Bug#387304: apt-mirror: Provided patch greatly improves speed of Packages/Sources parsing speed

[Mikhail Gusarov]

Package: apt-mirror
Severity: wishlist
Tags: patch

apt-mirror stat(2)'s all files found in Packages/Sources. Many of them
are stat(2)'ed many times, because Packages/Sources may point to the
same file (especially in testing/unstable).

Provided patch caches stat(2) results, and it greatly improves speed
of Packages/Sources.

This patch also has been sent upstream.

-- System Information:
Debian Release: testing/unstable
  APT prefers testing
  APT policy: (800, 'testing'), (700, 'unstable'), (1, 'experimental')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/dash
Kernel: Linux 2.6.17-2-686
Locale: LANG=C, LC_CTYPE=ru_RU.UTF-8 (charmap=UTF-8)

--- apt-mirror-0.4.4/apt-mirror 2006-09-13 21:22:32.000000000 +0700
+++ apt-mirror  2006-09-13 21:22:27.000000000 +0700
@@ -330,11 +330,25 @@
 open FILES_NEW, ">" . get_variable("var_path") . "/NEW" or die("apt-mirror: 
can't write to intermediate file (NEW)");
 open FILES_MD5, ">" . get_variable("var_path") . "/MD5" or die("apt-mirror: 
can't write to intermediate file (MD5)");
 
+my %stat_cache = ();
+
+sub _stat {
+  my ($filename) = shift;
+  return @{$stat_cache{$filename}} if exists $stat_cache{$filename};
+  my @res = stat($filename);
+  $stat_cache{$filename} = [EMAIL PROTECTED];
+  return @res;
+}
+
+sub clear_stat_cache {
+  %stat_cache = ();
+}
+
 sub need_update {
     my $filename = shift;
     my $size_on_server = shift;
 
-    my (undef, undef, undef, undef, undef, undef, undef, $size) = 
stat($filename);
+    my (undef, undef, undef, undef, undef, undef, undef, $size) = 
_stat($filename);
 
     return 1 unless($size);
     return 0 if $size_on_server == $size;
@@ -430,6 +444,8 @@
     }
 }
 
+clear_stat_cache();
+
 print "]\n\n";
 
 close FILES_ALL;