Add expire methods by key values

lib/identity_cache.rb

@@ -67,6 +67,8 @@ class DerivedModelError < StandardError; end
 
   class LockWaitTimeout < StandardError; end
 
+  class MissingKeyName < StandardError ; end
+
   mattr_accessor :cache_namespace
   self.cache_namespace = "IDC:#{CACHE_VERSION}:"
 

lib/identity_cache/cached/attribute.rb

@@ -47,6 +47,19 @@ def expire(record)
         end
       end
 
+      def expire_by_key_value(key_values)
+        missing_keys = missing_keys(key_values)
+        unless missing_keys.empty?
+          raise MissingKeyName,
+            "#{model.name} attribute #{alias_name} expire_by_key_value - "\
+            "required fields: #{key_fields.join(", ")}. "\
+            "missing: #{missing_keys.join(", ")}"
+        end
+
+        key = cache_key_by_values(key_values)
+        IdentityCache.cache.delete(key)
+      end
+
       def cache_key(index_key)
         values_hash = IdentityCache.memcache_hash(unhashed_values_cache_key_string(index_key))
         "#{model.rails_cache_key_namespace}#{cache_key_prefix}#{values_hash}"
@@ -100,6 +113,11 @@ def new_cache_key(record)
         cache_key_from_key_values(new_key_values)
       end
 
+      def cache_key_by_values(key_values)
+        new_key_values = key_fields.map { |field| key_values[field] }
+        cache_key_from_key_values(new_key_values)
+      end
+
       def old_cache_key(record)
         old_key_values = key_fields.map do |field|
           field_string = field.to_s
@@ -118,6 +136,10 @@ def old_cache_key(record)
       def fetch_method_suffix
         "#{alias_name}_by_#{key_fields.join("_and_")}"
       end
+
+      def missing_keys(key_values)
+        key_fields - key_values.keys
+      end
     end
   end
 end

test/expire_by_key_values_test.rb

@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+require "test_helper"
+
+class ExpireByKeyValuesTest < IdentityCache::TestCase
+  NAMESPACE = IdentityCache::CacheKeyGeneration::DEFAULT_NAMESPACE
+
+  def setup
+    super
+    AssociatedRecord.cache_attribute(:name)
+    AssociatedRecord.cache_attribute(:name, by: :item_id)
+    AssociatedRecord.cache_attribute(:name, by: [:id, :item_id])
+
+    @parent = Item.create!(title: "bob")
+    @record = @parent.associated_records.create!(name: "foo")
+    @name_attribute_key = "#{NAMESPACE}attr:AssociatedRecord:name:id:#{cache_hash(@record.id.to_s.inspect)}"
+    IdentityCache.cache.clear
+  end
+
+  def test_expire_by_key_values
+    assert_queries(3) do
+      assert_equal("foo", AssociatedRecord.fetch_name_by_id(1))
+      assert_equal("foo", AssociatedRecord.fetch_name_by_item_id(1))
+      assert_equal("foo", AssociatedRecord.fetch_name_by_id_and_item_id(1, 1))
+    end
+
+    assert_queries(0) do
+      assert_equal("foo", AssociatedRecord.fetch_name_by_id(1))
+      assert_equal("foo", AssociatedRecord.fetch_name_by_item_id(1))
+      assert_equal("foo", AssociatedRecord.fetch_name_by_id_and_item_id(1, 1))
+    end
+
+    key_values = {
+      id: 1,
+      item_id: 1,
+    }
+
+    AssociatedRecord.cache_indexes.each do |index|
+      index.expire_by_key_value(key_values)
+    end
+
+    assert_queries(3) do
+      assert_equal("foo", AssociatedRecord.fetch_name_by_id(1))
+      assert_equal("foo", AssociatedRecord.fetch_name_by_item_id(1))
+      assert_equal("foo", AssociatedRecord.fetch_name_by_id_and_item_id(1, 1))
+    end
+  end
+
+  def test_expire_by_key_values_raises_exception_on_missing_key
+    by_id_index, by_item_id_index, by_multi_index = AssociatedRecord.cache_indexes
+    missing_id_error_message =
+      "AssociatedRecord attribute name expire_by_key_value - required fields: id. missing: id"
+    missing_item_id_error_message =
+      "AssociatedRecord attribute name expire_by_key_value - required fields: item_id. missing: item_id"
+    missing_id_key_in_multi_error_message =
+      "AssociatedRecord attribute name expire_by_key_value - required fields: id, item_id. missing: id"
+
+    missing_id_error = assert_raises(IdentityCache::MissingKeyName) do
+      by_id_index.expire_by_key_value({ item_id: 1 })
+    end
+    missing_item_id_error = assert_raises(IdentityCache::MissingKeyName) do
+      by_item_id_index.expire_by_key_value({ id: 1 })
+    end
+    missing_id_in_multi_error = assert_raises(IdentityCache::MissingKeyName) do
+      by_multi_index.expire_by_key_value({ item_id: 1 })
+    end
+
+    assert_equal(missing_id_error_message, missing_id_error.message)
+    assert_equal(missing_item_id_error_message, missing_item_id_error.message)
+    assert_equal(missing_id_key_in_multi_error_message, missing_id_in_multi_error.message)
+  end
+end