NAME
Protocol Modules -
Protocol Implementation API.
Data Structures
struct globus_gass_transfer_request_proto_s
Protocol module request handling structure.
struct globus_gass_transfer_listener_proto_s
Protocol module listener handling structure.
struct globus_gass_transfer_proto_descriptor_t
Protocol module descriptor structure.
Typedefs
typedef typedefEXTERN_C_BEGIN struct
globus_gass_transfer_request_proto_s
globus_gass_transfer_request_proto_t
typedef struct globus_gass_transfer_listener_proto_s
globus_gass_transfer_listener_proto_t
typedef void(* globus_gass_transfer_proto_send_t
)(globus_gass_transfer_request_proto_t *proto,
globus_gass_transfer_request_t request, globus_byte_t *bytes,
globus_size_t send_length, globus_bool_t last_data)
typedef void(* globus_gass_transfer_proto_receive_t
)(globus_gass_transfer_request_proto_t *proto,
globus_gass_transfer_request_t request, globus_byte_t *bytes,
globus_size_t bytes_length, globus_size_t wait_for_length)
typedef void(* globus_gass_transfer_proto_func_t
)(globus_gass_transfer_request_proto_t *proto,
globus_gass_transfer_request_t request)
typedef void(* globus_gass_transfer_proto_new_request_t
)(globus_gass_transfer_request_t request,
globus_gass_transfer_requestattr_t *attr)
typedef int(* globus_gass_transfer_proto_create_listener_t
)(globus_gass_transfer_listener_t listener,
globus_gass_transfer_listenerattr_t *attr, char *scheme, char
**base_url, globus_gass_transfer_listener_proto_t **proto)
typedef void(* globus_gass_transfer_proto_listener_t
)(globus_gass_transfer_listener_proto_t *proto,
globus_gass_transfer_listener_t listener)
typedef globus_object_t *(* globus_gass_transfer_proto_new_attr_t
)(char *url_scheme)
typedef void(* globus_gass_transfer_proto_accept_t
)(globus_gass_transfer_listener_proto_t *proto,
globus_gass_transfer_listener_t listener,
globus_gass_transfer_request_t request,
globus_gass_transfer_requestattr_t *attr)
Functions
void globus_gass_transfer_proto_send_complete
(globus_gass_transfer_request_t request, globus_byte_t *bytes,
globus_size_t nbytes, globus_bool_t failed, globus_bool_t
last_data)
void globus_gass_transfer_proto_receive_complete
(globus_gass_transfer_request_t request, globus_byte_t *bytes,
globus_size_t nbytes, globus_bool_t failed, globus_bool_t
last_data)
void globus_gass_transfer_proto_listener_ready
(globus_gass_transfer_listener_t listener)
int globus_gass_transfer_proto_register_protocol
(globus_gass_transfer_proto_descriptor_t *proto_desc)
int globus_gass_transfer_proto_unregister_protocol
(globus_gass_transfer_proto_descriptor_t *proto_desc)
void globus_gass_transfer_proto_request_ready
(globus_gass_transfer_request_t request,
globus_gass_transfer_request_proto_t *proto)
void globus_gass_transfer_proto_new_listener_request
(globus_gass_transfer_listener_t listener,
globus_gass_transfer_request_t request,
globus_gass_transfer_request_proto_t *proto)
void globus_gass_transfer_proto_request_denied
(globus_gass_transfer_request_t request, int reason, char *message)
void globus_gass_transfer_proto_request_referred
(globus_gass_transfer_request_t request, char **url, globus_size_t
num_urls)
Detailed Description
Protocol Implementation API.
The GASS Protocol Module API is designed to make it possible to extend
the GASS client and server APIs to support additional protocols without
making any changes to the core of the GASS implementation. GASS
protocol modules are intended to to handle protocol-specific connection
and data handling. The GASS Transfer library includes protocol modules
which implement the HTTP, HTTPS, FTP, and GSI-FTP protocols.
