release v0.2.2

CHANGELOG.md

@@ -1,3 +1,14 @@
+## 0.2.2
+
+- Fix bug with refresh - typo would've prevented real use.
+- Clean up code.
+- Improve documentation a bit.
+- 100% test coverage.
+
+## 0.2.1
+
+- Fix bug when dealing with real-world Redis error conditions.
+
 ## 0.2.0
 
 - Refactor class methods into instance methods to simplify implementation.

README.md

@@ -1,4 +1,4 @@
-# Suo [![Build Status](https://travis-ci.org/nickelser/suo.svg?branch=master)](https://travis-ci.org/nickelser/suo) [![Gem Version](https://badge.fury.io/rb/suo.svg)](http://badge.fury.io/rb/suo)
+# Suo [![Build Status](https://travis-ci.org/nickelser/suo.svg?branch=master)](https://travis-ci.org/nickelser/suo) [![Code Climate](https://codeclimate.com/github/nickelser/suo/badges/gpa.svg)](https://codeclimate.com/github/nickelser/suo) [![Test Coverage](https://codeclimate.com/github/nickelser/suo/badges/coverage.svg)](https://codeclimate.com/github/nickelser/suo) [![Gem Version](https://badge.fury.io/rb/suo.svg)](http://badge.fury.io/rb/suo)
 
 :lock: Distributed semaphores using Memcached or Redis in Ruby.
 
@@ -41,16 +41,35 @@ Thread.new { suo.lock("other_key", 2) { puts "Three" } }
 suo = Suo::Client::Memcached.new(client: some_dalli_client, acquisition_timeout: 1) # in seconds
 
 # manually locking/unlocking
-suo.lock("a_key")
+# the return value from lock without a block is a unique token valid only for the current lock
+# which must be unlocked manually
+lock = suo.lock("a_key")
 foo.baz!
-suo.unlock("a_key")
+suo.unlock("a_key", lock)
 
