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[PATCH v3 7/8] t0021/rot13-filter: add capability functions

From
Christian Couder <christian.couder@gmail.com>
Date
Nov 10, 2017, 13:21 UTC
Message-ID
<20171110132200.7871-8-chriscool@tuxfamily.org>
In-Reply-To
<20171110132200.7871-1-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 8f255b6131..6cd9ecffee 100644
--- a/t/t0021/rot13-filter.pl
+++ b/t/t0021/rot13-filter.pl
@@ -151,24 +151,56 @@ 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();
 
-- 
2.15.0.132.g7ad97d78be
Previous: Christian CouderNext: Christian Couder
Message 8 of 10 in “Create Git/Packet.pm”
  1. 0/8 Create Git/Packet.pmChristian Couder, Nov 10, 2017
  2. 1/8 t0021/rot13-filter: fix list comparisonChristian Couder, Nov 10, 2017
  3. 2/8 t0021/rot13-filter: refactor packet reading functionsChristian Couder, Nov 10, 2017
  4. 3/8 t0021/rot13-filter: improve 'if .. elsif .. else' styleChristian Couder, Nov 10, 2017
  5. 4/8 t0021/rot13-filter: improve error messageChristian Couder, Nov 10, 2017
  6. 5/8 t0021/rot13-filter: add packet_initialize()Christian Couder, Nov 10, 2017
  7. 6/8 t0021/rot13-filter: refactor checking final lfChristian Couder, Nov 10, 2017
  8. 7/8 t0021/rot13-filter: add capability functionsChristian Couder, Nov 10, 2017
  9. 8/8 Add Git/Packet.pm from parts of t0021/rot13-filter.plChristian Couder, Nov 10, 2017
  10. Junio C HamanoNov 10, 2017

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