use 'retry' option to customize max retry attempts

e.g.
{ 'class' => 'HardWorker', 'args' => [1, 2, 'foo'], 'retry' => 5 }

Addresses Issue #313

lib/sidekiq/middleware/server/retry_jobs.rb

@@ -20,6 +20,13 @@ module Sidekiq
       #
       #     { 'class' => 'HardWorker', 'args' => [1, 2, 'foo'] }
       #
+      # The 'retry' option also accepts a number (in place of 'true'):
+      #
+      #     { 'class' => 'HardWorker', 'args' => [1, 2, 'foo'], 'retry' => 5 }
+      #
+      # The job will be retried this number of times before giving up. (If simply
+      # 'true', Sidekiq retries 25 times)
+      #
       # We'll add a bit more data to the message to support retries:
       #
       #  * 'queue' - the queue to use
@@ -35,13 +42,14 @@ module Sidekiq
         include Sidekiq::Util
 
         # delayed_job uses the same basic formula
-        MAX_COUNT = 25
+        DEFAULT_MAX_RETRY_ATTEMPTS = 25
         DELAY = proc { |count| (count ** 4) + 15 }
 
         def call(worker, msg, queue)
           yield
         rescue Exception => e
           raise e unless msg['retry']
+          max_retry_attempts = retry_attempts_from(msg['retry'], DEFAULT_MAX_RETRY_ATTEMPTS)
 
           msg['queue'] = queue
           msg['error_message'] = e.message
@@ -60,7 +68,7 @@ module Sidekiq
             msg['error_backtrace'] = e.backtrace[0..msg['backtrace'].to_i]
           end
 
-          if count <= MAX_COUNT
+          if count <= max_retry_attempts
             delay = DELAY.call(count)
             logger.debug { "Failure! Retry #{count} in #{delay} seconds" }
             retry_at = Time.now.to_f + delay
@@ -75,6 +83,14 @@ module Sidekiq
           raise e
         end
 
+        def retry_attempts_from(msg_retry, default)
+          if msg_retry.is_a?(Fixnum)
+            msg_retry
+          else
+            default
+          end
+        end
+
       end
     end
   end

test/test_retry.rb

@@ -88,7 +88,25 @@ class TestRetry < MiniTest::Unit::TestCase
       @redis.verify
     end
 
-    it 'throws away old messages after too many retries' do
+    it 'handles a recurring failed message before reaching user-specifed max' do
+      @redis.expect :zadd, 1, ['retry', String, String]
+      now = Time.now.utc
+      msg = {"class"=>"Bob", "args"=>[1, 2, "foo"], 'retry' => 11, "queue"=>"default", "error_message"=>"kerblammo!", "error_class"=>"RuntimeError", "failed_at"=>now, "retry_count"=>10}
+      handler = Sidekiq::Middleware::Server::RetryJobs.new
+      assert_raises RuntimeError do
+        handler.call('', msg, 'default') do
+          raise "kerblammo!"
+        end
+      end
+      assert_equal 'default', msg["queue"]
+      assert_equal 'kerblammo!', msg["error_message"]
+      assert_equal 'RuntimeError', msg["error_class"]
+      assert_equal 11, msg["retry_count"]
+      assert msg["failed_at"]
+      @redis.verify
+    end
+
+    it 'throws away old messages after too many retries (using the default)' do
       now = Time.now.utc
       msg = {"class"=>"Bob", "args"=>[1, 2, "foo"], "queue"=>"default", "error_message"=>"kerblammo!", "error_class"=>"RuntimeError", "failed_at"=>now, "retry"=>true, "retry_count"=>25}
       @redis.expect :zadd, 1, [ 'retry', String, String ]
@@ -101,6 +119,20 @@ class TestRetry < MiniTest::Unit::TestCase
       # MiniTest can't assert that a method call did NOT happen!?
       assert_raises(MockExpectationError) { @redis.verify }
     end
+
+    it 'throws away old messages after too many retries (using user-specified max)' do
+      now = Time.now.utc
+      msg = {"class"=>"Bob", "args"=>[1, 2, "foo"], "queue"=>"default", "error_message"=>"kerblammo!", "error_class"=>"RuntimeError", "failed_at"=>now, "retry"=>3, "retry_count"=>3}
+      @redis.expect :zadd, 1, [ 'retry', String, String ]
+      handler = Sidekiq::Middleware::Server::RetryJobs.new
+      assert_raises RuntimeError do
+        handler.call('', msg, 'default') do
+          raise "kerblammo!"
+        end
+      end
+      # MiniTest can't assert that a method call did NOT happen!?
+      assert_raises(MockExpectationError) { @redis.verify }
+    end
   end
 
   describe 'poller' do