From fe616a6eab165971e44130a0b098ca6dcc2bc914 Mon Sep 17 00:00:00 2001
From: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Date: Fri, 3 Dec 2010 17:58:42 +0100
Subject: [PATCH] Reader.pm: fixed packet size, refactor logging.

---
 SCX/Reader.pm | 69 +++++++++++++++++++++++++--------------------------
 1 file changed, 34 insertions(+), 35 deletions(-)

diff --git a/SCX/Reader.pm b/SCX/Reader.pm
index 5a98a6d..23f33ea 100644
--- a/SCX/Reader.pm
+++ b/SCX/Reader.pm
@@ -6,7 +6,7 @@ use Time::HiRes qw(gettimeofday tv_interval);
 use FileHandle;
 use SCX::CRC;
 
-our $PACKET_SIZE = 10;
+our $PACKET_SIZE = 9; # 9 bytes + 0x05
 our $LOG_ROTATE  = 600;
 
 sub new {
@@ -61,64 +61,63 @@ sub read {
 	die "Read error on $self->{portname}: $!"
 		if !$bytes_read;
 
-	my $now = gettimeofday;
-	if ($now - $self->{log_start} >= $LOG_ROTATE) {
-		close $self->{logfh};
-		$self->{log_gen} = $self->{log_gen} ? 0 : 1;
-		open my $fh, '>', $logfile . '.' . $self->{log_gen}
-			or die "Can't open $logfile.$self->{log_gen}: $!";
-		$self->{logfh} = $fh;
-		$self->{log_start} = $now;
-	}
-
 	my @bytes = unpack("C*", $data);
 
-	$self->{logfh}->print(sprintf('% 10.3f', $now - $self->{starttime}),
-		(map { sprintf(" %02x", $_) } @bytes),
-		"\n");
-
 	push @{ $self->{bytes} }, @bytes;
 	@bytes = @{ $self->{bytes} };
 
 	my @bad_bytes;
 
-	while (@bytes >= 2) {
+	while (@bytes > $PACKET_SIZE) {
 		if ($bytes[0] != 0x55) {
 			push @bad_bytes, shift @bytes;
 			next;
 		}
 		my $cmd = $bytes[1];
 
-		my $packet_size = $cmd >= 0x40 && $cmd <= 0x46 ? 4 : 9;
-		last if @bytes <= $packet_size;
-
-		if ($bytes[$packet_size] != 0x05
-			|| SCX::CRC::digest(@bytes[0..$packet_size-2])
-				!= $bytes[$packet_size-1]) {
+		if ($bytes[$PACKET_SIZE] != 0x05
+			|| SCX::CRC::digest(@bytes[0..$PACKET_SIZE-2])
+				!= $bytes[$PACKET_SIZE-1]) {
 			push @bad_bytes, shift @bytes;
 			next;
 		}
 		
-		if (@bad_bytes) {
-			$self->{logfh}->print("Cannot parse bytes",
-				(map { sprintf(' %02x', $_) } @bad_bytes),
-				"\n");
+		if (@bad_bytes) { # Report previous bad bytes first
+			$self->log_bytes(\@bad_bytes, "Cannot parse packet");
 			@bad_bytes = ();
 		}
 
-		$self->{logfh}->print("Callback\n");
-		&{ $self->{callback} }(@bytes[1..$packet_size]);
-		splice @bytes, 0, $packet_size+1;
-	}
-	if (@bad_bytes) {
-		$self->{logfh}->print("Cannot parse bytes",
-			(map { sprintf(' %02x', $_) } @bad_bytes),
-			"\n");
-		@bad_bytes = ();
+		my @packet = splice @bytes, 0, $PACKET_SIZE+1;
+		my $rv = &{ $self->{callback} }(@packet[1..$PACKET_SIZE]);
+		$self->log_bytes(@packet, $rv);
 	}
+	$self->log_bad_bytes(\@bad_bytes, "Cannot parse packet");
 
 	@{ $self->{bytes} } = @bytes;
 }
 
+sub log_bytes {
+	my ($self, $bytes, $msg) = @_;
+
+	return if !@$bytes;
+
+	$msg = defined $msg ? ' # ' . $msg : '';
+
+	my $now = gettimeofday;
+
+	if ($now - $self->{log_start} >= $LOG_ROTATE) {
+		close $self->{logfh};
+		$self->{log_gen} = $self->{log_gen} ? 0 : 1;
+		open my $fh, '>', $logfile . '.' . $self->{log_gen}
+			or die "Can't open $logfile.$self->{log_gen}: $!";
+		$self->{logfh} = $fh;
+		$self->{log_start} = $now;
+	}
+
+	$self->{logfh}->print(sprintf('% 10.3f', $now - $self->{starttime}),
+		(map { sprintf(" %02x", $_) } @bytes),
+		$msg, "\n");
+}
+
 1;
 
-- 
2.43.5