samer@3: :- module(recorder, 
samer@3: 	[	recorder/2
samer@3: 	,	save_events/1
samer@3: 	,	load_events/1
samer@4: 	,	get_events/1
samer@3: 	,	player/2
samer@3: 	,	player/3
samer@3: 	]).
samer@0: /** <module> event recording
samer@0: 
samer@0: This module provides a way to capture and record events processed by
samer@0: the reactive programming framework of reactive.pl.
samer@0: */
samer@3: :- meta_predicate recorder(1,?), player(1,?), player(2,2,?).
samer@0: :- dynamic start_time/1, event/2.
samer@0: 
samer@0: :- use_module(library(fileutils)).
samer@12: :- use_module(library(utils),[min/3]).
samer@0: :- use_module(reactive).
samer@0: 
samer@0: 
samer@0: %% recorder( +Client:ptail, -Proc:process) is det.
samer@0: %
samer@0: %  This predicate represents a reactive process that behaves as Client,
samer@0: %  but records all events in the Prolog dynamic database. The type signature
samer@0: %  implies that the term recorder(Client) is of type =|ptail|=. All previously
samer@0: %  recorded events are deleted first. The time at which this predicate was
samer@0: %  called is also recorded in the database. 
samer@0: 
samer@0: recorder(Client,Proc) :-
samer@0: 	get_time(Now),
samer@0: 	retractall(event(_,_)),
samer@0: 	retractall(start_time(_)),
samer@0: 	assert(start_time(Now)),
samer@1: 	format('recording events for ~w.\n',[Client]),
samer@0: 	call(Client,C1),
samer@0: 	recorder_cont(C1,Proc).
samer@0: 
samer@0: recorder_on_event(E,C1,Proc) :-
samer@0: 	assert(E),	
samer@0: 	step_event(E,C1,C2),
samer@0: 	recorder_cont(C2,Proc).
samer@0: 
samer@0: recorder_on_timeout(T,C1,Proc) :-
samer@0: 	step_timeout(T,C1,C2),
samer@0: 	recorder_cont(C2,Proc).
samer@0: 
samer@0: recorder_cont(C1,Proc) :-
samer@0: 	get_timeout(C1,T1),
samer@0: 	(	T1=inf
samer@0: 	->	req_message(E^recorder_on_event(E,C1), Proc)
samer@0: 	;	req_message_or_timeout(T1,
samer@0: 			recorder_on_timeout(T1,C1),
samer@0: 			E^recorder_on_event(E,C1), Proc)
samer@0: 	).
samer@0: 
samer@3: %% player( +Client:ptail, +Trans:pred(A,A), -Proc:process) is det.
samer@0: %% player( +Client:ptail, -Proc:process) is det.
samer@0: %
samer@0: %  This predicate represents a reactive process that behaves as Client,
samer@0: %  but plays back events in the Prolog dynamic database. The events are
samer@0: %  time shifted by the difference between the recorded start time and the
samer@0: %  time at which player/2 is called. The type signature
samer@0: %  implies that the term recorder(Client) is of type =|ptail|=.
samer@3: %
samer@3: %  player/3 allows an event transformer pred(+EventIn:A,-EventOut:A) to be
samer@3: %  specified. player/2 is equivalent to using=/2 as the transformer.
samer@0: 
samer@0: player(Client,Proc) :-
samer@0: 	get_time(Now), 
samer@0: 	start_time(T0), DT is Now-T0,
samer@0: 	setof(event(T,Msg),T1^(event(T1,Msg),T is DT+T1),Events),
samer@0: 	call(Client,C1),
samer@0: 	player_cont(Events,C1,Proc).
samer@0: 
samer@3: player(Client,Trans,Proc) :-
samer@3: 	get_time(Now), 
samer@3: 	start_time(T0), DT is Now-T0,
samer@3: 	setof(event(T,Msg),T1^Msg1^(event(T1,Msg1),T is DT+T1, call(Trans,Msg1,Msg)),Events),
samer@3: 	call(Client,C1),
samer@3: 	player_cont(Events,C1,Proc).
samer@3: 
samer@0: player_on_event(Events,C1,Proc) :-
samer@0: 	player_cont(Events,C1,Proc).
samer@0: 
samer@0: player_on_timeout(T,ET,Events,C1,Proc) :-
samer@0: 	(	T<ET 
samer@0: 	->	step_timeout(T,C1,C2),
samer@0: 		player_cont(Events,C2,Proc)
samer@0: 	;	Events=[E1|EX],
samer@0: 		step_event(E1,C1,C2),
samer@0: 		player_cont(EX,C2,Proc)
samer@0: 	).
samer@0: 
samer@0: player_cont([],C1,C1) :- !,
samer@0: 	writeln('Playback finished - continuing in interactive mode').
samer@0: 
samer@0: player_cont(Events,C1,Proc) :-
samer@0: 	Events=[event(ET,_)|_],
samer@0: 	get_timeout(C1,T1),
samer@0: 	min(ET,T1,TO),
samer@0: 
samer@0: 	req_message_or_timeout(TO,
samer@0: 		player_on_timeout(TO,ET,Events,C1),
samer@0: 		_^player_on_event(Events,C1), Proc).
samer@0: 
samer@0: 
samer@0: %% save_events(+FileName:atom) is det.
samer@0: %  Save events in the event database to the named file (as Prolog clauses).
samer@0: save_events(File) :- 
samer@0: 	with_output_to_file(File,(listing(start_time),listing(event))).
samer@0: 
samer@0: 
samer@0: %% load_events(+FileName:atom) is det.
samer@0: %  Load events from the named file to the event database, after removing
samer@0: %  any events currently in there.
samer@0: load_events(File) :-
samer@0: 	retractall(event(_,_)),
samer@0: 	retractall(start_time(_)),
samer@0: 	consult(File).
samer@0: 
samer@4: 
samer@4: %% get_events(-Events:list(event)) is det.
samer@4: %  Gets the currently loaded events as a list. Event times are relative
samer@4: %  to start time.
samer@4: get_events(Events) :-
samer@4: 	start_time(T0), 
samer@4: 	setof(event(T,Msg),T1^(event(T1,Msg),T is T1-T0),Events).