Improved index caching [skip ci]

Andrew Kane
1 parent 62e98f89
Showing 4 changed files with 82 additions and 2 deletions Show diff stats
lib/searchkick.rb
lib/searchkick/index_cache.rb
lib/searchkick/model.rb
test/index_cache_test.rb
@@ -12,6 +12,7 @@ require &quot;forwardable&quot;
 # modules
 require "searchkick/controller_runtime"
 require "searchkick/index"
+require "searchkick/index_cache"
 require "searchkick/index_options"
 require "searchkick/indexer"
 require "searchkick/hash_wrapper"
@@ -0,0 +1,30 @@
+module Searchkick
+  class IndexCache
+    def initialize(max_size: 20)
+      @data = {}
+      @mutex = Mutex.new
+      @max_size = max_size
+    end
+
+    # probably a better pattern for this
+    # but keep it simple
+    def fetch(name)
+      # thread-safe in MRI without mutex
+      # due to how context switching works
+      @mutex.synchronize do
+        if @data.key?(name)
+          @data[name]
+        else
+          @data.clear if @data.size >= @max_size
+          @data[name] = yield
+        end
+      end
+    end
+
+    def clear
+      @mutex.synchronize do
+        @data.clear
+      end
+    end
+  end
+end
@@ -55,7 +55,7 @@ module Searchkick
  
         class_variable_set :@@searchkick_options, options.dup
         class_variable_set :@@searchkick_klass, self
-        class_variable_set :@@searchkick_index_cache, {}
+        class_variable_set :@@searchkick_index_cache, Searchkick::IndexCache.new
  
         class << self
           def searchkick_search(term = "*", **options, &block)
@@ -71,7 +71,7 @@ module Searchkick
             index = name || searchkick_index_name
             index = index.call if index.respond_to?(:call)
             index_cache = class_variable_get(:@@searchkick_index_cache)
-            index_cache[index] ||= Searchkick::Index.new(index, searchkick_options)
+            index_cache.fetch(index) { Searchkick::Index.new(index, searchkick_options) }
           end
           alias_method :search_index, :searchkick_index unless method_defined?(:search_index)
  
@@ -0,0 +1,49 @@
+require_relative "test_helper"
+
+class IndexCacheTest < Minitest::Test
+  def setup
+    Product.class_variable_get(:@@searchkick_index_cache).clear
+  end
+
+  def test_default
+    object_id = Product.search_index.object_id
+    3.times do
+      assert_equal object_id, Product.search_index.object_id
+    end
+  end
+
+  def test_max_size
+    starting_ids = object_ids(20)
+    assert_equal starting_ids, object_ids(20)
+    Product.search_index(name: "other")
+    refute_equal starting_ids, object_ids(20)
+  end
+
+  def test_thread_safe
+    object_ids = with_threads { object_ids(20) }
+    assert_equal object_ids[0], object_ids[1]
+    assert_equal object_ids[0], object_ids[2]
+  end
+
+  # object ids can differ since threads progress at different speeds
+  # test to make sure doesn't crash
+  def test_thread_safe_max_size
+    with_threads { object_ids(1000) }
+  end
+
+  private
+
+  def object_ids(count)
+    count.times.map { |i| Product.search_index(name: "index#{i}").object_id }
+  end
+
+  def with_threads
+    previous = Thread.report_on_exception
+    begin
+      Thread.report_on_exception = true
+      3.times.map { Thread.new { yield } }.map(&:join).map(&:value)
+    ensure
+      Thread.report_on_exception = previous
+    end
+  end
+end
...	...	@@ -12,6 +12,7 @@ require "forwardable"
12	12	# modules
13	13	require "searchkick/controller_runtime"
14	14	require "searchkick/index"
	15	+require "searchkick/index_cache"
15	16	require "searchkick/index_options"
16	17	require "searchkick/indexer"
17	18	require "searchkick/hash_wrapper"
...	...
...	...	@@ -0,0 +1,30 @@
	1	+module Searchkick
	2	+ class IndexCache
	3	+ def initialize(max_size: 20)
	4	+ @data = {}
	5	+ @mutex = Mutex.new
	6	+ @max_size = max_size
	7	+ end
	8	+
	9	+ # probably a better pattern for this
	10	+ # but keep it simple
	11	+ def fetch(name)
	12	+ # thread-safe in MRI without mutex
	13	+ # due to how context switching works
	14	+ @mutex.synchronize do
	15	+ if @data.key?(name)
	16	+ @data[name]
	17	+ else
	18	+ @data.clear if @data.size >= @max_size
	19	+ @data[name] = yield
	20	+ end
	21	+ end
	22	+ end
	23	+
	24	+ def clear
	25	+ @mutex.synchronize do
	26	+ @data.clear
	27	+ end
	28	+ end
	29	+ end
	30	+end
...	...
...	...	@@ -55,7 +55,7 @@ module Searchkick
55	55
56	56	class_variable_set :@@searchkick_options, options.dup
57	57	class_variable_set :@@searchkick_klass, self
58		- class_variable_set :@@searchkick_index_cache, {}
	58	+ class_variable_set :@@searchkick_index_cache, Searchkick::IndexCache.new
59	59
60	60	class << self
61	61	def searchkick_search(term = "", *options, &block)
...	...	@@ -71,7 +71,7 @@ module Searchkick
71	71	index = name \|\| searchkick_index_name
72	72	index = index.call if index.respond_to?(:call)
73	73	index_cache = class_variable_get(:@@searchkick_index_cache)
74		- index_cache[index] \|\|= Searchkick::Index.new(index, searchkick_options)
	74	+ index_cache.fetch(index) { Searchkick::Index.new(index, searchkick_options) }
75	75	end
76	76	alias_method :search_index, :searchkick_index unless method_defined?(:search_index)
77	77
...	...
...	...	@@ -0,0 +1,49 @@
	1	+require_relative "test_helper"
	2	+
	3	+class IndexCacheTest < Minitest::Test
	4	+ def setup
	5	+ Product.class_variable_get(:@@searchkick_index_cache).clear
	6	+ end
	7	+
	8	+ def test_default
	9	+ object_id = Product.search_index.object_id
	10	+ 3.times do
	11	+ assert_equal object_id, Product.search_index.object_id
	12	+ end
	13	+ end
	14	+
	15	+ def test_max_size
	16	+ starting_ids = object_ids(20)
	17	+ assert_equal starting_ids, object_ids(20)
	18	+ Product.search_index(name: "other")
	19	+ refute_equal starting_ids, object_ids(20)
	20	+ end
	21	+
	22	+ def test_thread_safe
	23	+ object_ids = with_threads { object_ids(20) }
	24	+ assert_equal object_ids[0], object_ids[1]
	25	+ assert_equal object_ids[0], object_ids[2]
	26	+ end
	27	+
	28	+ # object ids can differ since threads progress at different speeds
	29	+ # test to make sure doesn't crash
	30	+ def test_thread_safe_max_size
	31	+ with_threads { object_ids(1000) }
	32	+ end
	33	+
	34	+ private
	35	+
	36	+ def object_ids(count)
	37	+ count.times.map { \|i\| Product.search_index(name: "index#{i}").object_id }
	38	+ end
	39	+
	40	+ def with_threads
	41	+ previous = Thread.report_on_exception
	42	+ begin
	43	+ Thread.report_on_exception = true
	44	+ 3.times.map { Thread.new { yield } }.map(&:join).map(&:value)
	45	+ ensure
	46	+ Thread.report_on_exception = previous
	47	+ end
	48	+ end
	49	+end
...	...