package DR::Tarantool;
=head1 NAME
DR::Tarantool - a Perl driver for L<Tarantool|http://tarantool.org>
=head1 SYNOPSIS
use DR::Tarantool ':constant', 'tarantool';
use DR::Tarantool ':all';
my $tnt = tarantool
host => '127.0.0.1',
port => 123,
spaces => {
...
}
;
$tnt->update( ... );
my $tnt = coro_tarantool
host => '127.0.0.1',
port => 123,
spaces => {
...
}
;
use DR::Tarantool ':constant', 'async_tarantool';
async_tarantool
host => '127.0.0.1',
port => 123,
spaces => {
...
},
sub {
...
}
;
$tnt->update(...);
=head1 DESCRIPTION
This module provides a synchronous and asynchronous driver for
L<Tarantool|http://tarantool.org>.
The driver does not have external dependencies, but includes the
official light-weight Tarantool C client (a single C header which
implements all protocol formatting) for packing requests and unpacking
server responses.
This driver implements "iproto" protocol described in
https://github.com/mailru/tarantool/blob/master/doc/box-protocol.txt
It is built on top of L<AnyEvent> - an asynchronous event
framework, and is therefore easiest to integrate into a program
which is already based on L<AnyEvent>. A synchronous version of
the driver exists as well, it starts L<AnyEvent> event machine for
every request.
The driver supports three work flow types:
=over
=item L<DR::Tarantool::AsyncClient>
The primary type, provides an asynchronous, callback-based
API. Requires a running L<AnyEvent> machine.
=item L<DR::Tarantool::SyncClient>
Is built on top of L<DR::Tarantool::AsyncClient>. Starts
L<AnyEvent> machine for every request. After a request is
served, the event loop is stopped, and the results
are returned to the caller, or, in case of an error, an
exception is thrown.
=item L<DR::Tarantool::CoroClient>
Is also built on top of L<DR::Tarantool::AsyncClient>, but is
designed to work in cooperative multitasking environment provided
by L<Coro>. Is fully syntax-compatible with
L<DR::Tarantool::SyncClient>, but requires a running event loop to
operate, like L<DR::Tarantool::AsyncClient>. Requests from
different coroutines are served concurrently.
=back
L<Tarantool|http://tarantool.org> binary protocol
contains no representation of database schema or tuple field types.
Due to this deficiency, to easily integrate with Perl and automatically
convert tuple fields to Perl values, the driver needs to know field names
and types. To tell the driver about them, an instance of a dedicated class
must be used.
L<DR::Tarantool::Spaces> is essentially a Perl hash which
describes field types and names for each space used in the program.
It can hardly be useful on its own, but once a connection is
"enlightened" with an instance of this class, access to all tuple
fields by a field name becomes possible. Type conversion, as
well as packing/unpacking from Tarantool binary format is
performed automatically.
Please follow the docs for L<DR::Tarantool::Spaces> to learn
how to describe a schema.
=head2 Establishing a connection
=head3 L<DR::Tarantool::AsyncClient>
DR::Tarantool::AsyncClient->connect(
host => $host,
port => $port,
spaces => { ... },
sub {
my ($tnt) = @_;
...
}
);
The callback passed to connect() gets invoked after a connection
is established. The only argument of the callback is the newly
established connection handle. The handle's type is
L<DR::Tarantool::AsyncClient>.
=head3 L<DR::Tarantool::CoroClient> and L<DR::Tarantool::SyncClient>
my $tnt = DR::Tarantool::SyncClient->connect(
host => $host,
port => $port,
spaces => { ... }
);
my $tnt = DR::Tarantool::CoroClient->connect(
host => $host,
port => $port,
spaces => { ... }
);
The only difference of synchronous versions from the asynchronous
one is absence of a callback. The created connection handle
is returned directly from connect().
In this spirit, the only difference of any synchronous API all
from the asynchronous counterpart is also in absence of the callback.
=head2 Working with tuples
=head3 Querying
my $user123 = $tnt->select('users' => 123);
my $users_by_roles = $tnt->select('users' => 'admins' => 'role_index');
It is possible to select data by a primary key (expects a Perl scalar),
secondary, multi-part key (expects an array).
The default index used for selection is the primary one, a non-default index
can be set by providing index name.
The contents of the result set is interpreted in accordance with
schema description provided in L<DR::Tarantool::Spaces>.
Supported data types are numbers, Unicode strings, JSON,
fixed-point decimals.
=head3 Insertion
$tnt->insert('users' => [ 123, 'vasya', 'admin' ]);
Insert a tuple into space 'users', defined in B<spaces> hash on
connect.
=head3 Deletion
$tnt->delete(users => 123);
Delete a tuple from space 'users'. The deletion is always
performed by the primary key.
=head3 Update
$tnt->update(users => 123 => [[ role => set => 'not_admin' ]]);
It is possible to modify any field in a tuple. A field can be
accessed by field name or number. A set of modifications can be
provided in a Perl array.
The following update operations are supported:
=over
=item set
Assign a field
=item add, and, or, xor
Arithmetic and bitwise operations for integers.
=item substr
Replace a substring with a paste (similar to Perl splice).
