# Copyright (C) 2015 all contributors
# License: AGPLv3 or later (https://www.gnu.org/licenses/agpl-3.0.txt)
# based on notmuch, but with no concept of folders, files or flags
#
# Read-only search interface for use by the web and NNTP interfaces
package PublicInbox::Search;
use strict;
use warnings;
# values for searching
use constant TS => 0; # timestamp
use constant NUM => 1; # NNTP article number
use constant BYTES => 2; # :bytes as defined in RFC 3977
use constant LINES => 3; # :lines as defined in RFC 3977
use constant YYYYMMDD => 4; # for searching in the WWW UI
use Search::Xapian qw/:standard/;
use PublicInbox::SearchMsg;
use PublicInbox::MIME;
use PublicInbox::MID qw/mid_clean id_compress/;
# This is English-only, everything else is non-standard and may be confused as
# a prefix common in patch emails
our $REPLY_RE = qr/^re:\s+/i;
our $LANG = 'english';
use constant {
# SCHEMA_VERSION history
# 0 - initial
# 1 - subject_path is lower-cased
# 2 - subject_path is id_compress in the index, only
# 3 - message-ID is compressed if it includes '%' (hack!)
# 4 - change "Re: " normalization, avoid circular Reference ghosts
# 5 - subject_path drops trailing '.'
# 6 - preserve References: order in document data
# 7 - remove references and inreplyto terms
# 8 - remove redundant/unneeded document data
# 9 - disable Message-ID compression (SHA-1)
# 10 - optimize doc for NNTP overviews
# 11 - merge threads when vivifying ghosts
# 12 - change YYYYMMDD value column to numeric
# 13 - fix threading for empty References/In-Reply-To
# (commit 83425ef12e4b65cdcecd11ddcb38175d4a91d5a0)
# 14 - fix ghost root vivification
SCHEMA_VERSION => 14,
# n.b. FLAG_PURE_NOT is expensive not suitable for a public website
# as it could become a denial-of-service vector
QP_FLAGS => FLAG_PHRASE|FLAG_BOOLEAN|FLAG_LOVEHATE|FLAG_WILDCARD,
};
# setup prefixes
my %bool_pfx_internal = (
type => 'T', # "mail" or "ghost"
thread => 'G', # newsGroup (or similar entity - e.g. a web forum name)
);
my %bool_pfx_external = (
mid => 'Q', # uniQue id (Message-ID)
);
my %prob_prefix = (
# for mairix compatibility
s => 'S',
m => 'XMID', # 'mid:' (bool) is exact, 'm:' (prob) can do partial
f => 'A',
t => 'XTO',
tc => 'XTO XCC',
c => 'XCC',
tcf => 'XTO XCC A',
a => 'XTO XCC A',
b => 'XNQ XQUOT',
bs => 'XNQ XQUOT S',
n => 'XFN',
q => 'XQUOT',
nq => 'XNQ',
dfn => 'XDFN',
dfa => 'XDFA',
dfb => 'XDFB',
dfhh => 'XDFHH',
dfctx => 'XDFCTX',
dfpre => 'XDFPRE',
dfpost => 'XDFPOST',
dfblob => 'XDFPRE XDFPOST',
# default:
'' => 'XMID S A XNQ XQUOT XFN',
);
# not documenting m: and mid: for now, the using the URLs works w/o Xapian
our @HELP = (
's:' => 'match within Subject e.g. s:"a quick brown fox"',
'd:' => < 'match within message body, including text attachments',
'nq:' => 'match non-quoted text within message body',
'q:' => 'match quoted text within message body',
'n:' => 'match filename of attachment(s)',
't:' => 'match within the To header',
'c:' => 'match within the Cc header',
'f:' => 'match within the From header',
'a:' => 'match within the To, Cc, and From headers',
'tc:' => 'match within the To and Cc headers',
'bs:' => 'match within the Subject and body',
'dfn:' => 'match filename from diff',
'dfa:' => 'match diff removed (-) lines',
'dfb:' => 'match diff added (+) lines',
