1MCE::Shared::Ordhash(3)User Contributed Perl DocumentatioMnCE::Shared::Ordhash(3)
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6 MCE::Shared::Ordhash - An ordered hash class featuring tombstone
7 deletion
8
10 This document describes MCE::Shared::Ordhash version 1.873
11
13 An ordered-hash helper class for use as a standalone or managed by
14 MCE::Shared.
15
16 This module implements an ordered hash featuring tombstone deletion,
17 inspired by Hash::Ordered. An ordered hash is very much like a normal
18 hash but with key insertion order preserved.
19
20 It provides "splice", sorting, plus extra capabilities for use with
21 MCE::Shared::Minidb. Tombstone deletion is further optimized to not
22 impact "store", "push", "unshift", and "merge". Tombstones are purged
23 in-place for lesser memory consumption. In addition, "pop" and "shift"
24 run optimally when an index is present. The optimization also applies
25 to forward and reverse deletes. The end result is achieving a new level
26 of performance, for a pure-Perl ordered hash implementation.
27
29 # non-shared or local construction for use by a single process
30
31 use MCE::Shared::Ordhash;
32
33 my $oh = MCE::Shared::Ordhash->new( @pairs );
34
35 # construction for sharing with other threads and processes
36
37 use MCE::Shared;
38
39 my $oh = MCE::Shared->ordhash( @pairs );
40
41 # hash-like dereferencing
42
43 my $val = $oh->{$key};
44 $oh->{$key} = $val;
45
46 %{$oh} = ();
47
48 # OO interface
49
50 if ( !defined ( $val = $oh->get("some_key") ) ) {
51 $val = $oh->set( some_key => "some_value" );
52 }
53
54 $val = $oh->set( $key, $val );
55 $ret = $oh->setnx( $key, $val ); # set only if the key exists
56 $val = $oh->get( $key );
57 $val = $oh->delete( $key ); # del is an alias for delete
58 $bool = $oh->exists( $key );
59 void = $oh->clear();
60 $len = $oh->len(); # scalar keys %{ $oh }
61 $len = $oh->len( $key ); # length $oh->{ $key }
62 @pair = $oh->pop();
63 $len = $oh->push( @pairs );
64 @pair = $oh->shift();
65 $len = $oh->unshift( @pairs );
66 %pairs = $oh->splice( $offset, $length, @pairs );
67
68 $oh2 = $oh->clone( @keys ); # @keys is optional
69 $oh3 = $oh->flush( @keys );
70 $iter = $oh->iterator( @keys ); # ($key, $val) = $iter->()
71 @keys = $oh->keys( @keys );
72 %pairs = $oh->pairs( @keys );
73 @vals = $oh->values( @keys ); # vals is an alias for values
74
75 $len = $oh->assign( $key/$val pairs ); # equivalent to ->clear, ->mset
76 $cnt = $oh->mdel( @keys );
77 @vals = $oh->mget( @keys );
78 $bool = $oh->mexists( @keys ); # true if all keys exists
79 $len = $oh->mset( $key/$val pairs ); # merge is an alias for mset
80
81 @vals = $oh->sort(); # by val $a <=> $b default
82 @vals = $oh->sort( "desc" ); # by val $b <=> $a
83 @vals = $oh->sort( "alpha" ); # by val $a cmp $b
84 @vals = $oh->sort( "alpha desc" ); # by val $b cmp $a
85
86 @vals = $oh->sort( "key" ); # by key $a <=> $b
87 @vals = $oh->sort( "key desc" ); # by key $b <=> $a
88 @vals = $oh->sort( "key alpha" ); # by key $a cmp $b
89 @vals = $oh->sort( "key alpha desc" ); # by key $b cmp $a
90
91 # included, sugar methods without having to call set/get explicitly
92
93 $len = $oh->append( $key, $string ); # $val .= $string
94 $val = $oh->decr( $key ); # --$val
95 $val = $oh->decrby( $key, $number ); # $val -= $number
96 $val = $oh->getdecr( $key ); # $val--
97 $val = $oh->getincr( $key ); # $val++
98 $val = $oh->incr( $key ); # ++$val
99 $val = $oh->incrby( $key, $number ); # $val += $number
100 $old = $oh->getset( $key, $new ); # $o = $v, $v = $n, $o
101
102 # pipeline, provides atomicity for shared objects, MCE::Shared v1.09+
103
104 @vals = $oh->pipeline( # ( "a_a", "b_b", "c_c" )
105 [ "set", foo => "a_a" ],
106 [ "set", bar => "b_b" ],
107 [ "set", baz => "c_c" ],
108 [ "mget", qw/ foo bar baz / ]
109 );
