libs/Tangram/Hash.pm

# (c) Sound Object Logic 2000-2001

use strict;

package Tangram::Hash;

use Tangram::AbstractHash;
use base qw( Tangram::AbstractHash );

use Carp;

sub reschema
{
    my ($self, $members, $class, $schema) = @_;

    foreach my $member (keys %$members)
    {
                my $def = $members->{$member};

                unless (ref($def))
                {
                        $def = { class => $def };
                        $members->{$member} = $def;
                }

                $def->{table} ||= $schema->{normalize}->($def->{class} . "_$member", 'tablename');
                $def->{coll} ||= 'coll';
                $def->{item} ||= 'item';
                $def->{slot} ||= 'slot';
                $def->{quote} = !exists $def->{key_type} || $def->{key_type} eq 'string' ? "'" : '';
    }
    
    return keys %$members;
}

sub defered_save
{
    my ($self, $storage, $obj, $members, $coll_id) = @_;

    foreach my $member (keys %$members)
    {
                next if tied($obj->{$member});
                next unless exists $obj->{$member} && defined $obj->{$member};

                my $def = $members->{$member};
                my ($table, $coll_col, $item_col, $slot_col) = @{ $def }{ qw( table coll item slot ) };
                my $Q = $def->{quote};
        
                my $coll = $obj->{$member};

                my $old_state = $self->get_load_state($storage, $obj, $member) || {};

                my %removed = %$old_state;
                delete @removed{ keys %$coll };
                my @free = keys %removed;

                my %new_state;

                foreach my $slot (keys %$coll)
                {
                        my $item_id = $storage->id($coll->{$slot});

                        if (exists $old_state->{$slot})
                        {
                                # key already exists

                                if ($item_id != $old_state->{$slot})
                                {
                                        # val has changed
                                        $storage->sql_do(
                                                                         "UPDATE $table SET $item_col = $item_id WHERE $coll_col = $coll_id AND $slot_col = $Q$slot$Q" );
                                }
                        }
                        else
                        {
                                # key does not exist

                                if (@free)
                                {
                                        # recycle an existing line
                                        my $rslot = shift @free;
                                        $storage->sql_do(
                                                                         "UPDATE $table SET $slot_col = $Q$slot$Q, $item_col = $item_id WHERE $coll_col = $coll_id AND $slot_col = $Q$rslot$Q" );
                                }
                                else
                                {
                                        # insert a new line
                                        $storage->sql_do(
                                                                         "INSERT INTO $table ($coll_col, $item_col, $slot_col) VALUES ($coll_id, $item_id, $Q$slot$Q)" );
                                }
                        }

                        $new_state{$slot} = $item_id;

                }                                               # foreach my $slot (keys %$coll)

                # remove lines in excess

                if (@free)
                {
                        @free = map { "$Q$_$Q" } @free if $Q;
                        $storage->sql_do( "DELETE FROM $table WHERE $coll_col = $coll_id AND $slot_col IN (@free)" );
                }

                $self->set_load_state($storage, $obj, $member, \%new_state );   
                $storage->tx_on_rollback(
            sub { $self->set_load_state($storage, $obj, $member, $old_state) } );
    }
}

sub erase
{
    my ($self, $storage, $obj, $members, $coll_id) = @_;

    foreach my $member (keys %$members)
    {
                my $def = $members->{$member};
        
                my $table = $def->{table} || $def->{class} . "_$member";
                my $coll_col = $def->{coll} || 'coll';
        
                my $sql = "DELETE FROM $table WHERE $coll_col = $coll_id";
                $storage->sql_do($sql);
    }
}

sub cursor                                              # ?? factorize ??
{
    my ($self, $def, $storage, $obj, $member) = @_;

    my $cursor = Tangram::CollCursor->new($storage, $def->{class}, $storage->{db});

    my $coll_id = $storage->id($obj);
    my $coll_tid = $storage->alloc_table;
    my $table = $def->{table};
    my $item_tid = $cursor->{-stored}->root_table;
    my $coll_col = $def->{coll};
    my $item_col = $def->{item};
    my $slot_col = $def->{slot};
    $cursor->{-coll_tid} = $coll_tid;
    $cursor->{-coll_cols} = "t$coll_tid.$slot_col";
    $cursor->{-coll_from} = "$table t$coll_tid";
    $cursor->{-coll_where} = "t$coll_tid.$coll_col = $coll_id AND t$coll_tid.$item_col = t$item_tid.id";
    
