Dgit.pm: Move reflog_cache_* from dgit

[dgit.git] / Debian / Dgit.pm

diff --git a/Debian/Dgit.pm b/Debian/Dgit.pm
index 3d517e1e56b8d350648f2a8c55252d15a4014708..91d4c7111f57dc80a16943714f38fe66850e0dfb 100644 (file)
--- a/Debian/Dgit.pm
+++ b/Debian/Dgit.pm
@@ -32,6 +32,7 @@ use IPC::Open2;
 use File::Path;
 use File::Basename;
 use Dpkg::Control::Hash;
+use Debian::Dgit::ExitStatus;
 
 BEGIN {
     use Exporter   ();
@@ -57,6 +58,8 @@ BEGIN {
                       git_for_each_tag_referring is_fast_fwd
                      git_check_unmodified
                      git_reflog_action_msg  git_update_ref_cmd
+                     make_commit_text
+                     reflog_cache_insert reflog_cache_lookup
                       $package_re $component_re $deliberately_re
                      $distro_re $versiontag_re $series_filename_re
                      $orig_f_comp_re $orig_f_sig_re $orig_f_tail_re
@@ -104,6 +107,11 @@ our $gdrlast_refprefix = 'debrebase-last';
 our $printdebug_when_debuglevel = 1;
 our $debugcmd_when_debuglevel = 1;
 
+# these three all go together, only valid after record_maindir
+our $maindir;
+our $maindir_gitdir;
+our $maindir_gitcommon;
+
 # policy hook exit status bits
 # see dgit-repos-server head comment for documentation
 # 1 is reserved in case something fails with `exit 1' and to spot
@@ -159,11 +167,21 @@ sub enabledebuglevel ($) {
 }
     
 sub printdebug {
+    # Prints a prefix, and @_, to DEBUG.  @_ should normally contain
+    # a trailing \n.
+
+    # With no (or only empty) arguments just prints the prefix and
+    # leaves the caller to do more with DEBUG.  The caller should make
+    # sure then to call printdebug with something ending in "\n" to
+    # get the prefix right in subsequent calls.
+
     return unless $debuglevel >= $printdebug_when_debuglevel;
-    print DEBUG $debugprefix;
+    our $printdebug_noprefix;
+    print DEBUG $debugprefix unless $printdebug_noprefix;
     pop @_ while @_ and !length $_[-1];
     return unless @_;
     print DEBUG @_ or die $!;
+    $printdebug_noprefix = $_[-1] !~ m{\n$};
 }
 
 sub messagequote ($) {
@@ -274,7 +292,7 @@ sub _us () {
 
 sub failmsg {
     my $s = "error: @_\n";
-    $s =~ s/\n\n$/\n/;
+    $s =~ s/\n\n$/\n/g;
     my $prefix = _us().": ";
     $s =~ s/^/$prefix/gm;
     return "\n".$s;
@@ -677,6 +695,88 @@ sub parsechangelog_loop ($$$) {
     close CLOGS or $?==SIGPIPE or failedcmd @$clogcmd;
 }      
 
+sub make_commit_text ($) {
+    my ($text) = @_;
+    my ($out, $in);
+    my @cmd = (qw(git hash-object -w -t commit --stdin));
+    debugcmd "|",@cmd;
+    print Dumper($text) if $debuglevel > 1;
+    my $child = open2($out, $in, @cmd) or die $!;
+    my $h;
+    eval {
+       print $in $text or die $!;
+       close $in or die $!;
+       $h = <$out>;
+       $h =~ m/^\w+$/ or die;
+       $h = $&;
+       printdebug "=> $h\n";
+    };
+    close $out;
+    waitpid $child, 0 == $child or die "$child $!";
+    $? and failedcmd @cmd;
+    return $h;
+}
+
+sub reflog_cache_insert ($$$) {
+    my ($ref, $cachekey, $value) = @_;
+    # you must call this in $maindir
+    # you must have called record_maindir
+
+    # When we no longer need to support squeeze, use --create-reflog
+    # instead of this:
+    my $parent = $ref; $parent =~ s{/[^/]+$}{};
+    ensuredir "$maindir_gitcommon/logs/$parent";
+    my $makelogfh = new IO::File "$maindir_gitcommon/logs/$ref", '>>'
+      or die $!;
+
+    my $oldcache = git_get_ref $ref;
+
+    if ($oldcache eq $value) {
+       my $tree = cmdoutput qw(git rev-parse), "$value:";
+       # git update-ref doesn't always update, in this case.  *sigh*
+       my $authline = (ucfirst _us()).
+           ' <'._us().'@example.com> 1000000000 +0000';
+       my $dummy = make_commit_text <<END;
+tree $tree
+parent $value
+author $authline
+committer $authline
+
+Dummy commit - do not use
+END
+       runcmd qw(git update-ref -m), _us()." - dummy", $ref, $dummy;
+    }
+    runcmd qw(git update-ref -m), $cachekey, $ref, $value;
+}
+
+sub reflog_cache_lookup ($$) {
+    my ($ref, $cachekey) = @_;
+    # you may call this in $maindir or in a playtree
+    # you must have called record_maindir
+    my @cmd = (qw(git log -g), '--pretty=format:%H %gs', $ref);
+    debugcmd "|(probably)",@cmd;
+    my $child = open GC, "-|";  defined $child or die $!;
+    if (!$child) {
+       chdir $maindir or die $!;
+       if (!stat "$maindir_gitcommon/logs/$ref") {
+           $! == ENOENT or die $!;
+           printdebug ">(no reflog)\n";
+           finish 0;
+       }
+       exec @cmd; die $!;
+    }
+    while (<GC>) {
+       chomp;
+       printdebug ">| ", $_, "\n" if $debuglevel > 1;
+       next unless m/^(\w+) (\S.*\S)$/ && $2 eq $cachekey;
+       close GC;
+       return $1;
+    }
+    die $! if GC->error;
+    failedcmd unless close GC;
+    return undef;
+}
+
 # ========== playground handling ==========
 
 # terminology:
@@ -725,11 +825,6 @@ sub parsechangelog_loop ($$$) {
 
 # ----- maindir -----
 
-# these three all go together
-our $maindir;
-our $maindir_gitdir;
-our $maindir_gitcommon;
-
 our $local_git_cfg;
 
 sub record_maindir () {