# -*- perl -*- # dgit # Debian::Dgit: functions common to dgit and its helpers and servers # # Copyright (C) 2015-2016 Ian Jackson # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program. If not, see . package Debian::Dgit; use strict; use warnings; use Carp; use POSIX; use IO::Handle; use Config; use Digest::SHA; use Data::Dumper; use IPC::Open2; use File::Path; use File::Basename; BEGIN { use Exporter (); our ($VERSION, @ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS); $VERSION = 1.00; @ISA = qw(Exporter); @EXPORT = qw(setup_sigwarn forkcheck_setup forkcheck_mainprocess dep14_version_mangle debiantags debiantag_old debiantag_new server_branch server_ref stat_exists link_ltarget hashfile fail ensuredir must_getcwd executable_on_path waitstatusmsg failedcmd_waitstatus failedcmd_report_cmd failedcmd runcmd cmdoutput cmdoutput_errok git_rev_parse git_cat_file git_get_ref git_get_symref git_for_each_ref git_for_each_tag_referring is_fast_fwd git_check_unmodified $package_re $component_re $deliberately_re $distro_re $versiontag_re $series_filename_re $extra_orig_namepart_re $git_null_obj $branchprefix $ffq_refprefix initdebug enabledebug enabledebuglevel printdebug debugcmd $debugprefix *debuglevel *DEBUG shellquote printcmd messagequote $negate_harmful_gitattrs changedir git_slurp_config_src playtree_setup); # implicitly uses $main::us %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; our $package_re = '[0-9a-z][-+.0-9a-z]*'; our $component_re = '[0-9a-zA-Z][-+.0-9a-zA-Z]*'; our $deliberately_re = "(?:TEST-)?$package_re"; our $distro_re = $component_re; our $versiontag_re = qr{[-+.\%_0-9a-zA-Z/]+}; our $branchprefix = 'dgit'; our $series_filename_re = qr{(?:^|\.)series(?!\n)$}s; our $extra_orig_namepart_re = qr{[-0-9a-z]+}; our $git_null_obj = '0' x 40; our $ffq_refprefix = 'ffq-prev'; # 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 # dynamic loader, runtime, etc., failures, which report 127 or 255 sub NOFFCHECK () { return 0x2; } sub FRESHREPO () { return 0x4; } sub NOCOMMITCHECK () { return 0x8; } our $debugprefix; our $debuglevel = 0; our $negate_harmful_gitattrs = "-text -eol -crlf -ident -filter"; our $forkcheck_mainprocess; sub forkcheck_setup () { $forkcheck_mainprocess = $$; } sub forkcheck_mainprocess () { # You must have called forkcheck_setup or setup_sigwarn already getppid != $forkcheck_mainprocess; } sub setup_sigwarn () { forkcheck_setup(); $SIG{__WARN__} = sub { confess $_[0] if forkcheck_mainprocess; }; } sub initdebug ($) { ($debugprefix) = @_; open DEBUG, ">/dev/null" or die $!; } sub enabledebug () { open DEBUG, ">&STDERR" or die $!; DEBUG->autoflush(1); $debuglevel ||= 1; } sub enabledebuglevel ($) { my ($newlevel) = @_; # may be undef (eg from env var) die if $debuglevel; $newlevel //= 0; $newlevel += 0; return unless $newlevel; $debuglevel = $newlevel; enabledebug(); } sub printdebug { print DEBUG $debugprefix, @_ or die $! if $debuglevel>0; } sub messagequote ($) { local ($_) = @_; s{\\}{\\\\}g; s{\n}{\\n}g; s{\x08}{\\b}g; s{\t}{\\t}g; s{[\000-\037\177]}{ sprintf "\\x%02x", ord $& }ge; $_; } sub shellquote { my @out; local $_; defined or confess 'internal error' foreach @_; foreach my $a (@_) { $_ = $a; if (!length || m{[^-=_./:0-9a-z]}i) { s{['\\]}{'\\$&'}g; push @out, "'$_'"; } else { push @out, $_; } } return join ' ', @out; } sub printcmd { my $fh = shift @_; my $intro = shift @_; print $fh $intro," " or die $!; print $fh shellquote @_ or die $!; print $fh "\n" or die $!; } sub debugcmd { my $extraprefix = shift @_; printcmd(\*DEBUG,$debugprefix.$extraprefix,@_) if $debuglevel>0; } sub dep14_version_mangle ($) { my ($v) = @_; # DEP-14 patch proposed 2016-11-09 "Version Mangling" $v =~ y/~:/_%/; $v =~ s/\.(?=\.|$|lock$)/.