Implemented evfs_io_server and first bits of evfs_iolit_io_server

src/evfs_io_server.erl

@@ -0,0 +1,112 @@
+-module(evfs_io_server).
+-behaviour(gen_server).
+-export([behaviour_info/1]).
+
+-export([start_link/2]).
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2, 
+         terminate/2, code_change/3]).
+
+behaviour_info(callbacks) ->
+    [];
+behaviour_info(_) ->
+    undefined.
+
+-record(state,
+        {
+          module :: module(),
+          handle :: term()
+        }).
+
+-type state() :: #state{}.
+
+-spec start_link(module(), term()) -> {ok, pid()} | {error, term()}.
+
+start_link(Module, Args) ->
+    gen_server:start_link(?MODULE, {Module, Args}, []).
+
+-spec init(module()) -> {ok, state()} | {stop, term()}.
+
+init({Module, Args}) ->
+    {ok, #state{ module = Module, handle = Args }}.
+
+-spec handle_call(term(), term(), state()) ->
+                         {noreply, state()} |
+                         {stop, normal, stopped, state()}.
+handle_call(_Request, _From, State) ->
+    {noreply, State}.
+
+-spec handle_cast(term(), state()) -> {noreply, state()}.
+
+handle_cast(_Msg, State) ->
+    {noreply, State}.
+
+-spec handle_info(term(), state()) ->
+        {noreply, state()} | {stop, term(), state()}.
+
+handle_info({file_request, From, ReplyAs, Request},
+            #state{ module = Module, handle = Handle } = State) when is_pid(From) ->
+    case file_request(Request, Module, Handle) of
+        {reply, Reply, Handle1} ->
+            From ! {file_reply, ReplyAs, Reply},
+            {noreply, State#state{ handle = Handle1} };
+        {error, Reply, Handle1} ->
+            From ! {file_reply, ReplyAs, Reply},
+            {noreply, State#state{ handle = Handle1} };
+        {stop, Reason, Reply, Handle1} ->
+            From ! {file_reply, ReplyAs, Reply},
+            {stop, Reason, State#state{ handle = Handle1 }}
+    end;
+
+handle_info({io_request, From, ReplyAs, Request},
+            #state{ module = Module, handle = Handle} = State) when is_pid(From) ->
+    case io_request(Request, Module, Handle) of
+        {reply, Reply, Handle1} ->
+            From ! {io_reply, ReplyAs, Reply},
+            {noreply, State#state{ handle = Handle1} };
+        {error, Reply, Handle1} ->
+            From ! {io_reply, ReplyAs, Reply},
+            {noreply, State#state{ handle = Handle1} };
+        {stop, Reason, Reply, Handle1} ->
+            From ! {io_reply, ReplyAs, Reply},
+            {stop, Reason, State#state{ handle = Handle1 }}
+    end.
+
+
+-spec terminate(term(), state()) -> ok.
+
+terminate(_Reason, _State) ->
+    ok.
+
+-spec code_change(term(), state(), term()) -> {ok, state()}.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+%% Private
+file_request(Request, Module, Handle) ->
+    Command = element(1, Request),
+    Args = tl(tuple_to_list(Request)),
+    case (catch apply(Module, Command, Args ++ [Handle])) of
+        {'EXIT', {undef, _}} ->
+            file_request(Request, evfs_iolist_io_server, Module:io_list(Handle));
+         Result ->
+            Result
+    end.
+
+io_request({requests, Requests}, Module, Handle) ->
+    io_request({requests, Requests, undefined}, Module, Handle);
+io_request({requests, [], Result}, _Module, _Handle) ->
+    Result;
+io_request({requests, [Request|Rest], _Result}, Module, Handle) ->
+    Result = io_request(Request, Module, Handle),
+    io_request({requests, Rest, Result}, Module, Handle);
+io_request(Request, Module, Handle) ->
+    Command = element(1, Request),
+    Args = tl(tuple_to_list(Request)),
+    case (catch apply(Module, Command, Args ++ [Handle])) of
+        {'EXIT', {undef, _}} ->
+            file_request(Request, evfs_iolist_io_server, Module:io_list(Handle));
+         Result ->
+            Result
+    end.

