--- /dev/null
+# Copyright (C) 2020 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# Detached/external index cross inbox search indexing support
+# read-write counterpart to PublicInbox::ExtSearch
+#
+# It's based on the same ideas as public-inbox-v2-format(5) using
+# over.sqlite3 for dedupe and sharded Xapian. msgmap.sqlite3 is
+# missing, so there is no Message-ID conflict resolution, meaning
+# no NNTP support for now.
+#
+# v2 has a 1:1 mapping of index:inbox or msgmap for NNTP support.
+# This is intended to be an M:N index:inbox mapping, but it'll likely
+# be 1:N in common practice (M==1)
+
+package PublicInbox::ExtSearchIdx;
+use strict;
+use v5.10.1;
+use parent qw(PublicInbox::ExtSearch PublicInbox::Lock);
+use Carp qw(croak carp);
+use PublicInbox::Search;
+use PublicInbox::SearchIdx qw(crlf_adjust);
+use PublicInbox::OverIdx;
+use PublicInbox::V2Writable;
+use PublicInbox::InboxWritable;
+use PublicInbox::Eml;
+use File::Spec;
+
+sub new {
+ my (undef, $dir, $opt, $shard) = @_;
+ my $l = $opt->{indexlevel} // 'full';
+ $l !~ $PublicInbox::SearchIdx::INDEXLEVELS and
+ die "invalid indexlevel=$l\n";
+ $l eq 'basic' and die "E: indexlevel=basic not yet supported\n";
+ my $self = bless {
+ xpfx => "$dir/ei".PublicInbox::Search::SCHEMA_VERSION,
+ topdir => $dir,
+ creat => $opt->{creat},
+ ibx_map => {}, # (newsgroup//inboxdir) => $ibx
+ ibx_list => [],
+ indexlevel => $l,
+ transact_bytes => 0,
+ total_bytes => 0,
+ current_info => '',
+ parallel => 1,
+ lock_path => "$dir/ei.lock",
+ }, __PACKAGE__;
+ $self->{shards} = $self->count_shards || nproc_shards($opt->{creat});
+ my $oidx = PublicInbox::OverIdx->new("$self->{xpfx}/over.sqlite3");
+ $oidx->{-no_fsync} = 1 if $opt->{-no_fsync};
+ $self->{oidx} = $oidx;
+ $self
+}
+
+sub attach_inbox {
+ my ($self, $ibx) = @_;
+ my $key = $ibx->eidx_key;
+ if (!$ibx->over || !$ibx->mm) {
+ warn "W: skipping $key (unindexed)\n";
+ return;
+ }
+ if (!defined($ibx->uidvalidity)) {
+ warn "W: skipping $key (no UIDVALIDITY)\n";
+ return;
+ }
+ my $ibxdir = File::Spec->canonpath($ibx->{inboxdir});
+ if ($ibxdir ne $ibx->{inboxdir}) {
+ warn "W: `$ibx->{inboxdir}' canonicalized to `$ibxdir'\n";
+ $ibx->{inboxdir} = $ibxdir;
+ }
+ $ibx = PublicInbox::InboxWritable->new($ibx);
+ $self->{ibx_map}->{$key} //= do {
+ push @{$self->{ibx_list}}, $ibx;
+ $ibx;
+ }
+}
+
+sub _ibx_attach { # each_inbox callback
+ my ($ibx, $self) = @_;
+ attach_inbox($self, $ibx);
+}
+
+sub attach_config {
+ my ($self, $cfg) = @_;
+ $cfg->each_inbox(\&_ibx_attach, $self);
+}
+
+sub git_blob_digest ($) {
+ my ($bref) = @_;
+ my $dig = Digest::SHA->new(1); # XXX SHA256 later
+ $dig->add('blob '.length($$bref)."\0");
+ $dig->add($$bref);
+ $dig;
