X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FTxnScopeGuard.pm;h=edf72057f280688edf67765def5f9e0f9393ab67;hb=a6543cfa5769989102af82b5308e23a4ebd3d24d;hp=04978f93a3816706a39f841fcd2e757e2e6126e7;hpb=1bc193ac4c3bb934d1877e49bf7c465fc82815d6;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/TxnScopeGuard.pm b/lib/DBIx/Class/Storage/TxnScopeGuard.pm
index 04978f9..edf7205 100644
--- a/lib/DBIx/Class/Storage/TxnScopeGuard.pm
+++ b/lib/DBIx/Class/Storage/TxnScopeGuard.pm
@@ -2,25 +2,113 @@ package DBIx::Class::Storage::TxnScopeGuard;
 
 use strict;
 use warnings;
+use Try::Tiny;
+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...
+  if (is_exception $@) {
+    weaken(
+      $guard->{existing_exception_ref} = (ref($@) eq '') ? \$@ : $@
+    );
+  }
+
   $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};
+
+  $self->{storage}->txn_commit;
+  $self->{inactivated} = 1;
 }
 
 sub DESTROY {
-  my ($dismiss, $storage) = @{$_[0]};
+  return if &detected_reinvoked_destructor;
+
+  my $self = shift;
 
-  $storage->txn_rollback unless $dismiss;
+  return if $self->{inactivated};
+
+  # if our dbh is not ours anymore, the $dbh weakref will go undef
+  $self->{storage}->_verify_pid unless DBIx::Class::_ENV_::BROKEN_FORK;
+  return unless $self->{dbh};
+
+  my $exception = $@ if (
+    is_exception $@
+      and
+    (
+      ! defined $self->{existing_exception_ref}
+        or
+      refaddr( ref($@) eq '' ? \$@ : $@ ) != refaddr($self->{existing_exception_ref})
+    )
+  );
+
+  {
+    local $@;
+
+    carp 'A DBIx::Class::Storage::TxnScopeGuard went out of scope without explicit commit or error. Rolling back.'
+      unless defined $exception;
+
+    my $rollback_exception;
+    # do minimal connectivity check due to weird shit like
+    # https://rt.cpan.org/Public/Bug/Display.html?id=62370
+    try { $self->{storage}->_seems_connected && $self->{storage}->txn_rollback }
+    catch { $rollback_exception = shift };
+
+    if ( $rollback_exception and (
+      ! defined blessed $rollback_exception
+          or
+      ! $rollback_exception->isa('DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION')
+    ) ) {
+      # append our text - THIS IS A TEMPORARY FIXUP!
+      # a real stackable exception object is in the works
+      if (ref $exception eq 'DBIx::Class::Exception') {
+        $exception->{msg} = "Transaction aborted: $exception->{msg} "
+          ."Rollback failed: ${rollback_exception}";
+      }
+      elsif ($exception) {
+        $exception = "Transaction aborted: ${exception} "
+          ."Rollback failed: ${rollback_exception}";
+      }
+      else {
+        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"
+        );
+      }
+    }
+  }
+
+  $@ = $exception;
 }
 
 1;
@@ -29,7 +117,7 @@ __END__
 
 =head1 NAME
 
-DBIx::Class::Storage::TxnScopeGuard
+DBIx::Class::Storage::TxnScopeGuard - Scope-based transaction handling
 
 =head1 SYNOPSIS
 
@@ -46,20 +134,21 @@ DBIx::Class::Storage::TxnScopeGuard
 =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
 
@@ -67,13 +156,15 @@ the transaction is rolled back.
 
 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>.