NAME
Hustle::Table - Cached general purpose dispatch and routing table
SYNOPSIS
use Hustle::Table;
Create a new table:
my $table=Hustle::Table->new;
Add entry as hash ref:
$table->add( { matcher => qr/regex (match)/, value=> "a value"});
Add entry as array ref (3 elements required):
$table->add( [qr/another/, "another value", undef])
Add entry as flat key value pairs:
$table->add(matcher=>"jones", value=> sub {"one more"}, type=>"begin");
Add entry as tuple
$table->add(qr|magic matcher| => "to a value");
Set the default entry:
$table->set_default("default value");
Prepare a dispatcher external cache:
my %cache;
my $dispatch = $table->prepare_dispatcher(cache=>\%cache);
Call dispatcher to return the matching entry and any regex captures
my ($entry, $captures)=$dispatch->("thing to match");
DESCRIPTION
This module provides a class to construct a routing table and build a
high performance dispatcher from it.
A table can have any combination of regex, exact string, begin string
end string or numeric matching of entries. The order in which the
entries are added defines their precedence. First in, first tested.
In the case of no entries matching the input, a default/fallback entry
always matches.
Once all the entries have been added to the table, a dispatcher is
prepared/created. The dispatcher is an anonymous subroutine, which tests
its argument against the matcher in each entry in the table.
It returns a list containing the first entry that matched, and an
anonymous array of any captures from regex matching.
If more entries are required to be added to the table, the dispatcher
must be prepared again.
A cache (hash) is used to drastically improve table lookup performance.
Entries are automatically added to the cache. However removal of cache
entries is up to the user to implement on a application basis.
CREATING A TABLE
Calling the class constructor returns a new table. There are no required
arguments:
my $table=Hustle::Table->new;
In this case, a default catch all entry (an undef value) is added
automatically.
If an argument is provided, it is the value used in the default/catch
all entry:
my $table=Hustle::Table->new($default);
ENTRIES
Structure
An entry is an anonymous array containing the following elements:
[matcher, value, type, default]
matcher
"matcher" can be a regex, a string or a numeric value.
When "matcher" is a regex, any captures are returned as the second
item when calling the dispatcher
When "matcher" is string or numeric value, the last field "type"
specifies how to perform the match. See "type" below.
If no "type" is specified or is "undef", the "matcher" is always
treated as a regex
value
This is the data you want to retrieve from the table when the
matches.
type
"type" is used to adjust how the matcher is interpreted. The
possible values are:
undef => matcher is always treated as a regex
"begin" => matches the begining of input string
"end" => matches the end of input string
"exact" => string equality
"numeric" => numeric equality
If "matcher" is a precompiled regex (i.e. "qr{}"), "type" is
ignored.
If "matcher" is a string or number, it is treated as a regex unless
"type" is as above.
default
This is a flag indicating if the entry was the default entry
Adding
Entries are added in anonymous hash, anonymous array or flattened
format, using the "add" method.
Anonymous array entries must contain six elements, in the order of:
$table->add([$matcher, $value, $type]);
Anonymous hashes format only need to specify the matcher and value pairs
$table->add({matcher=>$matcher, value=>$value, type=>$type});
Single flattened format takes a list directly. It must contain 4
elements
$table->add(matcher=>$matcher, value=> $value);
Single simple format takes two elements
$table->add(qr{some matcher}=>$value);
Or add multiple at once using mixed formats together
$table->add(
[$matcher, $value, $type],
{matcher=> $matcher, value=>$value},
matcher=>$matcher, value=>$value
);
In any case,"matcher" and "value" are the only items which must be
defined.
Default Matcher
Each list has a default matcher that will unconditionally match the
input. This entry is specified by using "undef" as the matcher when
adding an entry. When set this way only the array format can be used.
To make it more explicit, the it can also be changed via the
"set_default" method.
The default value of the 'default' entry is undef
PREPARING A DISPATCHER
Once all the entries are added to the table, the dispatcher can be
constructed by calling "prepare_dispatcher":
my $dispatcher=$table->prepare_dispatcher(%args);
Arguments to this method include:
cache
The hash ref to use as the dispatchers cache. Specifying a hash
allows external management. If no cache is specified an internal
cache is used.
USING A DISPATCHER
The dispatcher is simply a sub, which you call with the input to match
against the table entries:
my ($entry, $captures)=$dispatcher->("input");
my $value=$entry->[1];
The return from the dispatcher is a list of two elements.
The first is the array reference to the table entry that matched (or the
default entry if no match was found). The value associated with the
table entry is located in position 1
The second item returned is an anonymous array of any captures due to a
matching regex
COMPARISON TO OTHER MODULES
Solid performance compared to other perl routing/dispatch modules.
Faster in basic tests then other perl modules:
Smart::Dispatch Router::Simple Router::Boom
If you need even more performance then checkout URI::Router
TODO: make proper benchmark and comparison
AUTHOR
Ruben Westerberg, <drclaw@mac.com>
COPYRIGHT AND LICENSE
Copyright (C) 2022 by Ruben Westerberg
Licensed under MIT
DISCLAIMER OF WARRANTIES
THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.