1 # Copyright (C) 2020-2021 all contributors <meta@public-inbox.org>
2 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
4 # fork()-friendly key-value store. Will be used for making
5 # augmenting Maildirs and mboxes less expensive, maybe.
6 # We use flock(2) to avoid SQLite lock problems (busy timeouts, backoff)
7 package PublicInbox::SharedKV;
10 use parent qw(PublicInbox::Lock);
11 use File::Temp qw(tempdir);
13 use PublicInbox::Spawn;
14 use File::Path qw(rmtree);
17 my ($self, $lock) = @_;
19 my $f = $self->{filename};
20 $lock //= $self->lock_for_scope;
21 my $dbh = DBI->connect("dbi:SQLite:dbname=$f", '', '', {
25 sqlite_use_immediate_transaction => 1,
26 # no sqlite_unicode here, this is for binary data
28 my $opt = $self->{opt} // {};
29 $dbh->do('PRAGMA synchronous = OFF') if !$opt->{fsync};
30 $dbh->do('PRAGMA cache_size = '.($opt->{cache_size} || 80000));
31 $dbh->do('PRAGMA journal_mode = '.
32 ($opt->{journal_mode} // 'WAL'));
34 CREATE TABLE IF NOT EXISTS kv (
35 k VARBINARY PRIMARY KEY NOT NULL,
45 my ($cls, $dir, $base, $opt) = @_;
46 my $self = bless { opt => $opt }, $cls;
47 unless (defined $dir) {
48 $self->{tmpdir} = $dir = tempdir('skv-XXXXXX', TMPDIR => 1);
49 $self->{tmpid} = "$$.$self";
51 -d $dir or mkdir($dir) or die "mkdir($dir): $!";
53 my $f = $self->{filename} = "$dir/$base.sqlite3";
54 $self->{lock_path} = $opt->{lock_path} // "$dir/$base.flock";
56 open my $fh, '+>>', $f or die "failed to open $f: $!";
57 PublicInbox::Spawn::nodatacow_fd(fileno($fh));
64 my $lock = $self->lock_for_scope;
65 $self->dbh($lock)->do('CREATE INDEX IF NOT EXISTS idx_v ON kv (v)');
69 my ($self, $key, $val, $lock) = @_;
70 $lock //= $self->lock_for_scope;
71 my $e = $self->{dbh}->prepare_cached(<<'')->execute($key, $val);
72 INSERT OR IGNORE INTO kv (k,v) VALUES (?, ?)
77 # caller calls sth->fetchrow_array
80 my $sth = $self->{dbh}->prepare_cached(<<'', undef, 1);
88 my ($self, $val, $lock) = @_;
89 $lock //= $self->lock_for_scope;
90 $self->{dbh}->prepare_cached(<<'')->execute($val) + 0;
91 DELETE FROM kv WHERE v = ?
96 my ($self, $oldval, $newval, $lock) = @_;
97 $lock //= $self->lock_for_scope;
98 $self->{dbh}->prepare_cached(<<'')->execute($newval, $oldval) + 0;
99 UPDATE kv SET v = ? WHERE v = ?
104 my ($self, $key, $val) = @_;
106 my $e = $self->{dbh}->prepare_cached(<<'')->execute($key, $val);
107 INSERT OR REPLACE INTO kv (k,v) VALUES (?,?)
109 $e == 0 ? undef : $e;
111 $self->{dbh}->prepare_cached(<<'')->execute($key);
112 DELETE FROM kv WHERE k = ?
118 my ($self, $key) = @_;
119 my $sth = $self->{dbh}->prepare_cached(<<'', undef, 1);
120 SELECT v FROM kv WHERE k = ?
123 $sth->fetchrow_array;
127 my ($self, $key, $newval, $lock) = @_;
128 $lock //= $self->lock_for_scope;
129 my $oldval = get($self, $key);
130 if (defined $newval) {
131 set($self, $key, $newval);
133 $self->{dbh}->prepare_cached(<<'')->execute($key);
134 DELETE FROM kv WHERE k = ?
142 my $sth = $self->{dbh}->prepare_cached(<<'');
143 SELECT COUNT(k) FROM kv
146 $sth->fetchrow_array;
151 rmtree($self->{tmpdir}) if ($self->{tmpid} // '') eq "$$.$self";