support shared resoure as far as discovery goes

also correctly handles symlinks without infinite loops

1 files changed, 144 insertions, 0 deletions

diff --git a/src/rcl_dscv_util.erl b/src/rcl_dscv_util.erl
new file mode 100644
index 0000000..4fb6126
--- /dev/null
+++ b/src/rcl_dscv_util.erl
@@ -0,0 +1,144 @@
+%% -*- erlang-indent-level: 4; indent-tabs-mode: nil; fill-column: 80 -*-
+%%% Copyright 2012 Erlware, LLC. All Rights Reserved.
+%%%
+%%% This file is provided to you under the Apache License,
+%%% Version 2.0 (the "License"); you may not use this file
+%%% except in compliance with the License.  You may obtain
+%%% a copy of the License at
+%%%
+%%%   http://www.apache.org/licenses/LICENSE-2.0
+%%%
+%%% Unless required by applicable law or agreed to in writing,
+%%% software distributed under the License is distributed on an
+%%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+%%% KIND, either express or implied.  See the License for the
+%%% specific language governing permissions and limitations
+%%% under the License.
+%%%---------------------------------------------------------------------------
+%%% @author Eric Merritt <[email protected]>
+%%% @copyright (C) 2012 Erlware, LLC.
+%%%
+%%% @doc This provider uses the lib_dir setting of the state. It searches the
+%%% Lib Dirs looking for all OTP Applications that are available. When it finds
+%%% those OTP Applications it loads the information about them and adds them to
+%%% the state of available apps. This implements the rcl_provider behaviour.
+-module(rcl_dscv_util).
+
+-export([do/2,
+         format_error/1]).
+
+-include_lib("relcool/include/relcool.hrl").
+
+%%============================================================================
+%% Types
+%%============================================================================
+
+-type process_fun(Result) :: fun((filename:name(), file | directory) ->
+                                        {ok, Result} |
+                                        {error, term()} |
+                                        {ok, Result, Recurse::boolean()} |
+                                        {noresult, Recurse::boolean()} |
+                                        {error, term()}).
+
+%%============================================================================
+%% API
+%%============================================================================
+
+%% @doc recursively dig down into the library directories specified in the state
+%% looking for OTP Applications
+-spec do(process_fun([term()] | term()), [filename:name()]) ->
+                [term() | {error, term()}].
+do(ProcessDir, LibDirs) ->
+    lists:flatten(ec_plists:map(fun(LibDir) ->
+                                        discover_dir(ProcessDir, LibDir,
+                                                     ec_file:type(LibDir))
+                                end, LibDirs)).
+
+-spec format_error([ErrorDetail::term()]) -> iolist().
+format_error(ErrorDetails)
+  when erlang:is_list(ErrorDetails) ->
+    [[format_detail(ErrorDetail), "\n"] || ErrorDetail <- ErrorDetails].
+
+%%%===================================================================
+%%% Internal Functions
+%%%===================================================================
+-spec format_detail(ErrorDetail::term()) -> iolist().
+format_detail({accessing, File, eaccess}) ->
+    io_lib:format("permission denied accessing file ~s", [File]);
+format_detail({accessing, File, Type}) ->
+    io_lib:format("error (~p) accessing file ~s", [Type, File]);
+format_detail({not_a_directory, EbinDir}) ->
+    io_lib:format("~s is not a directory when it should be a directory", [EbinDir]).
+
+-spec discover_dir(process_fun([term()] | term()),
+                   file:name(),
+                   directory | file | symlink) ->
+                          [{ok, term()}
+                           | {error, Reason::term()}]
+                              | []
+                              | {ok, term()}
+                              | {error, Reason::term()}.
+discover_dir(ProcessDir, File, directory) ->
+    case ProcessDir(File, directory) of
+        {ok, Result, true} ->
+            [{ok, Result} | recurse(ProcessDir, File)];
+        {noresult, true} ->
+            recurse(ProcessDir, File);
+        {ok, Result, _} ->
+            [{ok, Result}];
+        {noresult, _} ->
+            [];
+        Err = {error, _} ->
+            [Err]
+    end;
+discover_dir(ProcessDir, File, file) ->
+    Res = ProcessDir(File, file),
+    io:format("Result -> ~p~n", [Res]),
+    case ProcessDir(File, file) of
+        {ok, Result} ->
+            [{ok, Result}];
+        {noresult, _} ->
+            [];
+        Err = {error, _} ->
+            [Err]
+    end;
+discover_dir(ProcessDir, File, symlink) ->
+    case filelib:is_dir(File) of
+        false ->
+            discover_dir(ProcessDir, File, file);
+        true ->
+            discover_real_symlink_dir(ProcessDir, File)
+    end.
+
+discover_real_symlink_dir(ProcessDir, File) ->
+    {ok, CurCwd} = file:get_cwd(),
+    ok = file:set_cwd(File),
+    {ok, ActualRealDir} = file:get_cwd(),
+    ok = file:set_cwd(CurCwd),
+    lists:prefix(iolist_to_list(filename:absname(ActualRealDir)),
+                 iolist_to_list(filename:absname(File))),
+    case ProcessDir(File, directory) of
+        {ok, Result, true} ->
+            [{ok, Result} | recurse(ProcessDir, File)];
+        {noresult, true} ->
+            recurse(ProcessDir, File);
+        {ok, Result, _} ->
+            [{ok, Result}];
+        {noresult, _} ->
+            [];
+        Err = {error, _} ->
+            [Err]
+    end.
+
+recurse(ProcessDir, File) ->
+    case file:list_dir(File) of
+        {error, Reason} ->
+            {error, {accessing, File, Reason}};
+        {ok, List} ->
+            ec_plists:map(fun(LibDir) ->
+                                  discover_dir(ProcessDir, LibDir, ec_file:type(LibDir))
+                          end, [filename:join([File, Dir]) || Dir <- List])
+    end.
+
+iolist_to_list(IoList) ->
+    erlang:binary_to_list(erlang:iolist_to_binary(IoList)).