X-Git-Url: http://www.git.stargrave.org/?p=public-inbox.git;a=blobdiff_plain;f=lib%2FPublicInbox%2FGit.pm;h=9c96b3f0b6920acbcfd4a103e3ec14a7ec8618b6;hp=59c274702174f9e165ba30f99b4ed0136b04f67f;hb=64a5e4f9b5cda6891d3dbd719d8a010da487bfc3;hpb=200fb98dd5d5f81344e9ab732d2c7ee3f92203e1 diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm index 59c27470..9c96b3f0 100644 --- a/lib/PublicInbox/Git.pm +++ b/lib/PublicInbox/Git.pm @@ -1,5 +1,5 @@ -# Copyright (C) 2014-2015 all contributors -# License: GPLv2 or later (https://www.gnu.org/licenses/gpl-2.0.txt) +# Copyright (C) 2014-2020 all contributors +# License: GPLv2 or later # # Used to read files from a git repository without excessive forking. # Used in our web interfaces as well as our -nntpd server. @@ -9,111 +9,238 @@ package PublicInbox::Git; use strict; use warnings; -use POSIX qw(dup2); -require IO::Handle; -use PublicInbox::Spawn qw(spawn popen_rd); +use POSIX (); +use IO::Handle; # ->autoflush +use File::Glob qw(bsd_glob GLOB_NOSORT); +use PublicInbox::Spawn qw(popen_rd); +use PublicInbox::Tmpfile; +use base qw(Exporter); +our @EXPORT_OK = qw(git_unquote git_quote); + +use constant MAX_INFLIGHT => + ($^O eq 'linux' ? 4096 : POSIX::_POSIX_PIPE_BUF()) + / + 65; # SHA-256 hex size + "\n" in preparation for git using non-SHA1 + +my %GIT_ESC = ( + a => "\a", + b => "\b", + f => "\f", + n => "\n", + r => "\r", + t => "\t", + v => "\013", + '"' => '"', + '\\' => '\\', +); +my %ESC_GIT = map { $GIT_ESC{$_} => $_ } keys %GIT_ESC; + + +# unquote pathnames used by git, see quote.c::unquote_c_style.c in git.git +sub git_unquote ($) { + return $_[0] unless ($_[0] =~ /\A"(.*)"\z/); + $_[0] = $1; + $_[0] =~ s/\\([\\"abfnrtv])/$GIT_ESC{$1}/g; + $_[0] =~ s/\\([0-7]{1,3})/chr(oct($1))/ge; + $_[0]; +} + +sub git_quote ($) { + if ($_[0] =~ s/([\\"\a\b\f\n\r\t\013]|[^[:print:]])/ + '\\'.($ESC_GIT{$1}||sprintf("%0o",ord($1)))/egs) { + return qq{"$_[0]"}; + } + $_[0]; +} sub new { my ($class, $git_dir) = @_; - bless { git_dir => $git_dir }, $class + my @st; + $st[7] = $st[10] = 0; + # may contain {-tmp} field for File::Temp::Dir + bless { git_dir => $git_dir, st => \@st, -git_path => {} }, $class } -sub _bidi_pipe { - my ($self, $batch, $in, $out, $pid) = @_; - return if $self->{$pid}; - my ($in_r, $in_w, $out_r, $out_w); +sub git_path ($$) { + my ($self, $path) = @_; + $self->{-git_path}->{$path} ||= do { + local $/ = "\n"; + chomp(my $str = $self->qx(qw(rev-parse --git-path), $path)); - pipe($in_r, $in_w) or fail($self, "pipe failed: $!"); - pipe($out_r, $out_w) or fail($self, "pipe failed: $!"); + # git prior to 2.5.0 did not understand --git-path + if ($str eq "--git-path\n$path") { + $str = "$self->{git_dir}/$path"; + } + $str; + }; +} + +sub alternates_changed { + my ($self) = @_; + my $alt = git_path($self, 'objects/info/alternates'); + my @st = stat($alt) or return 0; + my $old_st = $self->{st}; + # 10 - ctime, 7 - size + return 0 if ($st[10] == $old_st->[10] && $st[7] == $old_st->[7]); + $self->{st} = \@st; +} - my @cmd = ('git', "--git-dir=$self->{git_dir}", qw(cat-file), $batch); - my $redir = { 0 => fileno($out_r), 1 => fileno($in_w) }; - my $p = spawn(\@cmd, undef, $redir); - defined $p or fail($self, "spawn failed: $!"); +sub last_check_err { + my ($self) = @_; + my $fh = $self->{err_c} or return; + sysseek($fh, 0, 0) or fail($self, "sysseek failed: $!"); + defined(sysread($fh, my $buf, -s $fh)) or + fail($self, "sysread failed: $!"); + $buf; +} + +sub _bidi_pipe { + my ($self, $batch, $in, $out, $pid, $err) = @_; + if ($self->{$pid}) { + if (defined $err) { # "err_c" + my $fh = $self->{$err}; + sysseek($fh, 0, 0) or fail($self, "sysseek failed: $!"); + truncate($fh, 0) or fail($self, "truncate failed: $!"); + } + return; + } + my ($out_r, $out_w); + pipe($out_r, $out_w) or fail($self, "pipe failed: $!"); + my @cmd = (qw(git), "--git-dir=$self->{git_dir}", + qw(-c core.abbrev=40 cat-file), $batch); + my $redir = { 0 => $out_r }; + if ($err) { + my $id = "git.