RUBY-266 - expose execution profiles through cluster object

* Also bump version to 3.1.0.rc.1 in preparation of 3.1.0 release.

Author: stamhankar999

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    cassandra-driver (3.0.4.rc.1)
+    cassandra-driver (3.1.0.rc.1)
       ione (~> 1.2)
 
 GEM

lib/cassandra/cluster.rb

@@ -288,6 +288,12 @@ def close
       close_async.get
     end
 
+    # @param name [String] Name of profile to retrieve
+    # @return [Cassandra::Execution::Profile] execution profile of the given name.
+    def execution_profile(name)
+      @profile_manager.profiles[name]
+    end
+
     # @private
     def inspect
       "#<#{self.class.name}:0x#{object_id.to_s(16)} " \

lib/cassandra/execution/profile_manager.rb

@@ -33,13 +33,11 @@ def initialize(default_profile, profiles)
 
         @load_balancing_policies = Set.new
         @load_balancing_policies << default_profile.load_balancing_policy if default_profile.load_balancing_policy
+        @profiles = {DEFAULT_EXECUTION_PROFILE => default_profile}
 
-        profiles.each_value do |profile|
-          @load_balancing_policies << profile.load_balancing_policy if profile.load_balancing_policy
-          profile.merge_from(default_profile)
+        profiles.each do |name, profile|
+          add_profile(name, profile)
         end
-
-        @profiles = profiles.merge({DEFAULT_EXECUTION_PROFILE => default_profile})
       end
 
       def default_profile
@@ -59,6 +57,15 @@ def distance(host)
         return :ignore
       end
 
+      # NOTE: It's only safe to call add_profile when setting up the cluster object. In particular,
+      # this is only ok before calling Driver#connect.
+      # @private
+      def add_profile(name, profile)
+        @profiles[name] = profile
+        @load_balancing_policies << profile.load_balancing_policy if profile.load_balancing_policy
+        profile.merge_from(default_profile)
+      end
+
       # @private
       def inspect
         "#<#{self.class.name}:0x#{object_id.to_s(16)} " \

lib/cassandra/version.rb

@@ -17,5 +17,5 @@
 #++
 
 module Cassandra
-  VERSION = '3.0.4.rc.1'.freeze
+  VERSION = '3.1.0.rc.1'.freeze
 end