X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=dgit.git;a=blobdiff_plain;f=Debian%2FDgit.pm;h=d086cbe50d36d33e14cea82de5f00b8b367d569a;hp=1d713b920d92aefa195f768df07374b65e64c483;hb=012a80b3779e6241c270b73771f1d5019c1ca196;hpb=9ecc454c514558e7d49fa47083a69e456cc33239

diff --git a/Debian/Dgit.pm b/Debian/Dgit.pm
index 1d713b92..d086cbe5 100644
--- a/Debian/Dgit.pm
+++ b/Debian/Dgit.pm
@@ -49,7 +49,7 @@ BEGIN {
 		      failedcmd_report_cmd failedcmd
                       runcmd cmdoutput cmdoutput_errok
                       git_rev_parse git_cat_file
-		      git_get_ref git_for_each_ref
+		      git_get_ref git_get_symref git_for_each_ref
                       git_for_each_tag_referring is_fast_fwd
                       $package_re $component_re $deliberately_re
 		      $distro_re $versiontag_re $series_filename_re
@@ -60,11 +60,15 @@ BEGIN {
                       shellquote printcmd messagequote
                       $negate_harmful_gitattrs
 		      changedir git_slurp_config_src
-		      workarea_setup
-		      fresh_workarea in_workarea);
+		      playtree_setup);
     # implicitly uses $main::us
-    %EXPORT_TAGS = ( policyflags => [qw(NOFFCHECK FRESHREPO NOCOMMITCHECK)] );
-    @EXPORT_OK   = ( qw($wa), @{ $EXPORT_TAGS{policyflags} } );
+    %EXPORT_TAGS = ( policyflags => [qw(NOFFCHECK FRESHREPO NOCOMMITCHECK)],
+		     playground => [qw(record_maindir $maindir $local_git_cfg
+				       $maindir_gitdir $maindir_gitcommon
+				       fresh_playground
+                                       ensure_a_playground)]);
+    @EXPORT_OK   = ( @{ $EXPORT_TAGS{policyflags} },
+		     @{ $EXPORT_TAGS{playground} } );
 }
 
 our @EXPORT_OK;
@@ -104,7 +108,7 @@ sub forkcheck_mainprocess () {
 sub setup_sigwarn () {
     forkcheck_setup();
     $SIG{__WARN__} = sub { 
-	die $_[0] if forkcheck_mainprocess;
+	confess $_[0] if forkcheck_mainprocess;
     };
 }
 
@@ -344,11 +348,21 @@ sub git_rev_parse ($) {
     return cmdoutput qw(git rev-parse), "$_[0]~0";
 }
 
-sub git_cat_file ($) {
-    my ($objname) = @_;
+sub git_cat_file ($;$) {
+    my ($objname, $etype) = @_;
     # => ($type, $data) or ('missing', undef)
     # in scalar context, just the data
+    # if $etype defined, dies unless type is $etype or in @$etype
     our ($gcf_pid, $gcf_i, $gcf_o);
+    my $chk = sub {
+	my ($gtype, $data) = @_;
+	if ($etype) {
+	    $etype = [$etype] unless ref $etype;
+	    confess "$objname expected @$etype but is $gtype"
+		unless grep { $gtype eq $_ } @$etype;
+	}
+	return ($gtype, $data);
+    };
     if (!$gcf_pid) {
 	my @cmd = qw(git cat-file --batch);
 	debugcmd "GCF|", @cmd;
@@ -358,13 +372,26 @@ sub git_cat_file ($) {
     print $gcf_i $objname, "\n" or die $!;
     my $x = <$gcf_o>;
     printdebug "GCF<| ", $x;
-    if ($x =~ m/ (missing)$/) { return ($1, undef); }
+    if ($x =~ m/ (missing)$/) { return $chk->($1, undef); }
     my ($type, $size) = $x =~ m/^.* (\w+) (\d+)\n/ or die "$objname ?";
     my $data;
     (read $gcf_o, $data, $size) == $size or die "$objname $!";
     $x = <$gcf_o>;
     $x eq "\n" or die "$objname ($_) $!";
-    return ($type, $data);
+    return $chk->($type, $data);
+}
+
+sub git_get_symref (;$) {
+    my ($symref) = @_;  $symref //= 'HEAD';
+    # => undef if not a symref, otherwise refs/...
+    my @cmd = (qw(git symbolic-ref -q HEAD));
+    my $branch = cmdoutput_errok @cmd;
+    if (!defined $branch) {
+	$?==256 or failedcmd @cmd;
+    } else {
+	chomp $branch;
+    }
+    return $branch;
 }
 
 sub git_for_each_ref ($$;$) {
@@ -456,10 +483,114 @@ sub git_slurp_config_src ($) {
     return $r;
 }
 