=item insert
Insert a field before the given field.
=item delete
Delete a field.
=item push
Append a field at the tail of the tuple.
=item pop
Pop a field from the tail of the tuple.
=back
=head3 Lua
$tnt->call_lua(my_proc_name => [ arguments, ...]);
Invoke a Lua stored procedure by name.
=head2 Supported data types
The driver supports all Tarantool types (B<NUM>, B<NUM64>, B<STR>),
as well as some client-only types, which are converted to the
above server types automatically on the client:
=over
=item UTF8STR
A unicode string.
=item MONEY
Fixed decimal currency. Stores the value on the server in B<NUM> type,
by multiplying the given amount by 100. The largest amount
that can be stored in this type is, therefore, around 20 000 000.
Can store negative values.
=item BIGMONEY
The same as above, but uses B<NUM64> as the underlying storage.
=item JSON
An arbitrary Perl object is automatically serialized to JSON with
L<JSON::XS> on insertion, and deserialized on selection.
=back
The basic data transfer unit in Tarantool protocol is a single
tuple. A selected tuple is automatically wrapped into an instance
of class L<DR::Tarantool::Tuple>. An object of this class can be
used as an associative container, in which any field can be
accessed by field name:
my $user = $tnt->select(users => 123);
printf("user: %s, role: %s\n", $user->name, $user->role);
To run driver tests, the following Perl modules are also necessary:
L<AnyEvent>, L<Coro>, L<Test::Pod>, L<Test::Spelling>,
L<Devel::GlobalDestruction>, L<JSON::XS>.
To run tests, do:
perl Makefile.PL
make
make test
The test suite attempts to find the server and start it, thus
make sure L<tarantool_box> is available in the path, or export
TARANTOOL_BOX=/path/to/tarantool_box.
=cut
use 5.008008;
use strict;
use warnings;
use Carp;
$Carp::Internal{ (__PACKAGE__) }++;
use base qw(Exporter);
our %EXPORT_TAGS = (
client => [ qw( tarantool async_tarantool coro_tarantool) ],
constant => [
qw(
TNT_INSERT TNT_SELECT TNT_UPDATE TNT_DELETE TNT_CALL TNT_PING
TNT_FLAG_RETURN TNT_FLAG_ADD TNT_FLAG_REPLACE TNT_FLAG_BOX_QUIET
)
],
);
our @EXPORT_OK = ( map { @$_ } values %EXPORT_TAGS );
$EXPORT_TAGS{all} = \@EXPORT_OK;
our @EXPORT = @{ $EXPORT_TAGS{client} };
our $VERSION = '0.38';
=head1 EXPORT
=head2 tarantool
connects to L<Tarantool|http://tarantool.org> in synchronous mode
using L<DR::Tarantool::SyncClient>.
=cut
sub tarantool {
require DR::Tarantool::SyncClient;
no warnings 'redefine';
*tarantool = sub {
DR::Tarantool::SyncClient->connect(@_);
};
goto \&tarantool;
}
=head2 async_tarantool
connects to L<tarantool|http://tarantool.org> in async mode using
L<DR::Tarantool::AsyncClient>.
=cut
sub async_tarantool {
require DR::Tarantool::AsyncClient;
no warnings 'redefine';
*async_tarantool = sub {
DR::Tarantool::AsyncClient->connect(@_);
};
goto \&async_tarantool;
}
=head2 coro_tarantol
connects to L<tarantool|http://tarantool.org> in async mode using
L<DR::Tarantool::CoroClient>.
=cut
sub coro_tarantool {
require DR::Tarantool::CoroClient;
no warnings 'redefine';
*coro_tarantool = sub {
DR::Tarantool::CoroClient->connect(@_);
};
goto \&coro_tarantool;
}
=head2 :constant
Exports constants to use in a client request as flags:
=over
=item TNT_FLAG_RETURN
With this flag on, each INSERT/UPDATE request
returns the new value of the tuple. DELETE returns the deleted
tuple, if it is found.
=item TNT_FLAG_ADD
With this flag on, INSERT returns an error if an old tuple
with the same primary key already exists. No tuple is inserted
in this case.
=item TNT_FLAG_REPLACE
With this flag on, INSERT returns an error if an old
tuple for the primary key does not exist.
Without either of the flags, INSERT replaces the old
tuple if it doesn't exist.
=back
=cut
require XSLoader;
XSLoader::load('DR::Tarantool', $VERSION);
=head2 :all
Exports all functions and constants.
=head1 TODO
=over
=item *
Support push, pop in UPDATE.
=item *
Make it possible to construct B<select>, B<delete> keys from Perl
hashes, not just Perl arrays.
=item *
Support L<DR::Tarantool::Tuple> as an argument to B<insert>.
=back
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2011 Dmitry E. Oboukhov <unera@debian.org>
Copyright (C) 2011 Roman V. Nikolaev <rshadow@rambler.ru>
This program is free software, you can redistribute it and/or
modify it under the terms of the Artistic License.
=head1 VCS
The project is hosted on github in the following git repository:
L<https://github.com/dr-co/dr-tarantool/>.
=cut
1;