Merge 23e5740 into 4779a6c

README.md

@@ -168,6 +168,16 @@ if UNLEASH.is_enabled? "AwesomeFeature", @unleash_context, true
 end
 ```
 
+#### Client methods
+
+Method Name | Description | Return Type |
+---------|-------------|-------------|
+`is_enabled?` | Check if feature toggle is to be enabled or not. | Boolean |
+`enabled?` | Alias to the `is_enabled?` method. But more ruby idiomatic. | Boolean |
+`shutdown` | Save metrics to disk, flush metrics to server, and then kill ToggleFetcher and MetricsReporter threads. A safe shutdown. Not really useful in long running applications, like web applications. | nil |
+`shutdown!` | Kill ToggleFetcher and MetricsReporter threads immediately. | nil |
+
+
 ## Local test client
 
 ```

examples/simple.rb

@@ -50,4 +50,12 @@
   puts "> #{feature_name} is not enabled"
 end
 
+puts "> shutting down client..."
+
+@unleash.shutdown
+
+sleep 1
+
 puts ">> END simple.rb"
+
+

lib/unleash/client.rb

@@ -1,13 +1,16 @@
 require 'unleash/configuration'
 require 'unleash/toggle_fetcher'
 require 'unleash/metrics_reporter'
+require 'unleash/scheduled_executor'
 require 'unleash/feature_toggle'
 require 'logger'
 require 'time'
 
 module Unleash
 
   class Client
+    attr_accessor :fetcher_scheduled_executor, :metrics_scheduled_executor
+
     def initialize(*opts)
       Unleash.configuration ||= Unleash::Configuration.new(*opts)
       Unleash.configuration.validate!
@@ -17,13 +20,19 @@ def initialize(*opts)
 
       unless Unleash.configuration.disable_client
         Unleash.toggle_fetcher = Unleash::ToggleFetcher.new
+
         register
 
+        self.fetcher_scheduled_executor = Unleash::ScheduledExecutor.new('ToggleFetcher', Unleash.configuration.refresh_interval)
+        self.fetcher_scheduled_executor.run do
+          Unleash.toggle_fetcher.fetch
+        end
+
         unless Unleash.configuration.disable_metrics
           Unleash.toggle_metrics = Unleash::Metrics.new
           Unleash.reporter = Unleash::MetricsReporter.new
-          scheduledExecutor = Unleash::ScheduledExecutor.new('MetricsReporter', Unleash.configuration.metrics_interval)
-          scheduledExecutor.run do
+          self.metrics_scheduled_executor = Unleash::ScheduledExecutor.new('MetricsReporter', Unleash.configuration.metrics_interval)
+          self.metrics_scheduled_executor.run do
             Unleash.reporter.send
           end
         end
@@ -53,6 +62,27 @@ def is_enabled?(feature, context = nil, default_value = false)
         return toggle_result
     end
 
+    # enabled? is a more ruby idiomatic method name than is_enabled?
+    alias_method :enabled?, :is_enabled?
+
+
+    # safe shutdown: also flush metrics to server and toggles to disk
+    def shutdown
+      unless Unleash.configuration.disable_client
+        Unleash.toggle_fetcher.save!
+        Unleash.reporter.send unless Unleash.configuration.disable_metrics
+        shutdown!
+      end
+    end
+
+    # quick shutdown: just kill running threads
+    def shutdown!
+      unless Unleash.configuration.disable_client
+        self.fetcher_scheduled_executor.exit
+        self.metrics_scheduled_executor.exit unless Unleash.configuration.disable_metrics
+      end
+    end
+
     private
     def info
       return {

lib/unleash/metrics_reporter.rb

@@ -7,15 +7,12 @@
 module Unleash
 
   class MetricsReporter
-    attr_accessor :last_time, :client
+    attr_accessor :last_time
 
     def initialize
       self.last_time = Time.now
     end
 
-    def build_hash
-    end
-
     def generate_report
       now = Time.now
       start, stop, self.last_time = self.last_time, now, now

lib/unleash/scheduled_executor.rb

@@ -1,17 +1,18 @@
 module Unleash
 
   class ScheduledExecutor
-    attr_accessor :name, :interval, :max_exceptions, :retry_count
+    attr_accessor :name, :interval, :max_exceptions, :retry_count, :thread
 
     def initialize(name, interval, max_exceptions = 5)
       self.name = name || ''
       self.interval = interval
       self.max_exceptions = max_exceptions
       self.retry_count = 0
+      self.thread = nil
     end
 
