X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FSybase.pm;h=2e01e8e5ff594f5d17f51b833d3403aa730baa38;hb=1a58752c42ba9acf33e2943b678de4948cf3ee3f;hp=e28ee63cf0155997473ec4bc6c4098671f2c9da7;hpb=0ac07712a87c97ec1676410be95ddfef768bfe23;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/DBI/Sybase.pm b/lib/DBIx/Class/Storage/DBI/Sybase.pm
index e28ee63..2e01e8e 100644
--- a/lib/DBIx/Class/Storage/DBI/Sybase.pm
+++ b/lib/DBIx/Class/Storage/DBI/Sybase.pm
@@ -10,11 +10,18 @@ use base qw/
 use mro 'c3';
 use Carp::Clan qw/^DBIx::Class/;
 use List::Util ();
+use Sub::Name ();
 
 __PACKAGE__->mk_group_accessors('simple' =>
-    qw/_identity _blob_log_on_update insert_txn/
+    qw/_identity _blob_log_on_update _writer_storage _is_writer_storage
+       _identity_method/
 );
 
+my @also_proxy_to_writer_storage = qw/
+  disconnect _connect_info _sql_maker _sql_maker_opts disable_sth_caching
+  auto_savepoint unsafe cursor_class debug debugobj schema
+/;
+
 =head1 NAME
 
 DBIx::Class::Storage::DBI::Sybase - Sybase support for DBIx::Class
@@ -33,10 +40,7 @@ also enable that driver explicitly, see the documentation for more details.
 
 With this driver there is unfortunately no way to get the C<last_insert_id>
 without doing a C<SELECT MAX(col)>. This is done safely in a transaction
-(locking the table.) The transaction can be turned off if concurrency is not an
-issue, see L<DBIx::Class::Storage::DBI::Sybase/connect_call_unsafe_insert>.
-
-But your queries will be cached.
+(locking the table.) See L</INSERTS WITH PLACEHOLDERS>.
 
 A recommended L<DBIx::Class::Storage::DBI/connect_info> setting:
 
@@ -64,10 +68,6 @@ sub _rebless {
     } else { # real Sybase
       my $no_bind_vars = 'DBIx::Class::Storage::DBI::Sybase::NoBindVars';
 
-# This is reset to 0 in ::NoBindVars, only necessary because we use max(col) to
-# get the identity.
-      $self->insert_txn(1);
-
       if ($self->using_freetds) {
         carp <<'EOF' unless $ENV{DBIC_SYBASE_FREETDS_NOWARN};
 
@@ -95,11 +95,8 @@ EOF
             $self->_rebless;
           }
         }
-
-        $self->set_textsize; # based on LongReadLen in connect_info
-
       }
-      elsif (not $self->dbh->{syb_dynamic_supported}) {
+      elsif (not $self->_get_dbh->{syb_dynamic_supported}) {
         # not necessarily FreeTDS, but no placeholders nevertheless
         $self->ensure_class_loaded($no_bind_vars);
         bless $self, $no_bind_vars;
@@ -108,12 +105,41 @@ EOF
 # this is highly unlikely, but we check just in case
         $self->auto_cast(1);
       }
-
-      $self->_set_max_connect(256);
     }
   }
 }
 
+sub _init {
+  my $self = shift;
+  $self->_set_max_connect(256);
+
+  # based on LongReadLen in connect_info
+  $self->set_textsize if $self->using_freetds;
+
+# create storage for insert/(update blob) transactions,
+# unless this is that storage
+  return if $self->_is_writer_storage;
+
+  my $writer_storage = (ref $self)->new;
+
+  $writer_storage->_is_writer_storage(1);
+  $writer_storage->connect_info($self->connect_info);
+
+  $self->_writer_storage($writer_storage);
+}
+
+for my $method (@also_proxy_to_writer_storage) {
+  no strict 'refs';
+
+  my $replaced = __PACKAGE__->can($method);
+
+  *{$method} = Sub::Name::subname __PACKAGE__."::$method" => sub {
+    my $self = shift;
+    $self->_writer_storage->$replaced(@_) if $self->_writer_storage;
+    return $self->$replaced(@_);
+  };
+}
+
 # Make sure we have CHAINED mode turned on if AutoCommit is off in non-FreeTDS
 # DBD::Sybase (since we don't know how DBD::Sybase was compiled.) If however
 # we're using FreeTDS, CHAINED mode turns on an implicit transaction which we
@@ -163,32 +189,6 @@ sub connect_call_blob_setup {
     if exists $args{log_on_update};
 }
 
