codesearch: initial cut w/ -cindex tool

It seems relying on root commits is a reasonable way to
deduplicate and handle repositories with common history.

I initially wanted to shoehorn this into extindex, but decided a
separate Xapian index layout capable of being EITHER external to
handle many forks or internal (in $GIT_DIR/public-inbox-cindex)
for small projects is the right way to go.

Unlike most existing parts of public-inbox, this relies on
absolute paths of $GIT_DIR stored in the Xapian DB and does not
rely on the config file.  We'll be relying on the config file to
map absolute paths to public URL paths for WWW.

6 files changed, 672 insertions, 68 deletions

diff --git a/lib/PublicInbox/CodeSearch.pm b/lib/PublicInbox/CodeSearch.pm
new file mode 100644
index 00000000..1dfc124f
--- /dev/null
+++ b/lib/PublicInbox/CodeSearch.pm
@@ -0,0 +1,121 @@
+# Copyright (C) all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# read-only external index for coderepos
+# currently, it only indexes commits and repository metadata
+# (pathname, root commits); not blob contents
+package PublicInbox::CodeSearch;
+use v5.12;
+use parent qw(PublicInbox::Search);
+use PublicInbox::Search qw(retry_reopen int_val xap_terms);
+use constant {
+        AT => 0, # author time YYYYMMDDHHMMSS, dt: for mail)
+        CT => 1, # commit time (Unix time stamp, like TS/rt: in mail)
+        CIDX_SCHEMA_VER => 1, # brand new schema for code search
+        # for repos (`Tr'), CT(col=1) is used for the latest tip commit time
+        # in refs/{heads,tags}.  AT(col=0) may be used to store disk usage
+        # in the future, but disk usage calculation is espensive w/ alternates
+};
+
+# note: the non-X term prefix allocations are shared with Xapian omega,
+# see xapian-applications/omega/docs/termprefixes.rst
+# bool_pfx_internal:
+#        type => 'T', # 'c' - commit, 'r' - repo GIT_DIR
+#        tags are not indexed, only normal branches (refs/heads/*), not hidden
+#        'P' # (pathname) GIT_DIR # uniq
+#        'G' # (group) root commit (may have multiple roots)
+my %bool_pfx_external = (
+        oid => 'Q', # type:commit - git OID hex (40|64)-byte SHA-(1|256)
+                # type:repo - rel2abs_collapsed(GIT_DIR)
+        parent => 'XP',
+        %PublicInbox::Search::PATCH_BOOL_COMMON,
+);
+
+my %prob_prefix = ( # copied from PublicInbox::Search
+        # do we care about committer? or partial commit OID via Xapian?
+        # o => 'XQ', # 'oid:' (bool) is exact, 'o:' (prob) can do partial
+        %PublicInbox::Search::PATCH_PROB_COMMON,
+
+        # default:
+        '' => 'S A XQUOT XFN ' . $PublicInbox::Search::NON_QUOTED_BODY
+);
+
+sub new {
+        my ($cls, $dir) = @_;
+        bless { xpfx => "$dir/cidx".CIDX_SCHEMA_VER }, $cls;
+}
+
+sub cqparse_new ($) {
+        my ($self) = @_;
+        my $qp = $self->qp_init_common;
+        my $cb = $qp->can('add_valuerangeprocessor') //
+                $qp->can('add_rangeprocessor'); # Xapian 1.5.0+
+        $cb->($qp, $PublicInbox::Search::NVRP->new(AT, 'd:')); # mairix compat
+        $cb->($qp, $PublicInbox::Search::NVRP->new(AT, 'dt:')); # mail compat
+        $cb->($qp, $PublicInbox::Search::NVRP->new(CT, 'ct:'));
+
+        while (my ($name, $pfx) = each %bool_pfx_external) {
+                $qp->add_boolean_prefix($name, $_) for split(/ /, $pfx);
+        }
+        while (my ($name, $pfx) = each %prob_prefix) {
+                $qp->add_prefix($name, $_) for split(/ /, $pfx);
+        }
+        $qp;
+}
+
+# returns a Xapian::Query to filter by roots
+sub roots_filter { # retry_reopen callback
+        my ($self, $git_dir) = @_;
+        my $xdb = $self->xdb;
+        my $P = 'P'.$git_dir;
+        my ($cur, $end) = ($xdb->postlist_begin($P), $xdb->postlist_end($P));
+        if ($cur == $end) {
+                warn "W: $git_dir not indexed?\n";
+                return;
+        }
+        my @roots = xap_terms('G', $xdb, $cur->get_docid);
+        if (!@roots) {
+                warn "W: $git_dir has no root commits?\n";
+                return;
+        }
+        my $q = $PublicInbox::Search::X{Query}->new('G'.shift(@roots));
+        for my $r (@roots) {
+                $q = $PublicInbox::Search::X{Query}->new(
+                                        PublicInbox::Search::OP_OR(),
+                                        $q, 'G'.$r);
+        }
+        $q;
+}
+
+sub mset {
+        my ($self, $qry_str, $opt) = @_;
+        my $qp = $self->{qp} //= cqparse_new($self);
+        my $qry = $qp->parse_query($qry_str, $self->{qp_flags});
+
+        # limit to commits with shared roots
+        if (defined(my $git_dir = $opt->{git_dir})) {
+                my $rf = retry_reopen($self, \&roots_filter, $git_dir)
+                        or return;
+
+                $qry = $PublicInbox::Search::X{Query}->new(
+                                PublicInbox::Search::OP_FILTER(),
+                                $qry, $rf);
+        }
+
+        # we only want commits:
+        $qry = $PublicInbox::Search::X{Query}->new(
+                                PublicInbox::Search::OP_FILTER(),
+                                $qry, 'T'.'c');
+
+        my $enq = $PublicInbox::Search::X{Enquire}->new($self->xdb);
+        $enq->set_query($qry);
+        if ($opt->{relevance}) {
+                $enq->set_sort_by_relevance_then_value(CT, !$opt->{asc});
+        } else {
+                $enq->set_sort_by_value_then_relevance(CT, !$opt->{asc});
+        }
+        $self->retry_reopen($self->can('enquire_once'), $enq,
+                        $opt->{offset} || 0, $opt->{limit} || 50);
+}
+
+1;
diff --git a/lib/PublicInbox/CodeSearchIdx.pm b/lib/PublicInbox/CodeSearchIdx.pm
new file mode 100644
index 00000000..218338da
--- /dev/null
+++ b/lib/PublicInbox/CodeSearchIdx.pm
@@ -0,0 +1,425 @@
+# Copyright (C) all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+#
