1 package OpenSRF::Utils::Cache;
2 use strict; use warnings;
5 use OpenSRF::Utils::Logger qw/:level/;
6 use OpenSRF::Utils::Config;
7 use OpenSRF::Utils::SettingsClient;
8 use OpenSRF::EX qw(:try);
9 use OpenSRF::Utils::JSON;
11 my $log = 'OpenSRF::Utils::Logger';
19 This class just subclasses Cache::Memcached.
20 see Cache::Memcached for more options.
22 The value passed to the call to current is the cache type
23 you wish to access. The below example sets/gets data
24 from the 'user' cache.
26 my $cache = OpenSRF::Utils::Cache->current("user");
27 $cache->set( "key1", "value1" [, $expire_secs ] );
28 my $val = $cache->get( "key1" );
37 # ------------------------------------------------------
38 # Persist methods and method names
39 # ------------------------------------------------------
41 my $persist_push_stack;
42 my $persist_peek_stack;
43 my $persist_destroy_slot;
44 my $persist_slot_get_expire;
45 my $persist_slot_find;
48 my $persist_add_slot_name = "opensrf.persist.slot.create_expirable";
49 my $persist_push_stack_name = "opensrf.persist.stack.push";
50 my $persist_peek_stack_name = "opensrf.persist.stack.peek";
51 my $persist_destroy_slot_name = "opensrf.persist.slot.destroy";
52 my $persist_slot_get_expire_name = "opensrf.persist.slot.get_expire";
53 my $persist_slot_find_name = "opensrf.persist.slot.find";;
55 # ------------------------------------------------------
61 Return a named cache if it exists
66 my ( $class, $c_type ) = @_;
67 return undef unless $c_type;
68 return $caches{$c_type} if exists $caches{$c_type};
69 return $caches{$c_type} = $class->new( $c_type );
75 Create a new named memcache object.
81 my( $class, $cache_type, $persist ) = @_;
82 $cache_type ||= 'global';
83 $class = ref( $class ) || $class;
85 return $caches{$cache_type} if (defined $caches{$cache_type});
87 my $conf = OpenSRF::Utils::SettingsClient->new;
88 my $servers = $conf->config_value( cache => $cache_type => servers => 'server' );
89 $max_persist_time = $conf->config_value( cache => $cache_type => 'max_cache_time' );
91 $servers = [ $servers ] if(!ref($servers));
94 $self->{persist} = $persist || 0;
95 $self->{memcache} = Cache::Memcached->new( { servers => $servers } );
96 if(!$self->{memcache}) {
97 throw OpenSRF::EX::PANIC ("Unable to create a new memcache object for $cache_type");
100 bless($self, $class);
101 $caches{$cache_type} = $self;
111 my($self, $key, $value, $expiretime ) = @_;
113 return undef unless( defined $key and defined $value );
115 $key = _clean_cache_key($key);
117 return undef if( $key eq '' ); # no zero-length keys
119 $value = OpenSRF::Utils::JSON->perl2JSON($value);
121 if($self->{persist}){ _load_methods(); }
123 $expiretime ||= $max_persist_time;
125 unless( $self->{memcache}->set( $key, $value, $expiretime ) ) {
126 $log->error("Unable to store $key => [".length($value)." bytes] in memcached server" );
130 $log->debug("Stored $key => $value in memcached server", INTERNAL);
132 if($self->{"persist"}) {
134 my ($slot) = $persist_add_slot->run("_CACHEVAL_$key", $expiretime . "s");
137 # slot may already exist
138 ($slot) = $persist_slot_find->run("_CACHEVAL_$key");
139 if(!defined($slot)) {
140 throw OpenSRF::EX::ERROR ("Unable to create cache slot $key in persist server" );
142 #XXX destroy the slot and rebuild it to prevent DOS
146 ($slot) = $persist_push_stack->run("_CACHEVAL_$key", $value);
149 throw OpenSRF::EX::ERROR ("Unable to push data onto stack in persist slot _CACHEVAL_$key" );
162 my( $self, $key ) = @_;
163 return undef unless defined $key;
164 $key = _clean_cache_key($key);
165 return undef if $key eq ''; # no zero-length keys
166 if($self->{persist}){ _load_methods(); }
167 $self->{memcache}->delete($key);
168 if( $self->{persist} ) {
169 $persist_destroy_slot->run("_CACHEVAL_$key");
180 my($self, $key ) = @_;
182 return undef unless defined $key;
184 $key = _clean_cache_key($key);
186 return undef if $key eq ''; # no zero-length keys
188 my $val = $self->{memcache}->get( $key );
189 return OpenSRF::Utils::JSON->JSON2perl($val) if defined($val);
191 if($self->{persist}){ _load_methods(); }
193 # if not in memcache but we are persisting, the put it into memcache
194 if( $self->{"persist"} ) {
195 $val = $persist_peek_stack->( "_CACHEVAL_$key" );
197 my ($expire) = $persist_slot_get_expire->run("_CACHEVAL_$key");
199 $self->{memcache}->set( $key, $val, $expire);
201 $self->{memcache}->set( $key, $val, $max_persist_time);
203 return OpenSRF::Utils::JSON->JSON2perl($val);
216 if(!$persist_add_slot) {
218 OpenSRF::Application->method_lookup($persist_add_slot_name);
219 if(!ref($persist_add_slot)) {
220 throw OpenSRF::EX::PANIC ("Unable to retrieve method $persist_add_slot_name");
224 if(!$persist_push_stack) {
225 $persist_push_stack =
226 OpenSRF::Application->method_lookup($persist_push_stack_name);
227 if(!ref($persist_push_stack)) {
228 throw OpenSRF::EX::PANIC ("Unable to retrieve method $persist_push_stack_name");
232 if(!$persist_peek_stack) {
233 $persist_peek_stack =
234 OpenSRF::Application->method_lookup($persist_peek_stack_name);
235 if(!ref($persist_peek_stack)) {
236 throw OpenSRF::EX::PANIC ("Unable to retrieve method $persist_peek_stack_name");
240 if(!$persist_destroy_slot) {
241 $persist_destroy_slot =
242 OpenSRF::Application->method_lookup($persist_destroy_slot_name);
243 if(!ref($persist_destroy_slot)) {
244 throw OpenSRF::EX::PANIC ("Unable to retrieve method $persist_destroy_slot_name");
247 if(!$persist_slot_get_expire) {
248 $persist_slot_get_expire =
249 OpenSRF::Application->method_lookup($persist_slot_get_expire_name);
250 if(!ref($persist_slot_get_expire)) {
251 throw OpenSRF::EX::PANIC ("Unable to retrieve method $persist_slot_get_expire_name");
254 if(!$persist_slot_find) {
256 OpenSRF::Application->method_lookup($persist_slot_find_name);
257 if(!ref($persist_slot_find)) {
258 throw OpenSRF::EX::PANIC ("Unable to retrieve method $persist_slot_find_name");
264 =head2 _clean_cache_key
266 Try to make the requested cache key conform to memcached's requirements. Per
267 https://github.com/memcached/memcached/blob/master/doc/protocol.txt:
270 Data stored by memcached is identified with the help of a key. A key
271 is a text string which should uniquely identify the data for clients
272 that are interested in storing and retrieving it. Currently the
273 length limit of a key is set at 250 characters (of course, normally
274 clients wouldn't need to use such long keys); the key must not include
275 control characters or whitespace.
280 sub _clean_cache_key {
283 $key =~ s{(\p{Cntrl}|\s)}{}g;