1package MogileFS::ReplicationPolicy; 2use strict; 3 4=head1 NAME 5 6MogileFS::ReplicationPolicy - base class for file replication policies 7 8=head1 DESCRIPTION 9 10A MogileFS replication policy class implements policy for how files 11should be replicated around. 12 13.... 14 15=cut 16 17# parse a policy description string, instantiating object(s) along the way 18# given $str can be either a scalar, or a scalarref that's eaten away as it's parsed. 19sub new_from_policy_string { 20 my ($class, $str_a) = @_; 21 22 # simple case for normal callers: they give us a scalar, but internally 23 # we work with it as a scalarref that we eat away while parsing. 24 my $strref = ref $str_a ? $str_a : \$str_a; 25 26 $$strref =~ s/^\s*([\w:]+)// or die "Failed to parse policy string: $$strref"; 27 my ($polclass) = ($1); 28 $polclass = "MogileFS::ReplicationPolicy::$polclass" unless $polclass =~ /:/; 29 30 my $rv = eval "use $polclass; 1"; 31 if ($@ || !$rv) { 32 die "Failed to load replication policy class $polclass: $@\n"; 33 } 34 35 return $polclass->new_from_policy_args($strref); 36} 37 38# returns: 39# 0: replication sufficient 40# undef: no suitable recommendations currently. 41# >0: devid to replicate to. 42sub replicate_to { 43 my ($self, %args) = @_; 44 my $fid = delete $args{fid}; # fid scalar to copy 45 my $on_devs = delete $args{on_devs}; # arrayref of device objects 46 my $all_devs = delete $args{all_devs}; # hashref of { devid => MogileFS::Device } 47 my $failed = delete $args{failed}; # hashref of { devid => 1 } of failed attempts this round 48 my $min = delete $args{min}; # configured min devcount for this class 49 50 warn "Unknown parameters: " . join(", ", sort keys %args) if %args; 51 die "Missing parameters" unless $on_devs && $all_devs && $failed && $fid; 52 53 die "UNIMPLEMENTED 'replicate_to' in " . (ref($self) || $self); 54} 55 56 57 581; 59