File Coverage

blib/lib/DBIx/TransactionManager.pm

Criterion	Covered	Total	%
statement	12	68	17.6
branch	0	26	0.0
condition	0	7	0.0
subroutine	4	18	22.2
pod	2	7	28.5
total	18	126	14.2

package DBIx::TransactionManager;
use strict;
use warnings;
use Carp ();
our $VERSION = '1.13';

sub new {
    my ($class, $dbh) = @_;

    unless ($dbh) {
        Carp::croak('missing mandatory parameter dbh');
    }

    bless {
        dbh => $dbh,
        active_transactions => [],
        rollbacked_in_nested_transaction => 0,
    }, $class;
}

sub txn_scope {
    DBIx::TransactionManager::ScopeGuard->new( @_ );
}

sub txn_begin {
    my ($self, %args) = @_;

    my $caller = $args{caller} || [ caller(0) ];
    my $txns   = $self->{active_transactions};
    my $rc = 1;
    if (@$txns == 0 && $self->{dbh}->FETCH('AutoCommit')) {
        $rc = $self->{dbh}->begin_work;
    }
    if ($rc) {
        push @$txns, { caller => $caller, pid => $$ };
    }
}

sub txn_rollback {
    my $self = shift;
    my $txns = $self->{active_transactions};
    return unless @$txns;

    my $current = pop @$txns;
    if ( @$txns > 0 ) {
        # already popped, so if there's anything, we're in a nested
        # transaction, mate.
        $self->{rollbacked_in_nested_transaction}++;
    } else {
        $self->{dbh}->rollback;
        $self->_txn_end;
    }
}

sub txn_commit {
    my $self = shift;
    my $txns = $self->{active_transactions};
    return unless @$txns;

    if ( $self->{rollbacked_in_nested_transaction} ) {
        Carp::croak "tried to commit but already rollbacked in nested transaction.";
    }

    my $current = pop @$txns;
    if (@$txns == 0) {
        $self->{dbh}->commit;
        $self->_txn_end;
    }
}

sub _txn_end {
    @{$_[0]->{active_transactions}} = ();
    $_[0]->{rollbacked_in_nested_transaction} = 0;
}

sub active_transactions { $_[0]->{active_transactions} }

sub in_transaction {
    my $self = shift;
    my $txns = $self->{active_transactions};
    return @$txns ? $txns->[0] : ();
}

package DBIx::TransactionManager::ScopeGuard;
use Try::Tiny;

sub new {
    my($class, $obj, %args) = @_;

    my $caller = $args{caller} || [ caller(1) ];
    $obj->txn_begin( caller => $caller );
    bless [ 0, $obj, $caller, $$ ], $class;
}

sub rollback {
    return if $_[0]->[0]; # do not run twice.
    $_[0]->[1]->txn_rollback;
    $_[0]->[0] = 1;
}

sub commit {
    return if $_[0]->[0]; # do not run twice.
    $_[0]->[1]->txn_commit;
    $_[0]->[0] = 1;
}

sub DESTROY {
    my($dismiss, $obj, $caller, $pid) = @{ $_[0] };
    return if $dismiss;

    if ( $$ != $pid ) {
        return;
    }

    warn( "Transaction was aborted without calling an explicit commit or rollback. (Guard created at $caller->[1] line $caller->[2])" );

    try {
        $obj->txn_rollback;
    } catch {
        die "Rollback failed: $_";
    };
}

1;
__END__