+# indexer for git coderepos, just commits and repo paths for now
+# this stores normalized absolute paths of indexed GIT_DIR inside
+# the DB itself and is designed to handle forks by designating roots
+#
+# Unlike mail search, docid isn't tied to NNTP artnum or IMAP UID,
+# there's no serial number dependency at all.  The first 32-bits of
+# the commit SHA-(1|256) is used to select a shard.
+#
+# We shard repos using the first 32-bits of sha256($ABS_GIT_DIR)
+#
+# See PublicInbox::CodeSearch (read-only API) for more
+package PublicInbox::CodeSearchIdx;
+use v5.12;
+use parent qw(PublicInbox::Lock PublicInbox::CodeSearch PublicInbox::SearchIdx);
+use PublicInbox::Eml;
+use PublicInbox::DS ();
+use PublicInbox::IPC qw(nproc_shards);
+use PublicInbox::Admin;
+use POSIX qw(WNOHANG SEEK_SET);
+use File::Path ();
+use File::Spec ();
+use PublicInbox::SHA qw(sha256_hex);
+use PublicInbox::Search qw(xap_terms);
+use PublicInbox::SearchIdx qw(add_val);
+use PublicInbox::Config;
+use PublicInbox::Spawn qw(run_die);
+
+# stop walking history if we see >$SEEN_MAX existing commits, this assumes
+# branches don't diverge by more than this number of commits...
+# git walks commits quickly if it doesn't have to read trees
+our $SEEN_MAX = 100000;
+
+# TODO: do we care about committer name + email? or tree OID?
+my @FMT = qw(H P ct an ae at s b); # (b)ody must be last
+my @LOG_STDIN = (qw(log --no-decorate --no-color --no-notes -p --stat -M
+        --stdin --no-walk=unsorted), '--pretty=format:%n%x00'.
+        join('%n', map { "%$_" } @FMT));
+
+sub new {
+        my (undef, $dir, $opt) = @_;
+        my $l = $opt->{indexlevel} // 'full';
+        $l !~ $PublicInbox::SearchIdx::INDEXLEVELS and
+                die "invalid indexlevel=$l\n";
+        $l eq 'basic' and die "E: indexlevel=basic not supported\n";
+        my $self = bless {
+                xpfx => "$dir/cidx".  PublicInbox::CodeSearch::CIDX_SCHEMA_VER,
+                cidx_dir => $dir,
+                creat => 1, # TODO: get rid of this, should be implicit
+                indexlevel => $l,
+                transact_bytes => 0, # for checkpoint
+                total_bytes => 0, # for lock_release
+                current_info => '',
+                parallel => 1,
+                -opt => $opt,
+                lock_path => "$dir/cidx.lock",
+        }, __PACKAGE__;
+        $self->{nshard} = count_shards($self) ||
+                nproc_shards({nproc => $opt->{jobs}});
+        $self->{-no_fsync} = 1 if !$opt->{fsync};
+        $self->{-dangerous} = 1 if $opt->{dangerous};
+        $self;
+}
+
+# TODO: may be used for reshard/compact
+sub count_shards { scalar($_[0]->xdb_shards_flat) }
+
+sub add_commit ($$) {
+        my ($self, $cmt) = @_; # fields from @FMT
+        my $x = 'Q'.$cmt->{H};
+        for (docids_by_postlist($self, $x)) {
+                $self->{xdb}->delete_document($_)
+        }
+        my $doc = $PublicInbox::Search::X{Document}->new;
+        $doc->add_boolean_term($x);
+        $doc->add_boolean_term('G'.$_) for @{$self->{roots}};
+        $doc->add_boolean_term('XP'.$_) for split(/ /, $cmt->{P});
+        $doc->add_boolean_term('T'.'c');
+
+        # Author-Time is compatible with dt: for mail search schema_version=15
+        add_val($doc, PublicInbox::CodeSearch::AT,
+                POSIX::strftime('%Y%m%d%H%M%S', gmtime($cmt->{at})));
+
+        # Commit-Time is the fallback used by rt: (TS) for mail search:
+        add_val($doc, PublicInbox::CodeSearch::CT, $cmt->{ct});
+
+        $self->term_generator->set_document($doc);
+
+        # email address is always indexed with positional data for usability
+        $self->index_phrase("$cmt->{an} <$cmt->{ae}>", 1, 'A');
+
+        $x = $cmt->{'s'};
+        $self->index_text($x, 1, 'S') if $x =~ /\S/s;
+        $doc->set_data($x); # subject is the first (and currently only) line
+
+        $x = delete $cmt->{b};
+        $self->index_body_text($doc, \$x) if $x =~ /\S/s;
+        $self->{xdb}->add_document($doc);
+}
+
+sub progress {
+        my ($self, @msg) = @_;
+        my $pr = $self->{-opt}->{-progress} or return;
+        $pr->($self->{git} ? ("$self->{git}->{git_dir}: ") : (), @msg, "\n");
+}
+
+sub store_repo ($$) {
+        my ($self, $repo) = @_;
+        my $xdb = delete($repo->{shard})->idx_acquire;
+        $xdb->begin_transaction;
+        if (defined $repo->{id}) {
+                my $doc = $xdb->get_document($repo->{id}) //
+                        die "$self->{git}->{git_dir} doc #$repo->{id} gone";
+                add_val($doc, PublicInbox::CodeSearch::CT, $repo->{ct});
+                my %new = map { $_ => undef } @{$self->{roots}};
+                my $old = xap_terms('G', $doc);
+                delete @new{keys %$old};
+                $doc->add_boolean_term('G'.$_) for keys %new;
+                delete @$old{@{$self->{roots}}};
+                $doc->remove_term('G'.$_) for keys %$old;
+                $doc->set_data($repo->{fp});
+                $xdb->replace_document($repo->{id}, $doc);
+        } else {
+                my $new = $PublicInbox::Search::X{Document}->new;
+                add_val($new, PublicInbox::CodeSearch::CT, $repo->{ct});
+                $new->add_boolean_term("P$self->{git}->{git_dir}");
+                $new->add_boolean_term('T'.'r');
+                $new->add_boolean_term('G'.$_) for @{$repo->{roots}};
+                $new->set_data($repo->{fp}); # \n delimited
+                $xdb->add_document($new);
+        }
+        $xdb->commit_transaction;
+}
+
+# sharded reader for `git log --pretty=format: --stdin'
+sub shard_worker ($$$) {
+        my ($self, $r, $sigset) = @_;
+        my ($quit, $cmt);
+        my $batch_bytes = $self->{-opt}->{batch_size} //
+                                $PublicInbox::SearchIdx::BATCH_BYTES;
+        my $max = $batch_bytes;
+        $SIG{USR1} = sub { $max = -1 }; # similar to `git fast-import'