    return $cursor;
}

sub query_expr
{
    my ($self, $obj, $members, $tid) = @_;
    map { Tangram::CollExpr->new($obj, $_); } values %$members;
}

sub remote_expr
{
    my ($self, $obj, $tid) = @_;
    Tangram::CollExpr->new($obj, $self);
}

sub prefetch
{
    q{
        my ($self, $storage, $def, $coll, $class, $member, $filter) = @_;

        my $ritem = $storage->remote($def->{class});

        # first retrieve the collection-side ids of all objects satisfying $filter
        # empty the corresponding prefetch array

        my $ids = $storage->my_select_data( cols => [ $coll->{id} ], filter => $filter );
        my $prefetch = $storage->{PREFETCH}{$class}{$member} ||= {}; # weakref

        while (my $id = $ids->fetchrow)
        {
            $prefetch->{$id} = []
            }

        undef $ids;

        # now fetch the items

        my $cursor = Tangram::Cursor->new($storage, $ritem, $storage->{db});
        my $includes = $coll->{$member}->includes($ritem);

        # also retrieve collection-side id and index of elmt in sequence
        $cursor->retrieve($coll->{id},
                Tangram::Number->expr("t$includes->{link_tid}.$def->{slot}" ) );

        $cursor->select($filter ? $filter & $includes : $includes);
        
        while (my $item = $cursor->current)
        {
            my ($coll_id, $slot) = $cursor->residue;
            $prefetch->{$coll_id}[$slot] = $item;
            $cursor->next;
        }

    } # skipped
}

$Tangram::Schema::TYPES{hash} = Tangram::Hash->new;

