nntp: simplify the long_response API

[public-inbox.git] / lib / PublicInbox / Msgmap.pm

diff --git a/lib/PublicInbox/Msgmap.pm b/lib/PublicInbox/Msgmap.pm
index b66ad8af3d49a44b6c3aa7d4f273b6bb823479a0..c6a73155401b9bb3c1c6fd4c5adedddb79a01bbf 100644 (file)
--- a/lib/PublicInbox/Msgmap.pm
+++ b/lib/PublicInbox/Msgmap.pm
@@ -1,5 +1,5 @@
-# Copyright (C) 2015 all contributors <meta@public-inbox.org>
-# License: AGPLv3 or later (https://www.gnu.org/licenses/agpl-3.0.txt)
+# Copyright (C) 2015-2018 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # bidirectional Message-ID <-> Article Number mapping for the NNTP
 # and web interfaces.  This is required for implementing stable article
@@ -12,6 +12,7 @@ use strict;
 use warnings;
 use DBI;
 use DBD::SQLite;
+use File::Temp qw(tempfile);
 
 sub new {
        my ($class, $git_dir, $writable) = @_;
@@ -23,9 +24,8 @@ sub new {
        new_file($class, "$d/msgmap.sqlite3", $writable);
 }
 
-sub new_file {
-       my ($class, $f, $writable) = @_;
-
+sub dbh_new {
+       my ($f, $writable) = @_;
        my $dbh = DBI->connect("dbi:SQLite:dbname=$f",'','', {
                AutoCommit => 1,
                RaiseError => 1,
@@ -34,6 +34,14 @@ sub new_file {
                sqlite_use_immediate_transaction => 1,
        });
        $dbh->do('PRAGMA case_sensitive_like = ON');
+       $dbh;
+}
+
+sub new_file {
+       my ($class, $f, $writable) = @_;
+       return if !$writable && !-r $f;
+
+       my $dbh = dbh_new($f, $writable);
        my $self = bless { dbh => $dbh }, $class;
 
        if ($writable) {
@@ -45,6 +53,19 @@ sub new_file {
        $self;
 }
 
+# used to keep track of used numeric mappings for v2 reindex
+sub tmp_clone {
+       my ($self) = @_;
+       my ($fh, $fn) = tempfile('msgmap-XXXXXXXX', EXLOCK => 0, TMPDIR => 1);
+       $self->{dbh}->sqlite_backup_to_file($fn);
+       my $tmp = ref($self)->new_file($fn, 1);
+       $tmp->{dbh}->do('PRAGMA synchronous = OFF');
+       $tmp->{tmp_name} = $fn; # SQLite won't work if unlinked, apparently
+       $tmp->{pid} = $$;
+       close $fh or die "failed to close $fn: $!";
+       $tmp;
+}
+
 # n.b. invoked directly by scripts/xhdr-num2mid
 sub meta_accessor {
        my ($self, $key, $value) = @_;
@@ -140,6 +161,14 @@ sub mid_delete {
        $sth->execute;
 }
 
+sub num_delete {
+       my ($self, $num) = @_;
+       my $dbh = $self->{dbh};
+       my $sth = $dbh->prepare('DELETE FROM msgmap WHERE num = ?');
+       $sth->bind_param(1, $num);
+       $sth->execute;
+}
+
 sub create_tables {
        my ($dbh) = @_;
        my $e;
@@ -157,17 +186,26 @@ sub create_tables {
 }
 
 # used by NNTP.pm
-sub id_batch {
-       my ($self, $num, $cb) = @_;
+sub ids_after {
+       my ($self, $num) = @_;
+       my $ids = $self->{dbh}->selectcol_arrayref(<<'', undef, $$num);
+SELECT num FROM msgmap WHERE num > ?
+ORDER BY num ASC LIMIT 1000
+
+       $$num = $ids->[-1] if @$ids;
+       $ids;
+}
+
+sub msg_range {
+       my ($self, $beg, $end) = @_;
        my $dbh = $self->{dbh};
-       my $sth = $dbh->prepare('SELECT num FROM msgmap WHERE num > ? '.
-                               'ORDER BY num ASC LIMIT 1000');
-       $sth->execute($num);
-       my $ary = $sth->fetchall_arrayref;
-       @$ary = map { $_->[0] } @$ary;
-       my $nr = scalar @$ary;
-       $cb->($ary) if $nr;
-       $nr;
+       my $attr = { Columns => [] };
+       my $mids = $dbh->selectall_arrayref(<<'', $attr, $$beg, $end);
+SELECT num,mid FROM msgmap WHERE num >= ? AND num <= ?
+ORDER BY num ASC
+
+       $$beg = $mids->[-1]->[0] + 1 if @$mids;
+       $mids
 }
 
 # only used for mapping external serial numbers (e.g. articles from gmane)
@@ -181,4 +219,31 @@ sub mid_set {
        $sth->execute($num, $mid);
 }
 
+sub DESTROY {
+       my ($self) = @_;
+       delete $self->{dbh};
+       my $f = delete $self->{tmp_name};
+       if (defined $f && $self->{pid} == $$) {
+               unlink $f or warn "failed to unlink $f: $!\n";
+       }
+}
+
+sub atfork_parent {
+       my ($self) = @_;
+       my $f = $self->{tmp_name} or die "not a temporary clone\n";
+       delete $self->{dbh} and die "tmp_clone dbh not prepared for parent";
+       my $dbh = $self->{dbh} = dbh_new($f, 1);
+       $dbh->do('PRAGMA synchronous = OFF');
+}
+
+sub atfork_prepare {
+       my ($self) = @_;
+       my $f = $self->{tmp_name} or die "not a temporary clone\n";
+       $self->{pid} == $$ or
+               die "BUG: atfork_prepare not called from $self->{pid}\n";
+       $self->{dbh} or die "temporary clone not open\n";
+       # must clobber prepared statements
+       %$self = (tmp_name => $f, pid => $$);
+}
+
 1;