-sub workarea_setup ($) {
-    # for use in the workarea
+# ========== playground handling ==========
+
+# terminology:
+#
+#   $maindir      user's git working tree
+#   playground    area in .git/ where we can make files, unpack, etc. etc.
+#   playtree      git working tree sharing object store with the user's
+#                 inside playground, or identical to it
+#
+# other globals
+#
+#   $local_git_cfg    hash of arrays of values: git config from $maindir
+#
+# expected calling pattern
+#
+#  firstly
+#
+#    [record_maindir]
+#      must be run in directory containing .git
+#      assigns to $maindir if not already set
+#      also calls git_slurp_config_src to record git config
+#        in $local_git_cfg, unless it's already set
+#
+#    fresh_playground SUBDIR_PATH_COMPONENTS
+#      e.g fresh_playground 'dgit/unpack' ('.git/' is implied)
+#      default SUBDIR_PATH_COMPONENTS is playground_subdir
+#      calls record_maindir
+#      sets up a new playground (destroying any old one)
+#      returns playground pathname
+#      caller may call multiple times with different subdir paths
+#       createing different playgrounds
+#
+#    ensure_a_playground SUBDIR_PATH_COMPONENTS
+#      like fresh_playground except:
+#      merely ensures the directory exists; does not delete an existing one
+#
+#  then can use
+#
+#    changedir playground
+#    changedir $maindir
+#
+#    playtree_setup $local_git_cfg
+#            # ^ call in some (perhaps trivial) subdir of playground
+#
+#    rmtree playground
+
+# ----- maindir -----
+
+# these three all go together
+our $maindir;
+our $maindir_gitdir;
+our $maindir_gitcommon;
+
+our $local_git_cfg;
+
+sub record_maindir () {
+    if (!defined $maindir) {
+	$maindir = must_getcwd();
+	if (!stat "$maindir/.git") {
+	    fail "cannot stat $maindir/.git: $!";
+	}
+	if (-d _) {
+	    # we fall back to this in case we have a pre-worktree
+	    # git, which may not know git rev-parse --git-common-dir
+	    $maindir_gitdir    = "$maindir/.git";
+	    $maindir_gitcommon = "$maindir/.git";
+	} else {
+	    $maindir_gitdir    = cmdoutput qw(git rev-parse --git-dir);
+	    $maindir_gitcommon = cmdoutput qw(git rev-parse --git-common-dir);
+	}
+    }
+    $local_git_cfg //= git_slurp_config_src 'local';
+}
+
+# ----- playgrounds -----
+
+sub ensure_a_playground_parent ($) {
+    my ($spc) = @_;
+    record_maindir();
+    $spc = "$maindir_gitdir/$spc";
+    my $parent = dirname $spc;
+    mkdir $parent or $!==EEXIST
+	or fail "failed to mkdir playground parent $parent: $!";
+    return $spc;
+}    
+
+sub ensure_a_playground ($) {
+    my ($spc) = @_;
+    $spc = ensure_a_playground_parent $spc;
+    mkdir $spc or $!==EEXIST or fail "failed to mkdir a playground $spc: $!";
+    return $spc;
+}    
+
+sub fresh_playground ($) {
+    my ($spc) = @_;
+    $spc = ensure_a_playground_parent $spc;
+    rmtree $spc;
+    mkdir $spc or fail "failed to mkdir the playground $spc: $!";
+    return $spc;
+}
+
+# ----- playtrees -----
+
+sub playtree_setup (;$) {
     my ($t_local_git_cfg) = @_;
-    # should be run in a directory .git/FOO/BAR of a working tree
+    $t_local_git_cfg //= $local_git_cfg;
+    # for use in the playtree
+    # $maindir must be set, eg by calling record_maindir or fresh_playground
     runcmd qw(git init -q);
     runcmd qw(git config gc.auto 0);
     foreach my $copy (qw(user.email user.name user.useConfigOnly
@@ -470,39 +601,17 @@ sub workarea_setup ($) {
 	next unless $v;
 	runcmd qw(git config), $copy, $_ foreach @$v;
     }
+    # this is confusing: we have
+    #   .                   playtree, not a worktree, has .git/, our cwd
+    #   $maindir            might be a worktree so
+    #   $maindir_gitdir     contains our main working "dgit", HEAD, etc.
+    #   $maindir_gitcommon  the shared stuff, including .objects
     rmtree('.git/objects');
-    symlink '../../../../objects','.git/objects' or die $!;
+    symlink "$maindir_gitcommon/objects",'.git/objects' or die $!;
     ensuredir '.git/info';
     open GA, "> .git/info/attributes" or die $!;
     print GA "* $negate_harmful_gitattrs\n" or die $!;
     close GA or die $!;
 }
 
-our $wa;
-our $local_git_cfg;
-
-sub in_workarea ($;$) {
-    my $sub = pop @_; # in_workarea [$twa, sub { ... };]
-    # default $twa is global $wa (which caller must, in that case, set)
-    # $twa should be relative paths of the form .git/FOO/BAR
-    my ($twa) = @_;
-    $twa //= $wa;
-    changedir $twa or die "$twa $!";
-    my $r = eval { $sub->($twa); };
-    changedir '../../..' or die "$@; $!";
-    die $@ if length $@;
-    return $r;
-}
-
-sub fresh_workarea (;$) {
-    my ($twa) = @_;
-    $twa //= $wa;
-    $local_git_cfg //= git_slurp_config_src 'local';
-    my $parent = dirname $twa;
-    mkdir $parent or $!==EEXIST or fail "failed to mkdir $parent: $!";
-    rmtree $twa;
-    mkdir $twa or die "$twa $!";
-    in_workarea sub { workarea_setup $local_git_cfg; };
-}
-
 1;