110
111 For normal hash behavior, the TIE interface is supported.
112
113 # non-shared or local construction for use by a single process
114
115 use MCE::Shared::Ordhash;
116
117 tie my %oh, "MCE::Shared::Ordhash", @pairs;
118 tie my %oh, "MCE::Shared::Ordhash";
119
120 # construction for sharing with other threads and processes
121 # the ordered option is needed to know to use MCE::Shared::Ordhash
122
123 use MCE::Shared;
124
125 tie my %oh, "MCE::Shared", { ordered => 1 }, @pairs;
126 tie my %oh, "MCE::Shared", ordered => 1;
127
128 # usage
129
130 my $val;
131
132 if ( !defined ( $val = $oh{some_key} ) ) {
133 $val = $oh{some_key} = "some_value";
134 }
135
136 $oh{some_key} = 0;
137
138 tied(%oh)->incrby("some_key", 20);
139 tied(%oh)->incrby(some_key => 20);
140
142 Several methods take a query string for an argument. The format of the
143 string is described below. In the context of sharing, the query
144 mechanism is beneficial for the shared-manager process. It is able to
145 perform the query where the data resides versus the client-process grep
146 locally involving lots of IPC.
147
148 o Basic demonstration
149
150 @keys = $oh->keys( "query string given here" );
151 @keys = $oh->keys( "val =~ /pattern/" );
152
153 o Supported operators: =~ !~ eq ne lt le gt ge == != < <= > >=
154 o Multiple expressions delimited by :AND or :OR, mixed case allowed
155
156 "key eq 'some key' :or (val > 5 :and val < 9)"
157 "key eq some key :or (val > 5 :and val < 9)"
158 "key =~ /pattern/i :And val =~ /pattern/i"
159 "val eq foo baz :OR key !~ /pattern/i"
160
161 * key matches on keys in the hash
162 * likewise, val matches on values
163
164 o Quoting is optional inside the string
165
166 "key =~ /pattern/i :AND val eq 'foo bar'" # val eq "foo bar"
167 "key =~ /pattern/i :AND val eq foo bar" # val eq "foo bar"
168
169 Examples.
170
171 # search capability key/val: =~ !~ eq ne lt le gt ge == != < <= > >=
172 # key/val means to match against actual key/val respectively
173
174 @keys = $oh->keys( "key eq 'some key' :or (val > 5 :and val < 9)" );
175 @keys = $oh->keys( "key eq some key :or (val > 5 :and val < 9)" );
176
177 @keys = $oh->keys( "key =~ /$pattern/i" );
178 @keys = $oh->keys( "key !~ /$pattern/i" );
179 @keys = $oh->keys( "val =~ /$pattern/i" );
180 @keys = $oh->keys( "val !~ /$pattern/i" );
181
182 %pairs = $oh->pairs( "key == $number" );
183 %pairs = $oh->pairs( "key != $number :and val > 100" );
184 %pairs = $oh->pairs( "key < $number :or key > $number" );
185 %pairs = $oh->pairs( "val <= $number" );
186 %pairs = $oh->pairs( "val > $number" );
187 %pairs = $oh->pairs( "val >= $number" );
188
189 @vals = $oh->vals( "key eq $string" );
190 @vals = $oh->vals( "key ne $string with space" );
191 @vals = $oh->vals( "key lt $string :or val =~ /$pat1|$pat2/" );
192 @vals = $oh->vals( "val le $string :and val eq 'foo bar'" );
193 @vals = $oh->vals( "val le $string :and val eq foo bar" );
194 @vals = $oh->vals( "val gt $string" );
195 @vals = $oh->vals( "val ge $string" );
196
198 This module involves TIE when accessing the object via hash-like
199 behavior. Both non-shared and shared instances are impacted if doing
200 so. Although likely fast enough for many use cases, the OO interface is
201 recommended for best performance.