Every protocol module implementation must include the following header
file:
#include ’globus_gass_transfer_proto.h’
To implement a protocol module, one must create a
globus_gass_transfer_proto_descriptor_t structure which indicates what
the protocol module is able to do. This structure contains the URL
scheme which the protocol module supports, and function pointers which
indicate what type of operations (client or server) that the module
implements. To implement a client-side protocol module, the
new_requestattr and new_request fields must be set to the protocol
module’s implementations of those functions. To implement a server-side
protocol module, the new_listenerattr and new_listener functions must
be set to the protocol module’s implementations of those functions.
A protocol module implementor registers a protocol module with the GASS
Transfer library by calling the function
globus_gass_transfer_proto_register_protocol(), and unregisters the
module by calling globus_gass_transfer_proto_unregister_protocol().
This functions must be called after the GLOBUS_GASS_TRANSFER_MODULE has
already been activated. Once registered, applications may use URLs of
the scheme type provided by the protocol module for the standard client
or server operations.
Typedef Documentation
typedef typedefEXTERN_C_BEGIN struct globus_gass_transfer_request_proto_s
globus_gass_transfer_request_proto_t
Protocol module request handling structure. See also:
globus_gass_transfer_request_proto_s
typedef struct globus_gass_transfer_listener_proto_s
globus_gass_transfer_listener_proto_t
Protocol module listener handling structure. See also:
globus_gass_transfer_listener_proto_s
typedef void(*
globus_gass_transfer_proto_send_t)(globus_gass_transfer_request_proto_t
*proto, globus_gass_transfer_request_t request, globus_byte_t *bytes,
globus_size_t send_length, globus_bool_t last_data)
Protocol module function type to handle sending data. A function
pointer of this type is associated with the
globus_gass_transfer_request_proto_t associated with a request handle.
It is called when client or server has registered a bytes array for
sending to the client or server which is handling the request. The GASS
Transfer Library will only pass one bytes array to the protocol module
for processing per request at any given time.
Once the protocol module has processed the array, it must call
globus_gass_transfer_proto_send_complete() to let the GASS Transfer
library continue to process the request.
Parameters:
proto The protocol module’s request handler.
request The request handle with which this block of bytes is
associated.
bytes The user-supplied byte array containing the data associated
with the request.
bytes_length The length of the bytes array.
last_data A flag to indicate whether this is the final block of
data for the request. If this is true, then the callback function
will be delayed until the server acknowledges that the file has
been completely received.
See also:
globus_gass_transfer_send_bytes()
typedef void(*
globus_gass_transfer_proto_receive_t)(globus_gass_transfer_request_proto_t
*proto, globus_gass_transfer_request_t request, globus_byte_t *bytes,
globus_size_t bytes_length, globus_size_t wait_for_length)
Protocol module function type to handle receiving data. A function
pointer of this type is associated with the
globus_gass_transfer_request_proto_t associated with a request handle.
It is called when client or server has registered a bytes array for
receiving from the client or server which is handling the request. The
GASS Transfer Library will only pass one bytes array to the protocol
module for processing per request at any given time.
Once the protocol module has processed the array, it must call
globus_gass_transfer_proto_receive_complete() to let the GASS Transfer
library continue to process the request.
Parameters:
proto The protocol module’s request handler.
request The request handle with which this block of bytes is
associated.
bytes The user-supplied byte array containing the data associated
with the request.
bytes_length The length of the bytes array.
wait_for_length The minimum amount of data to receive before
calling globus_gass_transfer_proto_receive_complete() for the
request. The GASS Transfer protocol module may call that function
with a smaller value for the amount received if EOF has been
reached.
See also:
globus_gass_transfer_receive_bytes()
typedef void(*
globus_gass_transfer_proto_func_t)(globus_gass_transfer_request_proto_t
*proto, globus_gass_transfer_request_t request)
Protocol module implementation function type. Function pointers of this
type are associated with the globus_gass_transfer_request_proto_t
associated with a particular request handle. They are called when
certain functions which modify the status of a request have been called
by a client or server.
A function of this type is used for the fail, deny, refer, authorize,
and destroy fields of the globus_gass_transfer_request_proto_t. A
protocol module can query the request handle to determine the status
and, if applicable, denial reasons if necessary.
