lib/WebPAC/Store.pm

package WebPAC::Store;

use warnings;
use strict;

use base 'WebPAC::Common';
use Storable;
use File::Path;
use Data::Dump qw/dump/;

=head1 NAME

WebPAC::Store - Store WebPAC data on disk

=head1 VERSION

Version 0.11

=cut

our $VERSION = '0.11';

=head1 SYNOPSIS

This module provides disk storage for normalised data and lookups.

It is one of newer components of WebPAC, so it will change from time to
time.

I will try to keep backward compatiblity by providing multiple back-ends,
but this can't be garanteed. In other words, don't delete your input
databases just yet :-)

This has additional advantage. I can create single place to plugin other
file formats which provide better performance for particular type of data.

For now, this is a prototype version.

    use WebPAC::Store;

    my $foo = WebPAC::Store->new();
    ...

=head1 FUNCTIONS

=head2 new

Create new normalised database object

  my $db = new WebPAC::Store(
        path => '/path/to/cache/ds/',
        database => 'name',
        read_only => 1,
  );

Optional parameter C<path> defines path to directory
in which cache file for C<data_structure> call will be created.

If called with C<read_only> it will not disable caching if
called without write permission (but will die on C<save_ds>).

Optional parametar C<database> will be used used as subdirectory in path if no
database in specified when calling other functions.

=cut

sub new {
        my $class = shift;
        my $self = {@_};
        bless($self, $class);

        my $log = $self->_get_logger();

        foreach my $p (qw/path database/) {
                $log->logconfess("need $p") unless ($self->{$p});
        }

        $self->path( $self->{'path'} );

        $self ? return $self : return undef;
}

=head2 path

Check if specified cache directory exist, and if not, disable caching.

 $db->path('./cache/ds/');

If you pass false or zero value to this function, it will disable
cacheing.

You can also call this function to get current cache path.

 my $cache_path = $db->path;

=cut

sub path {
        my $self = shift;

        my $dir = shift;
        
        return $self->{path} unless defined($dir);

        my $log = $self->_get_logger();

        if ($dir) {
                my $msg;
                if (! -e $dir) {
                        if ($self->{'read_only'}) {
                                $msg = "doesn't exist";
                        } else {
                                $log->info("creating $dir");
                                mkpath $dir;
                        }
                } elsif (! -d $dir) {
                        $msg = "is not directory";
                } elsif (! -w $dir) {
                        $msg = "not writable" unless ($self->{'read_only'});
                }

                if ($msg) {
                        $log->warn("cache path $dir $msg, disabling...");
                        undef $self->{'path'};
                } else {
                        $log->debug("using cache dir $dir");
                        $self->{'path'} = $dir;
                }
        } else {
                $log->debug("disabling cache");
                undef $self->{'path'};
        }
}

=head2 load_ds

Retrive from disk one data_structure records usually using field 000 as key

  my $ds = $db->load_ds(
                database => 'ps',
                input => 'name',
                id => 42,
  );

This function will also perform basic sanity checking on returned
data and disable caching if data is corrupted (or changed since last
update).

C<input> is used to differenciate different source input databases
which are indexed in same database.

C<database> if B<optional> argument which will override database name used when creating
C<WebPAC::Store> object (for simple retrival from multiple databases).

Returns hash or undef if cacheing is disabled or unavailable.

=cut

sub load_ds {
        my $self = shift;

        my $log = $self->_get_logger;

        my $cache_path = $self->{'path'};

        if (! $cache_path) {
                $log->warn("path not set, ignoring load_ds");
                return;
        }

        $log->logconfess("arguments for load_ds must be HASH") unless (ref(\@_) eq 'ARRAY' && ($#_ % 2 == 1));

        my $args = {@_};
        my $id = $args->{id};

        $log->logconfess("got hash, but without id") unless (defined($id));
        $log->logconfess("got hash, but id [$id] isn't number") unless ($id =~ /^\d+$/);

        my $database = $args->{database} || $self->{database};
        my $input = $args->{input} || '';

        $log->logconfess("can't find database name") unless ($database);

        my $cache_file = "$cache_path/$database/$input/$id";
        $cache_file =~ s#//#/#go;

        $log->debug("using cache_file $cache_file");

        if (-r $cache_file) {
                my $ds_ref = retrieve($cache_file);
                if ($ds_ref) {
                        $log->debug("cache hit: $cache_file");
                        if ($ds_ref->{'ds'}) {
                                return $ds_ref->{'ds'};
                        } else {
                                $log->warn("cache entry $cache_file corrupt. Use rm $cache_path/* to re-create it on next run!");
                                undef $self->{'path'};
                        }
                }
        } else {
                #$log->warn("cache entry $cache_file doesn't exist");
                return undef;
        }

        return undef;
}

=head2 save_ds

Store data_structure on disk.

