X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FCursor.pm;h=ddad661105433ce9a6811b9c047919bb1b6c5c7d;hb=01c04b1b0550aeacf3e3214d687a1d056739c699;hp=361b1295373727189820d303ce0111b51a564230;hpb=71e65b395be8133d54b110a499f9e9619111c1f6;p=dbsrgits%2FDBIx-Class-Historic.git diff --git a/lib/DBIx/Class/Storage/DBI/Cursor.pm b/lib/DBIx/Class/Storage/DBI/Cursor.pm index 361b129..ddad661 100644 --- a/lib/DBIx/Class/Storage/DBI/Cursor.pm +++ b/lib/DBIx/Class/Storage/DBI/Cursor.pm @@ -5,20 +5,95 @@ use base qw/DBIx::Class::Cursor/; use strict; use warnings; +=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 = $cursor->next; + +=head1 DESCRIPTION + +A Cursor represents a query cursor on a L object. It +allows for traversing the result set with L, retrieving all results with +L and resetting the cursor with L. + +Usually, you would use the cursor methods built into L +to traverse it. See L, +L and L for more +information. + +=head1 METHODS + +=head2 new + +Returns a new L object. + +=cut + sub new { my ($class, $storage, $args, $attrs) = @_; - #use Data::Dumper; warn Dumper(@_); $class = ref $class if ref $class; + my $new = { storage => $storage, args => $args, pos => 0, - attrs => $attrs }; + attrs => $attrs, + _dbh_gen => $storage->{_dbh_gen}, + }; + return bless ($new, $class); } -sub next { - my ($self) = @_; +=head2 as_query + +=over 4 + +=item Arguments: none + +=item Return Value: \[ $sql, @bind ] + +=back + +Returns the SQL statement and bind vars associated with the invocant. + +=cut + +sub as_query { + my $self = shift; + + my $storage = $self->{storage}; + my $sql_maker = $storage->sql_maker; + local $sql_maker->{for}; + + my @args = $storage->_select_args(@{$self->{args}}); + my ($sql, $bind) = $storage->_prep_for_execute(@args[0 .. 2], [@args[4 .. $#args]]); + return \[ "($sql)", @{ $bind || [] }]; +} + +=head2 next + +=over 4 + +=item Arguments: none + +=item Return Value: \@row_columns + +=back + +Advances the cursor to the next row and returns an array of column +values (the result of L method). + +=cut + +sub _dbh_next { + my ($storage, $dbh, $self) = @_; + + $self->_check_dbh_gen; if ($self->{attrs}{rows} && $self->{pos} >= $self->{attrs}{rows}) { $self->{sth}->finish if $self->{sth}->{Active}; delete $self->{sth}; @@ -26,7 +101,7 @@ sub next { } return if $self->{done}; unless ($self->{sth}) { - $self->{sth} = ($self->{storage}->_select(@{$self->{args}}))[1]; + $self->{sth} = ($storage->_select(@{$self->{args}}))[1]; if ($self->{attrs}{software_limit}) { if (my $offset = $self->{attrs}{offset}) { $self->{sth}->fetch for 1 .. $offset; @@ -43,27 +118,83 @@ sub next { return @row; } -sub all { +sub next { my ($self) = @_; - return $self->SUPER::all if $self->{attrs}{rows}; + $self->{storage}->dbh_do($self->can('_dbh_next'), $self); +} + +=head2 all + +=over 4 + +=item Arguments: none + +=item Return Value: \@row_columns+ + +=back + +Returns a list of arrayrefs of column values for all rows in the +L. + +=cut + +sub _dbh_all { + my ($storage, $dbh, $self) = @_; + + $self->_check_dbh_gen; $self->{sth}->finish if $self->{sth}->{Active}; delete $self->{sth}; - my ($rv, $sth) = $self->{storage}->_select(@{$self->{args}}); + 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->SUPER::all; + } + $self->{storage}->dbh_do($self->can('_dbh_all'), $self); +} + +=head2 reset + +Resets the cursor to the beginning of the L. + +=cut + sub reset { my ($self) = @_; - $self->{sth}->finish if $self->{sth}->{Active}; + + # No need to care about failures here + eval { $self->{sth}->finish if $self->{sth} && $self->{sth}->{Active} }; + $self->_soft_reset; +} + +sub _soft_reset { + my ($self) = @_; + delete $self->{sth}; - $self->{pos} = 0; delete $self->{done}; + $self->{pos} = 0; return $self; } +sub _check_dbh_gen { + my ($self) = @_; + + if($self->{_dbh_gen} != $self->{storage}->{_dbh_gen}) { + $self->{_dbh_gen} = $self->{storage}->{_dbh_gen}; + $self->_soft_reset; + } +} + sub DESTROY { my ($self) = @_; - $self->{sth}->finish if $self->{sth}->{Active}; + + # None of the reasons this would die matter if we're in DESTROY anyways + local $@; + eval { $self->{sth}->finish if $self->{sth} && $self->{sth}->{Active} }; } 1;