[][src]Crate tarantool_module

Tarantool C API bindings for Rust. This library contains the following Tarantool API's:

  • Box: spaces, indexes, sequences
  • Fibers: fiber attributes, conditional variables
  • CoIO
  • Transactions
  • Latches
  • Tuple utils
  • Logging (see https://!docs.rs/log/0.4.11/log/)
  • Error handling

Caution! The library is currently under development. API may be unstable until version 1.0 will be released.


  • rustc 1.45.0 or newer (other versions were not tested)
  • tarantool 2.2

Stored procedures

Tarantool can call Rust code via a plugin, from Lua using FFI, or as a stored procedure. This tutorial only is about the third option, Rust stored procedures. In fact Rust routines are always "C functions" to Tarantool but the phrase "stored procedure" is commonly used for historical reasons.

This tutorial contains the following simple steps:

  1. examples/easy - prints "hello world";
  2. examples/harder - decodes a passed parameter value;
  3. examples/hardest - uses this library to do a DBMS insert;
  4. examples/read - uses this library to do a DBMS select;
  5. examples/write - uses this library to do a DBMS replace.

By following the instructions and seeing that the results users should become confident in writing their own stored procedures.


Check that these items exist on the computer:

  • Tarantool 2.2
  • A rustc compiler + cargo builder. Any modern version should work

Create cargo project:

$ cargo init --lib

Add the following lines to Cargo.toml:

name = "easy"
version = "0.1.0"
edition = "2018"
# author, license, etc

tarantool-module = "0.2.0" # (1)
serde = "1.0" # (2)

crate-type = ["cdylib"] # (3)
  1. add to dependencies tarantool-module library;
  2. add to dependencies Serde, this is optional and required if you want to use rust structures as a tuple values (see this example);
  3. you need to compile dynamic library.

Requests will be done using Tarantool as a client. Start Tarantool, and enter these requests:

net_box = require('net.box')
capi_connection = net_box:new(3306)

In plain language: create a space named capi_test, and make a connection to self named capi_connection.

Leave the client running. It will be used to enter more requests later.

Edit lib.rs file and add the following lines:

use std::os::raw::c_int;
use tarantool_module::tuple::{FunctionArgs, FunctionCtx};

pub extern "C" fn easy(_: FunctionCtx, _: FunctionArgs) -> c_int {
    println!("hello world");

pub extern "C" fn easy2(_: FunctionCtx, _: FunctionArgs) -> c_int {
    println!("hello world -- easy2");

Compile the program:

$ cargo build

Start another shell. Change directory (cd) so that it is the same as the directory that the client is running in. Copy the compiled library (it is located in subfolder target/debug at you project sources folder) to the current folder and rename it to easy.so

Now go back to the client and execute these requests:

box.schema.func.create('easy', {language = 'C'})
box.schema.user.grant('guest', 'execute', 'function', 'easy')

If these requests appear unfamiliar, read the descriptions of box.schema.func.create(), box.schema.user.grant() and conn:call().

The function that matters is capi_connection:call('easy').

Its first job is to find the 'easy' function, which should be easy because by default Tarantool looks on the current directory for a file named easy.so.

Its second job is to call the 'easy' function. Since the easy() function in lib.rs begins with println!("hello world"), the words "hello world" will appear on the screen.

Its third job is to check that the call was successful. Since the easy() function in lib.rs ends with return 0, there is no error message to display and the request is over.

The result should look like this:

tarantool> capi_connection:call('easy')
hello world
- []

Now let's call the other function in lib.rs - easy2(). This is almost the same as the easy() function, but there's a detail: when the file name is not the same as the function name, then we have to specify {file-name}.{function-name}

box.schema.func.create('easy.easy2', {language = 'C'})
box.schema.user.grant('guest', 'execute', 'function', 'easy.easy2')

... and this time the result will be hello world -- easy2.

Conclusion: calling a Rust function is easy.



The clock module returns time values derived from the Posix / C CLOCK_GETTIME function or equivalent.


Cooperative input/output


Error handling utils. See "failure" crate documentation for details


Сooperative multitasking module


Box: indices


Logging utils. See "log" crate documentation for details


Box: sequences


Box: spaces


Transaction management