Merge pull request #65 from launchdarkly/eb/ch18860/fail-fast-init

fail fast in initialization if there's a 401

Author: eli-darkly

ldclient-rb.gemspec

@@ -56,6 +56,4 @@ Gem::Specification.new do |spec|
   else
     spec.add_runtime_dependency "nio4r", "~> 1.1" # for maximum ruby version compatibility.
   end
-
-  spec.add_runtime_dependency "waitutil", "0.2"
 end

lib/ldclient-rb/ldclient.rb

@@ -1,7 +1,7 @@
+require "concurrent/atomics"
 require "digest/sha1"
 require "logger"
 require "benchmark"
-require "waitutil"
 require "json"
 require "openssl"
 
@@ -41,7 +41,9 @@ def initialize(sdk_key, config = Config.default, wait_for_sec = 5)
 
       requestor = Requestor.new(sdk_key, config)
 
-      if !@config.offline?
+      if @config.offline?
+        @update_processor = NullUpdateProcessor.new
+      else
         if @config.update_processor.nil?
           if @config.stream?
             @update_processor = StreamProcessor.new(sdk_key, config, requestor)
@@ -53,16 +55,15 @@ def initialize(sdk_key, config = Config.default, wait_for_sec = 5)
         else
           @update_processor = @config.update_processor
         end
-        @update_processor.start
       end
 
-      if !@config.offline? && wait_for_sec > 0
-        begin
-          WaitUtil.wait_for_condition("LaunchDarkly client initialization", timeout_sec: wait_for_sec, delay_sec: 0.1) do
-            initialized?
-          end
-        rescue WaitUtil::TimeoutError
+      ready = @update_processor.start
+      if wait_for_sec > 0
+        ok = ready.wait(wait_for_sec)
+        if !ok
           @config.logger.error { "[LDClient] Timeout encountered waiting for LaunchDarkly client initialization" }
+        elsif !@update_processor.initialized?
+          @config.logger.error { "[LDClient] LaunchDarkly client initialization failed" }
         end
       end
     end
@@ -220,9 +221,7 @@ def all_flags(user)
     # @return [void]
     def close
       @config.logger.info { "[LDClient] Closing LaunchDarkly client..." }
-      if not @config.offline?
-        @update_processor.stop
-      end
+      @update_processor.stop
       @event_processor.stop
       @store.stop
     end
@@ -255,4 +254,22 @@ def make_feature_event(flag, user, variation, value, default)
 
     private :evaluate, :log_exception, :sanitize_user, :make_feature_event
   end
+
+  #
+  # Used internally when the client is offline.
+  #
+  class NullUpdateProcessor
+    def start
+      e = Concurrent::Event.new
+      e.set
+      e
+    end
+
+    def initialized?
+      true
+    end
+
+    def stop
+    end
+  end
 end

lib/ldclient-rb/polling.rb

@@ -9,16 +9,18 @@ def initialize(config, requestor)
       @initialized = Concurrent::AtomicBoolean.new(false)
       @started = Concurrent::AtomicBoolean.new(false)
       @stopped = Concurrent::AtomicBoolean.new(false)
+      @ready = Concurrent::Event.new
     end
 
     def initialized?
       @initialized.value
     end
 
     def start
-      return unless @started.make_true
+      return @ready unless @started.make_true
       @config.logger.info { "[LDClient] Initializing polling connection" }
       create_worker
+      @ready
     end
 
     def stop
@@ -39,6 +41,7 @@ def poll
         })
         if @initialized.make_true
           @config.logger.info { "[LDClient] Polling connection initialized" }
+          @ready.set
         end
       end
     end
@@ -56,6 +59,7 @@ def create_worker
             end
           rescue InvalidSDKKeyError
             @config.logger.error { "[LDClient] Received 401 error, no further polling requests will be made since SDK key is invalid" };
+            @ready.set  # if client was waiting on us, make it stop waiting - has no effect if already set
             stop
           rescue StandardError => exn
             @config.logger.error { "[LDClient] Exception while polling: #{exn.inspect}" }

lib/ldclient-rb/stream.rb

@@ -24,14 +24,15 @@ def initialize(sdk_key, config, requestor)
       @initialized = Concurrent::AtomicBoolean.new(false)
       @started = Concurrent::AtomicBoolean.new(false)
       @stopped = Concurrent::AtomicBoolean.new(false)
+      @ready = Concurrent::Event.new
     end
 
     def initialized?
       @initialized.value
     end
 
     def start
-      return unless @started.make_true
+      return @ready unless @started.make_true
 
       @config.logger.info { "[LDClient] Initializing stream connection" }
 
@@ -51,10 +52,13 @@ def start
           @config.logger.error { "[LDClient] Unexpected status code #{err[:status_code]} from streaming connection" }
           if err[:status_code] == 401
             @config.logger.error { "[LDClient] Received 401 error, no further streaming connection will be made since SDK key is invalid" }
+            @ready.set  # if client was waiting on us, make it stop waiting - has no effect if already set
             stop
           end
         }
       end
+      
+      @ready
     end
 
     def stop
@@ -83,6 +87,7 @@ def process_message(message, method)
         })
         @initialized.make_true
         @config.logger.info { "[LDClient] Stream initialized" }
+        @ready.set
       elsif method == PATCH
         message = JSON.parse(message.data, symbolize_names: true)
         for kind in [FEATURES, SEGMENTS]

spec/ldclient_spec.rb

@@ -7,7 +7,7 @@
   let(:offline_client) do
     subject.new("secret", offline_config)
   end
-  let(:update_processor) { NullUpdateProcessor.new }
+  let(:update_processor) { LaunchDarkly::NullUpdateProcessor.new }
   let(:config) { LaunchDarkly::Config.new({send_events: false, update_processor: update_processor}) }
   let(:client) do
     subject.new("secret", config)
@@ -160,13 +160,4 @@ def event_processor
       expect(ep).not_to be_a(LaunchDarkly::NullEventProcessor)
     end
   end
-
-  class NullUpdateProcessor
-    def start
-    end
-
-    def initialized?
-      true
-    end
-  end
 end