X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FSybase.pm;h=68c2e20eef6a4c316caedb25b4cd36546b3e2133;hb=51ac7136944f82aa2675cc133a8d080c5fb367b1;hp=7995334798ed7032ba006e16f3d0d22d445d1ad5;hpb=44e538d00c41e69899b48178c9dede95e2ef7e77;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/DBI/Sybase.pm b/lib/DBIx/Class/Storage/DBI/Sybase.pm
index 7995334..68c2e20 100644
--- a/lib/DBIx/Class/Storage/DBI/Sybase.pm
+++ b/lib/DBIx/Class/Storage/DBI/Sybase.pm
@@ -4,14 +4,15 @@ use strict;
 use warnings;
 
 use base qw/
-    DBIx::Class::Storage::DBI::Sybase::Base
+    DBIx::Class::Storage::DBI::Sybase::Common
+    DBIx::Class::Storage::DBI::AutoCast
 /;
 use mro 'c3';
 use Carp::Clan qw/^DBIx::Class/;
 use List::Util ();
 
 __PACKAGE__->mk_group_accessors('simple' =>
-    qw/_identity _blob_log_on_update auto_cast _insert_txn/
+    qw/_identity _blob_log_on_update unsafe_insert _insert_dbh/
 );
 
 =head1 NAME
@@ -31,7 +32,10 @@ will be reblessed to L<DBIx::Class::Storage::DBI::Sybase::NoBindVars>. You can
 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)>.
+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, or you don't need the C<IDENTITY> value, see
+L<DBIx::Class::Storage::DBI::Sybase/connect_call_unsafe_insert>.
 
 But your queries will be cached.
 
@@ -48,7 +52,7 @@ sub _rebless {
 
   if (ref($self) eq 'DBIx::Class::Storage::DBI::Sybase') {
     my $dbtype = eval {
-      @{$self->last_dbh->selectrow_arrayref(qq{sp_server_info \@attribute_id=1})}[2]
+      @{$self->_get_dbh->selectrow_arrayref(qq{sp_server_info \@attribute_id=1})}[2]
     } || '';
 
     my $exception = $@;
@@ -61,10 +65,6 @@ 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};
 
@@ -83,8 +83,8 @@ See perldoc DBIx::Class::Storage::DBI::Sybase for more details.
 To turn off this warning set the DBIC_SYBASE_FREETDS_NOWARN environment
 variable.
 EOF
-        if (not $self->placeholders_with_type_conversion_supported) {
-          if ($self->placeholders_supported) {
+        if (not $self->_typeless_placeholders_supported) {
+          if ($self->_placeholders_supported) {
             $self->auto_cast(1);
           } else {
             $self->ensure_class_loaded($no_bind_vars);
@@ -95,13 +95,17 @@ EOF
 
         $self->set_textsize; # based on LongReadLen in connect_info
 
-      } elsif (not $self->dbh->{syb_dynamic_supported}) {
-# not necessarily FreeTDS, but no placeholders nevertheless
+      }
+      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;
         $self->_rebless;
+      } elsif (not $self->_typeless_placeholders_supported) {
+# this is highly unlikely, but we check just in case
+        $self->auto_cast(1);
       }
- 
+
       $self->_set_max_connect(256);
     }
   }
@@ -156,31 +160,30 @@ sub connect_call_blob_setup {
     if exists $args{log_on_update};
 }
 
-=head2 connect_call_set_auto_cast
+=head2 connect_call_unsafe_insert
 
-In some configurations (usually with L</FreeTDS>) statements with values bound
-to columns or conditions that are not strings will throw implicit type
-conversion errors. For L</FreeTDS> this is automatically detected, and this
-option is set.
+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.
 
-It converts placeholders to:
+When using C<DBIx::Class::Storage::DBI::Sybase::NoBindVars> transactions are
+disabled.
 
-  CAST(? as $type)
+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>,
 
-the type is taken from the L<DBIx::Class::ResultSource/data_type> setting from
-your Result class, and mapped to a Sybase type using a mapping based on
-L<SQL::Translator> if necessary.
+  on_connect_call => ['unsafe_insert']
 
-This setting can also be set outside of
-L<DBIx::Class::Storage::DBI/connect_info> at any time using:
+To manipulate this setting at runtime, use:
 
-  $schema->storage->auto_cast(1);
+  $schema->storage->unsafe_insert(0|1);
 
 =cut
 
-sub connect_call_set_auto_cast {
+sub connect_call_unsafe_insert {
   my $self = shift;
-  $self->auto_cast(1);
+  $self->unsafe_insert(1);
 }
 
 sub _is_lob_type {
@@ -189,55 +192,35 @@ sub _is_lob_type {
   $type && $type =~ /(?:text|image|lob|bytea|binary|memo)/i;
 }
 
-# The select-piggybacking-on-insert trick stolen from odbc/mssql
 sub _prep_for_execute {
   my $self = shift;
   my ($op, $extra_bind, $ident, $args) = @_;
 
   my ($sql, $bind) = $self->next::method (@_);
 