$self->{git_dir}$batch.err"; + my $fh = tmpfile($id) or fail($self, "tmpfile($id): $!"); + $self->{$err} = $fh; + $redir->{2} = $fh; + } + my ($in_r, $p) = popen_rd(\@cmd, undef, $redir); $self->{$pid} = $p; $out_w->autoflush(1); + if ($^O eq 'linux') { # 1031: F_SETPIPE_SZ + fcntl($out_w, 1031, 4096); + fcntl($in_r, 1031, 4096) if $batch eq '--batch-check'; + } $self->{$out} = $out_w; $self->{$in} = $in_r; } +sub read_cat_in_full ($$$) { + my ($self, $in, $left) = @_; + my $offset = 0; + my $buf = ''; + while ($left > 0) { + my $r = read($in, $buf, $left, $offset); + defined($r) or fail($self, "read failed: $!"); + $r == 0 and fail($self, 'exited unexpectedly'); + $left -= $r; + $offset += $r; + } + my $r = read($in, my $lf, 1); + defined($r) or fail($self, "read failed: $!"); + fail($self, 'newline missing after blob') if ($r != 1 || $lf ne "\n"); + \$buf; +} + +sub _cat_async_step ($$$) { + my ($self, $inflight, $in) = @_; + my $pair = shift @$inflight or die 'BUG: inflight empty'; + my ($cb, $arg) = @$pair; + local $/ = "\n"; + my $head = $in->getline; + $head =~ / missing$/ and return + eval { $cb->(undef, undef, undef, undef, $arg) }; + + $head =~ /^([0-9a-f]{40}) (\S+) ([0-9]+)$/ or + fail($self, "Unexpected result from async git cat-file: $head"); + my ($oid_hex, $type, $size) = ($1, $2, $3 + 0); + my $bref = read_cat_in_full($self, $in, $size); + eval { $cb->($bref, $oid_hex, $type, $size, $arg) }; +} + +sub cat_async_wait ($) { + my ($self) = @_; + my $inflight = delete $self->{inflight} or return; + my $in = $self->{in}; + while (scalar(@$inflight)) { + _cat_async_step($self, $inflight, $in); + } +} + sub cat_file { my ($self, $obj, $ref) = @_; - + my ($retried, $in, $head); + cat_async_wait($self); +again: batch_prepare($self); $self->{out}->print($obj, "\n") or fail($self, "write error: $!"); - my $in = $self->{in}; + $in = $self->{in}; local $/ = "\n"; - my $head = $in->getline; - $head =~ / missing$/ and return undef; - $head =~ /^[0-9a-f]{40} \S+ (\d+)$/ or - fail($self, "Unexpected result from git cat-file: $head"); - - my $size = $1; - my $ref_type = $ref ? ref($ref) : ''; - - my $rv; - my $left = $size; - $$ref = $size if ($ref_type eq 'SCALAR'); - my $cb_err; - - if ($ref_type eq 'CODE') { - $rv = eval { $ref->($in, \$left) }; - $cb_err = $@; - # drain the rest - my $max = 8192; - while ($left > 0) { - my $r = read($in, my $x, $left > $max ? $max : $left); - defined($r) or fail($self, "read failed: $!"); - $r == 0 and fail($self, 'exited unexpectedly'); - $left -= $r; - } - } else { - my $offset = 0; - my $buf = ''; - while ($left > 0) { - my $r = read($in, $buf, $left, $offset); - defined($r) or fail($self, "read failed: $!"); - $r == 0 and fail($self, 'exited unexpectedly'); - $left -= $r; - $offset += $r; + $head = $in->getline; + if ($head =~ / missing$/) { + if (!$retried && alternates_changed($self)) { + $retried = 1; + cleanup($self); + goto again; } - $rv = \$buf; + return; } + $head =~ /^[0-9a-f]{40} \S+ ([0-9]+)$/ or + fail($self, "Unexpected result from git cat-file: $head"); - my $r = read($in, my $buf, 1); - defined($r) or fail($self, "read failed: $!"); - fail($self, 'newline missing after blob') if ($r != 1 || $buf ne "\n"); - die $cb_err if $cb_err; - - $rv; + my $size = $1; + $$ref = $size if $ref; + read_cat_in_full($self, $in, $size); } sub batch_prepare ($) { _bidi_pipe($_[0], qw(--batch in out pid)) } sub check { my ($self, $obj) = @_; - $self->_bidi_pipe(qw(--batch-check in_c out_c pid_c)); + _bidi_pipe($self, qw(--batch-check in_c out_c pid_c err_c)); $self->{out_c}->print($obj, "\n") or fail($self, "write error: $!"); local $/ = "\n"; chomp(my $line = $self->{in_c}->getline); my ($hex, $type, $size) = split(' ', $line); - return if $type eq 'missing'; + + # Future