-=head2 connect_call_unsafe_insert
-
-With placeholders enabled, inserts are done in a transaction so that there are
-no concurrency issues with getting the inserted identity value using
-C<SELECT MAX(col)> when placeholders are enabled.
-
-When using C<DBIx::Class::Storage::DBI::Sybase::NoBindVars> transactions are
-disabled.
-
-To turn off transactions for inserts (for an application that doesn't need
-concurrency, or a loader, for example) use this setting in
-L<DBIx::Class::Storage::DBI/connect_info>,
-
-  on_connect_call => ['unsafe_insert']
-
-To manipulate this setting at runtime, use:
-
-  $schema->storage->insert_txn(0); # 1 to re-enable
-
-=cut
-
-sub connect_call_unsafe_insert {
-  my $self = shift;
-  $self->insert_txn(0);
-}
-
 sub _is_lob_type {
   my $self = shift;
   my $type = shift;
@@ -261,7 +261,7 @@ sub _native_data_type {
   my ($self, $type) = @_;
 
   $type = lc $type;
-  $type =~ s/ identity//;
+  $type =~ s/\s* identity//x;
 
   return uc($TYPE_MAPPING{$type} || $type);
 }
@@ -269,7 +269,9 @@ sub _native_data_type {
 sub _fetch_identity_sql {
   my ($self, $source, $col) = @_;
 
-  return "SELECT MAX($col) FROM ".$source->from;
+  return sprintf ("SELECT MAX(%s) FROM %s",
+    map { $self->sql_maker->_quote ($_) } ($col, $source->from)
+  );
 }
 
 sub _execute {
@@ -288,52 +290,82 @@ sub _execute {
 
 sub last_insert_id { shift->_identity }
 
-# override to handle TEXT/IMAGE and to do a transaction if necessary
+# handles TEXT/IMAGE and transaction for last_insert_id
 sub insert {
   my $self = shift;
-  my ($ident, $source, $to_insert) = @_;
+  my ($source, $to_insert) = @_;
 
   my $blob_cols = $self->_remove_blob_cols($source, $to_insert);
 
-  my $need_last_insert_id = 0;
-
-  my ($identity_col) =
-    map $_->[0],
-    grep $_->[1]{is_auto_increment},
-    map [ $_, $source->column_info($_) ],
+  my $identity_col = List::Util::first
+    { $source->column_info($_)->{is_auto_increment} }
     $source->columns;
 
-  $need_last_insert_id = 1
-    if $identity_col && (not exists $to_insert->{$identity_col});
-
-  # We have to do the insert in a transaction to avoid race conditions with the
-  # SELECT MAX(COL) identity method used when placeholders are enabled.
-  my $updated_cols = do {
-    if ($need_last_insert_id && $self->insert_txn &&
-        (not $self->{transaction_depth})) {
-      my $guard = $self->txn_scope_guard;
-      my $upd_cols = $self->next::method (@_);
-      $guard->commit;
-      return $upd_cols;
-    }
-    else {
-      $self->next::method(@_);
-    }
+  # do we need the horrific SELECT MAX(COL) hack?
+  my $dumb_last_insert_id =
+       $identity_col
+    && (not exists $to_insert->{$identity_col})
+    && ($self->_identity_method||'') ne '@@IDENTITY';
+
+  my $next = $self->next::can;
+
+  # we are already in a transaction, or there are no blobs
+  # and we don't need the PK - just (try to) do it
+  if ($self->{transaction_depth}
+        || (!$blob_cols && !$dumb_last_insert_id) 
+  ) {
+    return $self->_insert (
+      $next, $source, $to_insert, $blob_cols, $identity_col
+    );
+  }
+
+  # otherwise use the _writer_storage to do the insert+transaction on another
+  # connection
+  my $guard = $self->_writer_storage->txn_scope_guard;
+
+  my $updated_cols = $self->_writer_storage->_insert (
+    $next, $source, $to_insert, $blob_cols, $identity_col
+  );
+
+  $self->_identity($self->_writer_storage->_identity);
+
+  $guard->commit;
+
+  return $updated_cols;
+}
+
+sub _insert {
+  my ($self, $next, $source, $to_insert, $blob_cols, $identity_col) = @_;
+
+  my $updated_cols = $self->$next ($source, $to_insert);
+
+  my $final_row = {
+    $identity_col => $self->last_insert_id($source, $identity_col),
+    %$to_insert,
+    %$updated_cols,
   };
 
-  $self->_insert_blobs($source, $blob_cols, $to_insert) if %$blob_cols;
+  $self->_insert_blobs ($source, $blob_cols, $final_row) if $blob_cols;
 
   return $updated_cols;
 }
 
 sub update {
   my $self = shift;
-  my ($source, $fields, $ident_cond) = @_;
+  my ($source, $fields, $where) = @_;
 
   my $wantarray = wantarray;
-
   my $blob_cols = $self->_remove_blob_cols($source, $fields);
 
