# -*- 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 <http://www.gnu.org/licenses/>.
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 ();
$VERSION = 1.00;
@ISA = qw(Exporter);
- @EXPORT = qw(debiantag server_branch server_ref
- stat_exists git_for_each_ref
- $package_re $component_re $branchprefix
- initdebug enabledebug printdebug debugcmd
- $debugprefix $debuglevel
- shellquote printcmd);
- %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_for_each_ref
+ git_for_each_tag_referring is_fast_fwd
+ $package_re $component_re $deliberately_re
+ $distro_re $versiontag_re $series_filename_re
+ $branchprefix
+ 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 $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;
# policy hook exit status bits
# see dgit-repos-server head comment for documentation
-# 1 is reserved in case something fails with `exit 1'
+# 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; }
-# 0x80 is reserved
+sub NOCOMMITCHECK () { return 0x8; }
-sub debiantag ($) {
- my ($v) = @_;
- $v =~ y/~:/_%/;
- return "debian/$v";
-}
+our $debugprefix;
+our $debuglevel = 0;
-sub server_branch ($) { return "$branchprefix/$_[0]"; }
-sub server_ref ($) { return "refs/".server_branch($_[0]); }
+our $negate_harmful_gitattrs = "-text -eol -crlf -ident -filter";
-sub stat_exists ($) {
- my ($f) = @_;
- return 1 if stat $f;
- return 0 if $!==&ENOENT;
- die "stat $f: $!";
-}
+our $forkcheck_mainprocess;
-sub git_for_each_ref ($$) {
- my ($pattern,$func) = @_;
- # calls $func->($objid,$objtype,$fullrefname,$reftail);
- # $reftail is RHS of ref after refs/\w+/
- # breaks if $pattern matches any ref `refs/blah' where blah has no `/'
- my $fh = new IO::File "-|", qw(git for-each-ref), $pattern or die $!;
- while (<$fh>) {
- m#^(\w+)\s+(\w+)\s+(refs/\w+/(\S+))\s# or die "$_ ?";
- $func->($1,$2,$3,$4);
- }
- $!=0; $?=0; close $fh or die "$pattern $? $!";
+sub forkcheck_setup () {
+ $forkcheck_mainprocess = $$;
}
-sub git_for_each_tag_referring ($$) {
- my ($objreferring, $func) = @_;
- # calls $func->($objid,$fullrefname,$tagname);
- 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);
- });
+sub forkcheck_mainprocess () {
+ # You must have called forkcheck_setup or setup_sigwarn already
+ getppid != $forkcheck_mainprocess;
}
-our $debugprefix;
-our $debuglevel = 0;
+sub setup_sigwarn () {
+ forkcheck_setup();
+ $SIG{__WARN__} = sub {
+ die $_[0] if forkcheck_mainprocess;
+ };
+}
sub initdebug ($) {
($debugprefix) = @_;
- open ::DEBUG, ">/dev/null" or die $!;
+ open DEBUG, ">/dev/null" or die $!;
}
sub enabledebug () {
- open ::DEBUG, ">&STDERR" or die $!;
- ::DEBUG->autoflush(1);
+ 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;
+ 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 (m{[^-=_./0-9a-z]}i) {
+ if (!length || m{[^-=_./:0-9a-z]}i) {
s{['\\]}{'\\$&'}g;
push @out, "'$_'";
} else {
sub debugcmd {
my $extraprefix = shift @_;
- printcmd(\*::DEBUG,$debugprefix.$extraprefix,@_) if $debuglevel>0;
+ 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 = <P>; }
+ 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 ($$) {
+ my ($old,$new) = @_;
+ lstat $old or return undef;
+ if (-l _) {
+ $old = cmdoutput qw(realpath --), $old;
+ }
+ my $r = link $old, $new;
+ $r = symlink $old, $new if !$r && $!==EXDEV;
+ $r or die "(sym)link $old $new: $!";
+}
+
+sub hashfile ($) {
+ my ($fn) = @_;
+ my $h = Digest::SHA->new(256);
+ $h->addfile($fn);
+ return $h->hexdigest();
+}
+
+sub git_rev_parse ($) {
+ return cmdoutput qw(git rev-parse), "$_[0]~0";
+}
+
+sub git_cat_file ($) {
+ my ($objname) = @_;
+ # => ($type, $data) or ('missing', undef)
+ # in scalar context, just the data
+ our ($gcf_pid, $gcf_i, $gcf_o);
+ if (!$gcf_pid) {
+ my @cmd = qw(git cat-file --batch);
+ debugcmd "GCF|", @cmd;
+ $gcf_pid = open2 $gcf_o, $gcf_i, @cmd or die $!;
+ }
+ printdebug "GCF>| ", $objname, "\n";
+ print $gcf_i $objname, "\n" or die $!;
+ my $x = <$gcf_o>;
+ printdebug "GCF<| ", $x;
+ if ($x =~ m/ (missing)$/) { return ($1, undef); }
+ my ($type, $size) = $x =~ m/^.* (\w+) (\d+)\n/ or die "$objname ?";
+ my $data;
+ (read $gcf_o, $data, $size) == $size or die "$objname $!";
+ $x = <$gcf_o>;
+ $x eq "\n" or die "$objname ($_) $!";
+ return ($type, $data);
+}
+
+sub git_for_each_ref ($$;$) {
+ my ($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 $!;
+ debugcmd "|", @cmd;
+ while (<GFER>) {
+ chomp or die "$_ ?";
+ 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 ($$) {
+ my ($objreferring, $func) = @_;
+ # calls $func->($tagobjid,$refobjid,$fullrefname,$tagname);
+ printdebug "git_for_each_tag_referring ",
+ ($objreferring // 'UNDEF'),"\n";
+ git_for_each_ref('refs/tags', sub {
+ my ($tagobjid,$objtype,$fullrefname,$tagname) = @_;
+ return unless $objtype eq 'tag';
+ my $refobjid = git_rev_parse $tagobjid;
+ return unless
+ !defined $objreferring # caller wants them all
+ or $tagobjid eq $objreferring
+ or $refobjid eq $objreferring;
+ $func->($tagobjid,$refobjid,$fullrefname,$tagname);
+ });
+}
+
+sub is_fast_fwd ($$) {
+ 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 (<GITS>) {
+ 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)
+# assigns to $playground and returns the same pathname
+# caller may call multiple times with different subdir paths
+# createing different playgrounds; but $playground global can
+# refer only to one, obv.
+#
+# ensure_a_playground SUBDIR_PATH_COMPONENTS
+# like fresh_playground except:
+# merely ensures the directory exists; does not delete an existing one
+# never sets global $playground
+#
+# 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 -----
+
+our $playground;
+
+sub ensure_a_playground_parent ($) {
+ 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 $playground = $spc;
+}
+
+# ----- playtrees -----
+
+sub playtree_setup (;$) {
+ 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;