-# Some combinations of FreeTDS and Sybase throw implicit conversion errors for
-# all placeeholders, so we convert them into CASTs here.
-# Based on code in ::DBI::NoBindVars .
-#
-# If we're using ::NoBindVars, there are no binds by this point so this code
-# gets skippeed.
-  if ($self->auto_cast && @$bind) {
-    my $new_sql;
-    my @sql_part = split /\?/, $sql;
-    my $col_info = $self->_resolve_column_info($ident,[ map $_->[0], @$bind ]);
-
-    foreach my $bound (@$bind) {
-      my $col = $bound->[0];
-      my $syb_type = $self->_syb_base_type($col_info->{$col}{data_type});
-
-      foreach my $data (@{$bound}[1..$#$bound]) {
-        $new_sql .= shift(@sql_part) .
-          ($syb_type ? "CAST(? AS $syb_type)" : '?');
-      }
-    }
-    $new_sql .= join '', @sql_part;
-    $sql = $new_sql;
-  }
-
   if ($op eq 'insert') {
     my $table = $ident->from;
 
     my $bind_info = $self->_resolve_column_info(
       $ident, [map $_->[0], @{$bind}]
     );
-    my $identity_col =
-List::Util::first { $bind_info->{$_}{is_auto_increment} } (keys %$bind_info);
+    my $identity_col = List::Util::first
+      { $bind_info->{$_}{is_auto_increment} }
+      (keys %$bind_info)
+    ;
 
     if ($identity_col) {
-      $sql =
-"SET IDENTITY_INSERT $table ON\n" .
-"$sql\n" .
-"SET IDENTITY_INSERT $table OFF"
-    } else {
-      $identity_col = List::Util::first {
-        $ident->column_info($_)->{is_auto_increment}
-      } $ident->columns;
+      $sql = join ("\n",
+        "SET IDENTITY_INSERT $table ON",
+        $sql,
+        "SET IDENTITY_INSERT $table OFF",
+      );
+    }
+    else {
+      $identity_col = List::Util::first
+        { $ident->column_info($_)->{is_auto_increment} }
+        $ident->columns
+      ;
     }
 
     if ($identity_col) {
@@ -250,9 +233,10 @@ List::Util::first { $bind_info->{$_}{is_auto_increment} } (keys %$bind_info);
   return ($sql, $bind);
 }
 
-# Stolen from SQLT, with some modifications. This will likely change when the
-# SQLT Sybase stuff is redone/fixed-up.
-my %TYPE_MAPPING  = (
+# Stolen from SQLT, with some modifications. This is a makeshift
+# solution before a sane type-mapping library is available, thus
+# the 'our' for easy overrides.
+our %TYPE_MAPPING  = (
     number    => 'numeric',
     money     => 'money',
     varchar   => 'varchar',
@@ -270,11 +254,11 @@ my %TYPE_MAPPING  = (
     long      => 'varchar',
 );
 
-sub _syb_base_type {
+sub _native_data_type {
   my ($self, $type) = @_;
 
   $type = lc $type;
-  $type =~ s/ identity//;
+  $type =~ s/\s* identity//x;
 
   return uc($TYPE_MAPPING{$type} || $type);
 }
@@ -301,47 +285,79 @@ 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, $source, $to_insert) = splice @_, 0, 3;
-  my $dbh = $self->_dbh;
+  my $self = shift;
+  my ($source, $to_insert) = @_;
 
   my $blob_cols = $self->_remove_blob_cols($source, $to_insert);
 
-# 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.
+# insert+blob insert done atomically
+  my $guard = $self->txn_scope_guard if $blob_cols;
+
+  my $need_last_insert_id = 0;
+
+  my ($identity_col) =
+    map $_->[0],
+    grep $_->[1]{is_auto_increment},
+    map [ $_, $source->column_info($_) ],
+    $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 $updated_cols = do {
-    if ($self->_insert_txn && (not $self->{transaction_depth})) {
-      my $args = \@_;
-      my $method = $self->next::can;
-      $self->txn_do(
-        sub { $self->$method($source, $to_insert, @$args) }
-      );
-    } else {
-      $self->next::method($source, $to_insert, @_);
+    if (
+      $need_last_insert_id && !$self->unsafe_insert && !$self->{transaction_depth}
+    ) {
+      $self->_insert_dbh($self->_connect(@{ $self->_dbi_connect_info }))
+        unless $self->_insert_dbh;
+      local $self->{_dbh} = $self->_insert_dbh;
+      my $guard = $self->txn_scope_guard;
+      my $upd_cols = $self->next::method (@_);
+      $guard->commit;
+      $self->_insert_dbh($self->_dbh);
+      $upd_cols;
+    }
+    else {
+      $self->next::method(@_);
     }
   };
 
