# Copyright (C) 2018-2020 all contributors
# License: AGPL-3.0+
# Internal interface for a single Xapian shard in V2 inboxes.
# See L for more info on how we shard Xapian
package PublicInbox::SearchIdxShard;
use strict;
use v5.10.1;
use parent qw(PublicInbox::SearchIdx);
use IO::Handle (); # autoflush
use PublicInbox::Eml;
sub new {
my ($class, $v2w, $shard) = @_;
my $ibx = $v2w->{ibx};
my $self = $class->SUPER::new($ibx, 1, $shard);
# create the DB before forking:
$self->idx_acquire;
$self->set_metadata_once;
$self->idx_release;
$self->spawn_worker($v2w, $shard) if $v2w->{parallel};
$self;
}
sub spawn_worker {
my ($self, $v2w, $shard) = @_;
my ($r, $w);
pipe($r, $w) or die "pipe failed: $!\n";
$w->autoflush(1);
my $pid = fork;
defined $pid or die "fork failed: $!\n";
if ($pid == 0) {
my $bnote = $v2w->atfork_child;
close $w or die "failed to close: $!";
# F_SETPIPE_SZ = 1031 on Linux; increasing the pipe size here
# speeds V2Writable batch imports across 8 cores by nearly 20%
fcntl($r, 1031, 1048576) if $^O eq 'linux';
eval { shard_worker_loop($self, $v2w, $r, $shard, $bnote) };
die "worker $shard died: $@\n" if $@;
die "unexpected MM $self->{mm}" if $self->{mm};
exit;
}
$self->{pid} = $pid;
$self->{w} = $w;
close $r or die "failed to close: $!";
}
# this reads all the writes to $self->{w} from the parent process
sub shard_worker_loop ($$$$$) {
my ($self, $v2w, $r, $shard, $bnote) = @_;
$0 = "pi-v2-shard[$shard]";
$self->begin_txn_lazy;
while (my $line = readline($r)) {
$v2w->{current_info} = "[$shard] $line";
if ($line eq "commit\n") {
$self->commit_txn_lazy;
} elsif ($line eq "close\n") {
$self->idx_release;
} elsif ($line eq "barrier\n") {
$self->commit_txn_lazy;
# no need to lock < 512 bytes is atomic under POSIX
print $bnote "barrier $shard\n" or
die "write failed for barrier $!\n";
} elsif ($line =~ /\AD ([a-f0-9]{40,}) ([0-9]+)\n\z/s) {
$self->remove_by_oid($1, $2 + 0);
} else {
chomp $line;
# n.b. $mid may contain spaces(!)
my ($to_read, $bytes, $num, $blob, $ds, $ts, $tid, $mid)
= split(/ /, $line, 8);
$self->begin_txn_lazy;
my $n = read($r, my $msg, $to_read) or die "read: $!\n";
$n == $to_read or die "short read: $n != $to_read\n";
my $mime = PublicInbox::Eml->new(\$msg);
my $smsg = bless {
bytes => $bytes,
num => $num + 0,
blob => $blob,
mid => $mid,
tid => $tid,
ds => $ds,
ts => $ts,
}, 'PublicInbox::Smsg';
$self->add_message($mime, $smsg);
}
}
$self->worker_done;
}
sub index_raw {
my ($self, $msgref, $eml, $smsg) = @_;
if (my $w = $self->{w}) {
# mid must be last, it can contain spaces (but not LF)
print $w join(' ', @$smsg{qw(raw_bytes bytes
num blob ds ts tid mid)}),
"\n", $$msgref or die "failed to write shard $!\n";
} else {
if ($eml) {
undef $$msgref;
} else { # --xapian-only + --sequential-shard:
$eml = PublicInbox::Eml->new($msgref);
}
$self->begin_txn_lazy;
$self->add_message($eml, $smsg);
}
}
sub atfork_child {
close $_[0]->{w} or die "failed to close write pipe: $!\n";
}
sub shard_barrier {
my ($self) = @_;
if (my $w = $self->{w}) {
print $w "barrier\n" or die "failed to print: $!";
} else {
$self->commit_txn_lazy;
}
}
sub shard_commit {
my ($self) = @_;
if (my $w = $self->{w}) {
print $w "commit\n" or die "failed to write commit: $!";
} else {
$self->commit_txn_lazy;
}
}
sub shard_close {
my ($self) = @_;
if (my $w = delete $self->{w}) {
my $pid = delete $self->{pid} or die "no process to wait on\n";
print $w "close\n" or die "failed to write to pid:$pid: $!\n";
close $w or die "failed to close pipe for pid:$pid: $!\n";
waitpid($pid, 0) == $pid or die "remote process did not finish";
$? == 0 or die ref($self)." pid:$pid exited with: $?";
} else {
die "transaction in progress $self\n" if $self->{txn};
$self->idx_release if $self->{xdb};
}
}
sub shard_remove {
my ($self, $oid, $num) = @_;
if (my $w = $self->{w}) { # triggers remove_by_oid in a shard child
print $w "D $oid $num\n" or die "failed to write remove $!";
} else { # same process
$self->remove_by_oid($oid, $num);
}
}
1;