-# custom stale lock cleanup (cleaning of dead clients)
+# custom stale lock expiration (cleaning of dead locks)
 suo = Suo::Client::Redis.new(client: some_redis_client, stale_lock_expiration: 60*5)
 ```
 
+### Stale locks
+
+"Stale locks" - those acquired more than `stale_lock_expiration` (defaulting to 3600 or one hour) ago - are automatically cleared during any operation on the key (`lock`, `unlock`, `refresh`). The `locked?` method will not return true if only stale locks exist, but will not modify the key itself.
+
+To re-acquire a lock in the middle of a block, you can use the refresh method on client.
+
+```ruby
+suo = Suo::Client::Redis.new
+
+# lock is the same token as seen in the manual example, above
+suo.lock("foo") do |lock|
+  5.times do
+    baz.bar!
+    suo.refresh("foo", lock)
+  end
+end
+```
+
 ## TODO
- - better stale key handling (refresh blocks)
  - more race condition tests
 
 ## History

lib/suo.rb

@@ -1,2 +1,16 @@
+require "securerandom"
+require "monitor"
+
+require "dalli"
+require "dalli/cas/client"
+
+require "redis"
+
+require "msgpack"
+
 require "suo/version"
-require "suo/clients"
+
+require "suo/errors"
+require "suo/client/base"
+require "suo/client/memcached"
+require "suo/client/redis"

lib/suo/client/base.rb

@@ -24,7 +24,7 @@ module Suo
 
         if block_given? && token
           begin
-            yield
+            yield(token)
           ensure
             unlock(key, token)
           end
@@ -39,9 +39,9 @@ module Suo
 
       def locks(key)
         val, _ = get(key)
-        locks = deserialize_locks(val)
+        cleared_locks = deserialize_and_clear_locks(val)
 
-        locks
+        cleared_locks
       end
 
       def refresh(key, acquisition_token)
@@ -49,15 +49,15 @@ module Suo
           val, cas = get(key)
 
           if val.nil?
-            set_initial(key)
+            initial_set(key)
             next
           end
 
-          locks = deserialize_and_clear_locks(val)
+          cleared_locks = deserialize_and_clear_locks(val)
 
-          refresh_lock(locks, acquisition_token)
+          refresh_lock(cleared_locks, acquisition_token)
 
-          break if set(key, serialize_locks(locks), cas)
+          break if set(key, serialize_locks(cleared_locks), cas)
         end
       end
 
@@ -69,12 +69,12 @@ module Suo
 
           break if val.nil?
 
-          locks = deserialize_and_clear_locks(val)
+          cleared_locks = deserialize_and_clear_locks(val)
 
-          acquisition_lock = remove_lock(locks, acquisition_token)
+          acquisition_lock = remove_lock(cleared_locks, acquisition_token)
 
           break unless acquisition_lock
-          break if set(key, serialize_locks(locks), cas)
+          break if set(key, serialize_locks(cleared_locks), cas)
         end
       rescue LockClientError => _ # rubocop:disable Lint/HandleExceptions
         # ignore - assume success due to optimistic locking
@@ -94,16 +94,16 @@ module Suo
           val, cas = get(key)
 
           if val.nil?
-            set_initial(key)
+            initial_set(key)
             next
           end
 
-          locks = deserialize_and_clear_locks(val)
+          cleared_locks = deserialize_and_clear_locks(val)
 
-          if locks.size < resources
-            add_lock(locks, token)
+          if cleared_locks.size < resources
+            add_lock(cleared_locks, token)
 
-            newval = serialize_locks(locks)
+            newval = serialize_locks(cleared_locks)
 
             if set(key, newval, cas)
               acquisition_token = token
@@ -119,11 +119,11 @@ module Suo
         fail NotImplementedError
       end
 
-      def set(key, newval, oldval) # rubocop:disable Lint/UnusedMethodArgument
+      def set(key, newval, cas) # rubocop:disable Lint/UnusedMethodArgument
         fail NotImplementedError
       end
 
-      def set_initial(key) # rubocop:disable Lint/UnusedMethodArgument
+      def initial_set(key, val = "") # rubocop:disable Lint/UnusedMethodArgument
         fail NotImplementedError
       end
 
@@ -162,7 +162,7 @@ module Suo
         unpacked.map do |time, token|
           [Time.at(time), token]
         end
-      rescue EOFError => _
+      rescue EOFError, MessagePack::MalformedFormatError => _
         []
       end
 
@@ -171,8 +171,8 @@ module Suo
         locks.reject { |time, _| time < expired }
       end
 
-      def add_lock(locks, token)
-        locks << [Time.now.to_f, token]
+      def add_lock(locks, token, time = Time.now.to_f)
+        locks << [time, token]
       end
 
       def remove_lock(locks, acquisition_token)
@@ -182,7 +182,7 @@ module Suo
 
       def refresh_lock(locks, acquisition_token)