'dfhh:' => 'match diff hunk header context (usually a function name)',
'dfctx:' => 'match diff context lines',
'dfpre:' => 'match pre-image git blob ID',
'dfpost:' => 'match post-image git blob ID',
'dfblob:' => 'match either pre or post-image git blob ID',
);
chomp @HELP;
my $mail_query = Search::Xapian::Query->new('T' . 'mail');
sub xdir {
my (undef, $git_dir) = @_;
"$git_dir/public-inbox/xapian" . SCHEMA_VERSION;
}
sub new {
my ($class, $git_dir, $altid) = @_;
my $dir = $class->xdir($git_dir);
my $db = Search::Xapian::Database->new($dir);
bless { xdb => $db, git_dir => $git_dir, altid => $altid }, $class;
}
sub reopen { $_[0]->{xdb}->reopen }
# read-only
sub query {
my ($self, $query_string, $opts) = @_;
my $query;
$opts ||= {};
unless ($query_string eq '') {
$query = $self->qp->parse_query($query_string, QP_FLAGS);
$opts->{relevance} = 1 unless exists $opts->{relevance};
}
_do_enquire($self, $query, $opts);
}
sub get_thread {
my ($self, $mid, $opts) = @_;
my $smsg = eval { $self->lookup_message($mid) };
return { total => 0, msgs => [] } unless $smsg;
my $qtid = Search::Xapian::Query->new('G' . $smsg->thread_id);
my $path = $smsg->path;
if (defined $path && $path ne '') {
my $path = id_compress($smsg->path);
my $qsub = Search::Xapian::Query->new('XPATH' . $path);
$qtid = Search::Xapian::Query->new(OP_OR, $qtid, $qsub);
}
$opts ||= {};
$opts->{limit} ||= 1000;
# always sort threads by timestamp, this makes life easier
# for the threading algorithm (in SearchThread.pm)
$opts->{asc} = 1;
_do_enquire($self, $qtid, $opts);
}
sub retry_reopen {
my ($self, $cb) = @_;
my $ret;
for (1..10) {
eval { $ret = $cb->() };
return $ret unless $@;
# Exception: The revision being read has been discarded -
# you should call Xapian::Database::reopen()
if (ref($@) eq 'Search::Xapian::DatabaseModifiedError') {
reopen($self);
} else {
die;
}
}
}
sub _do_enquire {
my ($self, $query, $opts) = @_;
retry_reopen($self, sub { _enquire_once($self, $query, $opts) });
}
sub _enquire_once {
my ($self, $query, $opts) = @_;
my $enquire = $self->enquire;
if (defined $query) {
$query = Search::Xapian::Query->new(OP_AND,$query,$mail_query);
} else {
$query = $mail_query;
}
$enquire->set_query($query);
$opts ||= {};
my $desc = !$opts->{asc};
if ($opts->{relevance}) {
$enquire->set_sort_by_relevance_then_value(TS, $desc);
} elsif ($opts->{num}) {
$enquire->set_sort_by_value(NUM, 0);
} else {
$enquire->set_sort_by_value_then_relevance(TS, $desc);
}
my $offset = $opts->{offset} || 0;
my $limit = $opts->{limit} || 50;
my $mset = $enquire->get_mset($offset, $limit);
return $mset if $opts->{mset};
my @msgs = map {
PublicInbox::SearchMsg->load_doc($_->get_document);
} $mset->items;
{ total => $mset->get_matches_estimated, msgs => \@msgs }
}
# read-write
sub stemmer { Search::Xapian::Stem->new($LANG) }
# read-only
sub qp {
my ($self) = @_;
my $qp = $self->{query_parser};
return $qp if $qp;
# new parser
$qp = Search::Xapian::QueryParser->new;
$qp->set_default_op(OP_AND);
$qp->set_database($self->{xdb});
$qp->set_stemmer($self->stemmer);
$qp->set_stemming_strategy(STEM_SOME);
$qp->add_valuerangeprocessor(
Search::Xapian::NumberValueRangeProcessor->new(YYYYMMDD, 'd:'));
while (my ($name, $prefix) = each %bool_pfx_external) {
$qp->add_boolean_prefix($name, $prefix);