+        $SIG{QUIT} = $SIG{TERM} = $SIG{INT} = sub { $quit = shift };
+        PublicInbox::DS::sig_setmask($sigset);
+
+        # the parent process of this shard process writes directly to
+        # the stdin of `git log', we consume git log's stdout:
+        my $rd = $self->{git}->popen(@LOG_STDIN, undef, { 0 => $r });
+        close $r or die "close: $!";
+        my $nr = 0;
+
+        # a patch may have \0, see c4201214cbf10636e2c1ab9131573f735b42c8d4
+        # in linux.git, so we use $/ = "\n\0" to check end-of-patch
+        my $FS = "\n\0";
+        local $/ = $FS;
+        my $buf = <$rd> // return; # leading $FS
+        $buf eq $FS or die "BUG: not LF-NUL: $buf\n";
+        my $xdb = $self->idx_acquire;
+        $xdb->begin_transaction;
+        while (defined($buf = <$rd>)) {
+                chomp($buf);
+                $max -= length($buf);
+                @$cmt{@FMT} = split(/\n/, $buf, scalar(@FMT));
+                $/ = "\n";
+                add_commit($self, $cmt);
+                last if $quit; # likely SIGPIPE
+                ++$nr;
+                if ($max <= 0 && !$PublicInbox::Search::X{CLOEXEC_UNSET}) {
+                        progress($self, $nr);
+                        $xdb->commit_transaction;
+                        $max = $batch_bytes;
+                        $xdb->begin_transaction;
+                }
+                $/ = $FS;
+        }
+        close($rd);
+        if (!$? || ($quit && ($? & 127) == POSIX::SIGPIPE)) {
+                $xdb->commit_transaction;
+        } else {
+                warn "E: git @LOG_STDIN: \$?=$?\n";
+                $xdb->cancel_transaction;
+        }
+}
+
+sub seen ($$) {
+        my ($xdb, $q) = @_; # $q = "Q$COMMIT_HASH"
+        $xdb->postlist_begin($q) != $xdb->postlist_end($q)
+}
+
+# used to select the shard for a GIT_DIR
+sub git_dir_hash ($) { hex(substr(sha256_hex($_[0]), 0, 8)) }
+
+sub docids_by_postlist ($$) { # consider moving to PublicInbox::Search
+        my ($self, $q) = @_;
+        my $cur = $self->{xdb}->postlist_begin($q);
+        my $end = $self->{xdb}->postlist_end($q);
+        my @ids;
+        for (; $cur != $end; $cur++) { push(@ids, $cur->get_docid) };
+        @ids;
+}
+
+sub get_roots ($$) {
+        my ($self, $refs) = @_;
+        my @roots = $self->{git}->qx([qw(rev-list --stdin --max-parents=0)],
+                undef, { 0 => $refs });
+        die "git rev-list \$?=$?" if $?;
+        sysseek($refs, 0, SEEK_SET) or die "seek: $!"; # for rev-list --stdin
+        chomp(@roots);
+        scalar(@roots) ? \@roots : undef;
+}
+
+# this is different from the grokmirror-compatible fingerprint since we
+# only care about --heads (branches) and --tags, and not even their names
+sub cidx_fp ($) {
+        my ($self) = @_;
+        open my $refs, '+>', undef or die "open: $!";
+        run_die(['git', "--git-dir=$self->{git}->{git_dir}",
+                qw(show-ref --heads --tags --hash)], undef, { 1 => $refs });
+        seek($refs, 0, SEEK_SET) or die "seek: $!";
+        my $buf;
+        my $dig = PublicInbox::SHA->new(256);
+        while (read($refs, $buf, 65536)) { $dig->add($buf) }
+        sysseek($refs, 0, SEEK_SET) or die "seek: $!"; # for rev-list --stdin
+        ($dig->hexdigest, $refs);
+}
+
+# TODO: should we also index gitweb.owner and the full fingerprint for grokmirror?
+sub prep_git_dir ($) {
+        my ($self) = @_;
+        my $git_dir = $self->{git}->{git_dir};
+        my $ct = $self->{git}->qx([qw[for-each-ref
+                --sort=-committerdate --format=%(committerdate:raw) --count=1
+                refs/heads/ refs/tags/]]);
+        my $repo = {};
+        @$repo{qw(fp refs)} = cidx_fp($self);
+        $repo->{roots} = get_roots($self, $repo->{refs});
+        if (!$repo->{roots} || !defined($ct)) {
+                warn "W: $git_dir has no root commits, skipping\n";
+                return;
+        }
+        $ct =~ s/ .*\z//s; # drop TZ
+        $repo->{ct} = $ct + 0;
+        my $n = git_dir_hash($git_dir) % $self->{nshard};
+        my $shard = $repo->{shard} = bless { %$self, shard => $n }, ref($self);
+        delete @$shard{qw(lockfh lock_path)};
+        local $shard->{xdb};
+        my $xdb = $shard->idx_acquire;
+        my @docids = docids_by_postlist($shard, 'P'.$git_dir);
+        my $docid = shift(@docids) // return $repo;
+        if (@docids) {
+                warn "BUG: $git_dir indexed multiple times, culling\n";
+                $xdb->begin_transaction;
+                for (@docids) { $xdb->delete_document($_) }
+                $xdb->commit_transaction;
+        }
+        my $doc = $xdb->get_document($docid) //
+                die "BUG: no #$docid ($git_dir)";
+        my $old_fp = $doc->get_data;
+        if ($old_fp eq $repo->{fp}) { # no change
+                progress($self, 'unchanged');
+                return;
+        }
+        $repo->{id} = $docid;
+        $repo;
+}
+
+sub partition_refs ($$) {
+        my ($self, $refs) = @_; # show-ref --heads --tags --hash output
+        my $fh = $self->{git}->popen(qw(rev-list --stdin), undef,
+                                        { 0 => $refs });
+        close $refs or die "close: $!";
+        local $self->{xdb};
+        my $xdb = $self->{-opt}->{reindex} ? undef : $self->xdb;
+        my ($seen, $nchange, $nshard) = (0, 0, $self->{nshard});
+        my @shard_in;
+        for (0..($nshard - 1)) {
+                open $shard_in[$_], '+>', undef or die "open: $!";
+        }
+        while (defined(my $cmt = <$fh>)) {
+                chomp $cmt;
+                if ($xdb && seen($xdb, 'Q'.$cmt)) {
+                        last if ++$seen > $SEEN_MAX;
+                } else {
+                        my $n = hex(substr($cmt, 0, 8)) % $nshard;
+                        say { $shard_in[$n] } $cmt or die "say: $!";
+                        ++$nchange;
