add missing replication file

lib/bdb/replication.rb

@@ -0,0 +1,68 @@
+require 'socket'
+module Replication
+  DEFAULT_PORT = 3463
+  NUM_THREADS  = 1
+
+  ACK_POLICY = {
+    :all       => Bdb::DB_REPMGR_ACKS_ALL,
+    :all_peers => Bdb::DB_REPMGR_ACKS_ALL_PEERS,
+    :none      => Bdb::DB_REPMGR_ACKS_NONE,
+    :one       => Bdb::DB_REPMGR_ACKS_ONE,
+    :one_peer  => Bdb::DB_REPMGR_ACKS_ONE_PEER,
+    :quorom    => Bdb::DB_REPMGR_ACKS_QUORUM,
+  }
+
+  def replicate?
+    not @replicate.nil?
+  end
+
+  def master?
+    not replicate? or replicate[:master]
+  end
+
+  def replicate(opts = nil)
+    return @replicate if opts.nil?
+
+    master  = normalize_host(opts.delete(:from))
+    clients = [*opts.delete(:to)].compact.collect {|h| normalize_host(h)}
+    local   = normalize_host(opts.delete(:host) || ENV['BDB_REPLICATION_HOST'], opts.delete(:port))
+    remote  = clients + [master] - [local]
+
+    opts[:master] = (local == master)
+    opts[:local]  = local
+    opts[:remote] = remote
+    opts[:num_threads] ||= NUM_THREADS
+    @replicate = opts
+
+    env
+  end
+
+private
+
+  def init_replication(env)
+    env.set_verbose(Bdb::DB_VERB_REPLICATION, true) if replicate[:verbose]
+    env.rep_priority = replicate[:master] ? 1 : 0
+    env.repmgr_ack_policy = ACK_POLICY[replicate[:ack_policy]] if replicate[:ack_policy]
+    env.repmgr_set_local_site(*replicate[:local])
+    replicate[:remote].each do |s|
+      env.repmgr_add_remote_site(*s)
+    end
+    env.rep_nsites = replicate[:remote].size + 1
+  end
+
+  def start_replication(env)
+    env.repmgr_start(replicate[:num_threads], replicate[:master] ? Bdb::DB_REP_MASTER : Bdb::DB_REP_CLIENT)
+  end
+
+  def normalize_host(*host)
+    host = host.compact.join(':')
+    host, port = host.split(':')
+    host ||= Socket.gethostname
+    port ||= DEFAULT_PORT
+    port = port.to_i
+
+    addr_info = Socket.getaddrinfo(host.strip, port)
+    ip = addr_info.detect {|i| i[0] == 'AF_INET'}[3]
+    [ip, port]
+  end
+end