  $db->save_ds(
        database => 'name',
        input => 'name',
        id => $ds->{000}->[0],
        ds => $ds,
  );

B<Totally broken, but fast.>

Depends on filename generated by C<load_ds>.

=cut

sub save_ds {
        my $self = shift;

        die "can't write to database in read_only mode!" if ($self->{'read_only'});

        return unless($self->{'path'});

        my $args = {@_};

        my $log = $self->_get_logger;
        $log->debug("save_ds arguments:", dump( \@_ ));

        foreach my $f (qw/id ds/) {
                $log->logconfess("need $f") unless (defined($args->{$f}));
        }

        my $database = $args->{database} || $self->{database};
        $log->logconfess("can't find database name") unless ($database);

        my $input = $args->{input} || '';

        my $cache_file = $self->{path} . "/$database/$input/";
        $cache_file =~ s#//#/#go;

        mkpath($cache_file) unless (-d $cache_file);

        $cache_file .= $args->{id};

        $log->debug("creating storable cache file $cache_file");

        return store {
                ds => $args->{ds},
                id => $args->{id},
        }, $cache_file;

}

=head2 save_lookup

  $db->save_lookup(
        database => $database,
        input => $input,
        key => $key,
        data => $lookup,
  );

=cut

sub save_lookup {
        my $self = shift;
        my $args = {@_};

        my $log = $self->_get_logger;

        foreach my $r (qw/input key data/) {
                $log->logconfess("need '$r'") unless defined($args->{$r});
        }

        my $database = $args->{database} || $self->{database} || $log->logconfess("no database?");

        my $path = $self->{path} . "/lookup/$database/" . $args->{input};

        mkpath($path) unless (-d $path);

        $path .= "/" . $args->{key};

        if (store $args->{data}, $path) {
                $log->info("saved lookup $path");
                return 1;
        } else {
                $log->logwarn("can't store lookup $database/", $args->{input}, "/", $args->{key}, " in $path: $!");
                return undef;
        }
}


=head1 AUTHOR

Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>

=head1 COPYRIGHT & LICENSE

Copyright 2005 Dobrica Pavlinusic, All Rights Reserved.

