[ISSUE-66] Add cache_key_prefix option (#67)

* Add key prefix

* Add spec

* Bonus, add concurrency spec

lib/cached_resource/caching.rb

@@ -148,19 +148,31 @@ def cache_clear(options=nil)
             cached_resource.logger.info("#{CachedResource::Configuration::LOGGER_PREFIX} CLEAR ALL")
           end
         else
-          cached_resource.cache.delete_matched("^#{name_key}/*").tap do |result|
-            cached_resource.logger.info("#{CachedResource::Configuration::LOGGER_PREFIX} CLEAR #{name_key}/*")
+          cached_resource.cache.delete_matched(cache_key_delete_pattern).tap do |result|
+            cached_resource.logger.info("#{CachedResource::Configuration::LOGGER_PREFIX} CLEAR #{cache_key_delete_pattern}")
           end
         end
       end
 
+      def cache_key_delete_pattern
+        case cached_resource.cache.class.to_s
+        when "ActiveSupport::Cache::MemoryStore", "ActiveSupport::Cache::FileStore"
+          /^#{name_key}\//
+        else
+          "#{name_key}/*"
+        end
+      end
+
       # Generate the request cache key.
       def cache_key(*arguments)
         "#{name_key}/#{arguments.join('/')}".downcase.delete(' ')
       end
 
       def name_key
-        name.parameterize.gsub("-", "/")
+        @name_key ||= begin
+          prefix = cached_resource.cache_key_prefix.nil? ? "" : "#{cached_resource.cache_key_prefix}/"
+          prefix + name.parameterize.gsub("-", "/")
+        end
       end
 
       # Make a full duplicate of an ActiveResource record.

lib/cached_resource/configuration.rb

@@ -27,12 +27,13 @@ class Configuration < OpenStruct
     # :concurrent_write, default: false
     def initialize(options={})
       super({
-        :enabled => true,
         :cache => defined?(Rails.cache)  && Rails.cache || CACHE,
         :cache_collections => true,
+        :cache_key_prefix => nil,
         :collection_arguments => [:all],
         :collection_synchronize => false,
         :concurrent_write => false,
+        :enabled => true,
         :logger => defined?(Rails.logger) && Rails.logger || LOGGER,
         :race_condition_ttl => 86400,
         :ttl => 604800,

spec/cached_resource/caching_spec.rb

@@ -85,8 +85,70 @@ class NotTheThing < ActiveResource::Base
 
     include_examples "caching"
 
+    # NOTE: Possibly flaky, but best easy/cheap way to test concurrency.
     context 'when concurrency is turned on' do
-      include_examples "caching"
+      before do
+        # it's on by default, but lets call the method
+        # to make sure it works
+        Thing.cached_resource.cache.clear
+        Thing.cached_resource.on!
+        NotTheThing.cached_resource.cache.clear
+        NotTheThing.cached_resource.on!
+
+        ActiveResource::HttpMock.reset!
+        ActiveResource::HttpMock.respond_to do |mock|
+          mock.get "/things/5.json", {}, {:thing => {:id => 1, :name => ("x" * 1_000_000) }}.to_json
+        end
+      end
+
+      after do
+        Thing.cached_resource.concurrent_write = false
+      end
+
+      it "should cache a response asynchronusly when on" do
+        Thing.cached_resource.concurrent_write = true
+        result = Thing.find(5)
+        read_from_cache("thing/5").should == nil
+        loops = 0
+        begin
+          Timeout.timeout(5) do
+            loop do
+              loops += 1
+              if read_from_cache("thing/5") == result
+                break
+              else
+                sleep 0.5
+              end
+            end
+          end
+        rescue Timeout::Error
+          RSpec::Expectations.fail_with("Concurrency failed: Cache was not populated within the expected time")
+        end
+
+        loops.should > 0
+        read_from_cache("thing/5").should == result
+      end
+
+      it "will cache a response synchronously when off" do
+        Thing.cached_resource.concurrent_write = false
+        result = Thing.find(5)
+        read_from_cache("thing/5").should == result
+      end
+    end
+
+    context "When there is a cache prefix" do
+      before do
+        Thing.cached_resource.cache_key_prefix = "prefix123"
+      end
+
+      after do
+        Thing.cached_resource.cache_key_prefix = nil
+      end
+
+      it "caches with the cache_key_prefix" do
+        result = Thing.find(1)
+        read_from_cache("prefix123/thing/1").should == result
+      end
     end
 
     it "should cache a response for a string primary key" do