202
203 MCE::Shared::Ordhash->new ( key, value [, key, value, ... ] )
204 MCE::Shared->ordhash ( key, value [, key, value, ... ] )
205 Constructs a new object, with an optional list of key-value pairs.
206
207 # non-shared or local construction for use by a single process
208
209 use MCE::Shared::Ordhash;
210
211 $oh = MCE::Shared::Ordhash->new( @pairs );
212 $oh = MCE::Shared::Ordhash->new( );
213
214 # construction for sharing with other threads and processes
215
216 use MCE::Shared;
217
218 $oh = MCE::Shared->ordhash( @pairs );
219 $oh = MCE::Shared->ordhash( );
220
221 assign ( key, value [, key, value, ... ] )
222 Clears the hash, then sets multiple key-value pairs and returns the
223 number of keys stored in the hash. This is equivalent to "clear",
224 "mset".
225
226 $len = $oh->assign( "key1" => "val1", "key2" => "val2" ); # 2
227 $len = %{$oh} = ( "key1" => "val1", "key2" => "val2" ); # 4
228
229 API available since 1.007.
230
231 clear
232 Removes all key-value pairs from the hash.
233
234 $oh->clear;
235 %{$oh} = ();
236
237 clone ( key [, key, ... ] )
238 Creates a shallow copy, a "MCE::Shared::Ordhash" object. It returns an
239 exact copy if no arguments are given. Otherwise, the object includes
240 only the given keys in the same order. Keys that do not exist in the
241 hash will have the "undef" value.
242
243 $oh2 = $oh->clone( "key1", "key2" );
244 $oh2 = $oh->clone;
245
246 delete ( key )
247 Deletes and returns the value by given key or "undef" if the key does
248 not exists in the hash.
249
250 $val = $oh->delete( "some_key" );
251 $val = delete $oh->{ "some_key" };
252
253 del
254 "del" is an alias for "delete".
255
256 exists ( key )
257 Determines if a key exists in the hash.
258
259 if ( $oh->exists( "some_key" ) ) { ... }
260 if ( exists $oh->{ "some_key" } ) { ... }
261
262 flush ( key [, key, ... ] )
263 Same as "clone". Though, clears all existing items before returning.
264
265 get ( key )
266 Gets the value of a hash key or "undef" if the key does not exists.
267
268 $val = $oh->get( "some_key" );
269 $val = $oh->{ "some_key" };
270
271 iterator ( key [, key, ... ] )
272 Returns a code reference for iterating a list of key-value pairs stored
273 in the hash when no arguments are given. Otherwise, returns a code
274 reference for iterating the given keys in the same order. Keys that do
275 not exist will have the "undef" value.
276
277 The list of keys to return is set when the closure is constructed.
278 Later keys added to the hash are not included. Subsequently, the
279 "undef" value is returned for deleted keys.
280
281 $iter = $oh->iterator;
282 $iter = $oh->iterator( "key1", "key2" );
283
284 while ( my ( $key, $val ) = $iter->() ) {
285 ...
286 }
287
288 iterator ( "query string" )
289 Returns a code reference for iterating a list of key-value pairs that
290 match the given criteria. It returns an empty list if the search found
291 nothing. The syntax for the "query string" is described above.
292
293 $iter = $oh->iterator( "val eq some_value" );
294 $iter = $oh->iterator( "key eq some_key :AND val =~ /sun|moon|air|wind/" );
295 $iter = $oh->iterator( "val eq sun :OR val eq moon :OR val eq foo" );
296 $iter = $oh->iterator( "key =~ /$pattern/" );
297
298 while ( my ( $key, $val ) = $iter->() ) {
299 ...
