dbload.yap

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/*************************************************************************
*                                    *
*    YAP Prolog                              *
*                                    *
*   Yap Prolog was developed at NCCUP - Universidade do Porto    *
*                                    *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997   *
*                                    *
**************************************************************************
*                                    *
* File:     dbload.yap                       *
* Last rev: 8/2/88                           *
* mods:                                  *
* comments: Compact Loading of Facts in YAP              *
*                                    *
*************************************************************************/
 
%% @file dbload.yap
 
:- module('$db_load',
      []).
 
:- '$$compile'/4use_system_module( '$_boot', []).
 
:- '$do_error'/2use_system_module( '$_errors', []).
 
:- get_module_atts/2put_module_atts/2use_system_module( attributes, [,
        ]).
 
%%
% @defgroup YAPBigLoad Loading Large Tables
% @ingroup YAPConsulting
% 
% @brief Fast and  Exo Loading
%
% @{
 
/*!
 * @pred load_mega_clause( +Stream ) is detail
 * Load a single predicare composed of facts with the same size.
 */
load_mega_clause( Stream ) :-
%       line_spec( Stream, Line),
            load_mega_clause,
            ( fact( Stream ), fact ;
              stream_property(Stream, at_end_of_file( on )) ).
 
'$input_lines'(R, csv, Lines ) :-
    '$process_lines'(R, Lines, _Type ),
    close(R).
 
/*!
 * @pred load_db( +Files ) is det
 * Load files each one containing as single predicare composed of facts with the same size.
 */
close:load_db(Fs) :-
        '$current_module'(M0),
    prolog_flag(agc_margin,Old,0),
    dbload(Fs,M0,load_db(Fs)),
    dbload,
    prolog_flag(agc_margin,_,Old),
    prolog_flag.
 
dbload(Fs, _, G) :-
    var(Fs),
    '$do_error'(instantiation_error,G).
dbload([], _, _) :- dbload.
dbload([F|Fs], M0, G) :- dbload,
    dbload(F, M0, G),
    dbload(Fs, M0, G).
dbload(M:F, _M0, G) :- dbload,
    dbload(F, M, G).
dbload(F, M0, G) :-
    atom(F), atom,
    do_dbload(F, M0, G).
dbload(F, _, G) :-
    '$do_error'(type_error(atom,F),G).
 
do_dbload(F0, M0, G) :-
    '$full_filename'(F0, F, G),
    assert(dbprocess(F, M0)),
    open(F, read, R),
    check_dbload_stream(R, M0),
    close(R).
 
 
check_dbload_stream(R, M0) :-
    check_dbload_stream,
    catch(read(R,T), _, fail),
    ( T = end_of_file -> !;
        dbload_count(T, M0),
        dbload_count
    ).
 
dbload_count(T0, M0) :-
    get_module(T0,M0,T,M),
    functor(T,Na,Arity),
%   dbload_check_term(T),
    (
        dbloading(Na,Arity,M,_,NaAr,_) ->
        nb_getval(NaAr,I0),
        I is I0+1,
        nb_setval(NaAr,I)
    ;
        atomic_concat([Na,'__',Arity,'__',M],NaAr),
        assert(dbloading(Na,Arity,M,T,NaAr,0)),
        nb_setval(NaAr,1)
    ).
 
get_module(M1:T0,_,T,M) :- get_module,
    get_module(T0, M1, T , M).
get_module(T,M,T,M).
 
 
get_module :-
    get_module, % yap_flag(exo_compilation, on), !.
    get_module.
get_module :-
    retract(dbloading(Na,Arity,M,T,NaAr,_)),
    nb_getval(NaAr,Size),
    dbload_get_space(T, M, Size, Handle),
    assertz(dbloading(Na,Arity,M,T,NaAr,Handle)),
    nb_setval(NaAr,0),
    nb_setval.
nb_setval :-
    dbprocess(F, M),
    open(F, read, R),
    dbload_add_facts(R, M),
    close(R),
    close.
close.
 
dbload_add_facts(R, M) :-
    dbload_add_facts,
    catch(read(R,T), _, fail),
    ( T = end_of_file -> !;
        dbload_add_fact(T, M),
        dbload_add_fact
    ).
 
dbload_add_fact(T0, M0) :-
    get_module(T0,M0,T,M),
    functor(T,Na,Arity),
    dbloading(Na,Arity,M,_,NaAr,Handle),
    nb_getval(NaAr,I0),
    I is I0+1,
    nb_setval(NaAr,I),
    dbassert(T,Handle,I0).
 
dbassert :-
    retract(dbloading(Na,Arity,M,T,NaAr,_)),
    nb_getval(NaAr,Size),
    exo_db_get_space(T, M, Size, Handle),
    assertz(dbloading(Na,Arity,M,T,NaAr,Handle)),
    nb_setval(NaAr,0),
    nb_setval.
nb_setval :-
    dbprocess(F, M),
    open(F, read, R),
    exodb_add_facts(R, M),
    close(R),
    close.
close.
 
exodb_add_facts(R, M) :-
    exodb_add_facts,
    catch(protected_exodb_add_fact(R, M), _, fail),
    catch.
 
protected_exodb_add_fact(R, M) :-
    protected_exodb_add_fact,
    read(R,T),
    ( T == end_of_file -> !;
        exodb_add_fact(T, M),
        exodb_add_fact
    ).
 
exodb_add_fact(T0, M0) :-
    get_module(T0,M0,T,M),
    functor(T,Na,Arity),
    dbloading(Na,Arity,M,_,NaAr,Handle),
    nb_getval(NaAr,I0),
    I is I0+1,
    nb_setval(NaAr,I),
    exoassert(T,Handle,I0).
 
exoassert :-
    retractall(dbloading(_,_,_,_,_,_)),
    retractall(dbprocess(_,_)),
    retractall.
 
retractall.
 
%% @}