1/*  Part of SWISH
    2
    3    Author:        Jan Wielemaker
    4    E-mail:        J.Wielemaker@vu.nl
    5    WWW:           http://www.swi-prolog.org
    6    Copyright (c)  2015-2017, VU University Amsterdam
    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(swish_include,
   36          [ include/2                          % +File, +Options
   37          ]).   38:- use_module(storage).   39:- use_module(config).   40:- use_module(library(sandbox), []).   41:- use_module(library(debug)).   42:- use_module(library(option)).   43:- use_module(library(filesex)).   44:- use_module(library(error)).   45:- use_module(library(readutil)).

 include(+File, +Options)

Include file at a specific version. Supported options:

version(Version)

Include version Version of File, where Version is a gitty commit of the file. This is the same as :- include(Version)., but more explicit.

If the same file is included at two places it is included at most once. Additionally

• If neither is versioned the most recent version is included.
• If two versions resolve to the same content hash, this is included.
• If a specific version is included, subsequent unspecified includes are ignored. A subsequent incompatibly versioned include results in an error.

The envisioned model is that we can specify which version is, possibly indirectly, included by using directives like this:

:- include(File, [version(Hash)]).

   87include(File, Version) :-
   88    throw(error(context_error(nodirective, include(File, Version)), _)).
   89
   90swish:term_expansion(:- include(FileIn), Expansion) :-
   91    swish:term_expansion(:- include(FileIn, []), Expansion).
   92swish:term_expansion(:- include(FileIn, Options), Expansion) :-
   93    setup_call_cleanup(
   94        '$push_input_context'(swish_include),
   95        expand_include(FileIn, Options, Expansion),
   96        '$pop_input_context').
   97
   98expand_include(FileIn, Options, Expansion) :-
   99    include_file_id(FileIn, File, Options),
  100    arg(2, File, IncludeID),
  101    (   prolog_load_context(module, Module),
  102        clause(Module:'swish included'(IncludeID), true)
  103    ->  Expansion = []
  104    ;   Expansion = [ (:- discontiguous('swish included'/1)),
  105                      'swish included'(IncludeID),
  106                      (:- include(stream(URI, Stream, [close(true)])))
  107                    ],
  108        include_data(File, URI, Data),
  109        open_string(Data, Stream)
  110    ).

 include_data(+FileID, -URI, -Data)

Fetch the data to be included and obtain the URI for it.

  116include_data(file(Name, _Data, gitty(Meta)), URI, Data) :-
  117    !,
  118    catch(storage_file(Meta.commit, Data, _Meta),
  119          error(existence_error(_,_),_),
  120          fail),
  121    atom_concat('swish://', Name, URI).
  122include_data(file(Spec, Spec, filesystem), URI, Data) :-
  123    absolute_file_name(Spec, Path, [ file_type(prolog), access(read) ]),
  124    read_file_to_string(Path, Data, []),
  125    Spec =.. [Alias,_],
  126    file_base_name(Path, NameExt),
  127    format(atom(URI), 'swish://~w/~w', [Alias, NameExt]).

 include_file_id(+FileIn, -FileID, +Options) is det

Normalise an include file identifier and verify its safeness.

  134include_file_id(FileIn, file(File, IncludeID, gitty(Meta)), Options) :-
  135    atomic(FileIn),
  136    !,
  137    atom_string(File0, FileIn),
  138    add_extension(File0, File),
  139    (   option(version(Version), Options)
  140    ->  storage_meta_data(Version, Meta)
  141    ;   storage_meta_data(File, Meta)
  142    ),
  143    atom_concat('swish://', Meta.name, URI),
  144    IncludeID0 = gitty(Meta.commit, Meta.data, URI),
  145    (   prolog_load_context(module, Module),
  146        clause(Module:'swish included'(IncludeIDPrev), true),
  147        compatible_versions(IncludeIDPrev, IncludeID0, Version)
  148    ->  IncludeID = IncludeIDPrev
  149    ;   IncludeID = IncludeID0
  150    ).
  151include_file_id(FileIn, file(File, File, filesystem), _) :-
  152    compound(FileIn),
  153    FileIn =.. [Alias,NameIn],
  154    atom_string(Name, NameIn),
  155    (   safe_name(Name),
  156        swish_config(include_alias, Alias)
  157    ->  true
  158    ;   permission_error(include, file, Name)
  159    ),
  160    File =.. [Alias,Name].
  161
  162compatible_versions(Version, Version, _) :- !.
  163compatible_versions(gitty(_, DataHash, _), gitty(_, DataHash, _), _) :- !.
  164compatible_versions(Gitty1, Gitty2, Version) :- !,
  165    Gitty1 = gitty(_, _, URI),
  166    Gitty2 = gitty(_, _, URI),
  167    (   var(Version)
  168    ->  true
  169    ;   throw(error(version_error(Gitty1, Gitty2), _))
  170    ).
  171
  172safe_name(Name) :-
  173    \+ (   sub_atom(Name, 0, _, _, '../')
  174       ;   sub_atom(Name, _, _, _, '/../')
  175       ;   sub_atom(Name, _, _, 0, '/..')
  176       ;   Name == '..'
  177       ).

 file_alias(+File, -Spec) is semidet

Translate Alias/Name into Alias(Name) if Alias is known and Name is safe.

