%% %% %CopyrightBegin% %% %% Copyright Ericsson AB 2000-2016. All Rights Reserved. %% %% Licensed 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. %% %% %CopyrightEnd% %% %%%---------------------------------------------------------------------- %%% File : file_server.erl %%% Author : Raimo Niskanen %%% Purpose : A simple file server %%% Created : 13 Oct 2000 by Raimo Niskanen %%%---------------------------------------------------------------------- -module(file_server). -behaviour(gen_server). %% External exports -export([format_error/1]). -export([start/0, start_link/0, stop/0]). %% gen_server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). -define(FILE_IO_SERVER_TABLE, file_io_servers). -define(FILE_SERVER, file_server_2). % Registered name -define(FILE_IO_SERVER, file_io_server). % Module -define(PRIM_FILE, prim_file). % Module %%%---------------------------------------------------------------------- %%% API %%%---------------------------------------------------------------------- format_error({_Line, ?MODULE, Reason}) -> io_lib:format("~w", [Reason]); format_error({_Line, Mod, Reason}) -> Mod:format_error(Reason); format_error(ErrorId) -> erl_posix_msg:message(ErrorId). start() -> do_start(start). start_link() -> do_start(start_link). stop() -> gen_server:call(?FILE_SERVER, stop, infinity). %%%---------------------------------------------------------------------- %%% Callback functions from gen_server %%%---------------------------------------------------------------------- -type state() :: port(). % Internal type %%---------------------------------------------------------------------- %% Func: init/1 %% Returns: {ok, State} | %% {ok, State, Timeout} | %% ignore | %% {stop, Reason} %%---------------------------------------------------------------------- -spec init([]) -> {'ok', state()} | {'stop', term()}. init([]) -> process_flag(trap_exit, true), case ?PRIM_FILE:start() of {ok, Handle} -> ?FILE_IO_SERVER_TABLE = ets:new(?FILE_IO_SERVER_TABLE, [named_table]), {ok, Handle}; {error, Reason} -> {stop, Reason} end. %%---------------------------------------------------------------------- %% Func: handle_call/3 %% Returns: {reply, Reply, State} | %% {reply, Reply, State, Timeout} | %% {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, Reply, State} | (terminate/2 is called) %% {stop, Reason, State} (terminate/2 is called) %%---------------------------------------------------------------------- -spec handle_call(term(), term(), state()) -> {'noreply', state()} | {'reply', 'eof' | 'ok' | {'error', term()} | {'ok', term()}, state()} | {'stop', 'normal', 'stopped', state()}. handle_call({open, Name, ModeList}, {Pid, _Tag} = _From, Handle) when is_list(ModeList) -> Child = ?FILE_IO_SERVER:start_link(Pid, Name, ModeList), case Child of {ok, P} when is_pid(P) -> ets:insert(?FILE_IO_SERVER_TABLE, {P, Name}); _ -> ok end, {reply, Child, Handle}; handle_call({open, _Name, _Mode}, _From, Handle) -> {reply, {error, einval}, Handle}; handle_call({read_file, Name}, _From, Handle) -> {reply, ?PRIM_FILE:read_file(Name), Handle}; handle_call({write_file, Name, Bin}, _From, Handle) -> {reply, ?PRIM_FILE:write_file(Name, Bin), Handle}; handle_call({set_cwd, Name}, _From, Handle) -> {reply, ?PRIM_FILE:set_cwd(Handle, Name), Handle}; handle_call({delete, Name}, _From, Handle) -> {reply, ?PRIM_FILE:delete(Handle, Name), Handle}; handle_call({rename, Fr, To}, _From, Handle) -> {reply, ?PRIM_FILE:rename(Handle, Fr, To), Handle}; handle_call({make_dir, Name}, _From, Handle) -> {reply, ?PRIM_FILE:make_dir(Handle, Name), Handle}; handle_call({del_dir, Name}, _From, Handle) -> {reply, ?PRIM_FILE:del_dir(Handle, Name), Handle}; handle_call({list_dir, Name}, _From, Handle) -> {reply, ?PRIM_FILE:list_dir(Handle, Name), Handle}; handle_call({list_dir_all, Name}, _From, Handle) -> {reply, ?PRIM_FILE:list_dir_all(Handle, Name), Handle}; handle_call(get_cwd, _From, Handle) -> {reply, ?PRIM_FILE:get_cwd(Handle), Handle}; handle_call({get_cwd}, _From, Handle) -> {reply, ?PRIM_FILE:get_cwd(Handle), Handle}; handle_call({get_cwd, Name}, _From, Handle) -> {reply, ?PRIM_FILE:get_cwd(Handle, Name), Handle}; handle_call({read_file_info, Name}, _From, Handle) -> {reply, ?PRIM_FILE:read_file_info(Handle, Name), Handle}; handle_call({read_file_info, Name, Opts}, _From, Handle) -> {reply, ?PRIM_FILE:read_file_info(Handle, Name, Opts), Handle}; handle_call({altname, Name}, _From, Handle) -> {reply, ?PRIM_FILE:altname(Handle, Name), Handle}; handle_call({write_file_info, Name, Info}, _From, Handle) -> {reply, ?PRIM_FILE:write_file_info(Handle, Name, Info), Handle}; handle_call({write_file_info, Name, Info, Opts}, _From, Handle) -> {reply, ?PRIM_FILE:write_file_info(Handle, Name, Info, Opts), Handle}; handle_call({read_link_info, Name}, _From, Handle) -> {reply, ?PRIM_FILE:read_link_info(Handle, Name), Handle}; handle_call({read_link_info, Name, Opts}, _From, Handle) -> {reply, ?PRIM_FILE:read_link_info(Handle, Name, Opts), Handle}; handle_call({read_link, Name}, _From, Handle) -> {reply, ?PRIM_FILE:read_link(Handle, Name), Handle}; handle_call({read_link_all, Name}, _From, Handle) -> {reply, ?PRIM_FILE:read_link_all(Handle, Name), Handle}; handle_call({make_link, Old, New}, _From, Handle) -> {reply, ?PRIM_FILE:make_link(Handle, Old, New), Handle}; handle_call({make_symlink, Old, New}, _From, Handle) -> {reply, ?PRIM_FILE:make_symlink(Handle, Old, New), Handle}; handle_call({copy, SourceName, SourceOpts, DestName, DestOpts, Length}, _From, Handle) -> Reply = case ?PRIM_FILE:open(SourceName, [read, binary | SourceOpts]) of {ok, Source} -> SourceReply = case ?PRIM_FILE:open(DestName, [write, binary | DestOpts]) of {ok, Dest} -> DestReply = ?PRIM_FILE:copy(Source, Dest, Length), ?PRIM_FILE:close(Dest), DestReply; {error, _} = Error -> Error end, ?PRIM_FILE:close(Source), SourceReply; {error, _} = Error -> Error end, {reply, Reply, Handle}; handle_call(stop, _From, Handle) -> {stop, normal, stopped, Handle}; handle_call(Request, From, Handle) -> error_logger:error_msg("handle_call(~p, ~p, _)", [Request, From]), {noreply, Handle}. %%---------------------------------------------------------------------- %% Func: handle_cast/2 %% Returns: {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, State} (terminate/2 is called) %%---------------------------------------------------------------------- -spec handle_cast(term(), state()) -> {'noreply', state()}. handle_cast(Msg, State) -> error_logger:error_msg("handle_cast(~p, _)", [Msg]), {noreply, State}. %%---------------------------------------------------------------------- %% Func: handle_info/2 %% Returns: {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, State} (terminate/2 is called) %%---------------------------------------------------------------------- -spec handle_info(term(), state()) -> {'noreply', state()} | {'stop', 'normal', state()}. handle_info({'EXIT', Pid, _Reason}, Handle) when