+  if (not $blob_cols) {
+    return $self->next::method(@_);
+  }
+
+# update+blob update(s) done atomically on separate connection
+  $self = $self->_writer_storage;
+
+  my $guard = $self->txn_scope_guard;
+
   my @res;
   if ($wantarray) {
     @res    = $self->next::method(@_);
@@ -345,11 +377,70 @@ sub update {
     $self->next::method(@_);
   }
 
-  $self->_update_blobs($source, $blob_cols, $ident_cond) if %$blob_cols;
+  $self->_update_blobs($source, $blob_cols, $where);
+
+  $guard->commit;
 
   return $wantarray ? @res : $res[0];
 }
 
+### the insert_bulk stuff stolen from DBI/MSSQL.pm
+
+sub _set_identity_insert {
+  my ($self, $table) = @_;
+
+  my $sql = sprintf (
+    'SET IDENTITY_INSERT %s ON',
+    $self->sql_maker->_quote ($table),
+  );
+
+  my $dbh = $self->_get_dbh;
+  eval { $dbh->do ($sql) };
+  if ($@) {
+    $self->throw_exception (sprintf "Error executing '%s': %s",
+      $sql,
+      $dbh->errstr,
+    );
+  }
+}
+
+sub _unset_identity_insert {
+  my ($self, $table) = @_;
+
+  my $sql = sprintf (
+    'SET IDENTITY_INSERT %s OFF',
+    $self->sql_maker->_quote ($table),
+  );
+
+  my $dbh = $self->_get_dbh;
+  $dbh->do ($sql);
+}
+
+# XXX this should use the DBD::Sybase bulk API, where possible
+sub insert_bulk {
+  my $self = shift;
+  my ($source, $cols, $data) = @_;
+
+  my $is_identity_insert = (List::Util::first
+      { $source->column_info ($_)->{is_auto_increment} }
+      (@{$cols})
+  )
+     ? 1
+     : 0;
+
+  if ($is_identity_insert) {
+     $self->_set_identity_insert ($source->name);
+  }
+
+  $self->next::method(@_);
+
+  if ($is_identity_insert) {
+     $self->_unset_identity_insert ($source->name);
+  }
+}
+
+### end of stolen insert_bulk section
+
 sub _remove_blob_cols {
   my ($self, $source, $fields) = @_;
 
@@ -362,37 +453,33 @@ sub _remove_blob_cols {
     }
   }
 
-  return \%blob_cols;
+  return keys %blob_cols ? \%blob_cols : undef;
 }
 
 sub _update_blobs {
-  my ($self, $source, $blob_cols, $ident_cond) = @_;
+  my ($self, $source, $blob_cols, $where) = @_;
 
   my (@primary_cols) = $source->primary_columns;
 
-  croak "Cannot update TEXT/IMAGE column(s) without a primary key"
+  $self->throw_exception('Cannot update TEXT/IMAGE column(s) without a primary key')
     unless @primary_cols;
 
 # check if we're updating a single row by PK
   my $pk_cols_in_where = 0;
   for my $col (@primary_cols) {
-    $pk_cols_in_where++ if defined $ident_cond->{$col};
+    $pk_cols_in_where++ if defined $where->{$col};
   }
   my @rows;
 
   if ($pk_cols_in_where == @primary_cols) {
     my %row_to_update;
-    @row_to_update{@primary_cols} = @{$ident_cond}{@primary_cols};
+    @row_to_update{@primary_cols} = @{$where}{@primary_cols};
     @rows = \%row_to_update;
   } else {
-    my $rs = $source->resultset->search(
-      $ident_cond,
-      {
-        result_class => 'DBIx::Class::ResultClass::HashRefInflator',
-        select => \@primary_cols
-      }
-    );
-    @rows = $rs->all; # statement must finish
+    my $cursor = $self->select ($source, \@primary_cols, $where, {});
+    @rows = map {
+      my %row; @row{@primary_cols} = @$_; \%row
+    } $cursor->all;
   }
 
   for my $row (@rows) {
@@ -402,32 +489,25 @@ sub _update_blobs {
 
 sub _insert_blobs {
   my ($self, $source, $blob_cols, $row) = @_;
-  my $dbh = $self->dbh;
+  my $dbh = $self->_get_dbh;
 
   my $table = $source->from;
 
   my %row = %$row;
   my (@primary_cols) = $source->primary_columns;
 
-  croak "Cannot update TEXT/IMAGE column(s) without a primary key"
+  $self->throw_exception('Cannot update TEXT/IMAGE column(s) without a primary key')
     unless @primary_cols;
 
