improve with_deferred_fk_checks for Oracle, add tests

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

diff --git a/lib/DBIx/Class/Storage/DBI/Oracle/Generic.pm b/lib/DBIx/Class/Storage/DBI/Oracle/Generic.pm
index 0f0c97b..448c203 100644 (file)
--- a/lib/DBIx/Class/Storage/DBI/Oracle/Generic.pm
+++ b/lib/DBIx/Class/Storage/DBI/Oracle/Generic.pm
@@ -2,6 +2,8 @@ package DBIx::Class::Storage::DBI::Oracle::Generic;
 
 use strict;
 use warnings;
+use Scope::Guard ();
+use Context::Preserve ();
 
 =head1 NAME
 
@@ -209,11 +211,15 @@ sub connect_call_datetime_setup {
   my $timestamp_tz_format = $ENV{NLS_TIMESTAMP_TZ_FORMAT} ||=
     'YYYY-MM-DD HH24:MI:SS.FF TZHTZM';
 
-  $self->_do_query("alter session set nls_date_format = '$date_format'");
   $self->_do_query(
-"alter session set nls_timestamp_format = '$timestamp_format'");
+    "alter session set nls_date_format = '$date_format'"
+  );
   $self->_do_query(
-"alter session set nls_timestamp_tz_format='$timestamp_tz_format'");
+    "alter session set nls_timestamp_format = '$timestamp_format'"
+  );
+  $self->_do_query(
+    "alter session set nls_timestamp_tz_format='$timestamp_tz_format'"
+  );
 }
 
 =head2 source_bind_attributes
@@ -235,35 +241,42 @@ table with more than one LOB column.
 
 sub source_bind_attributes
 {
-       require DBD::Oracle;
-       my $self = shift;
-       my($source) = @_;
+  require DBD::Oracle;
+  my $self = shift;
+  my($source) = @_;
+
+  my %bind_attributes;
 
-       my %bind_attributes;
+  foreach my $column ($source->columns) {
+    my $data_type = $source->column_info($column)->{data_type} || '';
+    next unless $data_type;
 
-       foreach my $column ($source->columns) {
-               my $data_type = $source->column_info($column)->{data_type} || '';
-               next unless $data_type;
+    my %column_bind_attrs = $self->bind_attribute_by_data_type($data_type);
 
-               my %column_bind_attrs = $self->bind_attribute_by_data_type($data_type);
+    if ($data_type =~ /^[BC]LOB$/i) {
+      if ($DBD::Oracle::VERSION eq '1.23') {
+        $self->throw_exception(
+"BLOB/CLOB support in DBD::Oracle == 1.23 is broken, use an earlier or later ".
+"version.\n\nSee: https://rt.cpan.org/Public/Bug/Display.html?id=46016\n"
+        );
+      }
 
-               if ($data_type =~ /^[BC]LOB$/i) {
-                       $column_bind_attrs{'ora_type'} = uc($data_type) eq 'CLOB' ?
-                               DBD::Oracle::ORA_CLOB() :
-                               DBD::Oracle::ORA_BLOB();
-                       $column_bind_attrs{'ora_field'} = $column;
-               }
+      $column_bind_attrs{'ora_type'} = uc($data_type) eq 'CLOB'
+        ? DBD::Oracle::ORA_CLOB()
+        : DBD::Oracle::ORA_BLOB()
+      ;
+      $column_bind_attrs{'ora_field'} = $column;
+    }
 
-               $bind_attributes{$column} = \%column_bind_attrs;
-       }
+    $bind_attributes{$column} = \%column_bind_attrs;
+  }
 
-       return \%bind_attributes;
+  return \%bind_attributes;
 }
 
 sub _svp_begin {
-    my ($self, $name) = @_;
-
-    $self->_get_dbh->do("SAVEPOINT $name");
+  my ($self, $name) = @_;
+  $self->_get_dbh->do("SAVEPOINT $name");
 }
 
 # Oracle automatically releases a savepoint when you start another one with the
@@ -271,9 +284,8 @@ sub _svp_begin {
 sub _svp_release { 1 }
 
 sub _svp_rollback {
-    my ($self, $name) = @_;
-
-    $self->_get_dbh->do("ROLLBACK TO SAVEPOINT $name")
+  my ($self, $name) = @_;
+  $self->_get_dbh->do("ROLLBACK TO SAVEPOINT $name")
 }
 
 =head2 relname_to_table_alias
@@ -282,7 +294,8 @@ L<DBIx::Class> uses L<DBIx::Class::Relationship> names as table aliases in
 queries.
 
 Unfortunately, Oracle doesn't support identifiers over 30 chars in length, so
-if the L<DBIx::Class::Relationship> name is shortened here if necessary.
+the L<DBIx::Class::Relationship> name is shortened and appended with half of an
+MD5 hash.
 
 See L<DBIx::Class::Storage/"relname_to_table_alias">.
 
@@ -296,15 +309,52 @@ sub relname_to_table_alias {
 
   return $alias if length($alias) <= 30;
 
-  $alias =~ s/[aeiou]//ig;
+  # get a base64 md5 of the alias with join_count
+  require Digest::MD5;
+  my $ctx = Digest::MD5->new;
+  $ctx->add($alias);
+  my $md5 = $ctx->b64digest;
 
-  return $alias if length($alias) <= 30;
+  # remove alignment mark just in case
+  $md5 =~ s/=*\z//;
+
+  # truncate and prepend to truncated relname without vowels
+  (my $devoweled = $relname) =~ s/[aeiou]//g;
+  my $shortened = substr($devoweled, 0, 18);
+
+  my $new_alias =
+    $shortened . '_' . substr($md5, 0, 30 - length($shortened) - 1);
+
+  return $new_alias;
+}
+
+=head2 with_deferred_fk_checks
+
+Runs a coderef between:
+
+  alter session set constraints = deferred
+  ...
+  alter session set constraints = immediate
+
+to defer foreign key checks.
+
+Constraints must be declared C<DEFERRABLE> for this to work.
+
+=cut
+
+sub with_deferred_fk_checks {
+  my ($self, $sub) = @_;
+
+  my $txn_scope_guard = $self->txn_scope_guard;
 
-  ($alias = $relname) =~ s/[aeiou]//ig;
-  substr($alias, 0, 30 - length($join_count) - 1) = '';
-  $alias .= "_$join_count";
+  $self->_do_query('alter session set constraints = deferred');
+  
+  my $sg = Scope::Guard->new(sub {
+    $self->_do_query('alter session set constraints = immediate');
+  });
 
-  return $alias;
+  return Context::Preserve::preserve_context(sub { $sub->() },
+    after => sub { $txn_scope_guard->commit });
 }
 
 =head1 AUTHOR