Each line of the log contains five items of information: [date - rank - source file - source function - value]
It is mandatory for any event to call src/fsm/log/manager/fsm_add_log() to be published in the journal.
fsm_add_log() can filter the informations according to their nature or severity.
It then calls src/fsm/log/oper/fsm_add_log_event() to add the formatted line it produces.
In include/fsm.h are: fsm_enum_log_severity and fsm_enum_log_source
Four additional functions enable to initiate and close the log:
in src/fsm/log/manager.c: fsm_trigger_log_init() and fsm_trigger_log_publication()
in src/fsm/log/oper.c: fsm_init_log() and fsm_publish_log()
Some functions that a typical list should implement but whose utility remains to evaluate
in the case of a log list are in src/fsm/log/forget.c
