Add undocumented ability to disable the join optimizer

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

diff --git a/lib/DBIx/Class/Storage/DBI.pm b/lib/DBIx/Class/Storage/DBI.pm
index d54e0b2..d07bb76 100644 (file)
--- a/lib/DBIx/Class/Storage/DBI.pm
+++ b/lib/DBIx/Class/Storage/DBI.pm
@@ -54,10 +54,13 @@ __PACKAGE__->mk_group_accessors('simple' => @storage_options);
 # will get the same rdbms version). _determine_supports_X does not need to
 # exist on a driver, as we ->can for it before calling.
 
-my @capabilities = (qw/insert_returning placeholders typeless_placeholders/);
+my @capabilities = (qw/insert_returning placeholders typeless_placeholders join_optimizer/);
 __PACKAGE__->mk_group_accessors( dbms_capability => map { "_supports_$_" } @capabilities );
-__PACKAGE__->mk_group_accessors( use_dbms_capability => map { "_use_$_" } @capabilities );
+__PACKAGE__->mk_group_accessors( use_dbms_capability => map { "_use_$_" } (@capabilities ) );
 
+# on by default, not strictly a capability (pending rewrite)
+__PACKAGE__->_use_join_optimizer (1);
+sub _determine_supports_join_optimizer { 1 };
 
 # Each of these methods need _determine_driver called before itself
 # in order to function reliably. This is a purely DRY optimization
@@ -453,8 +456,7 @@ of available limit dialects see L<DBIx::Class::SQLMaker::LimitDialects>.
 
 =item quote_char
 
-Specifies what characters to use to quote table and column names. If
-you use this you will want to specify L</name_sep> as well.
+Specifies what characters to use to quote table and column names.
 
 C<quote_char> expects either a single character, in which case is it
 is placed on either side of the table/column name, or an arrayref of length
@@ -465,14 +467,9 @@ SQL Server you should use C<< quote_char => [qw/[ ]/] >>.
 
 =item name_sep
 
-This only needs to be used in conjunction with C<quote_char>, and is used to
+This parameter is only useful in conjunction with C<quote_char>, and is used to
 specify the character that separates elements (schemas, tables, columns) from
-each other. In most cases this is simply a C<.>.
-
-The consequences of not supplying this value is that L<SQL::Abstract>
-will assume DBIx::Class' uses of aliases to be complete column
-names. The output will look like I<"me.name"> when it should actually
-be I<"me"."name">.
+each other. If unspecified it defaults to the most commonly used C<.>.
 
 =item unsafe
 
@@ -525,7 +522,7 @@ L<DBIx::Class::Schema/connect>
       'postgres',
       'my_pg_password',
       { AutoCommit => 1 },
-      { quote_char => q{"}, name_sep => q{.} },
+      { quote_char => q{"} },
     ]
   );
 
@@ -784,8 +781,6 @@ sub txn_do {
   ref $coderef eq 'CODE' or $self->throw_exception
     ('$coderef must be a CODE reference');
 
-  return $coderef->(@_) if $self->{transaction_depth} && ! $self->auto_savepoint;
-
   local $self->{_in_dbh_do} = 1;
 
   my @result;
@@ -800,6 +795,7 @@ sub txn_do {
 
     try {
       $self->txn_begin;
+      my $txn_start_depth = $self->transaction_depth;
       if($want_array) {
           @result = $coderef->(@$args);
       }
@@ -809,14 +805,22 @@ sub txn_do {
       else {
           $coderef->(@$args);
       }
-      $self->txn_commit;
+
+      my $delta_txn = $txn_start_depth - $self->transaction_depth;
+      if ($delta_txn == 0) {
+        $self->txn_commit;
+      }
+      elsif ($delta_txn != 1) {
+        # an off-by-one would mean we fired a rollback
+        carp "Unexpected reduction of transaction depth by $delta_txn after execution of $coderef";
+      }
     } catch {
       $exception = $_;
     };
 
     if(! defined $exception) { return $want_array ? @result : $result[0] }
 
-    if($tried++ || $self->connected) {
+    if($self->transaction_depth > 1 || $tried++ || $self->connected) {
       my $rollback_exception;
       try { $self->txn_rollback } catch { $rollback_exception = shift };
       if(defined $rollback_exception) {
@@ -999,6 +1003,7 @@ sub sql_maker {
       bindtype=>'columns',
       array_datatypes => 1,
       limit_dialect => $dialect,
+      name_sep => '.',
       %opts,
     ));
   }
@@ -1373,9 +1378,8 @@ sub svp_rollback {
 }
 
 sub _svp_generate_name {
-    my ($self) = @_;
-
-    return 'savepoint_'.scalar(@{ $self->{'savepoints'} });
+  my ($self) = @_;
+  return 'savepoint_'.scalar(@{ $self->{'savepoints'} });
 }
 
 sub txn_begin {
@@ -1383,9 +1387,18 @@ sub txn_begin {
 
   # this means we have not yet connected and do not know the AC status
   # (e.g. coderef $dbh)
-  $self->ensure_connected if (! defined $self->_dbh_autocommit);
+  if (! defined $self->_dbh_autocommit) {
+    $self->ensure_connected;
+  }
+  # otherwise re-connect on pid changes, so
+  # that the txn_depth is adjusted properly
+  # the lightweight _get_dbh is good enoug here
+  # (only superficial handle check, no pings)
+  else {
+    $self->_get_dbh;
+  }
 
-  if($self->{transaction_depth} == 0) {
+  if($self->transaction_depth == 0) {
     $self->debugobj->txn_begin()
       if $self->debug;
     $self->_dbh_begin_work;
@@ -1425,6 +1438,9 @@ sub txn_commit {
     $self->svp_release
       if $self->auto_savepoint;
   }
+  else {
+    $self->throw_exception( 'Refusing to commit without a started transaction' );
+  }
 }
 
 sub _dbh_commit {