[PATCH v3 0/8] Create Git/Packet.pm

[Christian Couder <christian.couder@gmail.com>]

Goal
~~~~

Packet related functions in Perl can be useful to write new filters or
to debug or test existing filters. They might also in the future be
used by other software using the same packet line protocol. So instead
of having them in t0021/rot13-filter.pl, let's extract them into a new
Git/Packet.pm module.

Changes since the previous version
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

There are only a few small changes compared to v2:

Patch 2/8 has the following change:

  - packet_required_key_val_read() is renamed packet_key_val_read()
    and a comment is added before the function,

Patch 2/8 and 6/8 have the following change:

  - "if" is used instead of "unless" to make the logic easier to
    understand

The diff with the previous version is:

diff --git a/perl/Git/Packet.pm b/perl/Git/Packet.pm
index 255b28c098..1682403ffc 100644
--- a/perl/Git/Packet.pm
+++ b/perl/Git/Packet.pm
@@ -17,7 +17,7 @@ our @EXPORT = qw(
                        packet_compare_lists
                        packet_bin_read
                        packet_txt_read
-                       packet_required_key_val_read
+                       packet_key_val_read
                        packet_bin_write
                        packet_txt_write
                        packet_flush
@@ -68,28 +68,29 @@ sub packet_bin_read {
 
 sub remove_final_lf_or_die {
        my $buf = shift;
-       unless ( $buf =~ s/\n$// ) {
-               die "A non-binary line MUST be terminated by an LF.\n"
-                   . "Received: '$buf'";
+       if ( $buf =~ s/\n$// ) {
+               return $buf;
        }
-       return $buf;
+       die "A non-binary line MUST be terminated by an LF.\n"
+           . "Received: '$buf'";
 }

 sub packet_txt_read {
        my ( $res, $buf ) = packet_bin_read();
-       unless ( $res == -1 or $buf eq '' ) {
+       if ( $res != -1 and $buf ne '' ) {
                $buf = remove_final_lf_or_die($buf);
        }
        return ( $res, $buf );
 }
 
-sub packet_required_key_val_read {
+# Read a text line and check that it is in the form "key=value"
+sub packet_key_val_read {
        my ( $key ) = @_;
        my ( $res, $buf ) = packet_txt_read();
-       unless ( $res == -1 or ( $buf =~ s/^$key=// and $buf ne '' ) ) {
-               die "bad $key: '$buf'";
+       if ( $res == -1 or ( $buf =~ s/^$key=// and $buf ne '' ) ) {
+               return ( $res, $buf );
        }
-       return ( $res, $buf );
+       die "bad $key: '$buf'";
 }
 
 sub packet_bin_write {
diff --git a/t/t0021/rot13-filter.pl b/t/t0021/rot13-filter.pl
index 6fd7fa476b..f1678851de 100644
--- a/t/t0021/rot13-filter.pl
+++ b/t/t0021/rot13-filter.pl
@@ -70,7 +70,7 @@ print $debug "init handshake complete\n";
 $debug->flush();
 
 while (1) {
-       my ( $res, $command ) = packet_required_key_val_read("command");
+       my ( $res, $command ) = packet_key_val_read("command");
        if ( $res == -1 ) {
                print $debug "STOP\n";
                exit();
@@ -106,7 +106,7 @@ while (1) {
                packet_txt_write("status=success");
                packet_flush();
        } else {
-               my ( $res, $pathname ) = packet_required_key_val_read("pathname");
+               my ( $res, $pathname ) = packet_key_val_read("pathname");
                if ( $res == -1 ) {
                        die "unexpected EOF while expecting pathname";
                }

Links
~~~~~

This patch series is on the following branch:

https://github.com/chriscool/git/commits/gl-prep-external-odb

Version 1 and 2 of this patch series are on the mailing list here:

https://public-inbox.org/git/20171019123030.17338-1-chriscool@tuxfamily.org/
https://public-inbox.org/git/20171105213836.11717-1-chriscool@tuxfamily.org/

They are also available in the following branch:

https://github.com/chriscool/git/commits/gl-prep-external-odb1
https://github.com/chriscool/git/commits/gl-prep-external-odb14

This patch series was extracted from previous "Add initial
experimental external ODB support" patch series.

Version 1, 2, 3, 4, 5 and 6 of this previous series are on the mailing
list here:

https://public-inbox.org/git/20160613085546.11784-1-chriscool@tuxfamily.org/
https://public-inbox.org/git/20160628181933.24620-1-chriscool@tuxfamily.org/
https://public-inbox.org/git/20161130210420.15982-1-chriscool@tuxfamily.org/
https://public-inbox.org/git/20170620075523.26961-1-chriscool@tuxfamily.org/
https://public-inbox.org/git/20170803091926.1755-1-chriscool@tuxfamily.org/
https://public-inbox.org/git/20170916080731.13925-1-chriscool@tuxfamily.org/

They are also available in the following branches:

https://github.com/chriscool/git/commits/gl-external-odb12
https://github.com/chriscool/git/commits/gl-external-odb22
https://github.com/chriscool/git/commits/gl-external-odb61
https://github.com/chriscool/git/commits/gl-external-odb239
https://github.com/chriscool/git/commits/gl-external-odb373
https://github.com/chriscool/git/commits/gl-external-odb411


Christian Couder (8):
  t0021/rot13-filter: fix list comparison
  t0021/rot13-filter: refactor packet reading functions
  t0021/rot13-filter: improve 'if .. elsif .. else' style
  t0021/rot13-filter: improve error message
  t0021/rot13-filter: add packet_initialize()
  t0021/rot13-filter: refactor checking final lf
  t0021/rot13-filter: add capability functions
  Add Git/Packet.pm from parts of t0021/rot13-filter.pl

 perl/Git/Packet.pm      | 169 ++++++++++++++++++++++++++++++++++++++++++++++++
 perl/Makefile           |   1 +
 t/t0021/rot13-filter.pl | 127 ++++++++++--------------------------
 3 files changed, 203 insertions(+), 94 deletions(-)
 create mode 100644 perl/Git/Packet.pm

-- 
2.15.0.132.g7ad97d78be