This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

=cut

1; # End of WebPAC::Store
1	dpavlin	209	package WebPAC::Store;
2
3			use warnings;
4			use strict;
5
6			use base 'WebPAC::Common';
7			use Storable;
8	dpavlin	215	use File::Path;
9	dpavlin	713	use Data::Dump qw/dump/;
10	dpavlin	209
11			=head1 NAME
12
13	dpavlin	710	WebPAC::Store - Store WebPAC data on disk
14	dpavlin	209
15			=head1 VERSION
16
17	dpavlin	713	Version 0.11
18	dpavlin	209
19			=cut
20
21	dpavlin	713	our $VERSION = '0.11';
22	dpavlin	209
23			=head1 SYNOPSIS
24
25	dpavlin	710	This module provides disk storage for normalised data and lookups.
26	dpavlin	209
27	dpavlin	710	It is one of newer components of WebPAC, so it will change from time to
28			time.
29	dpavlin	209
30	dpavlin	710	I will try to keep backward compatiblity by providing multiple back-ends,
31			but this can't be garanteed. In other words, don't delete your input
32			databases just yet :-)
33
34	dpavlin	209	This has additional advantage. I can create single place to plugin other
35			file formats which provide better performance for particular type of data.
36
37			For now, this is a prototype version.
38
39			use WebPAC::Store;
40
41			my $foo = WebPAC::Store->new();
42			...
43
44			=head1 FUNCTIONS
45
46			=head2 new
47
48			Create new normalised database object
49
50			my $db = new WebPAC::Store(
51			path => '/path/to/cache/ds/',
52	dpavlin	217	database => 'name',
53	dpavlin	209	read_only => 1,
54			);
55
56			Optional parameter C<path> defines path to directory
57			in which cache file for C<data_structure> call will be created.
58
59			If called with C<read_only> it will not disable caching if
60			called without write permission (but will die on C<save_ds>).
61
62	dpavlin	713	Optional parametar C<database> will be used used as subdirectory in path if no
63			database in specified when calling other functions.
64	dpavlin	218
65	dpavlin	209	=cut
66
67			sub new {
68			my $class = shift;
69	dpavlin	710	my $self = {@_};
70			bless($self, $class);
71	dpavlin	209
72	dpavlin	218	my $log = $self->_get_logger();
73
74			foreach my $p (qw/path database/) {
75			$log->logconfess("need $p") unless ($self->{$p});
76			}
77
78	dpavlin	209	$self->path( $self->{'path'} );
79
80			$self ? return $self : return undef;
81			}
82
83			=head2 path
84
85			Check if specified cache directory exist, and if not, disable caching.
86
87			$db->path('./cache/ds/');
88
89			If you pass false or zero value to this function, it will disable
90			cacheing.
91
92	dpavlin	713	You can also call this function to get current cache path.
93	dpavlin	209
94	dpavlin	713	my $cache_path = $db->path;
95
96	dpavlin	209	=cut
97
98			sub path {
99			my $self = shift;
100
101			my $dir = shift;
102	dpavlin	713
103			return $self->{path} unless defined($dir);
104	dpavlin	209
105			my $log = $self->_get_logger();
106
107			if ($dir) {
108			my $msg;
109			if (! -e $dir) {
110	dpavlin	215	if ($self->{'read_only'}) {
111			$msg = "doesn't exist";
112			} else {
113			$log->info("creating $dir");
114			mkpath $dir;
115			}
116	dpavlin	209	} elsif (! -d $dir) {
117			$msg = "is not directory";
118			} elsif (! -w $dir) {
119			$msg = "not writable" unless ($self->{'read_only'});
120			}
121
122			if ($msg) {
123			$log->warn("cache path $dir $msg, disabling...");
124			undef $self->{'path'};
125			} else {
126			$log->debug("using cache dir $dir");
127			$self->{'path'} = $dir;
128			}
129			} else {
130			$log->debug("disabling cache");
131			undef $self->{'path'};
132			}
133			}
134
135			=head2 load_ds
136
137	dpavlin	217	Retrive from disk one data_structure records usually using field 000 as key
138	dpavlin	209
139	dpavlin	713	my $ds = $db->load_ds(
140			database => 'ps',
141			input => 'name',
142			id => 42,
143			);
144	dpavlin	209
145			This function will also perform basic sanity checking on returned
146			data and disable caching if data is corrupted (or changed since last
147			update).
148
149	dpavlin	713	C<input> is used to differenciate different source input databases
150	dpavlin	218	which are indexed in same database.
151
152	dpavlin	236	C<database> if B<optional> argument which will override database name used when creating
153			C<WebPAC::Store> object (for simple retrival from multiple databases).
154
155	dpavlin	209	Returns hash or undef if cacheing is disabled or unavailable.
156
157			=cut
158
159			sub load_ds {
160			my $self = shift;
161
