NAME

SYNOPSIS

 #include <distcache/dc_plug.h>

 DC_PLUG *DC_PLUG_new(NAL_CONNECTION *conn, unsigned int flags);
 int DC_PLUG_free(DC_PLUG *plug);
 void DC_PLUG_to_select(DC_PLUG *plug, NAL_SELECTOR *sel);
 int DC_PLUG_io(DC_PLUG *plug, NAL_SELECTOR *sel);

DESCRIPTION

 #define DC_PLUG_FLAG_TO_SERVER         (unsigned int)0x0001
 #define DC_PLUG_FLAG_NOFREE_CONN       (unsigned int)0x0002

If the DC_PLUG_FLAG_TO_SERVER flag is specified, the plug object will expect to be sending ``request'' messages and receiving ``response'' messages, otherwise will default to the opposite sense.

DC_PLUG_free() frees the DC_PLUG structure and, unless it had been created with the DC_PLUG_FLAG_NOFREE_CONN flag, will also destroy the connection object it encapsulates.

DC_PLUG_to_select() is used to add a plug object to the sel selector so that it can be tested for network events it is waiting on. This will automatically handle selection of flags depending on the plug object's state. Ie. it will select for writability on its underlying connection only if there is data waiting to be sent, and likewise will select for readability only if it is ready to receive any data that may have arrived.

DC_PLUG_io() is used to allow network I/O to be performed on a plug object's underlying connection depending on the results of the last select operation on sel.

RETURN VALUES

DC_PLUG_free() should never fail and should only return non-zero results.

DC_PLUG_to_select() has no return value.

DC_PLUG_io() return zero on an error, otherwise non-zero.

None of the DC_PLUG functions sets (or clears) errno because it is implemented on top of the libnal library which in turn is an abstraction layer for the system's networking interfaces. As such, any errno codes set by failure in system libraries will not be overwritten by these functions.

SEE ALSO

distcache(8) - Overview of the distcache architecture.

http://www.distcache.org/ - Distcache home page.

AUTHOR

Home Page: http://www.distcache.org