1 package DBIx::Data::Collection::Set;
4 use Method::Signatures::Simple;
5 use Data::Perl::Stream::Array;
6 use Data::Perl::Collection::Set;
7 use Scalar::Util qw(weaken refaddr);
9 has _store => (is => 'ro', required => 1, init_arg => 'store');
11 has _class => (is => 'ro', predicate => '_has_class', init_arg => 'class');
13 has _set_over => (is => 'ro', required => 1, init_arg => 'set_over');
15 ## member cache (all members)
17 has _member_cache => (
18 is => 'ro', lazy_build => 1,
19 predicate => '_member_cache_built',
20 writer => '_set_member_cache',
23 method _build__member_cache {
24 my $stream = $self->_new_raw_stream;
26 while (my ($raw) = $stream->next) {
28 if (my ($obj) = $self->_key_cache_get_raw($raw)) {
29 # can't just $self->_merge($obj, $raw) since $obj might have changed
30 $self->_refresh($obj, $raw)
32 $self->_add_to_key_cache($self->_inflate($raw))
37 $self->_notify_observers(all_members => \@cache);
41 method _add_to_member_cache ($to_add) {
42 return $to_add unless $self->_member_cache_built;
43 push @{$self->_member_cache}, $to_add;
47 method _remove_from_member_cache ($to_remove) {
48 return $to_remove unless $self->_member_cache_built;
49 @{$self->_member_cache} = grep $_ ne $to_remove, @{$self->_member_cache};
53 ## key cache - by primary/unique key
55 has _key_cache => (is => 'ro', default => sub { {} });
57 method _add_to_key_cache ($to_add) {
58 $self->_key_cache->{$self->_object_to_id($to_add)} = $to_add;
62 method _remove_from_key_cache ($to_remove) {
63 # should return $to_remove
64 delete $self->_key_cache->{$self->_object_to_id($to_remove)}
67 method _key_cache_has_raw ($raw) {
68 exists $self->_key_cache->{$self->_raw_to_id($raw)}
71 method _key_cache_has_object ($obj) {
72 exists $self->_key_cache->{$self->_object_to_id($obj)}
75 method _key_cache_get_raw ($raw) {
76 $self->_key_cache_get_id($self->_raw_to_id($raw))
79 method _key_cache_get_object ($obj) {
80 $self->_key_cache_get_id($self->_object_to_id($obj))
83 method _key_cache_get_object_spec ($spec) {
84 # see _object_spec_to_id for doc of what the difference is
85 $self->_key_cache_get_id($self->_object_spec_to_id($spec))
88 method _key_cache_get_id ($id) {
89 exists $self->_key_cache->{$id}
90 ? ($self->_key_cache->{$id})
94 method _all_key_cache_members {
95 values %{$self->_key_cache}
98 method _set_key_cache_members ($members) {
99 %{$self->_key_cache} = (map +($self->_object_to_id($_) => $_), @$members);
105 has _observer_callbacks => (
106 is => 'ro', default => sub { {} },
109 method _notify_observers ($event, $payload) {
110 my $oc = $self->_observer_callbacks;
111 foreach my $refaddr (keys %$oc) {
112 my ($obj, $cb) = @{$oc->{$refaddr}};
113 unless (defined $obj) { # weak ref was garbage collected
114 delete $oc->{$refaddr};
117 $obj->$cb($self, $event, $payload);
122 method _register_observer ($obj, $cb) {
123 my $entry = [ $obj, $cb ];
125 $self->_observer_callbacks->{refaddr($obj)} = $entry;
129 method _setup_observation_of ($other) {
130 $other->_register_observer($self, method ($from, $event, $payload) {
131 if ($event eq 'add' or $event eq 'get') {
132 $self->_add_to_caches($payload);
133 } elsif ($event eq 'remove') {
134 $self->_remove_from_caches($payload);
135 } elsif ($event eq 'all_members') {
136 # separate arrayref since future add will trigger push()
137 $self->_set_caches([ @$payload ]);
143 ## thunking between the store representation and the set representation
145 # _inflate is raw data -> final repr
146 # _deflate is final repr -> raw data
147 # _merge takes final repr + raw data and updates the repr
148 # (this is used for pk-generated values and later lazy loading)
150 # _deflate_spec is attributes of final repr -> raw data
151 # _merge_spec is final repr + extra attributes and update repr
153 method _inflate ($raw) {
154 bless($raw, $self->_class) if $self->_has_class;
158 method _deflate ($obj) {
162 method _merge ($obj, $raw) {
163 @{$obj}{keys %$raw} = values %$raw;
167 method _refresh ($obj, $raw) {
168 # if $obj has been changed but not flushed we'd destroy data doing
169 # a blind merge - but if $obj has change tracking of some sort then
170 # we -could- do something safely, so this method exists to be mangled
175 method _deflate_spec ($spec) {
179 method _merge_spec ($obj, $spec) {
180 @{$obj}{keys %$spec} = values %$spec;
184 ## methods to get ids
186 method _raw_to_id ($raw) {
187 # XXX must escape this. or do something else.