src/evfs_iolist_io_server.erl

@@ -0,0 +1,99 @@
+-module(evfs_iolist_io_server).
+-behaviour(evfs_io_server).
+%% File requests
+-export([
+         advise/4,
+         pread/3,
+         pwrite/3,
+         datasync/1,
+         sync/1,
+         close/1,
+         position/1,
+         truncate/1
+        ]).
+%% IO requests
+-export([
+         put_chars/2,
+         put_chars/3,
+         put_chars/4,
+         put_chars/5,
+         get_until/4,
+         get_until/5,
+         get_until/6,
+         get_chars/3,
+         get_chars/4,
+         get_line/2,
+         get_line/3,
+         setopts/2,
+         getopts/1
+        ]).
+
+%% File requests
+advise(_Offset, _Length, _Advise, Handle) ->
+    {reply, ok, Handle}.
+
+pread(At, Sz, Handle) ->
+    Binary = iolist_to_binary(Handle),
+    {reply, {ok, binary_to_list(binary:part(Binary, {At, Sz}))}, Handle}.
+
+pwrite(_At, _Data, Handle) ->
+    %% TODO
+    {reply, ok, Handle}.
+
+datasync(Handle) ->    
+    {reply, ok, Handle}.
+
+sync(Handle) ->
+    {reply, ok, Handle}.
+
+close(Handle) ->
+    {stop, normal, ok, Handle}.
+
+position(Handle) ->
+    {reply, 0, Handle}.
+
+truncate(Handle) ->
+    {reply, ok, Handle}.
+
+%% IO requests
+put_chars(Chars, Handle) ->
+    put_chars(latin1, Chars, Handle).
+
+put_chars(_Enc, _Mod, _Func, _Args, Handle) ->
+    {reply, {error, notsup}, Handle}.
+
+put_chars(Mod, Func, Args, Handle) ->
+    put_chars(latin1, Mod, Func, Args, Handle).
+
+
+put_chars(_Enc, _Chars, Handle) ->
+    {reply, {error, notsup}, Handle}.
+
+
+get_until(_Enc, _Prompt, _Mod, _Func, _XtraArgs, Handle) ->
+    {reply, {error, notsup}, Handle}.
+
+get_until(_Enc, _Prompt, _N, Handle) ->
+    {reply, {error, notsup}, Handle}.
+
+get_until(Prompt, Mod, Func, XtraArgs, Handle) ->
+    get_until(latin1, Prompt, Mod, Func, XtraArgs, Handle).
+
+get_chars(_Enc, _Prompt, _N, Handle) ->
+    {reply, {error, notsup}, Handle}.
+
+get_chars(Prompt, N, Handle) ->
+    get_chars(latin1, Prompt, N, Handle).
+
+get_line(_Enc, _Prompt, Handle) ->
+    {reply, {error, notsup}, Handle}.
+
+get_line(Prompt, Handle) ->
+    get_line(latin1, Prompt, Handle).
+
+setopts(_Opts, Handle) ->
+    {reply, {error, notsup}, Handle}.
+
+getopts(Handle) ->
+    {reply, {error, notsup}, Handle}.
+

test/evfs_test_fs.erl

@@ -1,5 +1,6 @@
 -module(evfs_test_fs).
 -behaviour(evfs_handler).
+-behaviour(evfs_io_server).
 -export([init/1, supports/2, terminate/2]).
 -export([open/3, 
          read_file/2,
@@ -21,6 +22,7 @@
          make_symlink/3,
          copy/6
         ]).
+-export([io_list/1]).
 
 init(Args) ->
     {ok, Args}.
@@ -32,8 +34,9 @@ supports(_, State) ->
 
 %% Filesystem API
 
-open(_Filename, _Mode, State) ->
-    {ok, {error, enotsup}, State}.
+open(Filename, _Mode, State) ->
+    Child = evfs_io_server:start_link(?MODULE, Filename),
+    {ok, Child, State}.
 
 read_file(Filename, State) ->
     {ok, {ok, list_to_binary(Filename)}, State}.
@@ -92,3 +95,6 @@ copy(_SourceName, _SourceOpts, _DestName, _DestOpts, _Length, State) ->
 terminate(_Reason, _State) ->
     ok.
 
+%% IO server
+io_list(Handle) ->
+    Handle.

test/evfs_tests.erl

@@ -17,6 +17,11 @@ t_read_file() ->
     ?assertEqual({error, eisdir}, file:read_file("/")),
     ?assertEqual({ok, <<"test://any">>}, file:read_file("test://any")).
 
+t_pread() ->
+    evfs:register(evfs_test_fs, []),
+    {ok, File} = file:open("test://anyfile",[read]),
+    ?assertEqual({ok, ["test://any"]}, file:pread(File, [{0,10}])).
+
 evfs_test_() ->
     {foreach,
      fun () ->
@@ -28,7 +33,8 @@ evfs_test_() ->
      [
       {"unregister", ?_test(t_unregister())},
       {"file:// scheme should route to the default file server", ?_test(t_file_scheme())},
-      {"test_fs read_file", ?_test(t_read_file())}
+      {"test_fs read_file", ?_test(t_read_file())},
+      {"test_fs pread", ?_test(t_pread())}
      ]
     }.