X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=dgit.git;a=blobdiff_plain;f=Debian%2FDgit.pm;h=ec402e4d270598e3f7f6ec725812ab7582c8c7a4;hp=c39ff72e6e2c9e388f3c0a473244f42b02500e38;hb=3991eff63504d351b858d3a84392dbb03245946c;hpb=96ac307f0b9d186d589d221dabfb0e403169aa08 diff --git a/Debian/Dgit.pm b/Debian/Dgit.pm index c39ff72e..ec402e4d 100644 --- a/Debian/Dgit.pm +++ b/Debian/Dgit.pm @@ -1,11 +1,36 @@ # -*- 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 (); @@ -13,30 +38,172 @@ BEGIN { $VERSION = 1.00; @ISA = qw(Exporter); - @EXPORT = qw(debiantag server_branch server_ref - stat_exists git_for_each_ref - $package_re $component_re $branchprefix); - %EXPORT_TAGS = ( policyflags => [qw(NOFFCHECK FRESHREPO)] ); - @EXPORT_OK = @{ $EXPORT_TAGS{policyflags} }; + @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 $ffq_refprefix = 'ffq-prev'; # policy hook exit status bits # see dgit-repos-server head comment for documentation -# 1 is reserved in case something fails with `exit 1' -sub NOFFCHECK () { return 2; } -sub FRESHREPO () { return 4; } -# 128 is reserved +# 1 is reserved in case something fails with `exit 1' and to spot +# dynamic loader, runtime, etc., failures, which report 127 or 255 +sub NOFFCHECK () { return 0x2; } +sub FRESHREPO () { return 0x4; } +sub NOCOMMITCHECK () { return 0x8; } -sub debiantag ($) { +our $debugprefix; +our $debuglevel = 0; + +our $negate_harmful_gitattrs = "-text -eol -crlf -ident -filter"; + +our $forkcheck_mainprocess; + +sub forkcheck_setup () { + $forkcheck_mainprocess = $$; +} + +sub forkcheck_mainprocess () { + # You must have called forkcheck_setup or setup_sigwarn already + getppid != $forkcheck_mainprocess; +} + +sub setup_sigwarn () { + forkcheck_setup(); + $SIG{__WARN__} = sub { + confess $_[0] if forkcheck_mainprocess; + }; +} + +sub initdebug ($) { + ($debugprefix) = @_; + open DEBUG, ">/dev/null" or die $!; +} + +sub enabledebug () { + open DEBUG, ">&STDERR" or die $!; + DEBUG->autoflush(1); + $debuglevel ||= 1; +} + +sub enabledebuglevel ($) { + my ($newlevel) = @_; # may be undef (eg from env var) + die if $debuglevel; + $newlevel //= 0; + $newlevel += 0; + return unless $newlevel; + $debuglevel = $newlevel; + enabledebug(); +} + +sub printdebug { + print DEBUG $debugprefix, @_ or die $! if $debuglevel>0; +} + +sub messagequote ($) { + local ($_) = @_; + s{\\}{\\\\}g; + s{\n}{\\n}g; + s{\x08}{\\b}g; + s{\t}{\\t}g; + s{[\000-\037\177]}{ sprintf "\\x%02x", ord $& }ge; + $_; +} + +sub shellquote { + my @out; + local $_; + defined or confess 'internal error' foreach @_; + foreach my $a (@_) { + $_ = $a; + if (!length || m{[^-=_./:0-9a-z]}i) { + s{['\\]}{'\\$&'}g; + push @out, "'$_'"; + } else { + push @out, $_; + } + } + return join ' ', @out; +} + +sub printcmd { + my $fh = shift @_; + my $intro = shift @_; + print $fh $intro," " or die $!; + print $fh shellquote @_ or die $!; + print $fh "\n" or die $!; +} + +sub debugcmd { + my $extraprefix = shift @_; + printcmd(\*DEBUG,$debugprefix.$extraprefix,@_) if $debuglevel>0; +} + +sub dep14_version_mangle ($) { my ($v) = @_; + # DEP-14 patch proposed 2016-11-09 "Version Mangling" $v =~ y/~:/_%/; - return "debian/$v"; + $v =~ s/\.(?=\.|$|lock$)/.#/g; + return $v; +} + +sub debiantag_old ($$) { + 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]"; } @@ -49,28 +216,428 @@ sub stat_exists ($) { die "stat $f: $!"; } -sub git_for_each_ref ($$) { - my ($pattern,$func) = @_; +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/\w+/ + # $reftail is RHS of ref after refs/[^/]+/ # breaks if $pattern matches any ref `refs/blah' where blah has no `/' - my $fh = new IO::File "-|", qw(git for-each-ref), $pattern or die $!; - while (<$fh>) { - m#^(\w+)\s+(\w+)\s+(refs/\w+/(\S+))\s# or die "$_ ?"; + # $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 $fh or die "$pattern $? $!"; + $!=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 ($$) { my ($objreferring, $func) = @_; - # calls $func->($objid,$fullrefname,$tagname); + # calls $func->($tagobjid,$refobjid,$fullrefname,$tagname); + printdebug "git_for_each_tag_referring ", + ($objreferring // 'UNDEF'),"\n"; git_for_each_ref('refs/tags', sub { - my ($objid,$objtype,$fullrefname,$tagname) = @_; - next unless $objtype eq 'tag'; - next if defined $objreferring and $objid ne $objreferring; - $func->($objid,$fullrefname,$tagname); + my ($tagobjid,$objtype,$fullrefname,$tagname) = @_; + return unless $objtype eq 'tag'; + my $refobjid = git_rev_parse $tagobjid; + return unless + !defined $objreferring # caller wants them all + or $tagobjid eq $objreferring + or $refobjid eq $objreferring; + $func->($tagobjid,$refobjid,$fullrefname,$tagname); }); } +sub git_check_unmodified () { + foreach my $cached (qw(0 1)) { + my @cmd = qw(git diff --quiet); + push @cmd, qw(--cached) if $cached; + push @cmd, qw(HEAD); + debugcmd "+",@cmd; + $!=0; $?=-1; system @cmd; + return if !$?; + if ($?==256) { + fail + $cached + ? "git index contains changes (does not match HEAD)" + : "working tree is dirty (does not match HEAD)"; + } else { + failedcmd @cmd; + } + } +} + +sub is_fast_fwd ($$) { + 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;