+                        $seen = 0;
+                }
+        }
+        close($fh);
+        if (!$? || (($? & 127) == POSIX::SIGPIPE && $seen > $SEEN_MAX)) {
+                $self->{nchange} += $nchange;
+                progress($self, "$nchange commits");
+                for my $fh (@shard_in) {
+                        $fh->flush or die "flush: $!";
+                        sysseek($fh, 0, SEEK_SET) or die "seek: $!";
+                }
+                return @shard_in;
+        }
+        die "git-rev-list: \$?=$?\n";
+}
+
+sub index_git_dir ($$) {
+        my ($self, $git_dir) = @_;
+        local $self->{git} = PublicInbox::Git->new($git_dir); # for ->patch_id
+        my $repo = prep_git_dir($self) or return;
+        local $self->{current_info} = $git_dir;
+        my @shard_in = partition_refs($self, delete($repo->{refs}));
+        my %pids;
+        my $fwd_kill = sub {
+                my ($sig) = @_;
+                kill($sig, $_) for keys %pids;
+        };
+        local $SIG{USR1} = $fwd_kill;
+        local $SIG{QUIT} = $fwd_kill;
+        local $SIG{INT} = $fwd_kill;
+        local $SIG{TERM} = $fwd_kill;
+        my $sigset = PublicInbox::DS::block_signals();
+        for (my $n = 0; $n <= $#shard_in; $n++) {
+                -s $shard_in[$n] or next;
+                my $pid = fork // die "fork: $!";
+                if ($pid == 0) { # no RNG use, here
+                        $0 = "code index [$n]";
+                        $self->{shard} = $n;
+                        $self->{current_info} = "$self->{current_info} [$n]";
+                        delete @$self{qw(lockfh lock_path)};
+                        my $in = $shard_in[$n];
+                        @shard_in = ();
+                        $self->{roots} = delete $repo->{roots};
+                        undef $repo;
+                        eval { shard_worker($self, $in, $sigset) };
+                        warn "E: $@" if $@;
+                        POSIX::_exit($@ ? 1 : 0);
+                } else {
+                        $pids{$pid} = "code index [$n]";
+                }
+        }
+        PublicInbox::DS::sig_setmask($sigset);
+        @shard_in = ();
+        my $err;
+        while (keys %pids) {
+                my $pid = waitpid(-1, 0) or last;
+                my $j = delete $pids{$pid} // "unknown PID:$pid";
+                next if $? == 0;
+                warn "PID:$pid $j exited with \$?=$?\n";
+                $err = 1;
+        }
+        die "subprocess(es) failed\n" if $err;
+        store_repo($self, $repo);
+        progress($self, 'done');
+        # TODO: check fp afterwards?
+}
+
+# for PublicInbox::SearchIdx::patch_id and with_umask
+sub git { $_[0]->{git} }
+
+sub load_existing ($) { # for -u/--update
+        my ($self) = @_;
+        my $dirs = $self->{git_dirs} // [];
+        if ($self->{-opt}->{update}) {
+                local $self->{xdb};
+                $self->xdb or
+                        die "E: $self->{cidx_dir} non-existent for --update\n";
+                my @cur = $self->all_terms('P');
+                push @$dirs, @cur;
+        }
+        my %uniq; # List::Util::uniq requires Perl 5.26+
+        @$dirs = grep { !$uniq{$_}++ } @$dirs;
+}
+
+sub cidx_init ($) {
+        my ($self) = @_;
+        my $dir = $self->{cidx_dir};
+        unless (-d $dir) {
+                warn "# creating $dir\n" if !$self->{-opt}->{quiet};
+                File::Path::mkpath($dir);
+        }
+        for my $n (0..($self->{nshard} - 1)) {
+                my $shard = bless { %$self, shard => $n }, ref($self);
+                $shard->idx_acquire;
+        }
+        # this warning needs to happen after idx_acquire
+        state $once;
+        warn <<EOM if $PublicInbox::Search::X{CLOEXEC_UNSET} && !$once++;
+W: Xapian v1.2.21..v1.2.24 were missing close-on-exec on OFD locks,
+W: memory usage may be high for large indexing runs
+EOM
+}
+
+sub cidx_run {
+        my ($self) = @_;
+        cidx_init($self);
+        local $self->{current_info} = '';
+        my $cb = $SIG{__WARN__} || \&CORE::warn;
+        local $SIG{__WARN__} = sub {
+                my $m = shift @_;
+                $self->{current_info} eq '' or
+                        $m =~ s/\A(#?\s*)/$1$self->{current_info}: /;
+                $cb->($m, @_);
+        };
+        $self->lock_acquire;
+        load_existing($self);
+        my @nc = grep { File::Spec->canonpath($_) ne $_ } @{$self->{git_dirs}};
+        if (@nc) {
+                warn "E: BUG? paths in $self->{cidx_dir} not canonicalized:\n";
+                for my $d (@{$self->{git_dirs}}) {
+                        my $c = File::Spec->canonpath($_);
+                        warn "E: $d => $c\n";
+                        $d = $c;
+                }
+                warn "E: canonicalized and attempting to continue\n";
+        }
+        local $self->{nchange} = 0;
+        # do_prune($self) if $self->{-opt}->{prune}; TODO
+        if ($self->{-opt}->{scan} // 1) {
+                for my $gd (@{$self->{git_dirs}}) {
+                        index_git_dir($self, $gd);
+                }
+        }
+        $self->lock_release(!!$self->{nchange});
+}
+
+1;
diff --git a/lib/PublicInbox/MiscIdx.pm b/lib/PublicInbox/MiscIdx.pm
index 19200b92..6708527d 100644
--- a/lib/PublicInbox/MiscIdx.pm
+++ b/lib/PublicInbox/MiscIdx.pm
@@ -5,7 +5,7 @@
 # Things indexed include:
 # * inboxes themselves
 # * epoch information
-# * (maybe) git code repository information
+# * (maybe) git code repository information (not commits)
 # Expect ~100K-1M documents with no parallelism opportunities,
 # so no sharding, here.
 #
diff --git a/lib/PublicInbox/Search.pm b/lib/PublicInbox/Search.pm
index 7aba2445..5133a3b7 100644
--- a/lib/PublicInbox/Search.pm
+++ b/lib/PublicInbox/Search.pm
@@ -110,43 +110,50 @@ sub load_xapian () {
 # a prefix common in patch emails
 our $LANG = 'english';
 
