1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
package DBIx::Class::ResultClass::HashRefInflator;
use strict;
use warnings;
=head1 NAME
DBIx::Class::ResultClass::HashRefInflator - Get raw hashrefs from a resultset
=head1 SYNOPSIS
use DBIx::Class::ResultClass::HashRefInflator;
my $rs = $schema->resultset('CD');
$rs->result_class('DBIx::Class::ResultClass::HashRefInflator');
while (my $hashref = $rs->next) {
...
}
OR as an attribute:
my $rs = $schema->resultset('CD')->search({}, {
result_class => 'DBIx::Class::ResultClass::HashRefInflator',
});
while (my $hashref = $rs->next) {
...
}
=head1 DESCRIPTION
DBIx::Class is faster than older ORMs like Class::DBI but it still isn't
designed primarily for speed. Sometimes you need to quickly retrieve the data
from a massive resultset, while skipping the creation of fancy row objects.
Specifying this class as a C<result_class> for a resultset will change C<< $rs->next >>
to return a plain data hash-ref (or a list of such hash-refs if C<< $rs->all >> is used).
There are two ways of applying this class to a resultset:
=over
=item *
Specify C<< $rs->result_class >> on a specific resultset to affect only that
resultset (and any chained off of it); or
=item *
Specify C<< __PACKAGE__->result_class >> on your source object to force all
uses of that result source to be inflated to hash-refs - this approach is not
recommended.
=back
=cut
##############
# NOTE
#
# Generally people use this to gain as much speed as possible. If a new &mk_hash is
# implemented, it should be benchmarked using the maint/benchmark_hashrefinflator.pl
# script (in addition to passing all tests of course :). Additional instructions are
# provided in the script itself.
#
# This coderef is a simple recursive function
# Arguments: ($me, $prefetch, $is_root) from inflate_result() below
my $mk_hash;
$mk_hash = sub {
if (ref $_[0] eq 'ARRAY') { # multi relationship
return [ map { $mk_hash->(@$_) || () } (@_) ];
}
else {
my $hash = {
# the main hash could be an undef if we are processing a skipped-over join
$_[0] ? %{$_[0]} : (),
# the second arg is a hash of arrays for each prefetched relation
map
{ $_ => $mk_hash->( @{$_[1]->{$_}} ) }
( $_[1] ? (keys %{$_[1]}) : () )
};
# if there is at least one defined column *OR* we are at the root of
# the resultset - consider the result real (and not an emtpy has_many
# rel containing one empty hashref)
# an empty arrayref is an empty multi-sub-prefetch - don't consider
# those either
return $hash if $_[2];
for (values %$hash) {
if (ref $_ eq 'ARRAY') {
return $hash if @$_;
}
elsif (defined $_) {
return $hash;
}
}
return undef;
}
};
=head1 METHODS
=head2 inflate_result
Inflates the result and prefetched data into a hash-ref (invoked by L<DBIx::Class::ResultSet>)
=cut
##################################################################################
# inflate_result is invoked as:
# HRI->inflate_result ($resultsource_instance, $main_data_hashref, $prefetch_data_hashref)
sub inflate_result {
return $mk_hash->($_[2], $_[3], 'is_root');
}
=head1 CAVEATS
=over
=item *
This will not work for relationships that have been prefetched. Consider the
following:
my $artist = $artitsts_rs->search({}, {prefetch => 'cds' })->first;
my $cds = $artist->cds;
$cds->result_class('DBIx::Class::ResultClass::HashRefInflator');
my $first = $cds->first;
C<$first> will B<not> be a hashref, it will be a normal CD row since
HashRefInflator only affects resultsets at inflation time, and prefetch causes
relations to be inflated when the master C<$artist> row is inflated.
=item *
Column value inflation, e.g., using modules like
L<DBIx::Class::InflateColumn::DateTime>, is not performed.
The returned hash contains the raw database values.
=back
=cut
1;
|
