Clean up some of the pending TODO comments (mongodb#3015)

* remove redundant operator definitions (TODO cleanup)

* cleaning up some long-standing TODO comments

Author: jamis

lib/mongo/cluster/reapers/cursor_reaper.rb

@@ -177,9 +177,10 @@ def kill_cursors
           end
 
           unless server
-            # TODO: We currently don't have a server for the address that the
-            # cursor is associated with. We should leave the cursor in the
-            # queue to be killed at a later time (when the server comes back).
+            # The server for this cursor has gone away --- maybe temporarily,
+            # maybe permanently, but we can't know. To prevent connections from
+            # leaking in the case of a permanent failure, we'll just silently
+            # drop this killspec and move on.
             next
           end
 

lib/mongo/cluster_time.rb

@@ -26,6 +26,8 @@ module Mongo
   #
   # @api private
   class ClusterTime < BSON::Document
+    include Comparable
+
     def initialize(elements = nil)
       super
 
@@ -62,25 +64,6 @@ def <=>(other)
       end
     end
 
-    # Older Rubies do not implement other logical operators through <=>.
-    # TODO revise whether these methods are needed when
-    # https://jira.mongodb.org/browse/RUBY-1622 is implemented.
-    def >=(other)
-      (self <=> other) != -1
-    end
-
-    def >(other)
-      (self <=> other) == 1
-    end
-
-    def <=(other)
-      (self <=> other) != 1
-    end
-
-    def <(other)
-      (self <=> other) == -1
-    end
-
     # Compares two ClusterTime instances by comparing their timestamps.
     def ==(other)
       if self['clusterTime'] && other['clusterTime'] &&

lib/mongo/operation/result.rb

@@ -104,9 +104,6 @@ class Result
       def initialize(replies, connection_description = nil, connection_global_id = nil, context: nil, connection: nil)
         @context = context
 
-        # TODO: older versions of MongoDB (2.4 and below?) could sometimes end
-        # up with nil here, which indicated an unackowledged write. Is that
-        # still the case? Can we simplify this?
         return unless replies
 
         if replies.is_a?(Array)

lib/mongo/protocol/msg.rb

@@ -208,8 +208,6 @@ def documents
       # @return [ Mongo::Protocol::Msg ] The encrypted message, or the original
       #   message if encryption was not possible or necessary.
       def maybe_encrypt(connection, context)
-        # TODO: verify compression happens later, i.e. when this method runs
-        # the message is not compressed.
         if context.encrypt?
           if connection.description.max_wire_version < 8
             raise Error::CryptError.new(

lib/mongo/socket/ocsp_cache.rb

@@ -19,7 +19,7 @@ class Socket
     # This module caches OCSP responses for their indicated validity time.
     #
     # The key is the CertificateId used for the OCSP request.
-    # The value is the SingleResponse.
+    # The value is an OcspVerifier::Response.
     #
     # @api private
     module OcspCache

lib/mongo/socket/ocsp_verifier.rb

@@ -14,6 +14,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+require 'delegate'
+
 module Net
   autoload :HTTP, 'net/http'
 end
@@ -31,6 +33,19 @@ class Socket
     #
     # @api private
     class OcspVerifier
+      # Wraps OpenSSL::OCSP::SingleResponse with the responder URI that supplied it.
+      #
+      # @api private
+      class Response < SimpleDelegator
+        attr_reader :uri, :original_uri
+
+        def initialize(single_response, uri, original_uri)
+          super(single_response)
+          @uri = uri
+          @original_uri = original_uri
+        end
+      end
+
       include Loggable
 
       # @param [ String ] host_name The host name being verified, for
@@ -228,18 +243,13 @@ def verify_one_responder(uri)
           return false
         end
 
-        resp = resp.find_response(cert_id)
-        unless resp
+        single_response = resp.find_response(cert_id)
+        unless single_response
           @resp_errors << "OCSP response from #{report_uri(original_uri,
                                                            uri)} did not include information about the requested certificate"
           return false
         end
-        # TODO: make a new class instead of patching the stdlib one?
-        resp.instance_variable_set(:@uri, uri)
-        resp.instance_variable_set(:@original_uri, original_uri)
-        class << resp
-          attr_reader :uri, :original_uri
-        end
+        resp = Response.new(single_response, uri, original_uri)
 
         unless resp.check_validity
           @resp_errors << "OCSP response from #{report_uri(original_uri,