+our %PATCH_BOOL_COMMON = (
+        dfpre => 'XDFPRE',
+        dfpost => 'XDFPOST',
+        dfblob => 'XDFPRE XDFPOST',
+        patchid => 'XDFID',
+);
+
 # note: the non-X term prefix allocations are shared with
 # Xapian omega, see xapian-applications/omega/docs/termprefixes.rst
 my %bool_pfx_external = (
         mid => 'Q', # Message-ID (full/exact), this is mostly uniQue
         lid => 'G', # newsGroup (or similar entity), just inside <>
-        dfpre => 'XDFPRE',
-        dfpost => 'XDFPOST',
-        dfblob => 'XDFPRE XDFPOST',
-        patchid => 'XDFID',
+        %PATCH_BOOL_COMMON
 );
 
-my $non_quoted_body = 'XNQ XDFN XDFA XDFB XDFHH XDFCTX XDFPRE XDFPOST XDFID';
-my %prob_prefix = (
-        # for mairix compatibility
+# for mairix compatibility
+our $NON_QUOTED_BODY = 'XNQ XDFN XDFA XDFB XDFHH XDFCTX XDFPRE XDFPOST XDFID';
+our %PATCH_PROB_COMMON = (
         s => 'S',
-        m => 'XM', # 'mid:' (bool) is exact, 'm:' (prob) can do partial
-        l => 'XL', # 'lid:' (bool) is exact, 'l:' (prob) can do partial
         f => 'A',
-        t => 'XTO',
-        tc => 'XTO XCC',
-        c => 'XCC',
-        tcf => 'XTO XCC A',
-        a => 'XTO XCC A',
-        b => $non_quoted_body . ' XQUOT',
-        bs => $non_quoted_body . ' XQUOT S',
+        b => $NON_QUOTED_BODY . ' XQUOT',
+        bs => $NON_QUOTED_BODY . ' XQUOT S',
         n => 'XFN',
 