  184file_alias(File, Spec) :-
  185    atomic_list_concat([Alias,Name], /, File),
  186    swish_config(include_alias, Alias),
  187    safe_name(Name),
  188    !,
  189    Spec =.. [Alias,Name].

 add_extension(+File, -FileExt) is det

Add a file name extension to indicate this is a Prolog file.

  195add_extension(File, FileExt) :-
  196    file_name_extension(_, Ext, File),
  197    Ext \== '',
  198    !,
  199    FileExt = File.
  200add_extension(Hash, Hash) :-
  201    is_hash(Hash),
  202    !.
  203add_extension(File, FileExt) :-
  204    file_name_extension(File, pl, FileExt).
  205
  206is_hash(Name) :-
  207    atom_length(Name, 40),
  208    split_string(Name, ":", "0123456789abcdef", [""]).
  209
  210
  211                 /*******************************
  212                 *            SANDBOX           *
  213                 *******************************/
  214
  215:- multifile
  216    sandbox:safe_directive/1.  217
  218sandbox:safe_directive(M:include(stream(Id, Stream, [close(true)]))) :-
  219    is_stream(Stream),
  220    sub_atom(Id, 0, _, _, 'swish://'),
  221    prolog_load_context(module, M).
  222
  223
  224                 /*******************************
  225                 *            COLOUR            *
  226                 *******************************/
  227
  228:- multifile
  229    prolog_colour:term_colours/2.  230
  231prolog_colour:term_colours((:- include(FileIn, Options)),
  232                           neck(directive) -
  233                           [ goal(built_in,include(FileIn)) -
  234                             [ FileClass,
  235                               classify
  236                             ]
  237                           ]) :-
  238    classify_include(FileIn, FileClass, Options).
  239prolog_colour:term_colours((:- include(FileIn)),
  240                           neck(directive) -
  241                           [ goal(built_in,include(FileIn)) -
  242                             [ FileClass
  243                             ]
  244                           ]) :-
  245    classify_include(FileIn, FileClass, []).
  246
  247classify_include(FileIn, FileClass, Options) :-
  248    debug(include, 'Classifying ~p', [FileIn]),
  249    (   catch(include_file_id(FileIn, FileID, Options), _, fail)
  250    ->  classify_include(FileID, FileClass)
  251    ;   FileClass = nofile
  252    ),
  253    debug(include, 'Class ~p', [FileClass]).
  254
  255classify_include(file(Name, _DataHash, gitty(Meta)), FileClass) :-
  256    !,
  257    (   is_hash(Name)
  258    ->  format(atom(Id), 'swish://~w@~w', [Meta.name, Name])
  259    ;   atom_concat('swish://', Name, Id)
  260    ),
  261    FileClass = file(Id).
  262classify_include(file(Spec, Spec, filesystem), FileClass) :-
  263    absolute_file_name(Spec, Path, [ file_type(prolog), access(read) ]),
  264    Spec =.. [Alias,_],
  265    file_base_name(Path, NameExt),
  266    format(atom(URI), 'swish://~w/~w', [Alias, NameExt]),
  267    FileClass = file(URI).
  268
  269
  270                 /*******************************
  271                 *            XREF              *
  272                 *******************************/
  273
  274:- multifile
  275    prolog:xref_open_source/2,
  276    prolog:xref_source_file/3,
  277    prolog:xref_source_identifier/2,
  278    prolog:xref_source_time/2.

 prolog:xref_source_identifier(+Src, -Id) is semidet

prolog:xref_open_source(+File, -Stream) is det

prolog:xref_source_time(+File, -Modified) is det

Map swish://file to a file from the gitty store.

  286prolog:xref_source_identifier(Src, Id) :-
  287    atom(Src),
  288    sub_atom(Src, 0, _, _, 'swish://'),
  289    !,
  290    Id = Src.
  291
  292prolog:xref_open_source(File, Stream) :-
  293    atom(File),
  294    atom_concat('swish://', Name, File),
  295    (   file_alias(File, Spec)
  296    ->  absolute_file_name(Spec, Path, [ file_type(prolog), access(read) ]),
  297        open(Path, read, Stream)
  298    ;   catch(storage_file(Name, Data, _Meta), _, fail),
  299        open_string(Data, Stream)
  300    ).
  301
  302prolog:xref_source_time(File, Modified) :-
  303    atom(File),
  304    atom_concat('swish://', Name, File),
  305    (   file_alias(File, Spec)
  306    ->  absolute_file_name(Spec, Path, [ file_type(prolog), access(read) ]),
  307        time_file(Path, Modified)
  308    ;   catch(storage_meta_data(Name, Meta), _, fail),
  309        Modified = Meta.get(time)
  310    ).

 prolog:xref_source_file(+Term, -Path, +Options)

Deal with the above expansion for :- include(program) to support the cross-referencer.

  317prolog:xref_source_file(stream(Id, _Stream, [close(true)]), Id, _).
  318prolog:xref_source_file(File, Id, Options) :-
  319    atom(File),
  320    option(relative_to(Src), Options),
  321    atom(Src),
  322    atom_concat('swish://', SrcFile, Src),
  323    add_extension(File, FileExt),
  324    file_directory_name(SrcFile, SrcDir),
  325    directory_file_path(SrcDir, FileExt, TargetFile),
  326    atom_concat('swish://', TargetFile, Id)