over+msgmap: respect WAL journal_mode if set

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

diff --git a/lib/PublicInbox/Msgmap.pm b/lib/PublicInbox/Msgmap.pm
index e86fb8541bb3e6c0e534317d9058c2809a7473da..d28e96c8588b002e62a09b64dc6eaaad51346309 100644 (file)
--- a/lib/PublicInbox/Msgmap.pm
+++ b/lib/PublicInbox/Msgmap.pm
@@ -9,11 +9,10 @@
 # This is maintained by ::SearchIdx
 package PublicInbox::Msgmap;
 use strict;
-use warnings;
 use DBI;
 use DBD::SQLite;
-use File::Temp qw(tempfile);
 use PublicInbox::Over;
+use PublicInbox::Spawn;
 
 sub new {
        my ($class, $git_dir, $writable) = @_;
@@ -32,12 +31,8 @@ sub new_file {
        my $self = bless { filename => $f }, $class;
        my $dbh = $self->{dbh} = PublicInbox::Over::dbh_new($self, $rw);
        if ($rw) {
-               create_tables($dbh);
-
-               # TRUNCATE reduces I/O compared to the default (DELETE)
-               $dbh->do('PRAGMA journal_mode = TRUNCATE');
-
                $dbh->begin_work;
+               create_tables($dbh);
                $self->created_at(time) unless $self->created_at;
 
                my $max = $self->max // 0;
@@ -49,14 +44,15 @@ sub new_file {
 
 # used to keep track of used numeric mappings for v2 reindex
 sub tmp_clone {
-       my ($self) = @_;
-       my ($fh, $fn) = tempfile('msgmap-XXXXXXXX', EXLOCK => 0, TMPDIR => 1);
+       my ($self, $dir) = @_;
+       require File::Temp;
+       my $tmp = "mm_tmp-$$-XXXXXX";
+       my ($fh, $fn) = File::Temp::tempfile($tmp, EXLOCK => 0, DIR => $dir);
+       PublicInbox::Spawn::nodatacow_fd(fileno($fh));
        $self->{dbh}->sqlite_backup_to_file($fn);
-       my $tmp = ref($self)->new_file($fn, 1);
-       $tmp->{dbh}->do('PRAGMA synchronous = OFF');
+       $tmp = ref($self)->new_file($fn, 2);
        $tmp->{dbh}->do('PRAGMA journal_mode = MEMORY');
        $tmp->{pid} = $$;
-       close $fh or die "failed to close $fn: $!";
        $tmp;
 }
 
@@ -176,18 +172,20 @@ sub num_delete {
 
 sub create_tables {
        my ($dbh) = @_;
-       my $e;
-
-       $e = eval { $dbh->selectrow_array('EXPLAIN SELECT * FROM msgmap;') };
-       defined $e or $dbh->do('CREATE TABLE msgmap (' .
-                       'num INTEGER PRIMARY KEY AUTOINCREMENT, '.
-                       'mid VARCHAR(1000) NOT NULL, ' .
-                       'UNIQUE (mid) )');
-
-       $e = eval { $dbh->selectrow_array('EXPLAIN SELECT * FROM meta') };
-       defined $e or $dbh->do('CREATE TABLE meta (' .
-                       'key VARCHAR(32) PRIMARY KEY, '.
-                       'val VARCHAR(255) NOT NULL)');
+
+       $dbh->do(<<'');
+CREATE TABLE IF NOT EXISTS msgmap (
+       num INTEGER PRIMARY KEY AUTOINCREMENT,
+       mid VARCHAR(1000) NOT NULL,
+       UNIQUE (mid)
+)
+
+       $dbh->do(<<'');
+CREATE TABLE IF NOT EXISTS meta (
+       key VARCHAR(32) PRIMARY KEY,
+       val VARCHAR(255) NOT NULL
+)
+
 }
 
 # used by NNTP.pm
@@ -229,29 +227,30 @@ sub mid_set {
 
 sub DESTROY {
        my ($self) = @_;
-       delete $self->{dbh};
-       my $f = $self->{filename};
+       my $dbh = $self->{dbh} or return;
        if (($self->{pid} // 0) == $$) {
+               my $f = $dbh->sqlite_db_filename;
                unlink $f or warn "failed to unlink $f: $!\n";
        }
 }
 
 sub atfork_parent {
        my ($self) = @_;
-       $self->{pid} or die "not a temporary clone\n";
-       delete $self->{dbh} and die "tmp_clone dbh not prepared for parent";
-       my $dbh = $self->{dbh} = PublicInbox::Over::dbh_new($self, 1);
-       $dbh->do('PRAGMA synchronous = OFF');
+       $self->{pid} or die 'BUG: not a temporary clone';
+       $self->{dbh} and die 'BUG: tmp_clone dbh not prepared for parent';
+       defined($self->{filename}) or die 'BUG: {filename} not defined';
+       $self->{dbh} = PublicInbox::Over::dbh_new($self, 2);
+       $self->{dbh}->do('PRAGMA journal_mode = MEMORY');
 }
 
 sub atfork_prepare {
        my ($self) = @_;
-       $self->{pid} or die "not a temporary clone\n";
-       $self->{pid} == $$ or
-               die "BUG: atfork_prepare not called from $self->{pid}\n";
-       $self->{dbh} or die "temporary clone not open\n";
+       my $pid = $self->{pid} or die 'BUG: not a temporary clone';
+       $pid == $$ or die "BUG: atfork_prepare not called by $pid";
+       my $dbh = $self->{dbh} or die 'BUG: temporary clone not open';
+
        # must clobber prepared statements
-       %$self = (filename => $self->{filename}, pid => $$);
+       %$self = (filename => $dbh->sqlite_db_filename, pid => $pid);
 }
 
 sub skip_artnum {