tvl-depot/contrib/long-running-filter/example.pl
Vincent Ambo 1b593e1ea4 Squashed 'third_party/git/' content from commit cb71568594
git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7
2020-01-11 23:36:56 +00:00

132 lines
3 KiB
Perl
Executable file

#!/usr/bin/perl
#
# Example implementation for the Git filter protocol version 2
# See Documentation/gitattributes.txt, section "Filter Protocol"
#
# Please note, this pass-thru filter is a minimal skeleton. No proper
# error handling was implemented.
#
use strict;
use warnings;
my $MAX_PACKET_CONTENT_SIZE = 65516;
sub packet_bin_read {
my $buffer;
my $bytes_read = read STDIN, $buffer, 4;
if ( $bytes_read == 0 ) {
# EOF - Git stopped talking to us!
exit();
}
elsif ( $bytes_read != 4 ) {
die "invalid packet: '$buffer'";
}
my $pkt_size = hex($buffer);
if ( $pkt_size == 0 ) {
return ( 1, "" );
}
elsif ( $pkt_size > 4 ) {
my $content_size = $pkt_size - 4;
$bytes_read = read STDIN, $buffer, $content_size;
if ( $bytes_read != $content_size ) {
die "invalid packet ($content_size bytes expected; $bytes_read bytes read)";
}
return ( 0, $buffer );
}
else {
die "invalid packet size: $pkt_size";
}
}
sub packet_txt_read {
my ( $res, $buf ) = packet_bin_read();
unless ( $buf =~ s/\n$// ) {
die "A non-binary line MUST be terminated by an LF.";
}
return ( $res, $buf );
}
sub packet_bin_write {
my $buf = shift;
print STDOUT sprintf( "%04x", length($buf) + 4 );
print STDOUT $buf;
STDOUT->flush();
}
sub packet_txt_write {
packet_bin_write( $_[0] . "\n" );
}
sub packet_flush {
print STDOUT sprintf( "%04x", 0 );
STDOUT->flush();
}
( packet_txt_read() eq ( 0, "git-filter-client" ) ) || die "bad initialize";
( packet_txt_read() eq ( 0, "version=2" ) ) || die "bad version";
( packet_bin_read() eq ( 1, "" ) ) || die "bad version end";
packet_txt_write("git-filter-server");
packet_txt_write("version=2");
packet_flush();
( packet_txt_read() eq ( 0, "capability=clean" ) ) || die "bad capability";
( packet_txt_read() eq ( 0, "capability=smudge" ) ) || die "bad capability";
( packet_bin_read() eq ( 1, "" ) ) || die "bad capability end";
packet_txt_write("capability=clean");
packet_txt_write("capability=smudge");
packet_flush();
while (1) {
my ($command) = packet_txt_read() =~ /^command=(.+)$/;
my ($pathname) = packet_txt_read() =~ /^pathname=(.+)$/;
if ( $pathname eq "" ) {
die "bad pathname '$pathname'";
}
packet_bin_read();
my $input = "";
{
binmode(STDIN);
my $buffer;
my $done = 0;
while ( !$done ) {
( $done, $buffer ) = packet_bin_read();
$input .= $buffer;
}
}
my $output;
if ( $command eq "clean" ) {
### Perform clean here ###
$output = $input;
}
elsif ( $command eq "smudge" ) {
### Perform smudge here ###
$output = $input;
}
else {
die "bad command '$command'";
}
packet_txt_write("status=success");
packet_flush();
while ( length($output) > 0 ) {
my $packet = substr( $output, 0, $MAX_PACKET_CONTENT_SIZE );
packet_bin_write($packet);
if ( length($output) > $MAX_PACKET_CONTENT_SIZE ) {
$output = substr( $output, $MAX_PACKET_CONTENT_SIZE );
}
else {
$output = "";
}
}
packet_flush(); # flush content!
packet_flush(); # empty list, keep "status=success" unchanged!
}