300 }
301
302 keys ( key [, key, ...] )
303 Returns hash keys in the same insertion order when no arguments are
304 given. Otherwise, returns the given keys in the same order. Keys that
305 do not exist will have the "undef" value. In scalar context, returns
306 the size of the hash.
307
308 @keys = $oh->keys( "key1", "key2" );
309
310 @keys = $oh->keys; # faster
311 @keys = keys %{$oh}; # involves TIE overhead
312
313 $len = $oh->keys; # ditto
314 $len = keys %{$oh};
315
316 keys ( "query string" )
317 Returns only keys that match the given criteria. It returns an empty
318 list if the search found nothing. The syntax for the "query string" is
319 described above. In scalar context, returns the size of the resulting
320 list.
321
322 @keys = $oh->keys( "val eq some_value" );
323 @keys = $oh->keys( "key eq some_key :AND val =~ /sun|moon|air|wind/" );
324 @keys = $oh->keys( "val eq sun :OR val eq moon :OR val eq foo" );
325 $len = $oh->keys( "key =~ /$pattern/" );
326
327 len ( key )
328 Returns the size of the hash when no arguments are given. For the given
329 key, returns the length of the value stored at key or the "undef" value
330 if the key does not exists.
331
332 $size = $oh->len;
333 $len = $oh->len( "key1" );
334 $len = length $oh->{ "key1" };
335
336 mdel ( key [, key, ... ] )
337 Deletes one or more keys in the hash and returns the number of keys
338 deleted. A given key which does not exist in the hash is not counted.
339
340 $cnt = $oh->mdel( "key1", "key2" );
341
342 mexists ( key [, key, ... ] )
343 Returns a true value if all given keys exists in the hash. A false
344 value is returned otherwise.
345
346 if ( $oh->mexists( "key1", "key2" ) ) { ... }
347
348 mget ( key [, key, ... ] )
349 Gets the values of all given keys. It returns "undef" for keys which do
350 not exists in the hash.
351
352 ( $val1, $val2 ) = $oh->mget( "key1", "key2" );
353
354 mset ( key, value [, key, value, ... ] )
355 Sets multiple key-value pairs in a hash and returns the number of keys
356 stored in the hash.
357
358 $len = $oh->mset( "key1" => "val1", "key2" => "val2" );
359
360 merge
361 "merge" is an alias for "mset".
362
363 pairs ( key [, key, ... ] )
364 Returns key-value pairs in the same insertion order when no arguments
365 are given. Otherwise, returns key-value pairs for the given keys in
366 the same order. Keys that do not exist will have the "undef" value. In
367 scalar context, returns the size of the hash.
368
369 @pairs = $oh->pairs( "key1", "key2" );
370
371 @pairs = $oh->pairs;
372 $len = $oh->pairs;
373
374 pairs ( "query string" )
375 Returns only key-value pairs that match the given criteria. It returns
376 an empty list if the search found nothing. The syntax for the "query
377 string" is described above. In scalar context, returns the size of the
378 resulting list.
379
380 @pairs = $oh->pairs( "val eq some_value" );
381 @pairs = $oh->pairs( "key eq some_key :AND val =~ /sun|moon|air|wind/" );
382 @pairs = $oh->pairs( "val eq sun :OR val eq moon :OR val eq foo" );
383 $len = $oh->pairs( "key =~ /$pattern/" );
384
385 pipeline ( [ func1, @args ], [ func2, @args ], ... )
386 Combines multiple commands for the object to be processed serially. For
387 shared objects, the call is made atomically due to single IPC to the
388 shared-manager process. The "pipeline" method is fully
389 "wantarray"-aware and receives a list of commands and their arguments.
390 In scalar or list context, it returns data from the last command in the
391 pipeline.
