1 package DBIx::Class::Storage::DBI::Cursor;
6 use base qw/DBIx::Class::Cursor/;
9 use Scalar::Util qw/refaddr weaken/;
12 __PACKAGE__->mk_group_accessors('simple' =>
13 qw/storage args attrs/
18 DBIx::Class::Storage::DBI::Cursor - Object representing a query cursor on a
23 my $cursor = $schema->resultset('CD')->cursor();
25 # raw values off the database handle in resultset columns/select order
26 my @next_cd_column_values = $cursor->next;
28 # list of all raw values as arrayrefs
29 my @all_cds_column_values = $cursor->all;
33 A Cursor represents a query cursor on a L<DBIx::Class::ResultSet> object. It
34 allows for traversing the result set with L</next>, retrieving all results with
35 L</all> and resetting the cursor with L</reset>.
37 Usually, you would use the cursor methods built into L<DBIx::Class::ResultSet>
38 to traverse it. See L<DBIx::Class::ResultSet/next>,
39 L<DBIx::Class::ResultSet/reset> and L<DBIx::Class::ResultSet/all> for more
46 Returns a new L<DBIx::Class::Storage::DBI::Cursor> object.
54 my ($class, $storage, $args, $attrs) = @_;
60 }, ref $class || $class;
62 weaken( $cursor_registry{ refaddr($self) } = $self )
63 if DBIx::Class::_ENV_::HAS_ITHREADS;
69 for (keys %cursor_registry) {
70 # once marked we no longer care about them, hence no
71 # need to keep in the registry, left alone renumber the
72 # keys (all addresses are now different)
73 my $self = delete $cursor_registry{$_}
76 $self->{_intra_thread} = 1;
87 =item Return Value: \@row_columns
91 Advances the cursor to the next row and returns an array of column
92 values (the result of L<DBI/fetchrow_array> method).
99 return if $self->{_done};
104 $self->{attrs}{software_limit}
105 && $self->{attrs}{rows}
106 && ($self->{_pos}||0) >= $self->{attrs}{rows}
108 if ($sth = $self->sth) {
109 # explicit finish will issue warnings, unlike the DESTROY below
110 $sth->finish if $sth->FETCH('Active');
117 unless ($sth = $self->sth) {
118 (undef, $sth) = $self->storage->_select( @{$self->{args}} );
120 if ( $self->{attrs}{software_limit} and $self->{attrs}{offset} ) {
121 $sth->fetch for 1 .. $self->{attrs}{offset};
127 my $row = $sth->fetchrow_arrayref;
142 =item Arguments: none
144 =item Return Value: \@row_columns+
148 Returns a list of arrayrefs of column values for all rows in the
149 L<DBIx::Class::ResultSet>.
156 # delegate to DBIC::Cursor which will delegate back to next()
157 if ($self->{attrs}{software_limit}
158 && ($self->{attrs}{offset} || $self->{attrs}{rows})) {
159 return $self->next::method(@_);
164 if ($sth = $self->sth) {
165 # explicit finish will issue warnings, unlike the DESTROY below
166 $sth->finish if ( ! $self->{_done} and $sth->FETCH('Active') );
170 (undef, $sth) = $self->storage->_select( @{$self->{args}} );
172 return @{$sth->fetchall_arrayref};
179 delete @{$self}{qw/_pos _done _pid _intra_thread/};
181 $self->{sth} = $_[0];
182 $self->{_pid} = $$ if ! DBIx::Class::_ENV_::BROKEN_FORK and $_[0];
184 elsif ($self->{sth} and ! $self->{_done}) {
186 my $invalidate_handle_reason;
188 if (DBIx::Class::_ENV_::HAS_ITHREADS and $self->{_intra_thread} ) {
189 $invalidate_handle_reason = 'Multi-thread';
191 elsif (!DBIx::Class::_ENV_::BROKEN_FORK and $self->{_pid} != $$ ) {
192 $invalidate_handle_reason = 'Multi-process';
195 if ($invalidate_handle_reason) {
196 $self->storage->throw_exception("$invalidate_handle_reason access attempted while cursor in progress (position $self->{_pos})")
199 # reinvokes the reset logic above
209 Resets the cursor to the beginning of the L<DBIx::Class::ResultSet>.
214 $_[0]->__finish_sth if $_[0]->{sth};
220 $_[0]->__finish_sth if $_[0]->{sth};
224 # It is (sadly) extremely important to finish() handles we are about
225 # to lose (due to reset() or a DESTROY() ). $rs->reset is the closest
226 # thing the user has to getting to the underlying finish() API and some
227 # DBDs mandate this (e.g. DBD::InterBase will segfault, DBD::Sybase
228 # won't start a transaction sanely, etc)
229 # We also can't use the accessor here, as it will trigger a fork/thread
230 # check, and resetting a cursor in a child is perfectly valid
234 # No need to care about failures here
235 try { local $SIG{__WARN__} = sub {}; $self->{sth}->finish } if (
236 $self->{sth} and ! try { ! $self->{sth}->FETCH('Active') }