versions of git.git may show 'ambiguous', but for now, + # we must handle 'dangling' below (and maybe some other oddball + # stuff): + # https://public-inbox.org/git/20190118033845.s2vlrb3wd3m2jfzu@dcvr/T/ + return if $type eq 'missing' || $type eq 'ambiguous'; + + if ($hex eq 'dangling' || $hex eq 'notdir' || $hex eq 'loop') { + $size = $type + length("\n"); + my $r = read($self->{in_c}, my $buf, $size); + defined($r) or fail($self, "read failed: $!"); + return; + } + ($hex, $type, $size); } sub _destroy { - my ($self, $in, $out, $pid) = @_; + my ($self, $in, $out, $pid, $err) = @_; my $p = delete $self->{$pid} or return; - foreach my $f ($in, $out) { - delete $self->{$f}; - } - waitpid $p, 0; + delete @$self{($in, $out)}; + delete $self->{$err} if $err; # `err_c' + + # PublicInbox::DS may not be loaded + eval { PublicInbox::DS::dwaitpid($p, undef, undef) }; + waitpid($p, 0) if $@; # wait synchronously if not in event loop +} + +sub cat_async_abort ($) { + my ($self) = @_; + my $inflight = delete $self->{inflight} or die 'BUG: not in async'; + cleanup($self); } sub fail { my ($self, $msg) = @_; - cleanup($self); + $self->{inflight} ? cat_async_abort($self) : cleanup($self); die $msg; } @@ -126,21 +253,106 @@ sub popen { sub qx { my ($self, @cmd) = @_; my $fh = $self->popen(@cmd); - defined $fh or return; local $/ = "\n"; return <$fh> if wantarray; local $/; <$fh> } +# returns true if there are pending "git cat-file" processes sub cleanup { my ($self) = @_; _destroy($self, qw(in out pid)); - _destroy($self, qw(in_c out_c pid_c)); + _destroy($self, qw(in_c out_c pid_c err_c)); + !!($self->{pid} || $self->{pid_c}); +} + +# assuming a well-maintained repo, this should be a somewhat +# accurate estimation of its size +# TODO: show this in the WWW UI as a hint to potential cloners +sub packed_bytes { + my ($self) = @_; + my $n = 0; + my $pack_dir = git_path($self, 'objects/pack'); + foreach my $p (bsd_glob("$pack_dir/*.pack", GLOB_NOSORT)) { + $n += -s $p; + } + $n } sub DESTROY { cleanup(@_) } +sub local_nick ($) { + my ($self) = @_; + my $ret = '???'; + # don't show full FS path, basename should be OK: + if ($self->{git_dir} =~ m!/([^/]+)(?:/\.git)?\z!) { + $ret = "/path/to/$1"; + } + wantarray ? ($ret) : $ret; +} + +sub host_prefix_url ($$) { + my ($env, $url) = @_; + return $url if index($url, '//') >= 0; + my $scheme = $env->{'psgi.url_scheme'}; + my $host_port = $env->{HTTP_HOST} // + "$env->{SERVER_NAME}:$env->{SERVER_PORT}"; + "$scheme://$host_port". ($env->{SCRIPT_NAME} || '/') . $url; +} + +sub pub_urls { + my ($self, $env) = @_; + if (my $urls = $self->{cgit_url}) { + return map { host_prefix_url($env, $_) } @$urls; + } + local_nick($self); +} + +sub cat_async_begin { + my ($self) = @_; + cleanup($self) if alternates_changed($self); + batch_prepare($self); + die 'BUG: already in async' if $self->{inflight}; + $self->{inflight} = []; +} + +sub cat_async ($$$;$) { + my ($self, $oid, $cb, $arg) = @_; + my $inflight = $self->{inflight} or die 'BUG: not in async'; + if (scalar(@$inflight) >= MAX_INFLIGHT) { + _cat_async_step($self, $inflight, $self->{in}); + } + + $self->{out}->print($oid, "\n") or fail($self, "write error: $!"); + push(@$inflight, [ $cb, $arg ]); +} + +sub extract_cmt_time { + my ($bref, undef, undef, undef, $modified) = @_; + + if ($$bref =~ /^committer .*?> ([0-9]+) [\+\-]?[0-9]+/sm) { + my $cmt_time = $1 + 0; + $$modified = $cmt_time if $cmt_time > $$modified; + } +} + +# returns the modified time of a git repo, same as the "modified" field +# of a grokmirror manifest +sub modified ($) { + my ($self) = @_; + my $modified = 0; + my $fh = popen($self, qw(rev-parse --branches)); + cat_async_begin($self); + local $/ = "\n"; + while (my $oid = <$fh>) { + chomp $oid; + cat_async($self, $oid, \&extract_cmt_time, \$modified); + } + cat_async_wait($self); + $modified || time; +} + 1; __END__ =pod