Massive cleanup of transaction handlers

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Storage / TxnScopeGuard.pm

diff --git a/lib/DBIx/Class/Storage/TxnScopeGuard.pm b/lib/DBIx/Class/Storage/TxnScopeGuard.pm
index 06c510c..f686cce 100644 (file)
--- a/lib/DBIx/Class/Storage/TxnScopeGuard.pm
+++ b/lib/DBIx/Class/Storage/TxnScopeGuard.pm
@@ -2,12 +2,18 @@ package DBIx::Class::Storage::TxnScopeGuard;
 
 use strict;
 use warnings;
+use Carp::Clan qw/^DBIx::Class/;
+use Try::Tiny;
+use Scalar::Util qw/weaken/;
+use namespace::clean;
 
 sub new {
   my ($class, $storage) = @_;
 
   $storage->txn_begin;
-  bless [ 0, $storage ], ref $class || $class;
+  my $guard = bless [ 0, $storage, $storage->_dbh ], ref $class || $class;
+  weaken ($guard->[2]);
+  $guard;
 }
 
 sub commit {
@@ -22,21 +28,41 @@ sub DESTROY {
 
   return if $dismiss;
 
-  my $exception = $@;
-
-  $DB::single = 1;
+  # if our dbh is not ours anymore, the weakref will go undef
+  $storage->_preserve_foreign_dbh;
+  return unless $_[0]->[2];
 
-  local $@;
-  eval { $storage->txn_rollback };
-  my $rollback_exception = $@;
-  if($rollback_exception) {
-    my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
+  my $exception = $@;
 
-    $storage->throw_exception(
-      "Transaction aborted: ${exception}. "
-      . "Rollback failed: ${rollback_exception}"
-    ) unless $rollback_exception =~ /$exception_class/;
+  {
+    local $@;
+
+    carp 'A DBIx::Class::Storage::TxnScopeGuard went out of scope without explicit commit or error. Rolling back.'
+      unless $exception;
+
+    my $rollback_exception;
+    # do minimal connectivity check due to weird shit like
+    # https://rt.cpan.org/Public/Bug/Display.html?id=62370
+    try { $storage->_seems_connected && $storage->txn_rollback }
+    catch { $rollback_exception = shift };
+
+    if (defined $rollback_exception && $rollback_exception !~ /DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION/) {
+      if ($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;
@@ -45,7 +71,7 @@ __END__
 
 =head1 NAME
 
-DBIx::Class::Storage::TxnScopeGuard
+DBIx::Class::Storage::TxnScopeGuard - Scope-based transaction handling
 
 =head1 SYNOPSIS
 
@@ -62,20 +88,21 @@ 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
 
@@ -87,7 +114,7 @@ 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.