#! /usr/bin/perl -w use strict; { my $ofh = select STDOUT; $| = 1; select $ofh; } #my @paths = ("/nix/store/caef3a49150506d233f474322a824e50-glibc-2.3.3", "/nix/store/a8a9d585d1ad4b1bc911be7743b3b996-glibc-2.3.3"); my @paths = ("/nix/store"); my $tmpfile = "/tmp/nix-optimise-hash-list"; #my $tmpfile = "/data/nix-optimise-hash-list"; system("find @paths -type f -print0 | xargs -0 md5sum -- > $tmpfile") == 0 or die "cannot hash store files"; system("sort $tmpfile > $tmpfile.sorted") == 0 or die "cannot sort list"; open LIST, "<$tmpfile.sorted" or die; my $prevFile; my $prevHash; my $totalSpace = 0; my $savedSpace = 0; my $files = 0; while (<LIST>) { # print "D"; /^([0-9a-f]*)\s+(.*)$/ or die; my $curFile = $2; my $curHash = $1; # print "A"; my $fileSize = (stat $curFile)[7]; # print "B"; # my $fileSize = 1; $totalSpace += $fileSize; if (defined $prevHash && $curHash eq $prevHash) { # print "$curFile = $prevFile\n"; $savedSpace += $fileSize; } else { $prevFile = $curFile; $prevHash = $curHash; } print "." if ($files++ % 100 == 0); #print "."; # print "C"; } print "\n"; print "total space = $totalSpace\n"; print "saved space = $savedSpace\n"; my $savings = ($savedSpace / $totalSpace) * 100.0; print "savings = $savings %\n"; close LIST;