-package # Hide from pause for now - till we get it working
- DBIx::Class::Storage::TxnScopeGuard;
+package DBIx::Class::Storage::TxnScopeGuard;
use strict;
use warnings;
+use Scalar::Util qw(weaken blessed refaddr);
+use DBIx::Class;
+use DBIx::Class::_Util qw(is_exception detected_reinvoked_destructor);
+use DBIx::Class::Carp;
+use namespace::clean;
sub new {
my ($class, $storage) = @_;
+ my $guard = {
+ inactivated => 0,
+ storage => $storage,
+ };
+
+ # we are starting with an already set $@ - in order for things to work we need to
+ # be able to recognize it upon destruction - store its weakref
+ # recording it before doing the txn_begin stuff
+ #
+ # FIXME FRAGILE - any eval that fails but *does not* rethrow between here
+ # and the unwind will trample over $@ and invalidate the entire mechanism
+ # There got to be a saner way of doing this...
+ #
+ # Deliberately *NOT* using is_exception - if someone left a misbehaving
+ # antipattern value in $@, it's not our business to whine about it
+ weaken(
+ $guard->{existing_exception_ref} = (length ref $@) ? $@ : \$@
+ ) if( defined $@ and length $@ );
+
$storage->txn_begin;
- bless [ 0, $storage ], ref $class || $class;
+
+ weaken( $guard->{dbh} = $storage->_dbh );
+
+ bless $guard, ref $class || $class;
+
+ $guard;
}
sub commit {
my $self = shift;
- $self->[1]->txn_commit;
- $self->[0] = 1;
-}
+ $self->{storage}->throw_exception("Refusing to execute multiple commits on scope guard $self")
+ if $self->{inactivated};
-sub dismiss {
- my $self = shift;
-
- $self->[0] = 1;
+ # FIXME - this assumption may be premature: a commit may fail and a rollback
+ # *still* be necessary. Currently I am not aware of such scenarious, but I
+ # also know the deferred constraint handling is *severely* undertested.
+ # Making the change of "fire txn and never come back to this" in order to
+ # address RT#107159, but this *MUST* be reevaluated later.
+ $self->{inactivated} = 1;
+ $self->{storage}->txn_commit;
}
sub DESTROY {
- my ($dismiss, $storage) = @{$_[0]};
-
- return if $dismiss;
-
- my $exception = $@;
- Carp::cluck("A DBIx::Class:: went out of scope without explicit commit/dismiss")
- unless $exception;
- {
- local $@;
- eval { $storage->txn_rollback };
- my $rollback_exception = $@;
- if($rollback_exception) {
- my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
-
- $storage->throw_exception(
- "Transaction aborted: ${exception}. "
- . "Rollback failed: ${rollback_exception}"
- ) unless $rollback_exception =~ /$exception_class/;
- }
+ return if &detected_reinvoked_destructor;
+
+ return if $_[0]->{inactivated};
+
+
+ # grab it before we've done volatile stuff below
+ my $current_exception = (
+ is_exception $@
+ and
+ (
+ ! defined $_[0]->{existing_exception_ref}
+ or
+ refaddr( (length ref $@) ? $@ : \$@ ) != refaddr($_[0]->{existing_exception_ref})
+ )
+ )
+ ? $@
+ : undef
+ ;
+
+
+ # if our dbh is not ours anymore, the $dbh weakref will go undef
+ $_[0]->{storage}->_verify_pid unless DBIx::Class::_ENV_::BROKEN_FORK;
+ return unless defined $_[0]->{dbh};
+
+
+ carp 'A DBIx::Class::Storage::TxnScopeGuard went out of scope without explicit commit or error. Rolling back'
+ unless defined $current_exception;
+
+
+ if (
+ my $rollback_exception = $_[0]->{storage}->__delicate_rollback(
+ defined $current_exception
+ ? \$current_exception
+ : ()
+ )
+ and
+ ! defined $current_exception
+ ) {
+ carp (join ' ',
+ "********************* ROLLBACK FAILED!!! ********************",
+ "\nA rollback operation failed after the guard went out of scope.",
+ 'This is potentially a disastrous situation, check your data for',
+ "consistency: $rollback_exception"
+ );
}
+
+ $@ = $current_exception
+ if DBIx::Class::_ENV_::UNSTABLE_DOLLARAT;
+
+ # Dummy NEXTSTATE ensuring the all temporaries on the stack are garbage
+ # collected before leaving this scope. Depending on the code above, this
+ # may very well be just a preventive measure guarding future modifications
+ undef;
}
1;
=head1 NAME
-DBIx::Class::Storage::TxnScopeGuard
+DBIx::Class::Storage::TxnScopeGuard - Scope-based transaction handling
=head1 SYNOPSIS
=head1 DESCRIPTION
An object that behaves much like L<Scope::Guard>, but hardcoded to do the
-right thing with transactions in DBIx::Class.
+right thing with transactions in DBIx::Class.
=head1 METHODS
=head2 new
-Creating an instance of this class will start a new transaction. Expects a
+Creating an instance of this class will start a new transaction (by
+implicitly calling L<DBIx::Class::Storage/txn_begin>. Expects a
L<DBIx::Class::Storage> object as its only argument.
=head2 commit
Commit the transaction, and stop guarding the scope. If this method is not
-called (i.e. an exception is thrown) and this object goes out of scope then
-the transaction is rolled back.
+called and this object goes out of scope (e.g. an exception is thrown) then
+the transaction is rolled back, via L<DBIx::Class::Storage/txn_rollback>
=cut
L<DBIx::Class::Schema/txn_scope_guard>.
-=head1 AUTHOR
+L<Scope::Guard> by chocolateboy (inspiration for this module)
-Ash Berlin, 2008.
+=head1 FURTHER QUESTIONS?
-Insipred by L<Scope::Guard> by chocolateboy.
+Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>.
-This module is free software. It may be used, redistributed and/or modified
-under the same terms as Perl itself.
+=head1 COPYRIGHT AND LICENSE
-=cut
+This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE>
+by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can
+redistribute it and/or modify it under the same terms as the
+L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>.