392
393 @vals = $oh->pipeline( # ( "a_a", "b_b", "c_c" )
394 [ "set", foo => "a_a" ],
395 [ "set", bar => "b_b" ],
396 [ "set", baz => "c_c" ],
397 [ "mget", qw/ foo bar baz / ]
398 );
399
400 $len = $oh->pipeline( # 3, same as $oh->len
401 [ "set", foo => "i_i" ],
402 [ "set", bar => "j_j" ],
403 [ "set", baz => "k_k" ],
404 [ "len" ]
405 );
406
407 $oh->pipeline(
408 [ "set", foo => "m_m" ],
409 [ "set", bar => "n_n" ],
410 [ "set", baz => "o_o" ]
411 );
412
413 Current API available since 1.809.
414
415 pipeline_ex ( [ func1, @args ], [ func2, @args ], ... )
416 Same as "pipeline", but returns data for every command in the pipeline.
417
418 @vals = $oh->pipeline_ex( # ( "a_a", "b_b", "c_c" )
419 [ "set", foo => "a_a" ],
420 [ "set", bar => "b_b" ],
421 [ "set", baz => "c_c" ]
422 );
423
424 Current API available since 1.809.
425
426 pop
427 Removes and returns the last key-value pair or value in scalar context
428 of the ordered hash. If there are no keys in the hash, returns the
429 undefined value.
430
431 ( $key, $val ) = $oh->pop;
432
433 $val = $oh->pop;
434
435 purge
436 A utility method for purging any *tombstones* in the keys array. It
437 also resets a couple counters internally. Call this method before
438 serializing to a file, which is the case in "MCE::Shared::Minidb".
439
440 $oh->purge;
441
442 push ( key, value [, key, value, ... ] )
443 Appends one or multiple key-value pairs to the tail of the ordered hash
444 and returns the new length. Any keys already existing in the hash are
445 re-inserted with the new values.
446
447 $len = $oh->push( "key1", "val1", "key2", "val2" );
448
449 set ( key, value )
450 Sets the value of the given hash key and returns its new value.
451
452 $val = $oh->set( "key", "value" );
453 $val = $oh->{ "key" } = "value";
454
455 setnx ( key, value )
456 Sets the value of a hash key, only if the key does not exist. Returns a
457 1 for new key or 0 if the key already exists and no operation was
458 performed.
459
460 $ret = $oh->setnx( "key", "value" );
461
462 Current API available since 1.872.
463
464 shift
465 Removes and returns the first key-value pair or value in scalar context
466 of the ordered hash. If there are no keys in the hash, returns the
467 undefined value.
468
469 ( $key, $val ) = $oh->shift;
470
471 $val = $oh->shift;
472
473 sort ( "BY key [ ASC | DESC ] [ ALPHA ]" )
474 sort ( "BY val [ ASC | DESC ] [ ALPHA ]" )
475 Returns sorted keys in list context, leaving the elements intact. In
476 void context, sorts the hash in-place. By default, sorting is numeric
477 and applied to values when no arguments are given.
478
479 @keys = $oh->sort( "BY val" );
480
481 $oh->sort();
482
483 If the keys or values contain string values and you want to sort them
484 lexicographically, specify the "ALPHA" modifier.
485
486 @keys = $oh->sort( "BY key ALPHA" );
487
488 $oh->sort( "BY val ALPHA" );
489
490 The default is "ASC" for sorting the hash from small to large. In order
491 to sort the hash from large to small, specify the "DESC" modifier.
492
493 @keys = $oh->sort( "BY val DESC ALPHA" );
494
495 $oh->sort( "BY key DESC ALPHA" );
496
497 splice ( offset [, length [, key, value, ... ] ] )
498 Removes the key-value pairs designated by "offset" and "length" from
499 the ordered hash, and replaces them with "key-value pairs", if any. The
500 behavior is similar to the Perl "splice" function.
