table of contents
| MR::Tarantool::Box::Singleton(3pm) | User Contributed Perl Documentation | MR::Tarantool::Box::Singleton(3pm) |
NAME¶
MR::Tarantool::Box::Singleton - A singleton wrapper for MR::Tarantool::Box.
Provides connection-persistence and replica fallback. Please read "MR::Tarantool::Box manual" first.
SYNOPSIS¶
package Some::Tarantool::Box::Singleton;
use MR::Tarantool::Box::Singleton;
use base 'MR::Tarantool::Box::Singleton';
BEGIN { # generates "TUPLE_$field_name" constants, and methods: FIELDS, FIELDS_HASH
__PACKAGE__->mkfields(qw/ id f1 f2 f3 field4 f5 f6 f7 misc_string /); # applicable for DEFAULT_SPACE only
}
sub SERVER { Some::Config->GetBoxServer() }
sub REPLICAS { Some::Config->GetBoxReplicas() }
sub DEFAULT_SPACE { 0 }
sub SPACES {[{
space => 0,
indexes => [ {
index_name => 'primary_id',
keys => [TUPLE_id],
}, {
index_name => 'secondary_f1f2',
keys => [TUPLE_f1, TUPLE_f2],
}, ],
format => 'QqLlSsCc&',
default_index => 'primary_id',
}, {
space => 1,
indexes => [ {
index_name => 'primary_id',
keys => [0],
}, ],
format => '&&&&',
fields => [qw/ string1 str2 s3 s4 /],
}]}
DESCRIPTION¶
METHODS¶
mkfields
BEGIN {
$CLASS->mkfields(@names);
}
- Generates constants "TUPLE_$fieldname" => $fieldposition in $CLASS. Just Like if you say "use constant TUPLE_id => 0, TUPLE_f1 => 1, ...;"
- Generates $CLASS variable @fields containing field names, and a $CLASS method "FIELDS" returning @fields.
- Generates $CLASS variable %fields containing field names mapping to positions, and a $CLASS method "FIELDS_HASH" returning "\%fields".
- These @fields are applied to the "DEFAULT_SPACE", if fields were not set explicitly for that space.
declare_stored_procedure
$CLASS->declare_stored_procedure(%args);
$CLASS->declare_stored_procedure(
name => "box.do.something", # internal procedure name, in da box
method_name => "CallMyTestingStoredProcedure", # will generate method named
options => { default => options }, # MR::Tarantool::Box->Call \%options
params => [ qw{ P1 P2 P3 Param4 }], # names
unpack_format => "&LSC(L$)*",
params_format => [qw{ C S L a* }],
params_default => [ 1, 2, undef, 'the_default' ], # undef's are mandatory params
);
...
my $data = $CLASS->CallMyTestingStoredProcedure(
P1 => $val1,
P2 => $val2,
P3 => $val3,
Param4 => $val3,
{ option => $value }, # optional
) or warn $CLASS->ErrorStr;
Declare a stored procedure. This generates $CLASS method $args{method_name} which calls Tarantool/Box procedure $args{name}, using $args{options} as default "\%options" for "MR::Tarantool::Box->Call" call. The generated method has the following prototype:
$CLASS->CallMyTestingStoredProcedure( %sp_params, \%optional_options );
Parameters description:
- %args:
- name => $tarantool_box_sp_name
- The name of procedure in Tarantool/Box to call.
- method_name => $class_method_name
- Class method name to generate.
- options => \%options
- Options to pass to MR::Taranatool::Box-Call|MR::Taranatool::Box/Call> method.
- params => \@names
- Procedure input parameters' names
- params_default => \@defaults
- Procedure input parameters default values. Undefined or absent value makes its parameter mandatory.
- params_format => \@format
- "pack()"-compatible format to pack input parameters. Must match "params".
- unpack_format => $format
- "pack()"-compatible format to unpack procedure output.
- %sp_params:
- "Name => $value" pairs.
- %optional_options:
- Options to pass to MR::Taranatool::Box-Call|MR::Taranatool::Box/Call> method. This overrides %options values key-by-key.
Configuration methods
- SERVER
- Must return a string of ip:port of master server.
- REPLICAS
- Must return a comma separated string of ip:port pairs of replica servers (see "is_replica"). Server is chosen from the list randomly.
- MR_TARANTOOL_BOX_CLASS
- Must return name of the class implementing MR::Tarantool::Box interface, or it's descendant.
- SPACES, RAISE, TIMEOUT, SELECT_TIMEOUT, RETRY, SELECT_RETRY, SOFT_RETRY, DEBUG
- See corresponding arguments of MR::Tarantool::Box-new|MR::Tarantool::Box/new> method.
Add, Insert, Replace, UpdateMulti, Delete
These methods operate on "SERVER" only. See corresponding methods of MR::Tarantool::Box class.
Select, Call
These methods operate on "SERVER" at first, and then may try to query "REPLICAS".
See corresponding methods of MR::Tarantool::Box class.
These methods have additional %options params:
- is_replica => \$is_result_from_replica
- If this option is set, then if the query to "SERVER" fails, "REPLICAS" will be queried one-by-one until query succeeds or the list ends, and $is_result_from_replica will be set to "true", no matter whether any query succeeds or not.
Error, ErrorStr
Return error code or description (see <MR::Tarantool::Box|MR::Tarantool::Box/Error>).
LICENCE AND COPYRIGHT¶
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
SEE ALSO¶
MR::Tarantool::Box
| 2020-07-21 | perl v5.30.3 |