I haven't tested this but believe it is cleaner to write as
sub commit () {
($T || ${ caller() . '::T' })->commit;
goto END_XACTION;
}
sub rollback () {
($T || ${ caller() . '::T' })->rollback;
goto END_XACTION;
}
sub transaction (&) {
my ($block) = @_;
local $T = ${ caller() . '::T' } or croak "\$T not set";
local $@;
eval {
$T->begin_work;
$block->();
};
$@ ? rollback : commit;
END_XACTION: die $@ . "commit not safe after errors, transaction r
+olled back"
if $@;
}
I would suggest you work with
die instead though - that will work with nested transactions and require fewer hoop jumps. You can then also easily add some more error checking:
sub commit {
require Carp;
Carp::croak("Can't commit outside a transaction");
}
sub rollback {
require Carp;
Carp::croak("Can't rollback outside a transaction");
}
sub transaction (&) {
my ($block) = @_;
my $caller = caller();
local *{"${caller}::commit"} = sub { die "!COMMIT\n" };
local *{"${caller}::rollback"} = sub { die "!ROLLBACK\n" };
local $@;
eval {
$T->begin_work;
$block->();
};
if(!$@ or $@ eq "!COMMIT\n") {
${"${caller}::T"}->commit;
}
elsif($@ eq "!ROLLBACK\n") {
${"${caller}::T"}->rollback;
}
else {
${"${caller}::T"}->rollback;
require Carp;
Carp::croak($@ . "commit not safe after errors, transaction ro
+lled back");
}
}
Makeshifts last the longest.