is_pid(Pid) -> ets:delete(?FILE_IO_SERVER_TABLE, Pid), {noreply, Handle}; handle_info({'EXIT', Handle, _Reason}, Handle) -> error_logger:error_msg("Port controlling ~w terminated in ~w", [?FILE_SERVER, ?MODULE]), {stop, normal, Handle}; handle_info(Info, State) -> error_logger:error_msg("handle_Info(~p, _)", [Info]), {noreply, State}. %%---------------------------------------------------------------------- %% Func: terminate/2 %% Purpose: Shutdown the server %% Returns: any (ignored by gen_server) %%---------------------------------------------------------------------- -spec terminate(term(), state()) -> 'ok'. terminate(_Reason, Handle) -> ?PRIM_FILE:stop(Handle). %%---------------------------------------------------------------------- %% Func: code_change/3 %% Purpose: Convert process state when code is changed %% Returns: {ok, NewState} %%---------------------------------------------------------------------- -spec code_change(term(), state(), term()) -> {'ok', state()}. code_change(_OldVsn, State, _Extra) -> {ok, State}. %%%---------------------------------------------------------------------- %%% Internal functions %%%---------------------------------------------------------------------- %%% The basic file server and start-up. %%% %%% The file server just handles the open command/message and acts as a %%% router for messages between the port and the file processes. If a %%% file process terminates we close the associated file. %% Start = start | start_link do_start(Start) -> case init:get_argument(master) of error -> gen_server:Start({local,?FILE_SERVER}, ?MODULE, [], []); {ok, [[Node]]} -> do_start(Start, list_to_atom(Node), ?FILE_SERVER); X -> {error, {get_argument, master, X}} end. %% Should mimic gen_server:Start do_start(Start, Node, Name) -> case rpc:call(Node, erlang, whereis, [Name]) of Filer when is_pid(Filer); Filer =:= undefined -> case catch do_start_slave(Start, Filer, Name) of {'EXIT', Reason} -> {error, Reason}; Result -> Result end; Other -> {error, {no_master, Other}} end. %% May exit upon failure, return {ok, SlavePid} if all well. do_start_slave(start_link, Filer, Name) -> Self = self(), Token = make_ref(), Slave = spawn_link(fun() -> relay_start(Self, Token, Filer, Name) end), receive {started, Token} -> {ok, Slave} end; do_start_slave(start, Filer, Name) -> Self = self(), Token = make_ref(), Slave = spawn(fun() -> relay_start(Self, Token, Filer, Name) end), SlaveMonitor = erlang:monitor(process, Slave), receive {started, Token} -> erlang:demonitor(SlaveMonitor, [flush]), {ok, Slave}; {'DOWN', SlaveMonitor, _, _, Reason} -> exit(Reason) end. %% We have the relay process file internal. %% We do not need to load slave as a mandatory module %% during system startup. relay_start(Parent, Token, Filer, Name) when is_pid(Filer) -> case catch register(Name, self()) of true -> ok; _ -> exit({already_started, whereis(Name)}) end, %% This will fail towards an R5 node or older, Filer is a pid() FilerMonitor = erlang:monitor(process, Filer), process_flag(trap_exit, true), Parent ! {started, Token}, relay_loop(Parent, Filer, FilerMonitor); relay_start(Parent, Token, undefined, _Name) -> %% Dummy process to keep kernel supervisor happy process_flag(trap_exit, true), Parent ! {started, Token}, receive {'EXIT', Parent, Reason} -> exit(Reason) end. relay_loop(Parent, Filer, FilerMonitor) -> receive {'DOWN', FilerMonitor, _, _, Reason} -> exit(Reason); {'EXIT', Parent, Reason} -> exit(Reason); Msg -> Filer ! Msg end, relay_loop(Parent, Filer, FilerMonitor).