#/g; return $v; } sub debiantag_old ($$) { my ($v,$distro) = @_; return "$distro/". dep14_version_mangle $v; } sub debiantag_new ($$) { my ($v,$distro) = @_; return "archive/$distro/".dep14_version_mangle $v; } sub debiantags ($$) { my ($version,$distro) = @_; map { $_->($version, $distro) } (\&debiantag_new, \&debiantag_old); } sub server_branch ($) { return "$branchprefix/$_[0]"; } sub server_ref ($) { return "refs/".server_branch($_[0]); } sub stat_exists ($) { my ($f) = @_; return 1 if stat $f; return 0 if $!==&ENOENT; die "stat $f: $!"; } sub _us () { $::us // ($0 =~ m#[^/]*$#, $&); } sub fail { my $s = "@_\n"; $s =~ s/\n\n$/\n/; my $prefix = _us().": "; $s =~ s/^/$prefix/gm; die $s; } sub ensuredir ($) { my ($dir) = @_; # does not create parents return if mkdir $dir; return if $! == EEXIST; die "mkdir $dir: $!"; } sub must_getcwd () { my $d = getcwd(); defined $d or fail "getcwd failed: $!"; return $d; } sub executable_on_path ($) { my ($program) = @_; return 1 if $program =~ m{/}; my @path = split /:/, ($ENV{PATH} // "/usr/local/bin:/bin:/usr/bin"); foreach my $pe (@path) { my $here = "$pe/$program"; return $here if stat_exists $here && -x _; } return undef; } our @signames = split / /, $Config{sig_name}; sub waitstatusmsg () { if (!$?) { return "terminated, reporting successful completion"; } elsif (!($? & 255)) { return "failed with error exit status ".WEXITSTATUS($?); } elsif (WIFSIGNALED($?)) { my $signum=WTERMSIG($?); return "died due to fatal signal ". ($signames[$signum] // "number $signum"). ($? & 128 ? " (core dumped)" : ""); # POSIX(3pm) has no WCOREDUMP } else { return "failed with unknown wait status ".$?; } } sub failedcmd_report_cmd { my $intro = shift @_; $intro //= "failed command"; { local ($!); printcmd \*STDERR, _us().": $intro:", @_ or die $!; }; } sub failedcmd_waitstatus { if ($? < 0) { return "failed to fork/exec: $!"; } elsif ($?) { return "subprocess ".waitstatusmsg(); } else { return "subprocess produced invalid output"; } } sub failedcmd { # Expects $!,$? as set by close - see below. # To use with system(), set $?=-1 first. # # Actual behaviour of perl operations: # success $!==0 $?==0 close of piped open # program failed $!==0 $? >0 close of piped open # syscall failure $! >0 $?=-1 close of piped open # failure $! >0 unchanged close of something else # success trashed $?==0 system # program failed trashed $? >0 system # syscall failure $! >0 unchanged system failedcmd_report_cmd undef, @_; fail failedcmd_waitstatus(); } sub runcmd { debugcmd "+",@_; $!=0; $?=-1; failedcmd @_ if system @_; } sub cmdoutput_errok { confess Dumper(\@_)." ?" if grep { !defined } @_; debugcmd "|",@_; open P, "-|", @_ or die "$_[0] $!"; my $d; $!=0; $?=0; { local $/ = undef; $d =

; } die $! if P->error; if (!close P) { printdebug "=>!$?\n"; return undef; } chomp $d; if ($debuglevel > 0) { $d =~ m/^.*/; my $dd = $&; my $more = (length $' ? '...' : ''); #'); $dd =~ s{[^\n -~]|\\}{ sprintf "\\x%02x", ord $& }ge; printdebug "=> \`$dd'",$more,"\n"; } return $d; } sub cmdoutput { my $d = cmdoutput_errok @_; defined $d or failedcmd @_; return $d; } sub link_ltarget ($$) { my ($old,$new) = @_; lstat $old or return undef; if (-l _) { $old = cmdoutput qw(realpath --), $old; } my $r = link $old, $new; $r = symlink $old, $new if !$r && $!==EXDEV; $r or die "(sym)link $old $new: $!"; } sub hashfile ($) { my ($fn) = @_; my $h = Digest::SHA->new(256); $h->addfile($fn); return $h->hexdigest(); } sub git_rev_parse ($) { return cmdoutput qw(git rev-parse), "$_[0]~0"; } sub git_cat_file ($;$) { my ($objname, $etype) = @_; # => ($type, $data) or ('missing', undef) # in scalar context, just the data # if $etype defined, dies unless type is $etype or in @$etype our ($gcf_pid, $gcf_i, $gcf_o); my $chk = sub { my ($gtype, $data) = @_; if ($etype) { $etype = [$etype] unless ref $etype; confess "$objname expected @$etype but is $gtype" unless grep { $gtype eq $_ } @$etype; } return ($gtype, $data); }; if (!