--- ram_file_io_server.erl.sav 2009-04-01 11:23:51.000000000 -0400 +++ ram_file_io_server.erl 1969-12-31 19:00:00.000000000 -0500 @@ -1,408 +0,0 @@ -%% ``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 via the world wide web 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. -%% -%% The Initial Developer of the Original Code is Ericsson Utvecklings AB. -%% Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings -%% AB. All Rights Reserved.'' -%% -%% $Id: ram_file_io_server.erl 970 2007-11-15 10:33:18Z mremond $ -%% -%% This file is mostly copied from Erlang file_io_server.erl -%% See: http://www.erlang.org/ml-archive/erlang-questions/200607/msg00080.html -%% for details on ram_file_io_server.erl (Erlang OTP R11B-2) --module(ram_file_io_server). - -%% A simple file server for io to one file instance per server instance. - --export([format_error/1]). --export([start/3, start_link/3]). - --record(state, {handle,owner,mref,buf,read_mode}). - --define(PRIM_FILE, ram_file). --define(READ_SIZE_LIST, 128). --define(READ_SIZE_BINARY, (8*1024)). - --define(eat_message(M, T), receive M -> M after T -> timeout end). - -%%%----------------------------------------------------------------- -%%% Exported functions - -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(Owner, FileName, ModeList) - when pid(Owner), list(FileName), list(ModeList) -> - do_start(spawn, Owner, FileName, ModeList). - -start_link(Owner, FileName, ModeList) - when pid(Owner), list(FileName), list(ModeList) -> - do_start(spawn_link, Owner, FileName, ModeList). - -%%%----------------------------------------------------------------- -%%% Server starter, dispatcher and helpers - -do_start(Spawn, Owner, FileName, ModeList) -> - Self = self(), - Ref = make_ref(), - Pid = - erlang:Spawn( - fun() -> - %% process_flag(trap_exit, true), - {ReadMode,Opts} = - case lists:member(binary, ModeList) of - true -> - {binary,ModeList}; - false -> - {list,[binary|ModeList]} - end, - case ?PRIM_FILE:open(FileName, Opts) of - {error, Reason} = Error -> - Self ! {Ref, Error}, - exit(Reason); - {ok, Handle} -> - %% XXX must I handle R6 nodes here? - M = erlang:monitor(process, Owner), - Self ! {Ref, ok}, - server_loop( - #state{handle = Handle, - owner = Owner, - mref = M, - buf = <<>>, - read_mode = ReadMode}) - end - end), - Mref = erlang:monitor(process, Pid), - receive - {Ref, {error, _Reason} = Error} -> - erlang:demonitor(Mref), - receive {'DOWN', Mref, _, _, _} -> ok after 0 -> ok end, - Error; - {Ref, ok} -> - erlang:demonitor(Mref), - receive - {'DOWN', Mref, _, _, Reason} -> - {error, Reason} - after 0 -> - {ok, Pid} - end; - {'DOWN', Mref, _, _, Reason} -> - {error, Reason} - end. - -server_loop(#state{mref = Mref} = State) -> - receive - {file_request, From, ReplyAs, Request} when pid(From) -> - case file_request(Request, State) of - {reply, Reply, NewState} -> - file_reply(From, ReplyAs, Reply), - server_loop(NewState); - {error, Reply, NewState} -> - %% error is the same as reply, except that - %% it breaks the io_request_loop further down - file_reply(From, ReplyAs, Reply), - server_loop(NewState); - {stop, Reason, Reply, _NewState} -> - file_reply(From, ReplyAs, Reply), - exit(Reason) - end; - {io_request, From, ReplyAs, Request} when pid(From) -> - case io_request(Request, State) of - {reply, Reply, NewState} -> - io_reply(From, ReplyAs, Reply), - server_loop(NewState); - {error, Reply, NewState} -> - %% error is the same as reply, except that - %% it breaks the io_request_loop further down - io_reply(From, ReplyAs, Reply), - server_loop(NewState); - {stop, Reason, Reply, _NewState} -> - io_reply(From, ReplyAs, Reply), - exit(Reason) - end; - {'DOWN', Mref, _, _, Reason} -> - exit(Reason); - _ -> - server_loop(State) - end. - -file_reply(From, ReplyAs, Reply) -> - From ! {file_reply, ReplyAs, Reply}. - -io_reply(From, ReplyAs, Reply) -> - From ! {io_reply, ReplyAs, Reply}. - -%%%----------------------------------------------------------------- -%%% file requests - -file_request({pread,At,Sz}, - #state{handle=Handle,buf=Buf,read_mode=ReadMode}=State) -> - case position(Handle, At, Buf) of - {ok,_Offs} -> - case ?PRIM_FILE:read(Handle, Sz) of - {ok,Bin} when ReadMode==list -> - std_reply({ok,binary_to_list(Bin)}, State); - Reply -> - std_reply(Reply, State) - end; - Reply -> - std_reply(Reply, State) - end; -file_request({pwrite,At,Data}, - #state{handle=Handle,buf=Buf}=State) -> - case position(Handle, At, Buf) of - {ok,_Offs} -> - std_reply(?PRIM_FILE:write(Handle, Data), State); - Reply -> - std_reply(Reply, State) - end; -file_request(sync, - #state{handle=Handle}=State) -> - case ?PRIM_FILE:sync(Handle) of - {error,_}=Reply -> - {stop,normal,Reply,State}; - Reply -> - {reply,Reply,State} - end; -file_request(close, - #state{handle=Handle}=State) -> - {stop,normal,?PRIM_FILE:close(Handle),State#state{buf= <<>>}}; -file_request({position,At}, - #state{handle=Handle,buf=Buf}=State) -> - std_reply(position(Handle, At, Buf), State); -file_request(truncate, - #state{handle=Handle}=State) -> - case ?PRIM_FILE:truncate(Handle) of - {error,_Reason}=Reply -> - {stop,normal,Reply,State#state{buf= <<>>}}; - Reply -> - {reply,Reply,State} - end; -file_request(Unknown, - #state{}=State) -> - Reason = {request, Unknown}, - {error,{error,Reason},State}. - -std_reply({error,_}=Reply, State) -> - {error,Reply,State#state{buf= <<>>}}; -std_reply(Reply, State) -> - {reply,Reply,State#state{buf= <<>>}}. - -%%%----------------------------------------------------------------- -%%% I/O request - -io_request({put_chars,Chars}, % binary(Chars) new in R9C - #state{buf= <<>>}=State) -> - put_chars(Chars, State); -io_request({put_chars,Chars}, % binary(Chars) new in R9C - #state{handle=Handle,buf=Buf}=State) -> - case position(Handle, cur, Buf) of - {error,_}=Reply -> - {stop,normal,Reply,State#state{buf= <<>>}}; - _ -> - put_chars(Chars, State#state{buf= <<>>}) - end; -io_request({put_chars,Mod,Func,Args}, - #state{}=State) -> - case catch apply(Mod, Func, Args) of - Chars when list(Chars); binary(Chars) -> - io_request({put_chars,Chars}, State); - _ -> - {error,{error,Func},State} - end; -io_request({get_until,_Prompt,Mod,Func,XtraArgs}, - #state{}=State) -> - get_chars(io_lib, get_until, {Mod, Func, XtraArgs}, State); -io_request({get_chars,_Prompt,N}, % New in R9C - #state{}=State) -> - get_chars(N, State); -io_request({get_chars,_Prompt,Mod,Func,XtraArg}, % New in R9C - #state{}=State) -> - get_chars(Mod, Func, XtraArg, State); -io_request({get_line,_Prompt}, % New in R9C - #state{}=State) -> - get_chars(io_lib, collect_line, [], State); -io_request({setopts, Opts}, % New in R9C - #state{}=State) when list(Opts) -> - setopts(Opts, State); -io_request({requests,Requests}, - #state{}=State) when list(Requests) -> - io_request_loop(Requests, {reply,ok,State}); -io_request(Unknown, - #state{}=State) -> - Reason = {request,Unknown}, - {error,{error,Reason},State}. - - - -%% Process a list of requests as long as the results are ok. - -io_request_loop([], Result) -> - Result; -io_request_loop([_Request|_Tail], - {stop,_Reason,_Reply,_State}=Result) -> - Result; -io_request_loop([_Request|_Tail], - {error,_Reply,_State}=Result) -> - Result; -io_request_loop([Request|Tail], - {reply,_Reply,State}) -> - io_request_loop(Tail, io_request(Request, State)). - - - -%% I/O request put_chars -%% -put_chars(Chars, #state{handle=Handle}=State) -> - case ?PRIM_FILE:write(Handle, Chars) of - {error,_}=Reply -> - {stop,normal,Reply,State}; - Reply -> - {reply,Reply,State} - end. - - -%% Process the I/O request get_chars -%% -get_chars(0, #state{read_mode=ReadMode}=State) -> - {reply,cast(<<>>, ReadMode),State}; -get_chars(N, #state{buf=Buf,read_mode=ReadMode}=State) - when integer(N), N > 0, N =< size(Buf) -> - {B1,B2} = split_binary(Buf, N), - {reply,cast(B1, ReadMode),State#state{buf=B2}}; -get_chars(N, #state{handle=Handle,buf=Buf,read_mode=ReadMode}=State) - when integer(N), N > 0 -> - BufSize = size(Buf), - NeedSize = N-BufSize, - Size = max(NeedSize, ?READ_SIZE_BINARY), - case ?PRIM_FILE:read(Handle, Size) of - {ok, B} -> - if BufSize+size(B) < N -> - std_reply(cat(Buf, B, ReadMode), State); - true -> - {B1,B2} = split_binary(B, NeedSize), - {reply,cat(Buf, B1, ReadMode),State#state{buf=B2}} - end; - eof when BufSize==0 -> - {reply,eof,State}; - eof -> - std_reply(cast(Buf, ReadMode), State); - {error,Reason}=Error -> - {stop,Reason,Error,State#state{buf= <<>>}} - end; -get_chars(_N, #state{}=State) -> - {error,{error,get_chars},State}. - -get_chars(Mod, Func, XtraArg, #state{buf= <<>>}=State) -> - get_chars_empty(Mod, Func, XtraArg, start, State); -get_chars(Mod, Func, XtraArg, #state{buf=Buf}=State) -> - get_chars_apply(Mod, Func, XtraArg, start, State#state{buf= <<>>}, Buf). - -get_chars_empty(Mod, Func, XtraArg, S, - #state{handle=Handle,read_mode=ReadMode}=State) -> - case ?PRIM_FILE:read(Handle, read_size(ReadMode)) of - {ok,Bin} -> - get_chars_apply(Mod, Func, XtraArg, S, State, Bin); - eof -> - get_chars_apply(Mod, Func, XtraArg, S, State, eof); - {error,Reason}=Error -> - {stop,Reason,Error,State} - end. - -get_chars_apply(Mod, Func, XtraArg, S0, - #state{read_mode=ReadMode}=State, Data0) -> - Data1 = case ReadMode of - list when binary(Data0) -> binary_to_list(Data0); - _ -> Data0 - end, - case catch Mod:Func(S0, Data1, XtraArg) of - {stop,Result,Buf} -> - {reply,Result,State#state{buf=cast_binary(Buf)}}; - {'EXIT',Reason} -> - {stop,Reason,{error,err_func(Mod, Func, XtraArg)},State}; - S1 -> - get_chars_empty(Mod, Func, XtraArg, S1, State) - end. - -%% Convert error code to make it look as before -err_func(io_lib, get_until, {_,F,_}) -> - F; -err_func(_, F, _) -> - F. - - - -%% Process the I/O request setopts -%% -%% setopts -setopts(Opts0, State) -> - Opts = proplists:substitute_negations([{list,binary}], Opts0), - case proplists:get_value(binary, Opts) of - true -> - {ok,ok,State#state{read_mode=binary}}; - false -> - {ok,ok,State#state{read_mode=list}}; - _ -> - {error,{error,badarg},State} - end. - - - -%% Concatenate two binaries and convert the result to list or binary -cat(B1, B2, binary) -> - list_to_binary([B1,B2]); -cat(B1, B2, list) -> - binary_to_list(B1)++binary_to_list(B2). - -%% Cast binary to list or binary -cast(B, binary) -> - B; -cast(B, list) -> - binary_to_list(B). - -%% Convert buffer to binary -cast_binary(Binary) when binary(Binary) -> - Binary; -cast_binary(List) when list(List) -> - list_to_binary(List); -cast_binary(_EOF) -> - <<>>. - -%% Read size for different read modes -read_size(binary) -> - ?READ_SIZE_BINARY; -read_size(list) -> - ?READ_SIZE_LIST. - -max(A, B) when A >= B -> - A; -max(_, B) -> - B. - -%%%----------------------------------------------------------------- -%%% ?PRIM_FILE helpers - -%% Compensates ?PRIM_FILE:position/2 for the number of bytes -%% we have buffered - -position(Handle, cur, Buf) -> - position(Handle, {cur, 0}, Buf); -position(Handle, {cur, Offs}, Buf) when list(Buf) -> - ?PRIM_FILE:position(Handle, {cur, Offs-length(Buf)}); -position(Handle, {cur, Offs}, Buf) when binary(Buf) -> - ?PRIM_FILE:position(Handle, {cur, Offs-size(Buf)}); -position(Handle, At, _Buf) -> - ?PRIM_FILE:position(Handle, At). -