Changeset 3588 for lang/perl/Archive-Lha/trunk/lib/Archive/Lha/Decode.pm

Timestamp:

12/26/07 12:00:47 (13 months ago)

Author:

charsbar

Message:

lang/perl/Archive-Lha: lots of changes, cleanups, pods and 0.02 -> CPAN

Files:

• lang/perl/Archive-Lha/trunk/lib/Archive/Lha/Decode.pm (modified) (2 diffs)

lang/perl/Archive-Lha/trunk/lib/Archive/Lha/Decode.pm

@@ -10 +10 @@
   croak "Header is missing" unless defined $options{header};
 
-  my $method = uc $options{header}->{method};
+  my $method = uc $options{header}->method;
 
   my $package = 'Archive::Lha::Decode::'.$method;
@@ -30 +30 @@
 =head1 SYNOPSIS
 
+  # don't forget :raw, or eol might be converted implicitly
+  open my $fh, '>:raw', $header->pathname;
+  binmode $fh;
+  $stream->seek( $header->data_top );
+  my $decoder = Archive::Lha::Decode->new(
+    header => $header,
+    read   => sub { $stream->read(@_) },
+    write  => sub { print $fh @_ },
+  )
+  my $crc16 = $decoder->decode;
+  croak "crc mismatch" if $crc16 != $header->crc16;
+
 =head1 DESCRIPTION
 
+This is used to decode/extract an archived file from the stream. Actually this ::Decode class is a factory and decoding is done by a delegated class according to the header's "method" property.
+
+All of the ::Decode subclasses require read/write callbacks. Read callback should take a byte length as an argument, and return the bytes of the length from a file or a string. Write callback should take a part of the decoded (probably binary) string as an argument, and the rest is up to you. You may want to write it down in a file as shown above, or maybe append it to a string to store in a database after finished. You may want to encode it first, or throw it away if the string contains unprintable binary. You may want to use a temporary file. You may want to update a progress indicator. Do whatever you want.
+
 =head1 METHODS
+
+=head2 new
+
+takes an Archive::Lha::Header object, and read/write callbacks and creates an appropriate object.
+
+=head2 decode
+
+does the decoding stuff and returns CRC-16 of the decoded string. The decoded string itself is passed to the write callback while decoding (step by step).
 
 =head1 AUTHOR