188 join ';', map $raw->{$_}, @{$self->_set_over}
191 method _object_to_id ($obj) {
192 $self->_raw_to_id($self->_deflate($obj))
195 method _object_spec_to_id ($spec) {
196 # intentionally C&P from _raw_to - this is not the same thing. If a column
197 # were mapped to an attribute of a different name, the raw would have the
198 # column name as a key but an object spec would have the attribute name
199 join ';', map $spec->{$_}, @{$self->_set_over}
202 ## array-ish operations - i.e. get all members
204 method _new_raw_stream {
205 $self->_store->new_select_command({})->execute
209 @{$self->_member_cache};
213 Data::Perl::Stream::Array->new(array => $self->_member_cache);
216 # theoretically inefficient except that if we're being asked this then
217 # either the data should have been pre-loaded or we're going to get all
221 scalar $self->flatten
225 Data::Perl::Collection::Set->new(
226 members => [ map $sub->($_), $self->flatten ]
230 method _set_caches ($members) {
231 $self->_set_member_cache($members);
232 $self->_set_key_cache_members($members);
239 if (my ($got) = $self->_key_cache_get_object_spec($spec)) {
242 if (my ($raw) = $self->_get_from_store($self->_deflate_spec($spec))) {
243 return $self->_notify_observers(
244 get => $self->_add_to_key_cache($self->_inflate($raw))
247 return undef # we aren't handling cache misses here yet
250 method _get_from_store ($raw) {
251 $self->_store->new_select_single_command($raw)->execute
257 $self->_add_to_store($new);
258 $self->_add_to_caches($new);
259 $self->_notify_observers(add => $new);
263 method _add_to_store ($new) {
264 my $new_raw = $self->_deflate($new);
265 $self->_merge($new, $self->_store->new_insert_command($new_raw)->execute);
269 method _add_to_caches ($new) {
270 $self->_add_to_member_cache($new);
271 $self->_add_to_key_cache($new);
277 method remove ($old) {
278 $self->_remove_from_store($old);
279 $self->_remove_from_caches($old);
280 $self->_notify_observers(remove => $old);
284 method _remove_from_store ($old) {
285 $self->_store->new_delete_single_command($self->_deflate($old))->execute
288 method _remove_from_caches ($old) {
289 $self->_remove_from_member_cache($old);
290 $self->_remove_from_key_cache($old);
296 method _update_in_store ($obj) {
297 # this is currently a call command but we should think about it
298 # being a row command so that we can have RETURNING or other
299 # mechanisms handle things like set-on-update datetime values
300 $self->_store->new_update_single_command($self->_deflate($obj))->execute
303 # I do wonder if we needed _merge_spec or if we'd be better off with
304 # just using the raw merge routine ...
306 method _update_set_in_store ($spec) {
307 $self->_store->new_update_command($self->_deflate_spec($spec))->execute;
308 if ($self->_member_cache_built) {
309 my $cache = $self->_member_cache;
310 foreach my $obj (@{$cache}) {
311 $self->_merge_spec($obj, $spec);
313 $self->_notify_observers(all_members => $cache);
318 method _remove_set_from_store {
319 $self->_store->new_delete_command->execute;
320 $self->_set_caches([]);
321 $self->_notify_observers(all_members => []);