+}
+
+sub is_bad_blob ($$$$) {
+ my ($oid, $type, $size, $expect_oid) = @_;
+ if ($type ne 'blob') {
+ carp "W: $expect_oid is not a blob (type=$type)";
+ return 1;
+ }
+ croak "BUG: $oid != $expect_oid" if $oid ne $expect_oid;
+ $size == 0 ? 1 : 0; # size == 0 means purged
+}
+
+sub do_xpost ($$) {
+ my ($req, $smsg) = @_;
+ my $self = $req->{eidx};
+ my $docid = $smsg->{num};
+ my $idx = $self->idx_shard($docid);
+ my $oid = $req->{oid};
+ my $xibx = $self->{sync}->{ibx};
+ my $eml = $req->{eml};
+ if (my $new_smsg = $req->{new_smsg}) { # 'm' on cross-posted message
+ my $xnum = $req->{xnum};
+ $idx->shard_add_xref3($docid, $xnum, $oid, $xibx, $eml);
+ } else { # 'd'
+ $idx->shard_remove_xref3($docid, $oid, $xibx, $eml);
+ }
+}
+
+sub index_unseen ($) {
+ my ($req) = @_;
+ my $new_smsg = $req->{new_smsg} or die 'BUG: {new_smsg} unset';
+ $new_smsg->populate($req->{eml}, $req);
+ my $self = $req->{eidx};
+ my $docid = $self->{oidx}->adj_counter('eidx_docid', '+');
+ $new_smsg->{num} = $docid;
+ my $idx = $self->idx_shard($docid);
+ my $eml = delete $req->{eml};
+ $self->{oidx}->add_overview($eml, $new_smsg);
+ $idx->index_raw(undef, $eml, $new_smsg, delete $new_smsg->{ibx});
+}
+
+sub do_finalize ($) {
+ my ($req) = @_;
+ if (my $indexed = $req->{indexed}) {
+ do_xpost($req, $_) for @$indexed;
+ } elsif (exists $req->{new_smsg}) { # totally unseen messsage
+ index_unseen($req);
+ } else {
+ warn "W: ignoring delete $req->{oid} (not found)\n";
+ }
+}
+
+sub do_step ($) { # main iterator for adding messages to the index
+ my ($req) = @_;
+ my $self = $req->{eidx};
+ while (1) {
+ if (my $next_arg = $req->{next_arg}) {
+ if (my $smsg = $self->{oidx}->next_by_mid(@$next_arg)) {
+ $req->{cur_smsg} = $smsg;
+ $self->git->cat_async($smsg->{blob},
+ \&ck_existing, $req);
+ return; # ck_existing calls do_step
+ }
+ delete $req->{cur_smsg};
+ delete $req->{next_arg};
+ }
+ my $mid = shift(@{$req->{mids}});
+ last unless defined $mid;
+ my ($id, $prev);
+ $req->{next_arg} = [ $mid, \$id, \$prev ];
+ # loop again
+ }
+ do_finalize($req);
+}
+
+sub ck_existing { # git->cat_async callback
+ my ($bref, $oid, $type, $size, $req) = @_;
+ my $smsg = $req->{cur_smsg} or die 'BUG: {cur_smsg} missing';
+ return if is_bad_blob($oid, $type, $size, $smsg->{blob});
+ my $cur = PublicInbox::Eml->new($bref);
+ if (content_digest($cur) eq $req->{chash}) {
+ push @{$req->{indexed}}, $smsg; # for do_xpost
+ } # else { index_unseen later }
+ do_step($req);
+}
+
+# is the messages visible in the inbox currently being indexed?
+# return the number if so
+sub cur_ibx_xnum ($$) {
+ my ($req, $bref) = @_;
+ my $ibx = $req->{sync}->{ibx} or die 'BUG: current {ibx} missing';
+
+ # XXX overkill?
