Mongo and DB ctors can now take array of nodes. Tests now close @db in teardown.

lib/mongo/db.rb

@@ -49,25 +49,47 @@ module XGen
         # The name of the database.
         attr_reader :name
 
-        attr_reader :host, :port
+        # Host to which we are currently connected.
+        attr_reader :host
+        # Port to which we are currently connected.
+        attr_reader :port
+
+        # An array of [host, port] pairs.
+        attr_reader :nodes
 
         # The database's socket. For internal (and Cursor) use only.
         attr_reader :socket
 
         # db_name :: The database name
         #
-        # host :: The database host name or IP address. Defaults to 'localhost'.
+        # nodes :: An array of [host, port] pairs.
         #
-        # port :: The database port number. Defaults to
-        #         XGen::Mongo::Driver::Mongo::DEFAULT_PORT.
-        #
-        def initialize(db_name, host='localhost', port=XGen::Mongo::Driver::Mongo::DEFAULT_PORT)
+        # When a DB object first connects, it tries the first node. If that
+        # fails, it keeps trying to connect to the remaining nodes until it
+        # sucessfully connects.
+        def initialize(db_name, nodes)
           raise "Invalid DB name" if !db_name || (db_name && db_name.length > 0 && db_name.include?("."))
-          @name, @host, @port = db_name, host, port
-          @socket = TCPSocket.new(@host, @port)
+          @name, @nodes = db_name, nodes
           @strict = false
           @semaphore = Object.new
           @semaphore.extend Mutex_m
+          connect_to_first_available_host
+        end
+
+        def connect_to_first_available_host
+          close if @socket
+          @host = @port = nil
+          @nodes.detect { |hp|
+            @host, @port = *hp
+            begin
+              @socket = TCPSocket.new(@host, @port)
+              break if ok?(db_command(:ismaster => 1)) # success
+            rescue => ex
+              close if @socket
+            end
+            @socket
+          }
+          raise "error: failed to connect to any given host:port" unless @socket
         end
 
         # Returns an array of collection names. Each name is of the form
@@ -183,7 +205,12 @@ module XGen
 
         # Close the connection to the database.
         def close
-          @socket.close
+          @socket.close if @socket
+          @socket = nil
+        end
+
+        def connected?
+          @socket != nil
         end
 
         # Send a MsgMessage to the database.

lib/mongo/mongo.rb

@@ -25,14 +25,36 @@ module XGen
 
         DEFAULT_PORT = 27017
 
-        # Host default is 'localhost', port default is DEFAULT_PORT.
-        def initialize(host='localhost', port=DEFAULT_PORT)
-          @host, @port = host, port
+        # Either nodes_or_host is a host name string and port is an optional
+        # port number that defaults to DEFAULT_PORT, or nodes_or_host is an
+        # array of arrays, where each is a host/port pair (or a host with no
+        # port). Finally, if both args are nil then host is 'localhost' and
+        # port is DEFAULT_PORT. Since that's so confusing, here are a few
+        # examples:
+        #
+        #  Mongo.new                         # localhost, DEFAULT_PORT
+        #  Mongo.new("localhost")            # localhost, DEFAULT_PORT
+        #  Mongo.new("localhost", 3000)      # localhost, 3000
+        #  Mongo.new([["localhost"]])        # localhost, DEFAULT_PORT
+        #  Mongo.new([["localhost", 3000]])  # localhost, 3000
+        #  Mongo.new([["db1.example.com", 3000], ["db2.example.com", 3000]]])
+        #
+        # When a DB object first connects, it tries nodes and stops at the
+        # first one it connects to.
+        def initialize(nodes_or_host, port=nil)
+          @nodes = case nodes_or_host
+                   when String
+                     [[nodes_or_host, port || DEFAULT_PORT]]
+                   when Array
+                     nodes_or_host.collect { |nh| [nh[0], nh[1] || DEFAULT_PORT] }
+                   when nil
+                     [['localhost', DEFAULT_PORT]]
+                   end
         end
 
         # Return the XGen::Mongo::Driver::DB named +db_name+.
         def db(db_name)
-          XGen::Mongo::Driver::DB.new(db_name, @host, @port)
+          XGen::Mongo::Driver::DB.new(db_name, @nodes)
         end
 
         # Not implemented.

tests/test_admin.rb

@@ -20,9 +20,10 @@ class AdminTest < Test::Unit::TestCase
   end
 
   def teardown
-    unless @db.socket.closed?
+    if @db.connected?
       @admin.profiling_level = :off
-      @coll.clear unless @coll == nil
+      @coll.clear if @coll
+      @db.close
     end
   end
 

tests/test_cursor.rb

@@ -18,7 +18,10 @@ class CursorTest < Test::Unit::TestCase
   end
 
   def teardown
-    @coll.clear unless @coll == nil || @db.socket.closed?
+    if @db.connected?
+      @coll.clear if @coll
+      @db.close
+    end
   end
 
   def test_explain

tests/test_db.rb

@@ -8,39 +8,44 @@ class DBAPITest < Test::Unit::TestCase
   include XGen::Mongo::Driver
 
   def setup
-    host = ENV['MONGO_RUBY_DRIVER_HOST'] || 'localhost'
-    port = ENV['MONGO_RUBY_DRIVER_PORT'] || Mongo::DEFAULT_PORT
-    @db = Mongo.new(host, port).db('ruby-mongo-test')
-    @coll = @db.collection('test')
-    @coll.clear
-    @r1 = @coll.insert('a' => 1) # collection not created until it's used
-    @coll_full_name = 'ruby-mongo-test.test'
+    @host = ENV['MONGO_RUBY_DRIVER_HOST'] || 'localhost'
+    @port = ENV['MONGO_RUBY_DRIVER_PORT'] || Mongo::DEFAULT_PORT
+    @db = Mongo.new(@host, @port).db('ruby-mongo-test')
   end
 
   def teardown
-    @coll.clear unless @coll == nil || @db.socket.closed?
+    if @db.connected?
+      @db.close
+    end
   end
 
   def test_close
     @db.close
-    assert @db.socket.closed?
+    assert !@db.connected?
     begin
-      @coll.insert('a' => 1)
-      fail "expected IOError exception"
-    rescue IOError => ex
-      assert_match /closed stream/, ex.to_s
+      @db.collection('test').insert('a' => 1)
+      fail "expected 'NilClass' exception"
+    rescue => ex
+      assert_match /NilClass/, ex.to_s
     end
   end
 
   def test_full_coll_name
-    assert_equal @coll_full_name, @db.full_coll_name(@coll.name)
+    coll = @db.collection('test')
+    assert_equal 'ruby-mongo-test.test', @db.full_coll_name(coll.name)
   end
 
   def test_master
     # Doesn't really test anything since we probably only have one database
     # during this test.
     @db.switch_to_master
-    assert_not_nil @db.socket
+    assert @db.connected?
+  end
+
+  def test_array
+    @db.close
+    @db = Mongo.new([["nosuch.example.com"], [@host, @port]]).db('ruby-mongo-test')
+    assert @db.connected?
   end
 
 end

tests/test_db_api.rb

@@ -18,7 +18,10 @@ class DBAPITest < Test::Unit::TestCase
   end
 
   def teardown
-    @coll.clear unless @coll == nil || @db.socket.closed?
+    if @db.connected?
+      @coll.clear unless @coll == nil
+      @db.close
+    end
   end
 
   def test_clear