diff options
Diffstat (limited to 'lib/stdlib/src/log_mf_h.erl')
| -rw-r--r-- | lib/stdlib/src/log_mf_h.erl | 35 |
1 files changed, 26 insertions, 9 deletions
diff --git a/lib/stdlib/src/log_mf_h.erl b/lib/stdlib/src/log_mf_h.erl index 2729f27e51..f7f128dac7 100644 --- a/lib/stdlib/src/log_mf_h.erl +++ b/lib/stdlib/src/log_mf_h.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1996-2009. All Rights Reserved. +%% Copyright Ericsson AB 1996-2011. 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 @@ -27,14 +27,13 @@ %%----------------------------------------------------------------- --type dir() :: file:filename(). -type b() :: non_neg_integer(). -type f() :: 1..255. -type pred() :: fun((term()) -> boolean()). %%----------------------------------------------------------------- --record(state, {dir :: dir(), +-record(state, {dir :: file:filename(), maxB :: b(), maxF :: f(), curB :: b(), @@ -67,11 +66,23 @@ %% EventMgr = pid() | atom(). %%----------------------------------------------------------------- --spec init(dir(), b(), f()) -> {dir(), b(), f(), pred()}. +-opaque args() :: {file:filename(), b(), f(), pred()}. + + +-spec init(Dir, MaxBytes, MaxFiles) -> Args when + Dir :: file:filename(), + MaxBytes :: non_neg_integer(), % b() + MaxFiles :: 1..255, % f() + Args :: args(). init(Dir, MaxB, MaxF) -> init(Dir, MaxB, MaxF, fun(_) -> true end). --spec init(dir(), b(), f(), pred()) -> {dir(), b(), f(), pred()}. +-spec init(Dir, MaxBytes, MaxFiles, Pred) -> Args when + Dir :: file:filename(), + MaxBytes :: non_neg_integer(), % b() + MaxFiles :: 1..255, % f() + Pred :: fun((Event :: term()) -> boolean()), % pred() + Args :: args(). init(Dir, MaxB, MaxF, Pred) -> {Dir, MaxB, MaxF, Pred}. @@ -79,7 +90,7 @@ init(Dir, MaxB, MaxF, Pred) -> {Dir, MaxB, MaxF, Pred}. %% Call-back functions from gen_event %%----------------------------------------------------------------- --spec init({dir(), b(), f(), pred()}) -> {'ok', #state{}} | {'error', term()}. +-spec init({file:filename(), non_neg_integer(), f(), pred()}) -> {'ok', #state{}} | {'error', term()}. init({Dir, MaxB, MaxF, Pred}) when is_integer(MaxF), MaxF > 0, MaxF < 256 -> First = @@ -185,13 +196,19 @@ read_index_file(Dir) -> %%----------------------------------------------------------------- %% Write the index file. This file contains one binary with %% the last used filename (an integer). +%% Write a temporary file and rename it in order to make the update +%% atomic. %%----------------------------------------------------------------- write_index_file(Dir, Index) -> - case file:open(Dir ++ "/index", [raw, write]) of + File = Dir ++ "/index", + TmpFile = File ++ ".tmp", + case file:open(TmpFile, [raw, write]) of {ok, Fd} -> - file:write(Fd, [Index]), - ok = file:close(Fd); + ok = file:write(Fd, [Index]), + ok = file:close(Fd), + ok = file:rename(TmpFile,File), + ok; _ -> exit(open_index_file) end. |