+ git_blob_digest($bref)->hexdigest eq $req->{oid} or die
+ "BUG: blob mismatch $req->{oid}";
+
+ $req->{eml} = PublicInbox::Eml->new($bref);
+ $req->{chash} = content_hash($req->{eml});
+ $req->{mids} = mids($req->{eml});
+ my @q = @{$req->{mids}}; # copy
+ while (defined(my $mid = shift @q)) {
+ my ($id, $prev);
+ while (my $x = $ibx->over->next_by_mid($mid, \$id, \$prev)) {
+ return $x->{num} if $x->{blob} eq $req->{oid};
+ }
+ }
+ undef;
+}
+
+sub m_start { # git->cat_async callback for 'm'
+ my ($bref, $oid, $type, $size, $req) = @_;
+ return if is_bad_blob($oid, $type, $size, $req->{oid});
+ my $new_smsg = $req->{new_smsg} = bless {
+ blob => $oid,
+ raw_bytes => $size,
+ }, 'PublicInbox::Smsg';
+ $new_smsg->{bytes} = $new_smsg->{raw_bytes} + crlf_adjust($$bref);
+ defined($req->{xnum} = cur_ibx_xnum($req, $bref)) or return;
+ $new_smsg->{ibx} = $req->{sync}->{ibx};
+ do_step($req);
+}
+
+sub d_start { # git->cat_async callback for 'd'
+ my ($bref, $oid, $type, $size, $req) = @_;
+ return if is_bad_blob($oid, $type, $size, $req->{oid});
+ return if defined(cur_ibx_xnum($req, $bref)); # was re-added
+ do_step($req);
+}
+
+sub eidx_last_epoch_commit ($$$) {
+ my ($self, $sync, $epoch) = @_;
+ my $key = $sync->{ibx}->eidx_key;
+ my $uidvalidity = $sync->{ibx}->uidvalidity;
+ $self->{oidx}->eidx_meta("lc-v2:$key//$uidvalidity;$epoch");
+}
+
+sub _sync_inbox ($$$) {
+ my ($self, $opt, $ibx) = @_;
+ my $sync = {
+ need_checkpoint => \(my $bool = 0),
+ unindex_range => {}, # EPOCH => oid_old..oid_new
+ reindex => $opt->{reindex},
+ -opt => $opt,
+ eidx => $self,
+ ibx => $ibx,
+ };
+ my $key = $ibx->eidx_key;
+ my $u = $ibx->uidvalidity;
+ my $oidx = $self->{oidx};
+ my $v = $ibx->version;
+ if ($v == 2) {
+ my $epoch_max;
+ defined($ibx->git_dir_latest(\$epoch_max)) or return;
+ my $heads = $sync->{ranges} = [];
+ for my $i (0..$epoch_max) {
+ $heads->[$i] = $oidx->eidx_meta("lc-v2:$key//$u;$i");
+ }
+
+
+ } elsif ($v == 1) {
+ my $lc = $oidx->eidx_meta("lc-v1:$key//$u");
+ prepare_stack($sync, $lc ? "$lc..HEAD" : 'HEAD');
+ } else {
+ warn "E: $key unsupported inbox version (v$v)\n";
+ return;
+ }
+}
+
+sub eidx_sync { # main entry point
+ my ($self, $opt) = @_;
+ $self->idx_init($opt); # acquire lock via V2Writable::_idx_init
+ $self->{oidx}->rethread_prepare($opt);
+
+ _sync_inbox($self, $opt, $_) for (@{$self->{ibx_list}});
+}
+
+sub idx_init { # similar to V2Writable
+ my ($self, $opt) = @_;
+ return if $self->{idx_shards};
+
+ $self->git->cleanup;
+
+ my $ALL = $self->git->{git_dir}; # ALL.git
+ PublicInbox::Import::init_bare($ALL) unless -d $ALL;
+ my $info_dir = "$ALL/objects/info";
+ my $alt = "$info_dir/alternates";
+ my $mode = 0644;
+ my (%old, @old, %new, @new);
+ if (-e $alt) {
+ open(my $fh, '<', $alt) or die "open $alt: $!";
+ $mode = (stat($fh))[2] & 07777;
+ while (<$fh>) {
+ push @old, $_ if !$old{$_}++;
+ }
+ }
+ for my $ibx (@{$self->{ibx_list}}) {
+ my $line = $ibx->git->{git_dir} . "/objects\n";
+ next if $old{$line};
+ $new{$line} = 1;
+ push @new, $line;
+ }
+ push @old, @new;
+ PublicInbox::V2Writable::write_alternates($info_dir, $mode, \@old);
+ $self->parallel_init($self->{indexlevel});
+ $self->umask_prepare;
+ $self->with_umask(\&PublicInbox::V2Writable::_idx_init, $self, $opt);
+ $self->{oidx}->begin_lazy;
+ $self->{oidx}->eidx_prep;
+}
+
+no warnings 'once';
+*done = \&PublicInbox::V2Writable::done;
+*umask_prepare = \&PublicInbox::InboxWritable::umask_prepare;
+*with_umask = \&PublicInbox::InboxWritable::with_umask;
+*parallel_init = \&PublicInbox::V2Writable::parallel_init;
+*nproc_shards = \&PublicInbox::V2Writable::nproc_shards;
+
+1;