From 46e1565e73bc4490d29f0193146d4d75d9dba226 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?John=20H=C3=B6gberg?= Date: Thu, 28 Mar 2019 11:59:47 +0100 Subject: erl_tar: Use read_ahead when reading compressed tar files Jumping around in a compressed file is nowhere near as cheap as for uncompressed files, as it requires reading and decompressing up until the desired position. Using read_ahead will improve performance slightly. --- lib/stdlib/src/erl_tar.erl | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/stdlib/src/erl_tar.erl b/lib/stdlib/src/erl_tar.erl index d8b8f466b1..7064fcacfa 100644 --- a/lib/stdlib/src/erl_tar.erl +++ b/lib/stdlib/src/erl_tar.erl @@ -324,7 +324,7 @@ do_open(Name, Mode) when is_list(Mode) -> open1({binary,Bin}, read, _Raw, Opts) when is_binary(Bin) -> case file:open(Bin, [ram,binary,read]) of {ok,File} -> - _ = [ram_file:uncompress(File) || Opts =:= [compressed]], + _ = [ram_file:uncompress(File) || lists:member(compressed, Opts)], {ok, #reader{handle=File,access=read,func=fun file_op/2}}; Error -> Error @@ -357,7 +357,7 @@ open_mode([read|Rest], false, Raw, Opts) -> open_mode([write|Rest], false, Raw, Opts) -> open_mode(Rest, write, Raw, Opts); open_mode([compressed|Rest], Access, Raw, Opts) -> - open_mode(Rest, Access, Raw, [compressed|Opts]); + open_mode(Rest, Access, Raw, [compressed,read_ahead|Opts]); open_mode([cooked|Rest], Access, _Raw, Opts) -> open_mode(Rest, Access, [], Opts); open_mode([], Access, Raw, Opts) -> -- cgit v1.2.3