Parameters:
proto The protocol module’s request handler.
request The request handle.
typedef void(*
globus_gass_transfer_proto_new_request_t)(globus_gass_transfer_request_t
request, globus_gass_transfer_requestattr_t *attr)
Protocol module implementation function type for new client requests. A
function pointer of this type is associated with the
globus_gass_transfer_proto_descriptor_t for a particular protocol
module’s implementation. It is called when the client has begun a file
transfer request by calling one of the functions in the ’@ref
globus_gass_transfer_client’ section of this manual.
When this function is called for a protocol module, the module should
query the request handle to determine the URL which is being requested
by the client, and the operation being done on that URL. The protocol
module should initiate the request, and once it has determined that it
has been authorized, denied, or referred, one of
globus_gass_transfer_proto_request_ready(),
globus_gass_transfer_proto_request_denied(), or
globus_gass_transfer_proto_request_referred() must be called.
Parameters:
request The request handle containing the information about the
request.
attr A protocol-specific attribute set, created by calling the
protocol module’s new_requestattr function pointer.
typedef int(*
globus_gass_transfer_proto_create_listener_t)(globus_gass_transfer_listener_t
listener, globus_gass_transfer_listenerattr_t *attr, char *scheme, char
**base_url, globus_gass_transfer_listener_proto_t **proto)
Protocol module implementation function type for new server listeners.
A function pointer of this type is associated with the
globus_gass_transfer_proto_descriptor_t for a particular protocol
module’s implementation. It is called when the server has called
globus_gass_transfer_create_listener().
Parameters:
listener The listener handle to assocate with the new proto created
by the protocol module.
attr A protocol-specific attribute set, created by calling the
protocol module’s new_listenerattr function pointer.
scheme The URL scheme that the server has requested for the new
listener. This will be one the scheme associated with a particular
protocol module.
base_url A pointer to be set the value of the base url of this
listener. For most protocols, this will contain the scheme,
hostname, and port number of the listener. This string must be
allocated using one of the memory allocators defined in the
globus_common library. It will be freed by the GASS Transfer
library when the listener is closed.
proto A pointer to be set to a new
globus_gass_transfer_listener_proto_t which will be associated with
this listener. This must be allocated by the protocol module using
one of the memory allocators defined in the globus_common library.
It will be freed by the GASS Transfer library when the listener is
closed.
Returns:
A GASS error value, or GLOBUS_SUCCESS.
typedef void(*
globus_gass_transfer_proto_listener_t)(globus_gass_transfer_listener_proto_t
*proto, globus_gass_transfer_listener_t listener)
Protocol module implementation function type for server operations.
Function pointers of this type are associated with the
globus_gass_transfer_listener_proto_t associated with a particular
listener handle. They are called when a server implementation wants to
close the listener, listen for new connections, or destroy the
listener.
Parameters:
proto The protocol-specific implementation of the
globus_gass_transfer_listener_proto_t for a particular listener.
listener The listener handle associated with the proto.
See also:
globus_gass_transfer_proto_create_listener_t
typedef globus_object_t*(* globus_gass_transfer_proto_new_attr_t)(char
*url_scheme)
Protocol module implementation function type for attribute creation. A
function pointer of this type is associated with the
globus_gass_transfer_proto_descriptor_t defining a protocol module. It
is called when a client requests a new request attribute set be created
for a URL scheme handled by a protocol module. The function
implementation must create a new request attribute usuable by the
protocol.
The returned attribute must be a globus object which inherits from one
of the base attributes defined in the GASS Transfer API. A client or
server operation will use a request attribute generated by this
function when creating a new globus_gass_transfer_request_proto_t to
handle a request.
Parameters:
url_scheme The URL scheme that the request attribute should be
compatible with.
Returns:
A globus_object_t-based request attribute.
See also:
globus_gass_transfer_proto_new_request_t,
globus_gass_transfer_proto_accept_t
typedef void(*
globus_gass_transfer_proto_accept_t)(globus_gass_transfer_listener_proto_t
*proto, globus_gass_transfer_listener_t listener,
globus_gass_transfer_request_t request,
globus_gass_transfer_requestattr_t *attr)
Protocol module implementation function type for server request
parsing. Function pointers of this type are associated with the
globus_gass_transfer_listener_proto_t associated with a particular
listener handle. They are called when a server implementation wants to
accept a new connection from the listener. A new request is generated
based on the protocol-specific request done on the new connection.
