

Raises:

Type	Description
DestinationNotAccessible	if the destination storage was not accessible.
ServiceUnavailable	if some generic error occurred in the library.
SourceNotFound	if the source file was not found on the referred storage.

delete(path) abstractmethod

Deletes a file from the connected RSE.

Parameters:

Name	Type	Description	Default
path		path to the to be deleted file	required

Raises:

Type	Description
ServiceUnavailable	if some generic error occurred in the library.
SourceNotFound	if the source file was not found on the referred storage.

rename(path, new_path) abstractmethod

Allows to rename a file stored inside the connected RSE.

Parameters:

Name	Type	Description	Default
path		path to the current file on the storage	required
new_path		path to the new file on the storage	required

Raises:

Type	Description
DestinationNotAccessible	if the destination storage was not accessible.
ServiceUnavailable	if some generic error occurred in the library.
SourceNotFound	if the source file was not found on the referred storage.

get_space_usage()

Get RSE space usage information.

Returns:

Type	Description
	a list with dict containing 'totalsize' and 'unusedsize'

Raises:

Type	Description
ServiceUnavailable	if some generic error occurred in the library.

stat(path)

Returns the stats of a file.

Parameters:

Name	Type	Description	Default
path		path to file	required

Returns:

Type	Description
	a dict with two keys, filesize and adler32 of the file provided in path.

Raises:

Type	Description
ServiceUnavailable	if some generic error occurred in the library.
SourceNotFound	if the source file was not found on the referred storage.