CDRS

CDRS is a native Cassandra driver written in Rust. The motivation to write it in Rust is a lack of native one. Existing ones are bindings to C clients.

Documentation

CDRS is under active development at the moment, so there is a lack of many features and API may not be stable (but in case of any breaking changes we will update a major version of the package in accordance to common practices of versioning).

At the moment CDRS is not an ORM or a client in usual meaning but rather a kind of quite low level driver which deals with different kind of frames. It supports 4-th version of Cassandra protocol.

Supported features

• lz4 decompression
• snappy decompression
• password authorization

Frames

Request

• STARTUP
• AUTH_RESPONSE
• OPTIONS
• QUERY
• PREPARE
• EXECUTE
• BATCH
• REGISTER

Response

• ERROR
• READY
• AUTHENTICATE
• SUPPORTED
• RESULT (Void)
• RESULT (Rows)
• RESULT (Set_keyspace)
• RESULT (Prepared)
• RESULT (Schema_change)
• EVENT
• AUTH_CHALLENGE
• AUTH_SUCCESS

Examples

Creating new connection and authorization

To use password authenticator, just include the one implemented in cdrs::authenticators.

use cdrs::client::CDRS;
use cdrs::authenticators::PasswordAuthenticator;

After that you can create a new instace of CDRS and establish new connection:

let user = "user".to_string();
let pass = "pass".to_string();
let authenticator = PasswordAuthenticator::new(user, pass);

// pass authenticator into CDRS' constructor
let client = CDRS::new(addr, authenticator).unwrap();
use cdrs::compression;
// without compression
let response_frame = try!(client.start(compression::None));

If Server does not require authorization authenticator won't be used, but is still required for the constructor (most probably it will be refactored in future).

Using compression

Two types of compression are supported - snappy and lz4. To use compression just start connection with desired type:

// client without compression
client.start(compression::None);
// client  lz4 compression
client.start(compression::Lz4);
// client with snappy compression
client.start(compression::Snappy);

Query execution

Use Query:

let use_query = String::from("USE my_namespace;");

match client.query(use_query) {
    Ok(set_keyspace) => {
        // use_keyspace is a result frame of type SetKeyspace
    },
    Err(err) => log!(err)
}

Select Query:

As a response to select query CDRS returns a result frame of type Rows with data items (columns) encoded in Cassandra's way. Currently there are decode helpers only, but no helper methods which could easily map results into Rust structures. To have them is a goal of first stable version of CDRS.

let select_query = String::from("SELECT * FROM ks.table;");

match client.query(select_query) {
    Ok(res) => println!("Result frame: {:?},\nparsed body: {:?}", res, res.get_body());,
    Err(err) => log!(err)
}

License

The MIT License (MIT)

Copyright (c) 2016 Alex Pikalov

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.