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[PATCH v2 7/8] t0021/rot13-filter: add capability functions

From
Christian Couder <christian.couder@gmail.com>
Date
Nov 5, 2017, 21:38 UTC
Message-ID
<20171105213836.11717-8-chriscool@tuxfamily.org>
In-Reply-To
<20171105213836.11717-1-chriscool@tuxfamily.org>
These function help read and write capabilities.

To make them more generic and make it easy to reuse them, the following changes are made:

- we don't require capabilities to come in a fixed order,
- we allow duplicates,
- we check that the remote supports the capabilities we
  advertise,
- we don't check if the remote declares any capability we
  don't know about.

The reason behind the last change is that the protocol should work using only the capabilities that both ends support, and it should not stop working if one end starts to advertise a new capability.

Despite those changes, we can still require a set of capabilities, and die if one of them is not supported.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 t/t0021/rot13-filter.pl | 58 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 45 insertions(+), 13 deletions(-)
diff --git a/t/t0021/rot13-filter.pl b/t/t0021/rot13-filter.pl
index d47b7f5666..f919d798a6 100644
--- a/t/t0021/rot13-filter.pl
+++ b/t/t0021/rot13-filter.pl
@@ -150,24 +150,56 @@ sub packet_initialize {
 	packet_flush();
 }
 
+sub packet_read_capabilities {
+	my @cap;
+	while (1) {
+		my ( $res, $buf ) = packet_bin_read();
+		if ( $res == -1 ) {
+			die "unexpected EOF when reading capabilities";
+		}
+		return ( $res, @cap ) if ( $res != 0 );
+		$buf = remove_final_lf_or_die($buf);
+		unless ( $buf =~ s/capability=// ) {
+			die "bad capability buf: '$buf'";
+		}
+		push @cap, $buf;
+	}
+}
+
+# Read remote capabilities and check them against capabilities we require
+sub packet_read_and_check_capabilities {
+	my @required_caps = @_;
+	my ($res, @remote_caps) = packet_read_capabilities();
+	my %remote_caps = map { $_ => 1 } @remote_caps;
+	foreach (@required_caps) {
+		unless (exists($remote_caps{$_})) {
+			die "required '$_' capability not available from remote" ;
+		}
+	}
+	return %remote_caps;
+}
+
+# Check our capabilities we want to advertise against the remote ones
+# and then advertise our capabilities
+sub packet_check_and_write_capabilities {
+	my ($remote_caps, @our_caps) = @_;
+	foreach (@our_caps) {
+		unless (exists($remote_caps->{$_})) {
+			die "our capability '$_' is not available from remote"
+		}
+		packet_txt_write( "capability=" . $_ );
+	}
+	packet_flush();
+}
+
 print $debug "START\n";
 $debug->flush();
 
 packet_initialize("git-filter", 2);
 
-packet_compare_lists([0, "capability=clean"], packet_txt_read()) ||
-	die "bad capability";
-packet_compare_lists([0, "capability=smudge"], packet_txt_read()) ||
-	die "bad capability";
-packet_compare_lists([0, "capability=delay"], packet_txt_read()) ||
-	die "bad capability";
-packet_compare_lists([1, ""], packet_bin_read()) ||
-	die "bad capability end";
-
-foreach (@capabilities) {
-	packet_txt_write( "capability=" . $_ );
-}
-packet_flush();
+my %remote_caps = packet_read_and_check_capabilities("clean", "smudge", "delay");
+packet_check_and_write_capabilities(\%remote_caps, @capabilities);
+
 print $debug "init handshake complete\n";
 $debug->flush();
 
-- 
2.15.0.7.ga9ff306ed9.dirty
Previous: Christian CouderNext: Junio C Hamano
Message 10 of 14 in “Create Git/Packet.pm”
  1. 0/8 Create Git/Packet.pmChristian Couder, Nov 5, 2017
  2. 1/8 t0021/rot13-filter: fix list comparisonChristian Couder, Nov 5, 2017
  3. Junio C HamanoNov 7, 2017
  4. 2/8 t0021/rot13-filter: refactor packet reading functionsChristian Couder, Nov 5, 2017
  5. Junio C HamanoNov 7, 2017
  6. Christian CouderNov 7, 2017
  7. 8/8 Add Git/Packet.pm from parts of t0021/rot13-filter.plChristian Couder, Nov 5, 2017
  8. 5/8 t0021/rot13-filter: add packet_initialize()Christian Couder, Nov 5, 2017
  9. 3/8 t0021/rot13-filter: improve 'if .. elsif .. else' styleChristian Couder, Nov 5, 2017
  10. 7/8 t0021/rot13-filter: add capability functionsChristian Couder, Nov 5, 2017
  11. Junio C HamanoNov 7, 2017
  12. 6/8 t0021/rot13-filter: refactor checking final lfChristian Couder, Nov 5, 2017
  13. Junio C HamanoNov 7, 2017
  14. 4/8 t0021/rot13-filter: improve error messageChristian Couder, Nov 5, 2017

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