X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FTxnScopeGuard.pm;h=580a32ba76379885642e05a52d4fde9c323bf72e;hb=04ab4eb1;hp=d69913874f04a995e05384f6d065e3f988849a83;hpb=dd018f09328dbfb2c28a199bbb271d8323cb9a77;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/TxnScopeGuard.pm b/lib/DBIx/Class/Storage/TxnScopeGuard.pm
index d699138..580a32b 100644
--- a/lib/DBIx/Class/Storage/TxnScopeGuard.pm
+++ b/lib/DBIx/Class/Storage/TxnScopeGuard.pm
@@ -1,43 +1,113 @@
-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 Try::Tiny;
+use Scalar::Util qw/weaken blessed refaddr/;
+use DBIx::Class;
+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 (defined $@ and $@ ne '') {
+    weaken(
+      $guard->{existing_exception_ref} = (ref $@ ne '') ? $@ : \$@
+    );
+  }
+
   $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 $dismiss;
-
-  my $exception = $@;
-
-  $DB::single = 1;
-
-  local $@;
-  eval { $storage->txn_rollback };
-  my $rollback_exception = $@;
-  if($rollback_exception) {
-    my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
+  my $self = shift;
 
-    $storage->throw_exception(
-      "Transaction aborted: ${exception}. "
-      . "Rollback failed: ${rollback_exception}"
-    ) unless $rollback_exception =~ /$exception_class/;
+  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 (
+    defined $@
+      and
+    $@ ne ''
+      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;
@@ -46,7 +116,7 @@ __END__
 
 =head1 NAME
 
-DBIx::Class::Storage::TxnScopeGuard
+DBIx::Class::Storage::TxnScopeGuard - Scope-based transaction handling
 
 =head1 SYNOPSIS
 
@@ -63,20 +133,21 @@ 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
 
@@ -88,7 +159,7 @@ L<DBIx::Class::Schema/txn_scope_guard>.
 
 Ash Berlin, 2008.
 
-Insipred by L<Scope::Guard> by chocolateboy.
+Inspired by L<Scope::Guard> by chocolateboy.
 
 This module is free software. It may be used, redistributed and/or modified
 under the same terms as Perl itself.