Merge branch 'tz/exclude-doc-smallfixes'
[git/git.git] / perl / Git / Packet.pm
1 package Git::Packet;
2 use 5.008;
3 use strict;
4 use warnings;
5 BEGIN {
6 require Exporter;
7 if ($] < 5.008003) {
8 *import = \&Exporter::import;
9 } else {
10 # Exporter 5.57 which supports this invocation was
11 # released with perl 5.8.3
12 Exporter->import('import');
13 }
14 }
15
16 our @EXPORT = qw(
17 packet_compare_lists
18 packet_bin_read
19 packet_txt_read
20 packet_key_val_read
21 packet_bin_write
22 packet_txt_write
23 packet_flush
24 packet_initialize
25 packet_read_capabilities
26 packet_read_and_check_capabilities
27 packet_check_and_write_capabilities
28 );
29 our @EXPORT_OK = @EXPORT;
30
31 sub packet_compare_lists {
32 my ($expect, @result) = @_;
33 my $ix;
34 if (scalar @$expect != scalar @result) {
35 return undef;
36 }
37 for ($ix = 0; $ix < $#result; $ix++) {
38 if ($expect->[$ix] ne $result[$ix]) {
39 return undef;
40 }
41 }
42 return 1;
43 }
44
45 sub packet_bin_read {
46 my $buffer;
47 my $bytes_read = read STDIN, $buffer, 4;
48 if ( $bytes_read == 0 ) {
49 # EOF - Git stopped talking to us!
50 return ( -1, "" );
51 } elsif ( $bytes_read != 4 ) {
52 die "invalid packet: '$buffer'";
53 }
54 my $pkt_size = hex($buffer);
55 if ( $pkt_size == 0 ) {
56 return ( 1, "" );
57 } elsif ( $pkt_size > 4 ) {
58 my $content_size = $pkt_size - 4;
59 $bytes_read = read STDIN, $buffer, $content_size;
60 if ( $bytes_read != $content_size ) {
61 die "invalid packet ($content_size bytes expected; $bytes_read bytes read)";
62 }
63 return ( 0, $buffer );
64 } else {
65 die "invalid packet size: $pkt_size";
66 }
67 }
68
69 sub remove_final_lf_or_die {
70 my $buf = shift;
71 if ( $buf =~ s/\n$// ) {
72 return $buf;
73 }
74 die "A non-binary line MUST be terminated by an LF.\n"
75 . "Received: '$buf'";
76 }
77
78 sub packet_txt_read {
79 my ( $res, $buf ) = packet_bin_read();
80 if ( $res != -1 and $buf ne '' ) {
81 $buf = remove_final_lf_or_die($buf);
82 }
83 return ( $res, $buf );
84 }
85
86 # Read a text packet, expecting that it is in the form "key=value" for
87 # the given $key. An EOF does not trigger any error and is reported
88 # back to the caller (like packet_txt_read() does). Die if the "key"
89 # part of "key=value" does not match the given $key, or the value part
90 # is empty.
91 sub packet_key_val_read {
92 my ( $key ) = @_;
93 my ( $res, $buf ) = packet_txt_read();
94 if ( $res == -1 or ( $buf =~ s/^$key=// and $buf ne '' ) ) {
95 return ( $res, $buf );
96 }
97 die "bad $key: '$buf'";
98 }
99
100 sub packet_bin_write {
101 my $buf = shift;
102 print STDOUT sprintf( "%04x", length($buf) + 4 );
103 print STDOUT $buf;
104 STDOUT->flush();
105 }
106
107 sub packet_txt_write {
108 packet_bin_write( $_[0] . "\n" );
109 }
110
111 sub packet_flush {
112 print STDOUT sprintf( "%04x", 0 );
113 STDOUT->flush();
114 }
115
116 sub packet_initialize {
117 my ($name, $version) = @_;
118
119 packet_compare_lists([0, $name . "-client"], packet_txt_read()) ||
120 die "bad initialize";
121 packet_compare_lists([0, "version=" . $version], packet_txt_read()) ||
122 die "bad version";
123 packet_compare_lists([1, ""], packet_bin_read()) ||
124 die "bad version end";
125
126 packet_txt_write( $name . "-server" );
127 packet_txt_write( "version=" . $version );
128 packet_flush();
129 }
130
131 sub packet_read_capabilities {
132 my @cap;
133 while (1) {
134 my ( $res, $buf ) = packet_bin_read();
135 if ( $res == -1 ) {
136 die "unexpected EOF when reading capabilities";
137 }
138 return ( $res, @cap ) if ( $res != 0 );
139 $buf = remove_final_lf_or_die($buf);
140 unless ( $buf =~ s/capability=// ) {
141 die "bad capability buf: '$buf'";
142 }
143 push @cap, $buf;
144 }
145 }
146
147 # Read remote capabilities and check them against capabilities we require
148 sub packet_read_and_check_capabilities {
149 my @required_caps = @_;
150 my ($res, @remote_caps) = packet_read_capabilities();
151 my %remote_caps = map { $_ => 1 } @remote_caps;
152 foreach (@required_caps) {
153 unless (exists($remote_caps{$_})) {
154 die "required '$_' capability not available from remote" ;
155 }
156 }
157 return %remote_caps;
158 }
159
160 # Check our capabilities we want to advertise against the remote ones
161 # and then advertise our capabilities
162 sub packet_check_and_write_capabilities {
163 my ($remote_caps, @our_caps) = @_;
164 foreach (@our_caps) {
165 unless (exists($remote_caps->{$_})) {
166 die "our capability '$_' is not available from remote"
167 }
168 packet_txt_write( "capability=" . $_ );
169 }
170 packet_flush();
171 }
172
173 1;