NAME

       DR::Tarantool - a Perl driver for Tarantool <http://tarantool.org>

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(...);

DESCRIPTION

       This module provides a synchronous and asynchronous driver for 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 AnyEvent - an asynchronous event framework, and is therefore easiest to integrate
       into a program which is already based on AnyEvent. A synchronous version of the driver exists as well, it
       starts AnyEvent event machine for every request.

       The driver supports three work flow types:

       DR::Tarantool::AsyncClient
           The primary type, provides an asynchronous, callback-based API. Requires a running AnyEvent machine.

       DR::Tarantool::SyncClient
           Is built on top of DR::Tarantool::AsyncClient. Starts 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.

       DR::Tarantool::CoroClient
           Is also built on top of DR::Tarantool::AsyncClient, but is designed to work in cooperative
           multitasking environment provided by Coro. Is fully syntax-compatible with DR::Tarantool::SyncClient,
           but requires a running event loop to operate, like DR::Tarantool::AsyncClient. Requests from
           different coroutines are served concurrently.

       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.  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 DR::Tarantool::Spaces to learn how to describe a schema.

   Establishing a connection
       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 DR::Tarantool::AsyncClient.

       DR::Tarantool::CoroClient and 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.

   Working with tuples
       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
       DR::Tarantool::Spaces.  Supported data types are numbers, Unicode strings, JSON, fixed-point decimals.

       Insertion

               $tnt->insert('users' => [ 123, 'vasya', 'admin' ]);

       Insert a tuple into space 'users', defined in spaces hash on connect.

       Deletion

               $tnt->delete(users => 123);

       Delete a tuple from space 'users'. The deletion is always performed by the primary key.

       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:

       set Assign a field

       add, and, or, xor
           Arithmetic and bitwise operations for integers.

       substr
           Replace a substring with a paste (similar to Perl splice).

       insert
           Insert a field before the given field.

       delete
           Delete a field.

       push
           Append a field at the tail of the tuple.

       pop Pop a field from the tail of the tuple.

       Lua

               $tnt->call_lua(my_proc_name => [ arguments, ...]);

       Invoke a Lua stored procedure by name.

   Supported data types
       The driver supports all Tarantool types (NUM, NUM64, STR), as well as some client-only types, which are
       converted to the above server types automatically on the client:

       UTF8STR
           A unicode string.

       MONEY
           Fixed decimal currency. Stores the value on the server in 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.

       BIGMONEY
           The same as above, but uses NUM64 as the underlying storage.

       JSON
           An arbitrary Perl object is automatically serialized to JSON with JSON::XS on insertion, and
           deserialized on selection.

       The basic data transfer unit in Tarantool protocol is a single tuple. A selected tuple is automatically
       wrapped into an instance of class 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: AnyEvent, Coro, Test::Pod,
       Test::Spelling, Devel::GlobalDestruction, 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 tarantool_box is available in the
       path, or export TARANTOOL_BOX=/path/to/tarantool_box.

EXPORT

   tarantool
       connects to Tarantool <http://tarantool.org> in synchronous mode using DR::Tarantool::SyncClient.

   rsync_tarantool
       connects to Tarantool <http://tarantool.org> in synchronous mode using DR::Tarantool::RealSyncClient.

   async_tarantool
       connects to tarantool <http://tarantool.org> in async mode using DR::Tarantool::AsyncClient.

   coro_tarantol
       connects to tarantool <http://tarantool.org> in async mode using DR::Tarantool::CoroClient.

   :constant
       Exports constants to use in a client request as flags:

       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.

       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.

       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.

   :all
       Exports all functions and constants.

TODO

       •   Support push, pop in UPDATE.

       •   Make it possible to construct select, delete keys from Perl hashes, not just Perl arrays.

       •   Support DR::Tarantool::Tuple as an argument to insert.

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.

VCS

       The project is hosted on github in the following git repository:
       <https://github.com/dr-co/dr-tarantool/>.