$gcf_pid) { my @cmd = qw(git cat-file --batch); debugcmd "GCF|", @cmd; $gcf_pid = open2 $gcf_o, $gcf_i, @cmd or die $!; } printdebug "GCF>| ", $objname, "\n"; print $gcf_i $objname, "\n" or die $!; my $x = <$gcf_o>; printdebug "GCF<| ", $x; if ($x =~ m/ (missing)$/) { return $chk->($1, undef); } my ($type, $size) = $x =~ m/^.* (\w+) (\d+)\n/ or die "$objname ?"; my $data; (read $gcf_o, $data, $size) == $size or die "$objname $!"; $x = <$gcf_o>; $x eq "\n" or die "$objname ($_) $!"; return $chk->($type, $data); } sub git_get_symref (;$) { my ($symref) = @_; $symref //= 'HEAD'; # => undef if not a symref, otherwise refs/... my @cmd = (qw(git symbolic-ref -q HEAD)); my $branch = cmdoutput_errok @cmd; if (!defined $branch) { $?==256 or failedcmd @cmd; } else { chomp $branch; } return $branch; } sub git_for_each_ref ($$;$) { my ($pattern,$func,$gitdir) = @_; # calls $func->($objid,$objtype,$fullrefname,$reftail); # $reftail is RHS of ref after refs/[^/]+/ # breaks if $pattern matches any ref `refs/blah' where blah has no `/' # $pattern may be an array ref to mean multiple patterns $pattern = [ $pattern ] unless ref $pattern; my @cmd = (qw(git for-each-ref), @$pattern); if (defined $gitdir) { @cmd = ('sh','-ec','cd "$1"; shift; exec "$@"','x', $gitdir, @cmd); } open GFER, "-|", @cmd or die $!; debugcmd "|", @cmd; while () { chomp or die "$_ ?"; printdebug "|> ", $_, "\n"; m#^(\w+)\s+(\w+)\s+(refs/[^/]+/(\S+))$# or die "$_ ?"; $func->($1,$2,$3,$4); } $!=0; $?=0; close GFER or die "$pattern $? $!"; } sub git_get_ref ($) { # => '' if no such ref my ($refname) = @_; local $_ = $refname; s{^refs/}{[r]efs/} or die "$refname $_ ?"; return cmdoutput qw(git for-each-ref --format=%(objectname)), $_; } sub git_for_each_tag_referring ($$) { my ($objreferring, $func) = @_; # calls $func->($tagobjid,$refobjid,$fullrefname,$tagname); printdebug "git_for_each_tag_referring ", ($objreferring // 'UNDEF'),"\n"; git_for_each_ref('refs/tags', sub { my ($tagobjid,$objtype,$fullrefname,$tagname) = @_; return unless $objtype eq 'tag'; my $refobjid = git_rev_parse $tagobjid; return unless !defined $objreferring # caller wants them all or $tagobjid eq $objreferring or $refobjid eq $objreferring; $func->($tagobjid,$refobjid,$fullrefname,$tagname); }); } sub git_check_unmodified () { foreach my $cached (qw(0 1)) { my @cmd = qw(git diff --quiet); push @cmd, qw(--cached) if $cached; push @cmd, qw(HEAD); debugcmd "+",@cmd; $!=0; $?=-1; system @cmd; return if !$?; if ($?==256) { fail $cached ? "git index contains changes (does not match HEAD)" : "working tree is dirty (does not match HEAD)"; } else { failedcmd @cmd; } } } sub is_fast_fwd ($$) { my ($ancestor,$child) = @_; my @cmd = (qw(git merge-base), $ancestor, $child); my $mb = cmdoutput_errok @cmd; if (defined $mb) { return git_rev_parse($mb) eq git_rev_parse($ancestor); } else { $?==256 or failedcmd @cmd; return 0; } } sub changedir ($) { my ($newdir) = @_; printdebug "CD $newdir\n"; chdir $newdir or confess "chdir: $newdir: $!"; } sub git_slurp_config_src ($) { my ($src) = @_; # returns $r such that $r->{KEY}[] = VALUE my @cmd = (qw(git config -z --get-regexp), "--$src", qw(.*)); debugcmd "|",@cmd; local ($debuglevel) = $debuglevel-2; local $/="\0"; my $r = { }; open GITS, "-|", @cmd or die $!; while () { chomp or die; printdebug "=> ", (messagequote $_), "\n"; m/\n/ or die "$_ ?"; push @{ $r->{$`} }, $'; #'; } $!=0; $?=0; close GITS or ($!==0 && $?==256) or failedcmd @cmd; return $r; } # ========== 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) = @_; $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 core.sharedRepository core.compression core.looseCompression core.bigFileThreshold core.fsyncObjectFiles)) { my $v = $t_local_git_cfg->{$copy}; 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. # $maindir_gitcommon the shared stuff, including .objects rmtree('.git/objects'); symlink "$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 $!; } 1;