         q => 'XQUOT',
-        nq => $non_quoted_body,
+        nq => $NON_QUOTED_BODY,
         dfn => 'XDFN',
         dfa => 'XDFA',
         dfb => 'XDFB',
         dfhh => 'XDFHH',
         dfctx => 'XDFCTX',
+);
 
+my %prob_prefix = (
+        m => 'XM', # 'mid:' (bool) is exact, 'm:' (prob) can do partial
+        l => 'XL', # 'lid:' (bool) is exact, 'l:' (prob) can do partial
+        t => 'XTO',
+        tc => 'XTO XCC',
+        c => 'XCC',
+        tcf => 'XTO XCC A',
+        a => 'XTO XCC A',
+        %PATCH_PROB_COMMON,
         # default:
-        '' => 'XM S A XQUOT XFN ' . $non_quoted_body,
+        '' => 'XM S A XQUOT XFN ' . $NON_QUOTED_BODY,
 );
 
 # not documenting m: and mid: for now, the using the URLs works w/o Xapian
@@ -305,7 +312,7 @@ sub date_parse_prepare {
                                 $x = "\0%Y%m%d%H%M%S$#$to_parse\0";
                         }
                 }
-        } else { # "rt", let git interpret "YYYY", deal with Y10K later :P
+        } else { # (rt|ct), let git interpret "YYYY", deal with Y10K later :P
                 for my $x (@r) {
                         next if $x eq '' || $x =~ /\A[0-9]{5,}\z/;
                         push @$to_parse, $x;
@@ -454,20 +461,24 @@ sub mset_to_smsg {
 # read-write
 sub stemmer { $X{Stem}->new($LANG) }
 
-# read-only
-sub qparse_new {
+sub qp_init_common {
         my ($self) = @_;
-
-        my $xdb = xdb($self);
         my $qp = $X{QueryParser}->new;
         $qp->set_default_op(OP_AND());
-        $qp->set_database($xdb);
+        $qp->set_database(xdb($self));
         $qp->set_stemmer(stemmer($self));
         $qp->set_stemming_strategy(STEM_SOME());
         my $cb = $qp->can('set_max_wildcard_expansion') //
                 $qp->can('set_max_expansion'); # Xapian 1.5.0+
         $cb->($qp, 100);
-        $cb = $qp->can('add_valuerangeprocessor') //
+        $qp;
+}
+
+# read-only
+sub qparse_new {
+        my ($self) = @_;
+        my $qp = qp_init_common($self);
+        my $cb = $qp->can('add_valuerangeprocessor') //
                 $qp->can('add_rangeprocessor'); # Xapian 1.5.0+
         $cb->($qp, $NVRP->new(YYYYMMDD, 'd:'));
         $cb->($qp, $NVRP->new(DT, 'dt:'));
@@ -546,7 +557,7 @@ sub xap_terms ($$;@) {
 }
 