501
502 @pairs = $oh->splice( 20, 2, @pairs );
503 @pairs = $oh->splice( 20, 2 );
504 @pairs = $oh->splice( 20 );
505
506 unshift ( key, value [, key, value, ... ] )
507 Prepends one or multiple key-value pairs to the head of the ordered
508 hash and returns the new length. Any keys already existing in the hash
509 are re-inserted with the new values.
510
511 $len = $oh->unshift( "key1", "val1", "key2", "val2" );
512
513 values ( key [, key, ... ] )
514 Returns hash values in the same insertion order when no arguments are
515 given. Otherwise, returns values for the given keys in the same order.
516 Keys that do not exist will have the "undef" value. In scalar context,
517 returns the size of the hash.
518
519 @vals = $oh->values( "key1", "key2" );
520
521 @vals = $oh->values; # faster
522 @vals = values %{$oh}; # involves TIE overhead
523
524 $len = $oh->values; # ditto
525 $len = values %{$oh};
526
527 values ( "query string" )
528 Returns only values that match the given criteria. It returns an empty
529 list if the search found nothing. The syntax for the "query string" is
530 described above. In scalar context, returns the size of the resulting
531 list.
532
533 @vals = $oh->values( "val eq some_value" );
534 @vals = $oh->values( "key eq some_key :AND val =~ /sun|moon|air|wind/" );
535 @vals = $oh->values( "val eq sun :OR val eq moon :OR val eq foo" );
536 $len = $oh->values( "key =~ /$pattern/" );
537
538 vals
539 "vals" is an alias for "values".
540
542 This module is equipped with sugar methods to not have to call "set"
543 and "get" explicitly. In shared context, the benefit is atomicity and
544 reduction in inter-process communication.
545
546 The API resembles a subset of the Redis primitives
547 <http://redis.io/commands#strings> with key representing the hash key.
548
549 append ( key, string )
550 Appends a value to a key and returns its new length.
551
552 $len = $oh->append( $key, "foo" );
553
554 decr ( key )
555 Decrements the value of a key by one and returns its new value.
556
557 $num = $oh->decr( $key );
558
559 decrby ( key, number )
560 Decrements the value of a key by the given number and returns its new
561 value.
562
563 $num = $oh->decrby( $key, 2 );
564
565 getdecr ( key )
566 Decrements the value of a key by one and returns its old value.
567
568 $old = $oh->getdecr( $key );
569
570 getincr ( key )
571 Increments the value of a key by one and returns its old value.
572
573 $old = $oh->getincr( $key );
574
575 getset ( key, value )
576 Sets the value of a key and returns its old value.
577
578 $old = $oh->getset( $key, "baz" );
579
580 incr ( key )
581 Increments the value of a key by one and returns its new value.
582
583 $num = $oh->incr( $key );
584
585 incrby ( key, number )
586 Increments the value of a key by the given number and returns its new
587 value.
588
589 $num = $oh->incrby( $key, 2 );
590
592 Many thanks to David Golden for Hash::Ordered. This implementation is
593 inspired by Hash::Ordered v0.009.
594
596 I wanted an ordered hash implementation for use with MCE::Shared
597 without any side effects. For example, linear scans, slow deletes, or
598 excessive memory consumption. The closest module on CPAN to pass in
599 this regard is Hash::Ordered by David Golden.
600
601 MCE::Shared has only one shared-manager process which is by design.
602 Therefore, re-factored tombstone deletion with extras for lesser impact
603 to the rest of the library. This module differs in personality from
604 Hash::Ordered mainly for compatibility with the other classes included
605 with MCE::Shared.
606
607 The following simulates a usage pattern inside MCE::Hobo involving
608 random key deletion. For example, an application joining a list of
609 Hobos provided by "MCE::Hobo->list_joinable".
610
611 use MCE::Shared::Ordhash;
612 use List::Util 'shuffle';
613 use Time::HiRes 'time';
614
615 srand 0;
616
617 my $oh = MCE::Shared::Ordhash->new();
618 my $num_keys = 200000;
619 my $start = time();
620
621 $oh->set($_,$_) for 1 .. $num_keys;
622
623 for ( shuffle $oh->keys ) {
624 $oh->delete($_);
625 }
626
627 printf "duration: %7.03f secs\n", time() - $start;
628
629 Both the runtime and memory consumption are captured for the
630 demonstration. Results are included for MCE::Shared::Hash (unordered
631 hash) for comparison.
