1 files changed, 76 insertions, 0 deletions
diff --git a/lib/App/Beam/History.pm b/lib/App/Beam/History.pm
new file mode 100644
index 0000000..0421c3e
--- /dev/null
+++ b/lib/App/Beam/History.pm
@@ -0,0 +1,76 @@
+package App::Beam::History;
+
+use strict;
+use Carp;
+use App::Beam::History::Record;
+use App::Beam::History::Entry qw(:state);
+
+require Exporter;
+our @ISA = qw(Exporter);
+
+use Fcntl qw(:flock SEEK_SET);
+use Storable qw(fd_retrieve nstore_fd);
+
+sub new {
+    my $class = shift;
+    my $filename = shift;
+    my $rounds = shift;
+    my $levels = shift;
+    
+    my $self = bless { filename => $filename }, $class;
+
+    my $v;
+    local %_ = @_;
+    if (defined($v = delete($_{dry_run}))) {
+	$self->{dry_run} = $v;
+    }
+
+    if (keys(%_)) {
+	croak "unknown or unhandled parameters: ".join(',', keys(%_));
+    }
+    
+    unless (open($self->{filehandle}, '+>>', $filename)) {
+	croak "can't open file $filename: $!";
+    }
+    unless (flock($self->{filehandle}, LOCK_EX | LOCK_NB)) {
+	croak "can't lock file $filename: $!";
+    }
+    seek($self->{filehandle}, 0, SEEK_SET);
+    if ((stat($self->{filehandle}))[7] == 0) {
+	$self->{history} = [];
+	unshift @{$self->{history}}, new App::Beam::History::Record;
+    } else {
+	$self->{history} = fd_retrieve($self->{filehandle})
+	    or croak "can't retrieve status from $self->{filehandle}: $!";
+	if (ref($self->{history}) ne 'ARRAY') {
+	    croak "$self->{filename}: malformed status file";
+	}
+	unshift @{$self->{history}},
+	        new App::Beam::History::Record(prev => $self->{history}[0],
+					       rounds => $rounds,
+					       levels => $levels);
+    }
+    return $self;
+}
+
+sub records {
+    my $self = shift;
+    return @{$self->{history}};
+}
+
+sub top {
+    my ($self, $idx) = @_;
+    return $self->{history}[$idx];
+}
+
+sub save {
+    my $self = shift;
+    if (!$self->{dry_run} && $self->top->state != STATE_PENDING) {
+	seek($self->{filehandle}, 0, SEEK_SET);
+	truncate($self->{filehandle}, 0);
+	nstore_fd($self->{history}, $self->{filehandle});
+    }
+    flock($self->{filehandle}, LOCK_UN);
+    close($self->{filehandle});
+}
+