162			my $log = $self->_get_logger;
163
164			my $cache_path = $self->{'path'};
165
166	dpavlin	217	if (! $cache_path) {
167			$log->warn("path not set, ignoring load_ds");
168			return;
169	dpavlin	209	}
170
171	dpavlin	217	$log->logconfess("arguments for load_ds must be HASH") unless (ref(\@_) eq 'ARRAY' && ($#_ % 2 == 1));
172
173			my $args = {@_};
174			my $id = $args->{id};
175
176			$log->logconfess("got hash, but without id") unless (defined($id));
177	dpavlin	218	$log->logconfess("got hash, but id [$id] isn't number") unless ($id =~ /^\d+$/);
178	dpavlin	217
179	dpavlin	236	my $database = $args->{database} \|\| $self->{database};
180	dpavlin	713	my $input = $args->{input} \|\| '';
181	dpavlin	217
182			$log->logconfess("can't find database name") unless ($database);
183
184	dpavlin	713	my $cache_file = "$cache_path/$database/$input/$id";
185	dpavlin	218	$cache_file =~ s#//#/#go;
186	dpavlin	217
187			$log->debug("using cache_file $cache_file");
188
189			if (-r $cache_file) {
190			my $ds_ref = retrieve($cache_file);
191			if ($ds_ref) {
192			$log->debug("cache hit: $cache_file");
193			if ($ds_ref->{'ds'}) {
194			return $ds_ref->{'ds'};
195			} else {
196			$log->warn("cache entry $cache_file corrupt. Use rm $cache_path/* to re-create it on next run!");
197			undef $self->{'path'};
198	dpavlin	209	}
199			}
200	dpavlin	217	} else {
201			#$log->warn("cache entry $cache_file doesn't exist");
202			return undef;
203	dpavlin	209	}
204
205			return undef;
206			}
207
208			=head2 save_ds
209
210			Store data_structure on disk.
211
212			$db->save_ds(
213	dpavlin	713	database => 'name',
214			input => 'name',
215	dpavlin	209	id => $ds->{000}->[0],
216			ds => $ds,
217			);
218
219			B<Totally broken, but fast.>
220
221			Depends on filename generated by C<load_ds>.
222
223			=cut
224
225			sub save_ds {
226			my $self = shift;
227
228			die "can't write to database in read_only mode!" if ($self->{'read_only'});
229
230			return unless($self->{'path'});
231
232	dpavlin	713	my $args = {@_};
233	dpavlin	209
234			my $log = $self->_get_logger;
235	dpavlin	713	$log->debug("save_ds arguments:", dump( \@_ ));
236	dpavlin	209
237			foreach my $f (qw/id ds/) {
238	dpavlin	713	$log->logconfess("need $f") unless (defined($args->{$f}));
239	dpavlin	209	}
240
241	dpavlin	713	my $database = $args->{database} \|\| $self->{database};
242	dpavlin	217	$log->logconfess("can't find database name") unless ($database);
243	dpavlin	209
244	dpavlin	713	my $input = $args->{input} \|\| '';
245	dpavlin	217
246	dpavlin	713	my $cache_file = $self->{path} . "/$database/$input/";
247	dpavlin	218	$cache_file =~ s#//#/#go;
248
249	dpavlin	299	mkpath($cache_file) unless (-d $cache_file);
250
251	dpavlin	713	$cache_file .= $args->{id};
252	dpavlin	299
253	dpavlin	209	$log->debug("creating storable cache file $cache_file");
254
255			return store {
256	dpavlin	713	ds => $args->{ds},
257			id => $args->{id},
258	dpavlin	209	}, $cache_file;
259
260			}
261
262	dpavlin	710	=head2 save_lookup
263
264	dpavlin	713	$db->save_lookup(
265			database => $database,
266			input => $input,
267			key => $key,
268			data => $lookup,
269			);
270	dpavlin	710
271			=cut
272
273			sub save_lookup {
274			my $self = shift;
275	dpavlin	713	my $args = {@_};
276	dpavlin	710
277			my $log = $self->_get_logger;
278
279	dpavlin	713	foreach my $r (qw/input key data/) {
280			$log->logconfess("need '$r'") unless defined($args->{$r});
281			}
282	dpavlin	710
283	dpavlin	713	my $database = $args->{database} \|\| $self->{database} \|\| $log->logconfess("no database?");
284
285			my $path = $self->{path} . "/lookup/$database/" . $args->{input};
286
287	dpavlin	710	mkpath($path) unless (-d $path);
288
289	dpavlin	713	$path .= "/" . $args->{key};
290	dpavlin	710
291	dpavlin	713	if (store $args->{data}, $path) {
292	dpavlin	710	$log->info("saved lookup $path");
293	dpavlin	713	return 1;
294	dpavlin	710	} else {
295	dpavlin	713	$log->logwarn("can't store lookup $database/", $args->{input}, "/", $args->{key}, " in $path: $!");
296			return undef;
297	dpavlin	710	}
298			}
299
300
301	dpavlin	209	=head1 AUTHOR
302
303			Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
304
305			=head1 COPYRIGHT & LICENSE
306
307			Copyright 2005 Dobrica Pavlinusic, All Rights Reserved.
308
309			This program is free software; you can redistribute it and/or modify it
310			under the same terms as Perl itself.
311
312			=cut
313
314			1; # End of WebPAC::Store