         remove_lock(locks, acquisition_token)
-        add_lock(locks, token)
+        add_lock(locks, acquisition_token)
       end
     end
   end

lib/suo/client/memcached.rb

@@ -20,8 +20,8 @@ module Suo
         @client.set_cas(key, newval, cas)
       end
 
-      def set_initial(key)
-        @client.set(key, "")
+      def initial_set(key, val = "")
+        @client.set(key, val)
       end
     end
   end

lib/suo/client/redis.rb

@@ -21,7 +21,7 @@ module Suo
           multi.set(key, newval)
         end
 
-        ret[0] == "OK"
+        ret && ret[0] == "OK"
       end
 
       def synchronize(key)
@@ -32,8 +32,8 @@ module Suo
         @client.unwatch
       end
 
-      def set_initial(key)
-        @client.set(key, "")
+      def initial_set(key, val = "")
+        @client.set(key, val)
       end
     end
   end

lib/suo/clients.rb

@@ -1,14 +0,0 @@
-require "securerandom"
-require "monitor"
-
-require "dalli"
-require "dalli/cas/client"
-
-require "redis"
-
-require "msgpack"
-
-require "suo/errors"
-require "suo/client/base"
-require "suo/client/memcached"
-require "suo/client/redis"

lib/suo/version.rb

@@ -1,3 +1,3 @@
 module Suo
-  VERSION = "0.2.0"
+  VERSION = "0.2.2"
 end

suo.gemspec

@@ -30,4 +30,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake", "~> 10.0"
   spec.add_development_dependency "rubocop", "~> 0.30.0"
   spec.add_development_dependency "minitest", "~> 5.5.0"
+  spec.add_development_dependency "codeclimate-test-reporter", "~> 0.4.7"
 end

test/client_test.rb

@@ -3,6 +3,10 @@ require "test_helper"
 TEST_KEY = "suo_test_key".freeze
 
 module ClientTests
+  def client(options)
+    @client.class.new(options.merge(client: @client.client))
+  end
+
   def test_throws_failed_error_on_bad_client
     assert_raises(Suo::LockClientError) do
       client = @client.class.new(client: {})
@@ -10,7 +14,7 @@ module ClientTests
     end
   end
 
-  def test_class_single_resource_locking
+  def test_single_resource_locking
     lock1 = @client.lock(TEST_KEY, 1)
     refute_nil lock1
 
@@ -27,7 +31,24 @@ module ClientTests
     assert_equal false, locked
   end
 
-  def test_class_multiple_resource_locking
+  def test_empty_lock_on_invalid_data
+    @client.send(:initial_set, TEST_KEY, "bad value")
+    locked = @client.locked?(TEST_KEY)
+    assert_equal false, locked
+  end
+
+  def test_clear
+    lock1 = @client.lock(TEST_KEY, 1)
+    refute_nil lock1
+
+    @client.clear(TEST_KEY)
+
+    locked = @client.locked?(TEST_KEY, 1)
+
+    assert_equal false, locked
+  end
+
+  def test_multiple_resource_locking
     lock1 = @client.lock(TEST_KEY, 2)
     refute_nil lock1
 
@@ -72,8 +93,9 @@ module ClientTests
     output = Queue.new
     threads = []
 
-    threads << Thread.new { @client.lock(TEST_KEY, 2) { output << "One"; sleep 2 } }
-    threads << Thread.new { @client.lock(TEST_KEY, 2) { output << "Two"; sleep 2 } }
+    threads << Thread.new { @client.lock(TEST_KEY, 2) { output << "One"; sleep 0.5 } }
+    threads << Thread.new { @client.lock(TEST_KEY, 2) { output << "Two"; sleep 0.5 } }
+    sleep 0.1
     threads << Thread.new { @client.lock(TEST_KEY, 2) { output << "Three" } }
 
     threads.map(&:join)
@@ -86,18 +108,19 @@ module ClientTests
     ret.sort!
 
     assert_equal 0, output.size
-    assert_equal ["One", "Two"], ret
+    assert_equal %w(One Two), ret
+    assert_equal false, @client.locked?(TEST_KEY)
   end
 
-  def test_instance_multiple_resource_locking
+  def test_block_multiple_resource_locking
     success_counter = Queue.new
     failure_counter = Queue.new
 
-    client = @client.class.new(acquisition_timeout: 0.9, client: @client.client)
+    client = client(acquisition_timeout: 0.9)
 
     100.times.map do |i|
       Thread.new do
-        success = @client.lock(TEST_KEY, 50) do
+        success = client.lock(TEST_KEY, 50) do
           sleep(3)
           success_counter << i
         end
@@ -108,13 +131,14 @@ module ClientTests
 
     assert_equal 50, success_counter.size
     assert_equal 50, failure_counter.size
+    assert_equal false, client.locked?(TEST_KEY)
   end
 
-  def test_instance_multiple_resource_locking_longer_timeout
+  def test_block_multiple_resource_locking_longer_timeout
     success_counter = Queue.new
     failure_counter = Queue.new
 
-    client = @client.class.new(acquisition_timeout: 3, client: @client.client)
+    client = client(acquisition_timeout: 3)
 
     100.times.map do |i|
       Thread.new do
@@ -129,6 +153,153 @@ module ClientTests
 
     assert_equal 100, success_counter.size
     assert_equal 0, failure_counter.size
+    assert_equal false, client.locked?(TEST_KEY)
+  end
+
+  def test_unstale_lock_acquisition
