Ilios

Ilios that Cassandra driver written by C language for Ruby using DataStax C/C++ Driver.

Installation

Install the gem and add to the application's Gemfile by executing:

$ bundle add ilios

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install ilios

This gem's installer will install the DataStax C/C++ Driver to the appropriate location automatically. However, if you prefer to install the DataStax C/C++ Driver manually, you can do so by executing:

$ bundle config set --local build.ilios --with-libuv-dir=/path/to/libuv-installed-dir
$ bundle config set --local build.ilios --with-cassandra-driver-dir=/path/to/cassandra-cpp-driver-installed-dir
$ bundle add ilios

or

$ gem install ilios -- --with-libuv-dir=/path/to/libuv-installed-dir --with-cassandra-driver-dir=/path/to/cassandra-cpp-driver-installed-dir

Requirements

• cmake (in order to build the DataStax C/C++ Driver and libuv)

Supported

• Ruby 3.0 or later
• Cassandra 3.0 or later
• Linux and macOS platform

Example

Basic usage

Create the keyspace in advance using the cqlsh command.

CREATE KEYSPACE IF NOT EXISTS ilios
WITH REPLICATION = {
  'class' : 'SimpleStrategy',
  'replication_factor' : 1
};

Then, you can run the following code.

require 'ilios'

cluster = Ilios::Cassandra::Cluster.new
cluster.keyspace('ilios')
cluster.hosts(['127.0.0.1'])
session = cluster.connect

# Create the table
statement = session.prepare(<<~CQL)
  CREATE TABLE IF NOT EXISTS ilios.example (
    id bigint,
    message text,
    created_at timestamp,
    PRIMARY KEY (id)
  ) WITH compaction = { 'class' : 'LeveledCompactionStrategy' }
  AND gc_grace_seconds = 691200;
CQL
session.execute(statement)

# Insert the records
statement = session.prepare(<<~CQL)
  INSERT INTO ilios.example (
    id,
    message,
    created_at
  ) VALUES (?, ?, ?)
CQL

100.times do |i|
  statement.bind({
    id: i,
    message: 'Hello World',
    created_at: Time.now,
  })
  session.execute(statement)
end

# Select the records
statement = session.prepare(<<~CQL)
  SELECT * FROM ilios.example
CQL
statement.idempotent = true
statement.page_size = 25
result = session.execute(statement)
result.each do |row|
  p row
end

while(result.next_page)
  result.each do |row|
    p row
  end
end

Synchronous API

Ilios::Cassandra::Session#prepare and Ilios::Cassandra::Session#execute are provided as synchronous API.

statement = session.prepare(<<~CQL)
  SELECT * FROM ilios.example
CQL
result = session.execute(statement)

Asynchronous API

Ilios::Cassandra::Session#prepare_async and Ilios::Cassandra::Session#execute_async are provided as asynchronous API.

prepare_future = session.prepare_async(<<~CQL)
  INSERT INTO ilios.example (
    id,
    message,
    created_at
  ) VALUES (?, ?, ?)
CQL

prepare_future.on_success { |statement|
  futures = []

  10.times do |i|
    statement.bind({
      id: i,
      message: 'Hello World',
      created_at: Time.now,
    })
    result_future = session.execute_async(statement)
    result_future.on_success { |result|
      p result
      p "success"
    }
    result_future.on_failure {
      p "fail"
    }

    futures << result_future
  end
  futures.each(&:await)
}

prepare_future.await

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Watson1978/ilios.