632
633 for ( shuffle $oh->keys ) { $oh->delete($_) }
634
635 0.378 secs. 35 MB MCE::Shared::Hash (unordered)
636 0.437 secs. 49 MB Tie::Hash::Indexed (XS)
637 0.743 secs. 54 MB MCE::Shared::Ordhash
638 1.028 secs. 60 MB Hash::Ordered
639 1.752 secs. 112 MB Tie::LLHash
640 > 42 mins. 66 MB Tie::IxHash
641
642 Using the same demonstration above, another usage pattern inside
643 MCE::Hobo involves orderly hash-key deletion. For example, waiting for
644 and joining all Hobos provided by "MCE::Hobo->list".
645
646 for ( $oh->keys ) { $oh->delete($_) }
647
648 0.353 secs. 35 MB MCE::Shared::Hash (unordered)
649 0.349 secs. 49 MB Tie::Hash::Indexed (XS)
650 0.452 secs. 41 MB MCE::Shared::Ordhash
651 0.735 secs. 54 MB Hash::Ordered
652 1.338 secs. 112 MB Tie::LLHash
653 > 42 mins. 66 MB Tie::IxHash
654
655 No matter if orderly or randomly, even backwards, hash-key deletion in
656 "MCE::Shared::Ordhash" performs reasonably well. The following provides
657 the construction used for the modules mentioned.
658
659 my $oh = Hash::Ordered->new();
660 $oh->set($_,$_); $oh->keys; $oh->delete($_);
661
662 my $oh = Tie::Hash::Indexed->new();
663 $oh->set($_,$_); $oh->keys; $oh->delete($_);
664
665 my $oh = Tie::IxHash->new();
666 $oh->STORE($_,$_); $oh->Keys; $oh->DELETE($_);
667
668 my $oh = tie my %hash, 'Tie::LLHash';
669 $oh->last($_,$_); keys %hash; $oh->DELETE($_);
670
671 Hash::Ordered is supported for use with MCE::Shared. This includes on-
672 demand hash-like dereferencing, similarly to "hash" and "ordhash".
673
674 use feature 'say';
675
676 use MCE::Hobo;
677 use MCE::Shared;
678 use Hash::Ordered; # 0.010 or later
679
680 my $ha = MCE::Shared->hash(); # shared MCE::Shared::Hash
681 my $oh = MCE::Shared->ordhash(); # shared MCE::Shared::Ordhash
682
683 my $ho = MCE::Shared->share( Hash::Ordered->new() );
684
685 sub parallel_task {
686 my ($id) = @_;
687
688 # OO interface
689 if ($id == 1) {
690 $ha->set("$id", "foo");
691 $oh->set("$id", "foo");
692 $ho->set("$id", "foo");
693 }
694 # hash-like dereferencing
695 elsif ($id == 2) {
696 $ha->{"$id"} = "baz";
697 $oh->{"$id"} = "baz";
698 $ho->{"$id"} = "baz";
699 }
700
701 return;
702 }
703
704 MCE::Hobo->create("parallel_task", $_) for 1..2;
705 MCE::Hobo->waitall;
706
707 say $ha->{"1"}; # foo
708 say $oh->{"1"};
709 say $ho->{"1"};
710
711 say $ha->get("2"); # baz
712 say $oh->get("2");
713 say $ho->get("2");
714
716 · Hash::Ordered
717
718 · Tie::Hash::Indexed
719
720 · Tie::IxHash
721
722 · Tie::LLHash
723
725 MCE, MCE::Hobo, MCE::Shared
726
728 Mario E. Roy, <marioeroy AT gmail DOT com>
729
730
731
732perl v5.32.0 2020-08-02 MCE::Shared::Ordhash(3)