-  if ((grep { defined $row{$_} } @primary_cols) != @primary_cols) {
-    if (@primary_cols == 1) {
-      my $col = $primary_cols[0];
-      $row{$col} = $self->last_insert_id($source, $col);
-    } else {
-      croak "Cannot update TEXT/IMAGE column(s) without primary key values";
-    }
-  }
+  $self->throw_exception('Cannot update TEXT/IMAGE column(s) without primary key values')
+    if ((grep { defined $row{$_} } @primary_cols) != @primary_cols);
 
   for my $col (keys %$blob_cols) {
     my $blob = $blob_cols->{$col};
 
     my %where = map { ($_, $row{$_}) } @primary_cols;
-    my $cursor = $source->resultset->search(\%where, {
-      select => [$col]
-    })->cursor;
+
+    my $cursor = $self->select ($source, [$col], \%where, {});
     $cursor->next;
     my $sth = $cursor->sth;
 
@@ -454,12 +534,12 @@ sub _insert_blobs {
     $sth->finish if $sth;
     if ($exception) {
       if ($self->using_freetds) {
-        croak (
+        $self->throw_exception (
           'TEXT/IMAGE operation failed, probably because you are using FreeTDS: '
           . $exception
         );
       } else {
-        croak $exception;
+        $self->throw_exception($exception);
       }
     }
   }
@@ -518,7 +598,7 @@ sub _dbh_begin_work {
   my $self = shift;
   $self->next::method(@_);
   if ($self->using_freetds) {
-    $self->dbh->do('BEGIN TRAN');
+    $self->_get_dbh->do('BEGIN TRAN');
   }
 }
 
@@ -543,7 +623,7 @@ sub _dbh_rollback {
 sub _svp_begin {
   my ($self, $name) = @_;
 
-  $self->dbh->do("SAVE TRANSACTION $name");
+  $self->_get_dbh->do("SAVE TRANSACTION $name");
 }
 
 # A new SAVE TRANSACTION with the same name releases the previous one.
@@ -552,7 +632,7 @@ sub _svp_release { 1 }
 sub _svp_rollback {
   my ($self, $name) = @_;
 
-  $self->dbh->do("ROLLBACK TRANSACTION $name");
+  $self->_get_dbh->do("ROLLBACK TRANSACTION $name");
 }
 
 1;
@@ -601,6 +681,55 @@ Open Client libraries.
 
 Inserts or updates of TEXT/IMAGE columns will B<NOT> work with FreeTDS.
 
+=head1 INSERTS WITH PLACEHOLDERS
+
+With placeholders enabled, inserts are done in a transaction so that there are
+no concurrency issues with getting the inserted identity value using
+C<SELECT MAX(col)>, which is the only way to get the C<IDENTITY> value in this
+mode.
+
+In addition, they are done on a separate connection so that it's possible to
+have active cursors when doing an insert.
+
+When using C<DBIx::Class::Storage::DBI::Sybase::NoBindVars> transactions are
+disabled, as there are no concurrency issues with C<SELECT @@IDENTITY> as it's a
+session variable.
+
+=head1 TRANSACTIONS
+
+Due to limitations of the TDS protocol, L<DBD::Sybase>, or both; you cannot
+begin a transaction while there are active cursors. An active cursor is, for
+example, a L<ResultSet|DBIx::Class::ResultSet> that has been executed using
+C<next> or C<first> but has not been exhausted or
+L<reset|DBIx::Class::ResultSet/reset>.
+
+For example, this will not work:
+
+  $schema->txn_do(sub {
+    my $rs = $schema->resultset('Book');
+    while (my $row = $rs->next) {
+      $schema->resultset('MetaData')->create({
+        book_id => $row->id,
+        ...
+      });
+    }
+  });
+
+Transactions done for inserts in C<AutoCommit> mode when placeholders are in use
+are not affected, as they are done on an extra database handle.
+
+Some workarounds:
+
+=over 4
+
+=item * use L<DBIx::Class::Storage::DBI::Replicated>
+
+=item * L<connect|DBIx::Class::Schema/connect> another L<Schema|DBIx::Class::Schema>
+
+=item * load the data from your cursor with L<DBIx::Class::ResultSet/all>
+
+=back
+
 =head1 MAXIMUM CONNECTIONS
 
 The TDS protocol makes separate connections to the server for active statements
@@ -642,7 +771,7 @@ C<SET TEXTSIZE> command on connection.
 See L</connect_call_blob_setup> for a L<DBIx::Class::Storage::DBI/connect_info>
 setting you need to work with C<IMAGE> columns.
 
-=head1 AUTHORS
+=head1 AUTHOR
 
 See L<DBIx::Class/CONTRIBUTORS>.