1;
1	joko	1.1	# (c) Sound Object Logic 2000-2001
2
3			use strict;
4
5			package Tangram::Hash;
6
7			use Tangram::AbstractHash;
8			use base qw( Tangram::AbstractHash );
9
10			use Carp;
11
12			sub reschema
13			{
14			my ($self, $members, $class, $schema) = @_;
15
16			foreach my $member (keys %$members)
17			{
18			my $def = $members->{$member};
19
20			unless (ref($def))
21			{
22			$def = { class => $def };
23			$members->{$member} = $def;
24			}
25
26			$def->{table} \|\|= $schema->{normalize}->($def->{class} . "_$member", 'tablename');
27			$def->{coll} \|\|= 'coll';
28			$def->{item} \|\|= 'item';
29			$def->{slot} \|\|= 'slot';
30			$def->{quote} = !exists $def->{key_type} \|\| $def->{key_type} eq 'string' ? "'" : '';
31			}
32
33			return keys %$members;
34			}
35
36			sub defered_save
37			{
38			my ($self, $storage, $obj, $members, $coll_id) = @_;
39
40			foreach my $member (keys %$members)
41			{
42			next if tied($obj->{$member});
43			next unless exists $obj->{$member} && defined $obj->{$member};
44
45			my $def = $members->{$member};
46			my ($table, $coll_col, $item_col, $slot_col) = @{ $def }{ qw( table coll item slot ) };
47			my $Q = $def->{quote};
48
49			my $coll = $obj->{$member};
50
51			my $old_state = $self->get_load_state($storage, $obj, $member) \|\| {};
52
53			my %removed = %$old_state;
54			delete @removed{ keys %$coll };
55			my @free = keys %removed;
56
57			my %new_state;
58
59			foreach my $slot (keys %$coll)
60			{
61			my $item_id = $storage->id($coll->{$slot});
62
63			if (exists $old_state->{$slot})
64			{
65			# key already exists
66
67			if ($item_id != $old_state->{$slot})
68			{
69			# val has changed
70			$storage->sql_do(
71			"UPDATE $table SET $item_col = $item_id WHERE $coll_col = $coll_id AND $slot_col = $Q$slot$Q" );
72			}
73			}
74			else
75			{
76			# key does not exist
77
78			if (@free)
79			{
80			# recycle an existing line
81			my $rslot = shift @free;
82			$storage->sql_do(
83			"UPDATE $table SET $slot_col = $Q$slot$Q, $item_col = $item_id WHERE $coll_col = $coll_id AND $slot_col = $Q$rslot$Q" );
84			}
85			else
86			{
87			# insert a new line
88			$storage->sql_do(
89			"INSERT INTO $table ($coll_col, $item_col, $slot_col) VALUES ($coll_id, $item_id, $Q$slot$Q)" );
90			}
91			}
92
93			$new_state{$slot} = $item_id;
94
95			} # foreach my $slot (keys %$coll)
96
97			# remove lines in excess
98
99			if (@free)
100			{
101			@free = map { "$Q$_$Q" } @free if $Q;
102			$storage->sql_do( "DELETE FROM $table WHERE $coll_col = $coll_id AND $slot_col IN (@free)" );
103			}
104
105			$self->set_load_state($storage, $obj, $member, \%new_state );
106			$storage->tx_on_rollback(
107			sub { $self->set_load_state($storage, $obj, $member, $old_state) } );
108			}
109			}
110
111			sub erase
112			{
113			my ($self, $storage, $obj, $members, $coll_id) = @_;
114
115			foreach my $member (keys %$members)
116			{
117			my $def = $members->{$member};
118
119			my $table = $def->{table} \|\| $def->{class} . "_$member";
120			my $coll_col = $def->{coll} \|\| 'coll';
121
122			my $sql = "DELETE FROM $table WHERE $coll_col = $coll_id";
123			$storage->sql_do($sql);
124			}
125			}
126
127			sub cursor # ?? factorize ??
128			{
129			my ($self, $def, $storage, $obj, $member) = @_;
130
131			my $cursor = Tangram::CollCursor->new($storage, $def->{class}, $storage->{db});
132
133			my $coll_id = $storage->id($obj);
134			my $coll_tid = $storage->alloc_table;
135			my $table = $def->{table};
136			my $item_tid = $cursor->{-stored}->root_table;
137			my $coll_col = $def->{coll};
138			my $item_col = $def->{item};
139			my $slot_col = $def->{slot};
140			$cursor->{-coll_tid} = $coll_tid;
141			$cursor->{-coll_cols} = "t$coll_tid.$slot_col";
142			$cursor->{-coll_from} = "$table t$coll_tid";
143			$cursor->{-coll_where} = "t$coll_tid.$coll_col = $coll_id AND t$coll_tid.$item_col = t$item_tid.id";
144
145			return $cursor;
146			}
147
148			sub query_expr
149			{
150			my ($self, $obj, $members, $tid) = @_;
151			map { Tangram::CollExpr->new($obj, $_); } values %$members;
152			}
153
154			sub remote_expr
155			{
156			my ($self, $obj, $tid) = @_;
157			Tangram::CollExpr->new($obj, $self);
158			}
159
160			sub prefetch
161			{
162			q{
163			my ($self, $storage, $def, $coll, $class, $member, $filter) = @_;
164
165			my $ritem = $storage->remote($def->{class});
166
167			# first retrieve the collection-side ids of all objects satisfying $filter
168			# empty the corresponding prefetch array
169
170			my $ids = $storage->my_select_data( cols => [ $coll->{id} ], filter => $filter );
171			my $prefetch = $storage->{PREFETCH}{$class}{$member} \|\|= {}; # weakref
172
173			while (my $id = $ids->fetchrow)
174			{
175			$prefetch->{$id} = []
176			}
177
178			undef $ids;
179
180			# now fetch the items
181
182			my $cursor = Tangram::Cursor->new($storage, $ritem, $storage->{db});
183			my $includes = $coll->{$member}->includes($ritem);
184
185			# also retrieve collection-side id and index of elmt in sequence
186			$cursor->retrieve($coll->{id},
187			Tangram::Number->expr("t$includes->{link_tid}.$def->{slot}" ) );
188
189			$cursor->select($filter ? $filter & $includes : $includes);
190
191			while (my $item = $cursor->current)
192			{
193			my ($coll_id, $slot) = $cursor->residue;
194			$prefetch->{$coll_id}[$slot] = $item;
195			$cursor->next;
196			}
197
198			} # skipped
199			}
200
201			$Tangram::Schema::TYPES{hash} = Tangram::Hash->new;
202
203			1;
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