The new request will be created with the attributes specified in the
attr parameter. Once the protocol module has parsed the request, it
must call globus_gass_transfer_proto_new_listener_request() to let the
server implementation decide how to process this request.
The protocol module should update the request to indicate the type of
operation being requested, the size of the file (if applicable), and
the identity of the client (if applicable).
Parameters:
proto The protocol specific listener data structure associated with
the listener handle.
listener The listener handle which the user requested the listen
on.
request The new request handle.
attr The request attribute set to be used when processing this
request.
Function Documentation
void globus_gass_transfer_proto_send_complete
(globus_gass_transfer_request_t request, globus_byte_t * bytes,
globus_size_t nbytes, globus_bool_t failed, globus_bool_t last_data)
Data send complete. A protocol module must call this function once a
byte range registered for sending via the protocol module’s send_buffer
method has been completely processed. This function is called for
protocol modules implementing either server or client functionality.
Parameters:
request The request handle associated with this byte array.
bytes The byte array which was sent. This should be the same as the
pointer passed in the send_buffer method.
nbytes The number of bytes which were sent from this byte array.
This may be different than length passed to the send_buffer method
if an error occurred.
failed A boolean indicating whether this byte range was
successfully sent or not. This should be set to GLOBUS_TRUE if
either a protocol error or a user-generated abort has occurred
while processing the byte range. If this is set to GLOBUS_TRUE,
then the last_data parameter must also be set to GLOBUS_TRUE.
last_data A boolean indicating whether this byte range was the
final one which can be processed for this request. This should be
set to GLOBUS_TRUE if an error occurred while processing this byte
range, and user-generated abort occurred, or this is the final byte
range in the data transfer.
See also:
globus_gass_transfer_send_bytes()
void globus_gass_transfer_proto_receive_complete
(globus_gass_transfer_request_t request, globus_byte_t * bytes,
globus_size_t nbytes, globus_bool_t failed, globus_bool_t last_data)
Data receive complete. A protocol module must call this function once a
byte range registered for receive via the protocol module’s recv_buffer
method has been completely processed. This function is called for
protocol modules implementing either server or client functionality.
Parameters:
request The request handle associated with this byte array.
bytes The byte array which was received into. This should be the
same as the pointer passed in the send_buffer method.
nbytes The number of bytes which were sent from this byte array.
This may be different than length passed to the send_buffer method
if an error occurred or EOF was reached while receiving the data.
failed A boolean indicating whether this byte range was
successfully received or not. This should be set to GLOBUS_TRUE if
either a protocol error or a user-generated abort has occurred
while processing the byte range. If this is set to GLOBUS_TRUE,
then the last_data parameter must also be set to GLOBUS_TRUE.
last_data A boolean indicating whether this byte range was the
final one which can be processed for this request. This should be
set to GLOBUS_TRUE if an error occurred while processing this byte
range, and user-generated abort occurred, or this is the final byte
range in the data transfer.
See also:
globus_gass_transfer_send_bytes()
void globus_gass_transfer_proto_listener_ready
(globus_gass_transfer_listener_t listener)
Server listener ready. This function notifies the GASS Transfer Library
that the protocol module has decided that a new request can be accepted
on this particular listener. It must only be called after the GASS
Transfer Library has called the listen function in a
globus_gass_transfer_listener_proto_t protocol module-specific listener
structure.
Parameters:
listener The listener handle which is now ready for accepting a new
connection.
int globus_gass_transfer_proto_register_protocol
(globus_gass_transfer_proto_descriptor_t * proto_desc)
Register protocol. This function registers a protocol module handler
with the GASS Transfer library. If this succeeds, then users of the
library may use the URLs with the protocol scheme implemented by this
module descriptor in GASS Transfer operations.
Parameters:
proto_desc The protocol module descriptor. See the ’@ref
globus_gass_transfer_protocol’ section of the manual for
information on this structure.
Return values:
GLOBUS_SUCCESS The protocol module was successfully registered with
GASS.
