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authorJohn Högberg <[email protected]>2019-03-28 11:59:47 +0100
committerJohn Högberg <[email protected]>2019-03-28 12:05:15 +0100
commit46e1565e73bc4490d29f0193146d4d75d9dba226 (patch)
tree49f4d02f60a9ef12b9d9c68d103bd0d49cf5e8ce
parentbaa461cbd791ec7d09ab4a609d87c1d254907973 (diff)
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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.
-rw-r--r--lib/stdlib/src/erl_tar.erl4
1 files 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) ->