-  $self->_insert_blobs($source, $blob_cols, $to_insert) if %$blob_cols;
+  $self->_insert_blobs($source, $blob_cols, $to_insert) if $blob_cols;
+
+  $guard->commit if $guard;
 
   return $updated_cols;
 }
 
 sub update {
-  my ($self, $source)  = splice @_, 0, 2;
-  my ($fields, $where) = @_;
-  my $wantarray        = wantarray;
+  my $self = shift;
+  my ($source, $fields, $where) = @_;
+
+  my $wantarray = wantarray;
 
   my $blob_cols = $self->_remove_blob_cols($source, $fields);
 
+# update+blob update(s) done atomically
+  my $guard = $self->txn_scope_guard if $blob_cols;
+
   my @res;
   if ($wantarray) {
-    @res    = $self->next::method($source, @_);
-  } else {
-    $res[0] = $self->next::method($source, @_);
+    @res    = $self->next::method(@_);
+  }
+  elsif (defined $wantarray) {
+    $res[0] = $self->next::method(@_);
+  }
+  else {
+    $self->next::method(@_);
   }
 
-  $self->_update_blobs($source, $blob_cols, $where) if %$blob_cols;
+  $self->_update_blobs($source, $blob_cols, $where) if $blob_cols;
+
+  $guard->commit if $guard;
 
   return $wantarray ? @res : $res[0];
 }
@@ -358,7 +374,7 @@ sub _remove_blob_cols {
     }
   }
 
-  return \%blob_cols;
+  return keys %blob_cols ? \%blob_cols : undef;
 }
 
 sub _update_blobs {
@@ -398,7 +414,7 @@ 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;
 
@@ -450,9 +466,10 @@ sub _insert_blobs {
     $sth->finish if $sth;
     if ($exception) {
       if ($self->using_freetds) {
-        croak
-"TEXT/IMAGE operation failed, probably because you're using FreeTDS: " .
-$exception;
+        croak (
+          'TEXT/IMAGE operation failed, probably because you are using FreeTDS: '
+          . $exception
+        );
       } else {
         croak $exception;
       }
@@ -487,7 +504,7 @@ C<SMALLDATETIME> columns only have minute precision.
     my $dbh = $self->_dbh;
 
     if ($dbh->can('syb_date_fmt')) {
-# amazingly, this works with FreeTDS
+      # amazingly, this works with FreeTDS
       $dbh->syb_date_fmt('ISO_strict');
     } elsif (not $old_dbd_warned) {
       carp "Your DBD::Sybase is too old to support ".
@@ -513,7 +530,7 @@ 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');
   }
 }
 
@@ -538,7 +555,7 @@ 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.
@@ -547,7 +564,7 @@ sub _svp_release { 1 }
 sub _svp_rollback {
   my ($self, $name) = @_;
 
-  $self->dbh->do("ROLLBACK TRANSACTION $name");
+  $self->_get_dbh->do("ROLLBACK TRANSACTION $name");
 }
 
 1;
@@ -559,7 +576,7 @@ allow you to dump a schema from most (if not all) versions of Sybase.
 
 It is available via subversion from:
 
-  http://dev.catalyst.perl.org/repos/bast/branches/DBIx-Class-Schema-Loader/mssql_tweaks
+  http://dev.catalyst.perl.org/repos/bast/branches/DBIx-Class-Schema-Loader/current/
 
 =head1 FreeTDS
 
@@ -582,17 +599,45 @@ Some versions of the libraries involved will not support placeholders, in which
 case the storage will be reblessed to
 L<DBIx::Class::Storage::DBI::Sybase::NoBindVars>.
 
-In some configurations, placeholders will work but will throw implicit
+In some configurations, placeholders will work but will throw implicit type
 conversion errors for anything that's not expecting a string. In such a case,
-the C<auto_cast> option is automatically set, which you may enable yourself with
-L</connect_call_set_auto_cast> (see the description of that method for more
-details.)
+the C<auto_cast> option from L<DBIx::Class::Storage::DBI::AutoCast> is
+automatically set, which you may enable on connection with
+L<DBIx::Class::Storage::DBI::AutoCast/connect_call_set_auto_cast>. The type info
+for the C<CAST>s is taken from the L<DBIx::Class::ResultSource/data_type>
+definitions in your Result classes, and are mapped to a Sybase type (if it isn't
+already) using a mapping based on L<SQL::Translator>.
 
 In other configurations, placeholers will work just as they do with the Sybase
 Open Client libraries.
 
 Inserts or updates of TEXT/IMAGE columns will B<NOT> work with FreeTDS.
 
+=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>.
+
+Transactions done for inserts in C<AutoCommit> mode when placeholders are in use
+are not affected, as they use an extra database handle to do the insert.
+
+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>
+
+=item * enlarge the scope of the transaction
+
+=back
+
 =head1 MAXIMUM CONNECTIONS
 
 The TDS protocol makes separate connections to the server for active statements
@@ -634,7 +679,7 @@ 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>.