GLOBUS_GASS_TRANSFER_ERROR_NULL_POINTER The proto_desc parameter
was GLOBUS_NULL.
GLOBUS_GASS_TRANSFER_ERROR_ALREADY_REGISTERED A protocol module has
already been registered with GASS to handle this URL scheme.
int globus_gass_transfer_proto_unregister_protocol
(globus_gass_transfer_proto_descriptor_t * proto_desc)
Unregister protocol. This function unregisters a protocol module
handler from the GASS Transfer library. If this succeeds, then users of
the library may no longer user URLs with the protocol scheme
implemented by this module descriptor in GASS Transfer operations.
Parameters:
proto_desc The protocol module descriptor. See the ’@ref
globus_gass_transfer_protocol’ section of the manual for
information on this structure.
Return values:
GLOBUS_SUCCESS The protocol module was successfully registered with
GASS.
GLOBUS_GASS_TRANSFER_ERROR_NULL_POINTER The proto_desc parameter
was GLOBUS_NULL.
GLOBUS_GASS_TRANSFER_ERROR_INVALID_USE A protocol module has not
been registered with GASS to handle this URL scheme.
void globus_gass_transfer_proto_request_ready
(globus_gass_transfer_request_t request,
globus_gass_transfer_request_proto_t * proto)
Request ready. This function notifies the GASS Transfer Library that
new request generated by a client has begun processing in a protocol
module, and that protocol module is now ready to send or receive data
to handle this request.
Parameters:
request The request handle used for this request. This was created
by the user calling one of the functions in the ’@ref
globus_gass_transfer_client’ section of this manual.
proto The protocol-module specific request structure. This
structure contains a set of function pointers to allow GASS to
continue to process this request.
See also:
globus_gass_transfer_proto_request_referred(),
globus_gass_transfer_proto_request_denied()
void globus_gass_transfer_proto_new_listener_request
(globus_gass_transfer_listener_t listener,
globus_gass_transfer_request_t request,
globus_gass_transfer_request_proto_t * proto)
New listener request. This function notifies the GASS Transfer Library
that new request generated by a server calling the
globus_gass_transfer_register_accept() function has begun processing in
a protocol module, and that protocol module is now ready to send or
receive data to handle this request.
Parameters:
listener The listener handle used to accept this request.
request The request handle used for this request. This was created
by the user calling one of the functions in the ’@ref
globus_gass_transfer_client’ section of this manual.
proto The protocol-module specific request structure. This
structure contains a set of function pointers to allow GASS to
continue to process this request.
void globus_gass_transfer_proto_request_denied
(globus_gass_transfer_request_t request, int reason, char * message)
Request denied. This function notifies the GASS Transfer Library that
new request generated by a client calling one of the functions in the
’@ref globus_gass_transfer_client’ section of the manual has been
denied by the server, and so cannot be processed by the protocol
module.
Parameters:
request The request handle used for this request. This was created
by the user calling one of the functions in the ’@ref
globus_gass_transfer_client’ section of this manual.
reason A protocol-specific reason code.
message A string containing a message describing why the request
was denied. The GASS Transfer library is responsible for freeing
this message. It must be allocated using one of the memory
allocators defined in the Globus Common Library.
See also:
globus_gass_transfer_proto_request_ready(),
globus_gass_transfer_proto_request_referred()
void globus_gass_transfer_proto_request_referred
(globus_gass_transfer_request_t request, char ** url, globus_size_t
num_urls)
Request referred. This function notifies the GASS Transfer Library that
new request generated by a client calling one of the functions in the
’@ref globus_gass_transfer_client’ section of the manual has been
referred to another URL by the server, and so processing has stopped.
Parameters:
request The request handle used for this request. This was created
by the user calling one of the functions in the ’@ref
globus_gass_transfer_client’ section of this manual.
url An array of url strings containing alternate locations for this
file. The GASS transfer library is responsible for freeing this
array. It must be allocated using one of the memory allocators
defined in the Globus Common Library.
num_urls The length of the url array.
See also:
globus_gass_transfer_proto_request_ready(),
globus_gass_transfer_proto_request_denied(),
globus_gass_transfer_proto_request_referred()
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