angrydutchman.peedee.es
Absolute hinky bare-bones implementation of multiformats in Perl
1package
2 Multiformats::Multicodec {
3 use strict;
4 use warnings;
5 use feature 'signatures';
6 use Multiformats::Varint qw/varint_decode_raw varint_encode/;
7
8 use Exporter 'import';
9 our @EXPORT_OK = qw/multicodec_wrap multicodec_unwrap multicodec_get_codec/;
10
11 use constant MULTICODEC_MAP => [
12 [ 'raw', 0x55 ],
13 [ 'dag-cbor', 0x71 ],
14 ];
15
16 sub wrap($self, $as, $value) {
17 return multihash_wrap($as, $value);
18 }
19
20 sub unwrap($self, $value) {
21 return multihash_unwrap($value);
22 }
23
24 sub get_codec($self, $value) {
25 return multihash_codec($value);
26 }
27
28 sub new($pkg) {
29 return bless({}, $pkg);
30 }
31
32 sub _get_by_name($as) {
33 foreach my $entry (@{__PACKAGE__->MULTICODEC_MAP}) {
34 return $entry if($entry->[0] eq $as);
35 }
36 return _get_by_tag($as);
37 }
38
39 sub _get_by_tag($tag) {
40 foreach my $entry (@{__PACKAGE__->MULTICODEC_MAP}) {
41 return $entry if($entry->[1] == $tag);
42 }
43 return undef;
44 }
45
46 sub multicodec_wrap($as, $value) {
47 utf8::downgrade($value, 1);
48 if(my $e = _get_by_name($as)) {
49 my $id = varint_encode($e->[1]);
50 return $id . $value;
51 } else {
52 die 'Unsupported multicodec type ', $as, ', ';
53 }
54 }
55
56 sub multicodec_unwrap($value) {
57 utf8::downgrade($value, 1);
58 my ($id, $bytes) = varint_decode_raw($value);
59 return substr($value, $bytes);
60
61 }
62
63 sub multicodec_get_codec($value) {
64 utf8::downgrade($value, 1);
65 my ($id, $bytes) = varint_decode_raw($value);
66 if(my $e = _get_by_tag($id)) {
67 return $e;
68 } else {
69 die 'Unsupported multicodec type ', $id, ', ';
70 }
71 }
72}
73
74=pod
75
76=head1 NAME
77
78Multiformats::Multicodec - Multicodec encoding/decoding/wrapping
79
80=head1 SYNOPSIS
81
82 use Multiformats::Multicodec qw/multicodec_get_codec multicodec_unwrap multicodec_wrap/;
83
84 my $data = '...';
85
86 my $encoded = multicodec_wrap('dag-cbor', $data);
87 my $decoded = multicodec_unwrap($encoded);
88
89 my $codec = multicodec_get_codec($encoded);
90
91 $codec->[0]; # dag-cbor
92 $codec->[1]; # 0x71
93
94
95=head1 FUNCTIONS
96
97=head2 multicodec_wrap($codec, $data);
98
99Wraps the given data with the proper multicodec tag
100
101=head2 multicodec_unwrap($data)
102
103Unwraps the given data and returns the original raw data
104
105=head2 multicodec_get_codec($data)
106
107Returns an arrayref containing the codec information that the data is encoded with. First item in the arrayref is the codec name, second item is the codec tag value.
108
109=head1 SUPPORTED CODECS
110
111=over
112
113=item * raw
114
115=item * dag-cbor
116
117=back
118
119=cut
120
1211;