rebar3/src/rebar_digraph.erl

115 lines
4.5 KiB
Erlang

%%% @doc build a digraph of applications in order to figure out dependency
%%% and compile order.
-module(rebar_digraph).
-export([compile_order/1
,restore_graph/1
,subgraph/2
,format_error/1]).
-include("rebar.hrl").
%% @doc Sort apps with topological sort to get proper build order
-spec compile_order([rebar_app_info:t()]) ->
{ok, [rebar_app_info:t()]} | {error, no_sort | {cycles, [[binary(),...]]}}.
compile_order(Apps) ->
Graph = digraph:new(),
lists:foreach(fun(App) ->
Name = rebar_app_info:name(App),
Deps = all_apps_deps(App),
add(Graph, {Name, Deps})
end, Apps),
Order =
case digraph_utils:topsort(Graph) of
false ->
case digraph_utils:is_acyclic(Graph) of
true ->
{error, no_sort};
false ->
Cycles = lists:sort(
[lists:sort(Comp) || Comp <- digraph_utils:strong_components(Graph),
length(Comp)>1]),
{error, {cycles, Cycles}}
end;
V ->
{ok, names_to_apps(lists:reverse(V), Apps)}
end,
true = digraph:delete(Graph),
Order.
%% @private Add a package and its dependencies to an existing digraph
-spec add(digraph:graph(), {PkgName, [Dep]}) -> ok when
PkgName :: binary(),
Dep :: {Name, term()} | Name,
Name :: atom() | iodata().
add(Graph, {PkgName, Deps}) ->
case digraph:vertex(Graph, PkgName) of
false ->
V = digraph:add_vertex(Graph, PkgName);
{V, []} ->
V
end,
lists:foreach(fun(DepName) ->
Name1 = case DepName of
{Name, _Vsn} ->
rebar_utils:to_binary(Name);
Name ->
rebar_utils:to_binary(Name)
end,
V3 = case digraph:vertex(Graph, Name1) of
false ->
digraph:add_vertex(Graph, Name1);
{V2, []} ->
V2
end,
digraph:add_edge(Graph, V, V3)
end, Deps).
%% @doc based on a list of vertices and edges, build a digraph.
-spec restore_graph({[digraph:vertex()], [digraph:edge()]}) -> digraph:graph().
restore_graph({Vs, Es}) ->
Graph = digraph:new(),
lists:foreach(fun({V, LastUpdated}) ->
digraph:add_vertex(Graph, V, LastUpdated)
end, Vs),
lists:foreach(fun({V1, V2}) ->
digraph:add_edge(Graph, V1, V2)
end, Es),
Graph.
%% @doc convert a given exception's payload into an io description.
-spec format_error(any()) -> iolist().
format_error(no_solution) ->
io_lib:format("No solution for packages found.", []).
%%====================================================================
%% Internal Functions
%%====================================================================
%% @doc alias for `digraph_utils:subgraph/2'.
subgraph(Graph, Vertices) ->
digraph_utils:subgraph(Graph, Vertices).
%% @private from a list of app names, fetch the proper app info records
%% for them.
-spec names_to_apps([atom()], [rebar_app_info:t()]) -> [rebar_app_info:t()].
names_to_apps(Names, Apps) ->
[element(2, App) || App <- [find_app_by_name(Name, Apps) || Name <- Names], App =/= error].
%% @private fetch the proper app info record for a given app name.
-spec find_app_by_name(atom(), [rebar_app_info:t()]) -> {ok, rebar_app_info:t()} | error.
find_app_by_name(Name, Apps) ->
ec_lists:find(fun(App) ->
rebar_app_info:name(App) =:= Name
end, Apps).
%% @private The union of all entries in the applications list for an app and
%% the deps listed in its rebar.config is all deps that may be needed
%% for building the app.
-spec all_apps_deps(rebar_app_info:t()) -> [binary()].
all_apps_deps(App) ->
Applications = lists:usort([atom_to_binary(X, utf8) || X <- rebar_app_info:applications(App)]),
Deps = lists:usort(lists:map(fun({Name, _}) -> Name; (Name) -> Name end, rebar_app_info:deps(App))),
lists:umerge(Deps, Applications).