}
# we do not actually create AltId objects,
# just parse the spec to avoid the extra DB handles for now.
if (my $altid = $self->{altid}) {
my $user_pfx = $self->{-user_pfx} ||= [];
for (@$altid) {
# $_ = 'serial:gmane:/path/to/gmane.msgmap.sqlite3'
/\Aserial:(\w+):/ or next;
my $pfx = $1;
push @$user_pfx, "$pfx:", < XGMANE
$qp->add_boolean_prefix($pfx, 'X'.uc($pfx));
}
chomp @$user_pfx;
}
while (my ($name, $prefix) = each %prob_prefix) {
$qp->add_prefix($name, $_) foreach split(/ /, $prefix);
}
$self->{query_parser} = $qp;
}
sub num_range_processor {
$_[0]->{nrp} ||= Search::Xapian::NumberValueRangeProcessor->new(NUM);
}
# only used for NNTP server
sub query_xover {
my ($self, $beg, $end, $offset) = @_;
my $qp = Search::Xapian::QueryParser->new;
$qp->set_database($self->{xdb});
$qp->add_valuerangeprocessor($self->num_range_processor);
my $query = $qp->parse_query("$beg..$end", QP_FLAGS);
_do_enquire($self, $query, {num => 1, limit => 200, offset => $offset});
}
sub lookup_message {
my ($self, $mid) = @_;
$mid = mid_clean($mid);
my $doc_id = $self->find_unique_doc_id('Q' . $mid);
my $smsg;
if (defined $doc_id) {
# raises on error:
my $doc = $self->{xdb}->get_document($doc_id);
$smsg = PublicInbox::SearchMsg->wrap($doc, $mid);
$smsg->{doc_id} = $doc_id;
}
$smsg;
}
sub lookup_mail { # no ghosts!
my ($self, $mid) = @_;
retry_reopen($self, sub {
my $smsg = lookup_message($self, $mid) or return;
PublicInbox::SearchMsg->load_doc($smsg->{doc});
});
}
sub find_unique_doc_id {
my ($self, $termval) = @_;
my ($begin, $end) = $self->find_doc_ids($termval);
return undef if $begin->equal($end); # not found
my $rv = $begin->get_docid;
# sanity check
$begin->inc;
$begin->equal($end) or die "Term '$termval' is not unique\n";
$rv;
}
# returns begin and end PostingIterator
sub find_doc_ids {
my ($self, $termval) = @_;
my $db = $self->{xdb};
($db->postlist_begin($termval), $db->postlist_end($termval));
}
# normalize subjects so they are suitable as pathnames for URLs
# XXX: consider for removal
sub subject_path {
my $subj = pop;
$subj = subject_normalized($subj);
$subj =~ s![^a-zA-Z0-9_\.~/\-]+!_!g;
lc($subj);
}
sub subject_normalized {
my $subj = pop;
$subj =~ s/\A\s+//s; # no leading space
$subj =~ s/\s+\z//s; # no trailing space
$subj =~ s/\s+/ /gs; # no redundant spaces
$subj =~ s/\.+\z//; # no trailing '.'
$subj =~ s/$REPLY_RE//igo; # remove reply prefix
$subj;
}
sub enquire {
my ($self) = @_;
$self->{enquire} ||= Search::Xapian::Enquire->new($self->{xdb});
}
sub help {
my ($self) = @_;
$self->qp; # parse altids
my @ret = @HELP;
if (my $user_pfx = $self->{-user_pfx}) {
push @ret, @$user_pfx;
}
\@ret;
}
1;