 # get combined docid from over.num:
-# (not generic Xapian, only works with our sharding scheme)
+# (not generic Xapian, only works with our sharding scheme for mail)
 sub num2docid ($$) {
         my ($self, $num) = @_;
         my $nshard = $self->{nshard};
diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index fc464383..3baeaa9c 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -134,6 +134,7 @@ sub idx_acquire {
                 load_xapian_writable();
                 $flag = $self->{creat} ? $DB_CREATE_OR_OPEN : $DB_OPEN;
         }
+        my $owner = $self->{ibx} // $self->{eidx} // $self;
         if ($self->{creat}) {
                 require File::Path;
                 $self->lock_acquire;
@@ -145,14 +146,13 @@ sub idx_acquire {
                         File::Path::mkpath($dir);
                         require PublicInbox::Syscall;
                         PublicInbox::Syscall::nodatacow_dir($dir);
-                        $self->{-set_has_threadid_once} = 1;
-                        if (($self->{ibx} // $self->{eidx})->{-dangerous}) {
-                                $flag |= $DB_DANGEROUS;
-                        }
+                        # owner == self for CodeSearchIdx
+                        $self->{-set_has_threadid_once} = 1 if $owner != $self;
+                        $flag |= $DB_DANGEROUS if $owner->{-dangerous};
                 }
         }
         return unless defined $flag;
-        $flag |= $DB_NO_SYNC if ($self->{ibx} // $self->{eidx})->{-no_fsync};
+        $flag |= $DB_NO_SYNC if $owner->{-no_fsync};
         my $xdb = eval { ($X->{WritableDatabase})->new($dir, $flag) };
         croak "Failed opening $dir: $@" if $@;
         $self->{xdb} = $xdb;
@@ -350,43 +350,30 @@ sub index_diff ($$$) {
         index_text($self, join("\n", @$xnq), 1, 'XNQ');
 }
 
-sub index_xapian { # msg_iter callback
-        my $part = $_[0]->[0]; # ignore $depth and $idx
-        my ($self, $doc) = @{$_[1]};
-        my $ct = $part->content_type || 'text/plain';
-        my $fn = $part->filename;
-        if (defined $fn && $fn ne '') {
-                index_phrase($self, $fn, 1, 'XFN');
-        }
-        if ($part->{is_submsg}) {
-                my $mids = mids_for_index($part);
-                index_ids($self, $doc, $part, $mids);
-                my $smsg = bless {}, 'PublicInbox::Smsg';
-                $smsg->populate($part);
-                index_headers($self, $smsg);
-        }
-
-        my ($s, undef) = msg_part_text($part, $ct);
-        defined $s or return;
-        $_[0]->[0] = $part = undef; # free memory
+sub patch_id {
+        my ($self) = @_; # $_[1] is the diff (may be huge)
+        open(my $fh, '+>:utf8', undef) or die "open: $!";
+        open(my $eh, '+>', undef) or die "open: $!";
+        $fh->autoflush(1);
+        print $fh $_[1] or die "print: $!";
+        sysseek($fh, 0, SEEK_SET) or die "sysseek: $!";
+        my $id = ($self->{ibx} // $self->{eidx} // $self)->git->qx(
+                        [qw(patch-id --stable)], {}, { 0 => $fh, 2 => $eh });
+        seek($eh, 0, SEEK_SET) or die "seek: $!";
+        while (<$eh>) { warn $_ }
+        $id =~ /\A([a-f0-9]{40,})/ ? $1 : undef;
+}
 
-        if ($s =~ /^(?:diff|---|\+\+\+) /ms) {
-                open(my $fh, '+>:utf8', undef) or die "open: $!";
-                open(my $eh, '+>', undef) or die "open: $!";
-                $fh->autoflush(1);
-                print $fh $s or die "print: $!";
-                sysseek($fh, 0, SEEK_SET) or die "sysseek: $!";
-                my $id = ($self->{ibx} // $self->{eidx})->git->qx(
-                                                [qw(patch-id --stable)],
-                                                {}, { 0 => $fh, 2 => $eh });
-                $id =~ /\A([a-f0-9]{40,})/ and $doc->add_term('XDFID'.$1);
-                seek($eh, 0, SEEK_SET) or die "seek: $!";
-                while (<$eh>) { warn $_ }
+sub index_body_text {
+        my ($self, $doc, $sref) = @_;
+        if ($$sref =~ /^(?:diff|---|\+\+\+) /ms) {
+                my $id = patch_id($self, $$sref);
+                $doc->add_term('XDFID'.$id) if defined($id);
         }
 
