1/*  Part of Extended Libraries for SWI-Prolog
    2
    3    Author:        Edison Mera
    4    E-mail:        efmera@gmail.com
    5    WWW:           https://github.com/edisonm/xlibrary
    6    Copyright (C): 2021, Process Design Center, Breda, The Netherlands.
    7    All rights reserved.
    8
    9    Redistribution and use in source and binary forms, with or without
   10    modification, are permitted provided that the following conditions
   11    are met:
   12
   13    1. Redistributions of source code must retain the above copyright
   14       notice, this list of conditions and the following disclaimer.
   15
   16    2. Redistributions in binary form must reproduce the above copyright
   17       notice, this list of conditions and the following disclaimer in
   18       the documentation and/or other materials provided with the
   19       distribution.
   20
   21    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   22    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   23    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   24    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   25    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   26    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   27    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   28    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   29    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   31    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   32    POSSIBILITY OF SUCH DAMAGE.
   33*/
   34
   35:- module(broker, []).   36
   37:- use_module(library(lists)).   38:- use_module(library(neck)).   39:- use_module(library(codegen)).   40:- use_module(library(change_alias)).   41:- reexport(library(compound_expand)).   42:- reexport(library(interface)).   43:- init_expansors.

fallback(local)
timeout
timereset

   59alias_file(RelTo, Alias, File) :-
   60    absolute_file_name(Alias, File, [file_type(prolog), relative_to(RelTo)]).
   61
   62generate_server(File, Alias, Module, AliasTo) -->
   63    { prolog_load_context(source, RelTo),
   64      atom_concat(Module, '_intf', Interface),
   65      atom_concat(Module, '_remt', ImplRemote),
   66      atom_concat(Module, '_locl', ImplLocal),
   67      generate_intf(File, RelTo, Module, Interface,  AliasTo, AliasIntf),
   68      generate_locl(File, RelTo, Alias,  ImplLocal,  AliasTo, AliasIntf),
   69      generate_remt('_remt', File, RelTo, Module, ImplRemote, AliasTo, AliasIntf),
   70      generate_serv(File, RelTo, Module, AliasTo, AliasServ)
   71    },
   72    [(:- use_module(AliasServ, []))].
   73
   74generate_proxy(ImplProxy, File, Module, AliasIntf, AliasTo) -->
   75    { prolog_load_context(source, RelTo),
   76      generate_remt('', File, RelTo, Module, ImplProxy, AliasTo, AliasIntf),
   77      generate_prxy(File, RelTo, Module, ImplProxy, AliasTo, AliasSuff)
   78    },
   79    [(:- use_module(AliasSuff, []))].
   80
   81generate_intf(File, RelTo, Module, Interface, AliasTo, AliasIntf) :-
   82    generate_file('_intf', File, RelTo, AliasTo, AliasIntf, dump_interface(Module, Interface)).
   83
   84generate_locl(File, RelTo, Alias, ImplLocal, AliasTo, AliasIntf) :-
   85    generate_file('_locl', File, RelTo, AliasTo, _, dump_local(Alias, ImplLocal, AliasIntf)).
   86
   87generate_remt(Suff, File, RelTo, Module, ImplRemote, AliasTo, AliasIntf) :-
   88    generate_file(Suff, File, RelTo, AliasTo, _, dump_remote(Module, ImplRemote, AliasIntf)).
   89
   90generate_prxy(File, RelTo, Module, ImplRemote, AliasTo, AliasSuff) :-
   91    atom_concat(ImplRemote, '_serv', ModuleServ),
   92    generate_file('_serv', File, RelTo, AliasTo, AliasSuff, dump_server(Module, ModuleServ)).
   93
   94generate_serv(File, RelTo, Module, AliasTo, AliasSuff) :-
   95    atom_concat(Module, '_serv', ModuleServ),
   96    generate_file('_serv', File, RelTo, AliasTo, AliasSuff, dump_server(Module, ModuleServ)).
   97
   98:- meta_predicate
   99    generate_file(+,+,+,+,+,2).  100
  101generate_file(Suffix, File, RelTo, AliasIntf, AliasSuff, Dump) :-
  102    change_alias(add_suffix(Suffix), AliasIntf, AliasSuff),
  103    alias_file(RelTo, AliasSuff, FileSuff),
  104    ( is_newer(FileSuff, File)
  105    ->true
  106    ; term_to_file(FileSuff, Dump)
  107    ).
  108
  109dump_interface(Module, Interface) -->
  110    {module_property(Module, exports(PIL))},
  111    [ (:- module(Interface, PIL)),
  112      (:- use_module(library(interface))),
  113      (:- init_expansors),
  114      (:- interface)
  115    ].
  116
  117dump_local(Alias, ImplLocal, AliasIntf) -->
  118    [ (:- module(ImplLocal, [])),
  119      (:- use_module(library(interface))),
  120      (:- reexport(Alias)),
  121      (:- init_expansors),
  122      (:- implements(AliasIntf))
  123    ].
  124
  125dump_remote(Module, ImplRemote, AliasIntf) -->
  126    [ (:- module(ImplRemote, [])),
  127      (:- use_module(library(interface))),
  128      (:- use_module(library(broker_rt))),
  129      (:- init_expansors),
  130      (:- implements(AliasIntf))
  131    ],
  132    findall((H :- remote_call(H, Module)),
  133            ( module_property(Module, exports(PIL)),
  134              member(F/A, PIL),
  135              functor(H, F, A)
  136            )).
  137
  138dump_server(Module, ImplService) -->
  139    [ (:- module(ImplService, [])),
  140      (:- use_module(library(http/http_dispatch))),
  141      (:- use_module(library(http/websocket))),
  142      (:- use_module(library(broker_ws))),
  143      (:- init_expansors),
  144      (:- http_handler(root(broker/Module),
  145                       http_upgrade_to_websocket(broker_ws(Module), []),
  146                       [spawn([])]))
  147    ].
  148
  149term_expansion_proxy(ImplRemote, AliasIntf, AliasImpl, AliasPrxy) -->
  150    { prolog_load_context(source, RelTo),
  151      absolute_file_name(AliasImpl, File, [file_type(prolog), access(read), relative_to(RelTo)]),
  152      use_module(AliasImpl, []), % Ensure that the module is loaded
  153      module_property(Module, file(File))
  154    },
  155    generate_proxy(ImplRemote, File, Module, AliasIntf, AliasPrxy).
  156
  157term_expansion_server(Alias, AliasIntf) -->
  158    { prolog_load_context(source, RelTo),
  159      absolute_file_name(Alias, File, [file_type(prolog), access(read), relative_to(RelTo)]),
  160      use_module(Alias, []), % Ensure that the module is loaded
  161      module_property(Module, file(File))
  162    },
  163    generate_server(File, Alias, Module, AliasIntf).
  164
  165term_expansion((:- broker_server(Alias, AliasIntf)), Clauses) :-
  166    phrase(term_expansion_server(Alias, AliasIntf), Clauses).
  167term_expansion((:- broker_proxy(ImplRemote, AliasIntf, AliasImpl, AliasPrxy)), Clauses) :-
  168    phrase(term_expansion_proxy(ImplRemote, AliasIntf, AliasImpl, AliasPrxy), Clauses)