aboutsummaryrefslogtreecommitdiffstats
path: root/lib/kernel/src/file_server.erl
diff options
context:
space:
mode:
authorErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
committerErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
commit84adefa331c4159d432d22840663c38f155cd4c1 (patch)
treebff9a9c66adda4df2106dfd0e5c053ab182a12bd /lib/kernel/src/file_server.erl
downloadotp-84adefa331c4159d432d22840663c38f155cd4c1.tar.gz
otp-84adefa331c4159d432d22840663c38f155cd4c1.tar.bz2
otp-84adefa331c4159d432d22840663c38f155cd4c1.zip
The R13B03 release.OTP_R13B03
Diffstat (limited to 'lib/kernel/src/file_server.erl')
-rw-r--r--lib/kernel/src/file_server.erl325
1 files changed, 325 insertions, 0 deletions
diff --git a/lib/kernel/src/file_server.erl b/lib/kernel/src/file_server.erl
new file mode 100644
index 0000000000..74f2fb94a9
--- /dev/null
+++ b/lib/kernel/src/file_server.erl
@@ -0,0 +1,325 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2000-2009. All Rights Reserved.
+%%
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+%%%----------------------------------------------------------------------
+%%% File : file_server.erl
+%%% Author : Raimo Niskanen <[email protected]>
+%%% Purpose : A simple file server
+%%% Created : 13 Oct 2000 by Raimo Niskanen <[email protected]>
+%%%----------------------------------------------------------------------
+
+-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
+%%%----------------------------------------------------------------------
+
+%%----------------------------------------------------------------------
+%% Func: init/1
+%% Returns: {ok, State} |
+%% {ok, State, Timeout} |
+%% ignore |
+%% {stop, Reason}
+%%----------------------------------------------------------------------
+init([]) ->
+ process_flag(trap_exit, true),
+ case ?PRIM_FILE:start() of
+ {ok, Handle} ->
+ 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)
+%%----------------------------------------------------------------------
+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(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({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({read_link_info, Name}, _From, Handle) ->
+ {reply, ?PRIM_FILE:read_link_info(Handle, Name), Handle};
+
+handle_call({read_link, Name}, _From, Handle) ->
+ {reply, ?PRIM_FILE:read_link(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)
+%%----------------------------------------------------------------------
+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)
+%%----------------------------------------------------------------------
+
+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)
+%%----------------------------------------------------------------------
+terminate(_Reason, Handle) ->
+ ?PRIM_FILE:stop(Handle).
+
+%%----------------------------------------------------------------------
+%% Func: code_change/3
+%% Purpose: Convert process state when code is changed
+%% Returns: {ok, NewState}
+%%----------------------------------------------------------------------
+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),
+ receive {'DOWN', SlaveMonitor, _, _, _} -> ok after 0 -> ok end,
+ {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).