         # split off quoted and unquoted blocks:
-        my @sections = PublicInbox::MsgIter::split_quotes($s);
-        undef $s; # free memory
+        my @sections = PublicInbox::MsgIter::split_quotes($$sref);
+        undef $$sref; # free memory
         for my $txt (@sections) {
                 if ($txt =~ /\A>/) {
                         if ($txt =~ /^[>\t ]+GIT binary patch\r?/sm) {
@@ -396,8 +383,7 @@ sub index_xapian { # msg_iter callback
                                         (?:[>\h]+$BASE85\h*\r?\n)+/$1/gsmx;
                         }
                         index_text($self, $txt, 0, 'XQUOT');
-                } else {
-                        # does it look like a diff?
+                } else { # does it look like a diff?
                         if ($txt =~ /^(?:diff|---|\+\+\+) /ms) {
                                 index_diff($self, \$txt, $doc);
                         } else {
@@ -408,6 +394,28 @@ sub index_xapian { # msg_iter callback
         }
 }
 
+sub index_xapian { # msg_iter callback
+        my $part = $_[0]->[0]; # ignore $depth and $idx
+        my ($self, $doc) = @{$_[1]};
+        my $ct = $part->content_type || 'text/plain';
+        my $fn = $part->filename;
+        if (defined $fn && $fn ne '') {
+                index_phrase($self, $fn, 1, 'XFN');
+        }
+        if ($part->{is_submsg}) {
+                my $mids = mids_for_index($part);
+                index_ids($self, $doc, $part, $mids);
+                my $smsg = bless {}, 'PublicInbox::Smsg';
+                $smsg->populate($part);
+                index_headers($self, $smsg);
+        }
+
+        my ($s, undef) = msg_part_text($part, $ct);
+        defined $s or return;
+        $_[0]->[0] = $part = undef; # free memory
+        index_body_text($self, $doc, \$s);
+}
+
 sub index_list_id ($$$) {
         my ($self, $doc, $hdr) = @_;
         for my $l ($hdr->header_raw('List-Id')) {
diff --git a/lib/PublicInbox/TestCommon.pm b/lib/PublicInbox/TestCommon.pm
index ed28ac48..494323c0 100644
--- a/lib/PublicInbox/TestCommon.pm
+++ b/lib/PublicInbox/TestCommon.pm
@@ -21,6 +21,7 @@ BEGIN {
         @EXPORT = qw(tmpdir tcp_server tcp_connect require_git require_mods
                 run_script start_script key2sub xsys xsys_e xqx eml_load tick
                 have_xapian_compact json_utf8 setup_public_inboxes create_inbox
+                create_coderepo
                 tcp_host_port test_lei lei lei_ok $lei_out $lei_err $lei_opt
                 test_httpd xbail require_cmd is_xdeeply tail_f
                 ignore_inline_c_missing);
@@ -325,7 +326,7 @@ sub run_script ($;$$) {
                 }
         }
         my $tail = @tail_paths ? tail_f(@tail_paths) : undef;
-        if ($key =~ /-(index|convert|extindex|convert|xcpdb)\z/) {
+        if ($key =~ /-(index|cindex|extindex|convert|xcpdb)\z/) {
                 unshift @argv, '--no-fsync';
         }
         if ($run_mode == 0) {
@@ -698,6 +699,44 @@ sub setup_public_inboxes () {
         @ret;
 }
 
+our %COMMIT_ENV = (
+        GIT_AUTHOR_NAME => 'A U Thor',
+        GIT_COMMITTER_NAME => 'C O Mitter',
+        GIT_AUTHOR_EMAIL => 'a@example.com',
+        GIT_COMMITTER_EMAIL => 'c@example.com',
+);
+
+sub create_coderepo ($$;@) {
+        my $ident = shift;
+        my $cb = pop;
+        my %opt = @_;
+        require PublicInbox::Lock;
+        require PublicInbox::Import;
+        my ($base) = ($0 =~ m!\b([^/]+)\.[^\.]+\z!);
+        my ($db) = (PublicInbox::Import::default_branch() =~ m!([^/]+)\z!);
+        my $dir = "t/data-gen/$base.$ident-$db";
+        my $new = !-d $dir;
+        if ($new && !mkdir($dir)) {
+                my $err = $!;
+                -d $dir or xbail "mkdir($dir): $err";
+        }
+        my $lk = bless { lock_path => "$dir/creat.lock" }, 'PublicInbox::Lock';
+        my $scope = $lk->lock_for_scope;
+        my $tmpdir = delete $opt{tmpdir};
+        if (!-f "$dir/creat.stamp") {
+                opendir(my $dfh, '.') or xbail "opendir .: $!";
+                chdir($dir) or xbail "chdir($dir): $!";
+                local %ENV = (%ENV, %COMMIT_ENV);
+                $cb->($dir);
+                chdir($dfh) or xbail "cd -: $!";
+                open my $s, '>', "$dir/creat.stamp" or
+                        BAIL_OUT "error creating $dir/creat.stamp: $!";
+        }
+        return $dir if !defined($tmpdir);
+        xsys_e([qw(/bin/cp -Rp), $dir, $tmpdir]);
+        $tmpdir;
+}
+
 sub create_inbox ($$;@) {
         my $ident = shift;
         my $cb = pop;