+    success_counter = Queue.new
+    failure_counter = Queue.new
+
+    client = client(stale_lock_expiration: 0.5)
+
+    t1 = Thread.new { client.lock(TEST_KEY) { sleep 0.6; success_counter << 1 } }
+    sleep 0.3
+    t2 = Thread.new do
+      locked = client.lock(TEST_KEY) { success_counter << 1 }
+      failure_counter << 1 unless locked
+    end
+
+    [t1, t2].map(&:join)
+
+    assert_equal 1, success_counter.size
+    assert_equal 1, failure_counter.size
+    assert_equal false, client.locked?(TEST_KEY)
+  end
+
+  def test_stale_lock_acquisition
+    success_counter = Queue.new
+    failure_counter = Queue.new
+
+    client = client(stale_lock_expiration: 0.5)
+
+    t1 = Thread.new { client.lock(TEST_KEY) { sleep 0.6; success_counter << 1 } }
+    sleep 0.55
+    t2 = Thread.new do
+      locked = client.lock(TEST_KEY) { success_counter << 1 }
+      failure_counter << 1 unless locked
+    end
+
+    [t1, t2].map(&:join)
+
+    assert_equal 2, success_counter.size
+    assert_equal 0, failure_counter.size
+    assert_equal false, client.locked?(TEST_KEY)
+  end
+
+  def test_refresh
+    client = client(stale_lock_expiration: 0.5)
+
+    lock1 = client.lock(TEST_KEY)
+
+    assert_equal true, client.locked?(TEST_KEY)
+
+    client.refresh(TEST_KEY, lock1)
+
+    assert_equal true, client.locked?(TEST_KEY)
+
+    sleep 0.55
+
+    assert_equal false, client.locked?(TEST_KEY)
+
+    lock2 = client.lock(TEST_KEY)
+
+    client.refresh(TEST_KEY, lock1)
+
+    assert_equal true, client.locked?(TEST_KEY)
+
+    client.unlock(TEST_KEY, lock1)
+
+    # edge case with refresh lock in the middle
+    assert_equal true, client.locked?(TEST_KEY)
+
+    client.clear(TEST_KEY)
+
+    assert_equal false, client.locked?(TEST_KEY)
+
+    client.refresh(TEST_KEY, lock2)
+
+    assert_equal true, client.locked?(TEST_KEY)
+
+    client.unlock(TEST_KEY, lock2)
+
+    # now finally unlocked
+    assert_equal false, client.locked?(TEST_KEY)
+  end
+
+  def test_block_refresh
+    success_counter = Queue.new
+    failure_counter = Queue.new
+
+    client = client(stale_lock_expiration: 0.5)
+
+    t1 = Thread.new do
+      client.lock(TEST_KEY) do |token|
+        sleep 0.6
+        client.refresh(TEST_KEY, token)
+        sleep 1
+        success_counter << 1
+      end
+    end
+
+    t2 = Thread.new do
+      sleep 0.8
+      locked = client.lock(TEST_KEY) { success_counter << 1 }
+      failure_counter << 1 unless locked
+    end
+
+    [t1, t2].map(&:join)
+
+    assert_equal 1, success_counter.size
+    assert_equal 1, failure_counter.size
+    assert_equal false, client.locked?(TEST_KEY)
+  end
+
+  def test_refresh_multi
+    success_counter = Queue.new
+    failure_counter = Queue.new
+
+    client = client(stale_lock_expiration: 0.5)
+
+    t1 = Thread.new do
+      client.lock(TEST_KEY, 2) do |token|
+        sleep 0.4
+        client.refresh(TEST_KEY, token)
+        success_counter << 1
+        sleep 0.5
+      end
+    end
+
+    t2 = Thread.new do
+      sleep 0.55
+      locked = client.lock(TEST_KEY, 2) do
+        success_counter << 1
+        sleep 0.5
+      end
+
+      failure_counter << 1 unless locked
+    end
+
+    t3 = Thread.new do
+      sleep 0.75
+      locked = client.lock(TEST_KEY, 2) { success_counter << 1 }
+      failure_counter << 1 unless locked
+    end
+
+    [t1, t2, t3].map(&:join)
+
+    assert_equal 2, success_counter.size
+    assert_equal 1, failure_counter.size
+    assert_equal false, client.locked?(TEST_KEY)
   end
 end
 
@@ -141,6 +312,18 @@ class TestBaseClient < Minitest::Test
     assert_raises(NotImplementedError) do
       @client.send(:get, TEST_KEY)
     end
+
+    assert_raises(NotImplementedError) do
+      @client.send(:set, TEST_KEY, "", "")
+    end
+
+    assert_raises(NotImplementedError) do
+      @client.send(:initial_set, TEST_KEY)
+    end
+
+    assert_raises(NotImplementedError) do
+      @client.send(:clear, TEST_KEY)
+    end
   end
 end
 
@@ -150,6 +333,7 @@ class TestMemcachedClient < Minitest::Test
   def setup
     @dalli = Dalli::Client.new("127.0.0.1:11211")
     @client = Suo::Client::Memcached.new
+    teardown
   end
 
   def teardown
@@ -163,6 +347,7 @@ class TestRedisClient < Minitest::Test
   def setup
     @redis = Redis.new
     @client = Suo::Client::Redis.new
+    teardown
   end
 
   def teardown

test/test_helper.rb

@@ -1,9 +1,13 @@
 $LOAD_PATH.unshift File.expand_path("../../lib", __FILE__)
 
+if ENV["CODECLIMATE_REPO_TOKEN"]
+  require "codeclimate-test-reporter"
+  CodeClimate::TestReporter.start
+end
+
 require "suo"
 require "thread"
 require "minitest/autorun"
 require "minitest/benchmark"
 
 ENV["SUO_TEST"] = "true"
-