WIP: start fleshing out an FFI provider

lib/hermann/provider/ffi_producer.rb

@@ -0,0 +1,56 @@
+require 'ffi'
+
+require 'hermann/errors'
+require 'hermann/provider/abstract_producer'
+
+module Hermann
+  module Provider
+    class FFIProducer < AbstractProducer
+      extend FFI::Library
+      ffi_lib 'rdkafka'
+
+      attr_reader :brokers
+
+      # Initialize a librdkafka-backed Producer class which relies on FFI to
+      # call into the shared library
+      #
+      # @param [String] brokers A list of comma separated host:port pairs
+      # @return [FFIProducer]
+      def initialize(brokers)
+        validate_brokers!(brokers)
+        @brokers = brokers
+      end
+
+      # Connect to the Kafka brokers
+      #
+      # @param [Integer] timeout_sec Seconds to timeout a connection
+      #   attempt after
+      # @return [Boolean] True if we've successfully connected
+      def connect(timeout_sec)
+      end
+
+      private
+
+      def validate_brokers!(brokers)
+        if brokers.nil?
+          raise Hermann::Errors::ConfigurationError
+        end
+
+        brokers.split(',').each do |broker|
+          # Make sure we've got a host:port pair
+          host, port = broker.split(':')
+          if host.nil? || port.nil?
+            raise Hermann::Errors::ConfigurationError
+          end
+
+          port = port.to_i
+
+          # We should have a valid port number
+          if (port <= 0) || (port > 65536)
+            raise Hermann::Errors::ConfigurationError
+          end
+        end
+      end
+    end
+  end
+end

spec/providers/ffi_producer_spec.rb

@@ -0,0 +1,45 @@
+require 'spec_helper'
+require 'hermann/provider/ffi_producer'
+
+describe Hermann::Provider::FFIProducer do
+  describe '.initialize' do
+    subject(:producer) { described_class.new(brokers) }
+    shared_examples_for 'a configuration error' do
+      it 'should raise' do
+        expect { subject }.to raise_error(Hermann::Errors::ConfigurationError)
+      end
+    end
+
+    context 'with nil brokers' do
+      let(:brokers) { nil }
+      it_behaves_like 'a configuration error'
+    end
+
+    context 'without host:port pairs' do
+      let(:brokers) { 'foo' }
+      it_behaves_like 'a configuration error'
+    end
+
+    context 'without a numeric port' do
+      let(:brokers) { 'rspec:rules' }
+      it_behaves_like 'a configuration error'
+    end
+  end
+
+  context 'instance methods' do
+    describe '#connect' do
+    end
+
+    describe '#connected?' do
+    end
+
+    describe '#errored?' do
+    end
+
+    describe '#push_single' do
+    end
+
+    describe '#tick' do
+    end
+  end
+end