     def run(&blk)
-      thread = Thread.new do
+      self.thread = Thread.new do
         Thread.current[:name] = self.name
 
         loop do
@@ -29,11 +30,22 @@ def run(&blk)
           end
 
           if self.retry_count > self.max_exceptions
-            Unleash.logger.info "thread #{name} retry_count (#{self.retry_count}) exceeded max_exceptions (#{self.max_exceptions}). Stopping with retries."
+            Unleash.logger.error "thread #{name} retry_count (#{self.retry_count}) exceeded max_exceptions (#{self.max_exceptions}). Stopping with retries."
             break
           end
         end
-        Unleash.logger.info "thread #{name} ended"
+        Unleash.logger.warn "thread #{name} loop ended"
+      end
+    end
+
+    def running?
+      self.thread.is_a?(Thread) && self.thread.alive?
+    end
+
+    def exit
+      if self.running?
+        Unleash.logger.warn "thread #{name} will exit!"
+        self.thread.exit
       end
     end
   end

lib/unleash/toggle_fetcher.rb

@@ -1,5 +1,4 @@
 require 'unleash/configuration'
-require 'unleash/scheduled_executor'
 require 'net/http'
 require 'json'
 require 'thread'
@@ -24,9 +23,7 @@ def initialize
         read!
       end
 
-      # once we have initialized, start the fetcher loop
-      scheduledExecutor = Unleash::ScheduledExecutor.new('ToggleFetcher', Unleash.configuration.refresh_interval)
-      scheduledExecutor.run { remote_toggles = fetch() }
+      # once initialized, somewhere else you will want to start a loop with fetch()
     end
 
     def toggles
@@ -38,7 +35,7 @@ def toggles
     end
 
     # rename to refresh_from_server!  ??
-    # TODO: should simplify by moving uri / http initialization to class initialization
+    # TODO: should simplify by moving uri / http initialization elsewhere
     def fetch
       Unleash.logger.debug "fetch()"
       Unleash.logger.debug "ETag: #{self.etag}" unless self.etag.nil?
@@ -82,6 +79,27 @@ def fetch
       save!
     end
 
+    def save!
+      begin
+        backup_file = Unleash.configuration.backup_file
+        backup_file_tmp = "#{backup_file}.tmp"
+
+        self.toggle_lock.synchronize do
+          file = File.open(backup_file_tmp, "w")
+          file.write(self.toggle_cache.to_json)
+          File.rename(backup_file_tmp, backup_file)
+        end
+
+      rescue Exception => e
+        # This is not really the end of the world. Swallowing the exception.
+        Unleash.logger.error "Unable to save backup file. Exception thrown #{e.class}:'#{e}'"
+        Unleash.logger.error "stacktrace: #{e.backtrace}"
+      ensure
+        file.close unless file.nil?
+        self.toggle_lock.unlock if self.toggle_lock.locked?
+      end
+    end
+
     private
 
     def synchronize_with_local_cache!(features)
@@ -102,29 +120,9 @@ def update_client!
       end
     end
 
-    def backup_file_exists?
-      File.exists?(backup_file)
-    end
-
-    def save!
-      begin
-        file = File.open(Unleash.configuration.backup_file, "w")
-
-        self.toggle_lock.synchronize do
-          file.write(self.toggle_cache.to_json)
-        end
-      rescue Exception => e
-        # This is not really the end of the world. Swallowing the exception.
-        Unleash.logger.error "Unable to save backup file. Exception thrown #{e.class}:'#{e}'"
-        Unleash.logger.error "stacktrace: #{e.backtrace}"
-      ensure
-        file.close unless file.nil?
-      end
-    end
-
     def read!
       Unleash.logger.debug "read!()"
-      return nil unless File.exists?(Unleash.configuration.backup_file)
+      return nil unless File.exist?(Unleash.configuration.backup_file)
 
       begin
         file = File.open(Unleash.configuration.backup_file, "r")

spec/unleash/scheduled_executor_spec.rb

@@ -0,0 +1,18 @@
+require 'spec_helper'
+
+RSpec.describe Unleash::ScheduledExecutor do
+  # context 'parameters correctly assigned in initialization'
+  it "can start and exit a thread" do
+    scheduled_executor = Unleash::ScheduledExecutor.new('TesterLoop', 0.1)
+    scheduled_executor.run do
+      loop do
+        sleep 0.1
+      end
+    end
+
+    expect(scheduled_executor.running?).to be true
+    scheduled_executor.exit
+    scheduled_executor.thread.join
+    expect(scheduled_executor.running?).to be false
+  end
+end