X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FCursor.pm;h=eee5cbbb2232e6495da5ac84a9d26585cafee26e;hb=a6646e1b0a25acfd21cc3e32b8c479dd0f3526ef;hp=143425bc252cd00bcecfb6f4b8a26c468390d585;hpb=aeaf3ce2ab5d86cbdaca6857f5ee3c9cea3f1fd6;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/DBI/Cursor.pm b/lib/DBIx/Class/Storage/DBI/Cursor.pm
index 143425b..eee5cbb 100644
--- a/lib/DBIx/Class/Storage/DBI/Cursor.pm
+++ b/lib/DBIx/Class/Storage/DBI/Cursor.pm
@@ -1,57 +1,186 @@
 package DBIx::Class::Storage::DBI::Cursor;
 
-use base qw/DBIx::Class::Cursor/;
-
 use strict;
 use warnings;
 
+use base qw/DBIx::Class::Cursor/;
+
+use Try::Tiny;
+use namespace::clean;
+
+__PACKAGE__->mk_group_accessors('simple' =>
+    qw/sth/
+);
+
+=head1 NAME
+
+DBIx::Class::Storage::DBI::Cursor - Object representing a query cursor on a
+resultset.
+
+=head1 SYNOPSIS
+
+  my $cursor = $schema->resultset('CD')->cursor();
+  my $first_cd = $cursor->next;
+
+=head1 DESCRIPTION
+
+A Cursor represents a query cursor on a L<DBIx::Class::ResultSet> object. It
+allows for traversing the result set with L</next>, retrieving all results with
+L</all> and resetting the cursor with L</reset>.
+
+Usually, you would use the cursor methods built into L<DBIx::Class::ResultSet>
+to traverse it. See L<DBIx::Class::ResultSet/next>,
+L<DBIx::Class::ResultSet/reset> and L<DBIx::Class::ResultSet/all> for more
+information.
+
+=head1 METHODS
+
+=head2 new
+
+Returns a new L<DBIx::Class::Storage::DBI::Cursor> object.
+
+=cut
+
 sub new {
-  my ($it_class, $sth, $args, $attrs) = @_;
-  #use Data::Dumper; warn Dumper(@_);
-  $it_class = ref $it_class if ref $it_class;
+  my ($class, $storage, $args, $attrs) = @_;
+  $class = ref $class if ref $class;
+
   my $new = {
-    sth => $sth,
+    storage => $storage,
     args => $args,
     pos => 0,
-    attrs => $attrs };
-  return bless ($new, $it_class);
+    attrs => $attrs,
+    _dbh_gen => $storage->{_dbh_gen},
+  };
+
+  return bless ($new, $class);
 }
 
-sub next {
-  my ($self) = @_;
-  return if $self->{attrs}{rows}
-    && $self->{pos} >= $self->{attrs}{rows}; # + $self->{attrs}{offset});
-  my $sth = $self->{sth};
-  unless ($self->{live_sth}) {
-    $sth->execute(@{$self->{args} || []});
-    $self->{live_sth} = 1;
+=head2 next
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: \@row_columns
+
+=back
+
+Advances the cursor to the next row and returns an array of column
+values (the result of L<DBI/fetchrow_array> method).
+
+=cut
+
+sub _dbh_next {
+  my ($storage, $dbh, $self) = @_;
+
+  $self->_check_dbh_gen;
+  if (
+    $self->{attrs}{software_limit}
+      && $self->{attrs}{rows}
+        && $self->{pos} >= $self->{attrs}{rows}
+  ) {
+    $self->sth->finish if $self->sth->{Active};
+    $self->sth(undef);
+    $self->{done} = 1;
+  }
+  return if $self->{done};
+  unless ($self->sth) {
+    $self->sth(($storage->_select(@{$self->{args}}))[1]);
+    if ($self->{attrs}{software_limit}) {
+      if (my $offset = $self->{attrs}{offset}) {
+        $self->sth->fetch for 1 .. $offset;
+      }
+    }
+  }
+  my @row = $self->sth->fetchrow_array;
+  if (@row) {
+    $self->{pos}++;
+  } else {
+    $self->sth(undef);
+    $self->{done} = 1;
   }
-  my @row = $sth->fetchrow_array;
-  $self->{pos}++ if @row;
   return @row;
 }
 
-sub all {
+sub next {
   my ($self) = @_;
-  return $self->SUPER::all if $self->{attrs}{rows};
-  my $sth = $self->{sth};
-  $sth->finish if $sth->{Active};
-  $sth->execute(@{$self->{args} || []});
-  delete $self->{live_sth};
+  $self->{storage}->dbh_do($self->can('_dbh_next'), $self);
+}
+
+=head2 all
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: \@row_columns+
+
+=back
+
+Returns a list of arrayrefs of column values for all rows in the
+L<DBIx::Class::ResultSet>.
+
+=cut
+
+sub _dbh_all {
+  my ($storage, $dbh, $self) = @_;
+
+  $self->_check_dbh_gen;
+  $self->sth->finish if $self->sth && $self->sth->{Active};
+  $self->sth(undef);
+  my ($rv, $sth) = $storage->_select(@{$self->{args}});
   return @{$sth->fetchall_arrayref};
 }
 
+sub all {
+  my ($self) = @_;
+  if ($self->{attrs}{software_limit}
+        && ($self->{attrs}{offset} || $self->{attrs}{rows})) {
+    return $self->next::method;
+  }
+
+  $self->{storage}->dbh_do($self->can('_dbh_all'), $self);
+}
+
+=head2 reset
+
+Resets the cursor to the beginning of the L<DBIx::Class::ResultSet>.
+
+=cut
+
 sub reset {
   my ($self) = @_;
-  $self->{sth}->finish if $self->{sth}->{Active};
+
+  # No need to care about failures here
+  try { $self->sth->finish }
+    if $self->sth && $self->sth->{Active};
+  $self->_soft_reset;
+  return undef;
+}
+
+sub _soft_reset {
+  my ($self) = @_;
+
+  $self->sth(undef);
+  delete $self->{done};
   $self->{pos} = 0;
-  $self->{live_sth} = 0;
-  return $self;
 }
 
-sub DESTROY {
+sub _check_dbh_gen {
   my ($self) = @_;
-  $self->{sth}->finish if $self->{sth}->{Active};
+
+  if($self->{_dbh_gen} != $self->{storage}->{_dbh_gen}) {
+    $self->{_dbh_gen} = $self->{storage}->{_dbh_gen};
+    $self->_soft_reset;
+  }
+}
+
+sub DESTROY {
+  # None of the reasons this would die matter if we're in DESTROY anyways
+  if (my $sth = $_[0]->sth) {
+    try { $sth->finish } if $sth->FETCH('Active');
+  }
 }
 
 1;