typhoeus · hanshasselberg · Dec 27, 2013 · Dec 24, 2013 · Dec 26, 2013 · hanshasselberg
diff --git a/README.md b/README.md
@@ -226,27 +226,63 @@ Typhoeus includes built in support for caching. In the following example, if the
 
 ```ruby
 class Cache
-  attr_accessor :memory
-
   def initialize
     @memory = {}
   end
 
   def get(request)
-    memory[request]
+    @memory[request]
   end
 
   def set(request, response)
-    memory[request] = response
+    @memory[request] = response
   end
 end
 
 Typhoeus::Config.cache = Cache.new
 
-Typhoeus.get("www.example.com") == Typhoeus.get("www.example.com")
+Typhoeus.get("www.example.com").cached?
+#=> false
+Typhoeus.get("www.example.com").cached?
 #=> true
 ```
 
+For use with [Dalli](https://github.com/mperham/dalli):
+
+```ruby
+class Cache
+  def initialize
+    @client = Dalli::Client.new
+  end
+
+  def get(request)
+    @client.get(request.cache_key)
+  end
+
+  def set(request, response)
+    @client.set(request.cache_key, response)
+  end
+end
+
+Typhoeus::Config.cache = Cache.new
+```
+
+For use with Rails:
+
+```ruby
+class Cache
+  def get(request)
+    Rails.cache.read(request)
+  end
+
+  def set(request, response)
+    Rails.cache.write(request, response)
+  end
+end
+
+Typhoeus::Config.cache = Cache.new
+```
+
 ### Direct Stubbing
 
 Hydra allows you to stub out specific urls and patterns to avoid hitting

diff --git a/lib/typhoeus/request.rb b/lib/typhoeus/request.rb
@@ -154,7 +154,15 @@ def eql?(other)
     #
     # @api private
     def hash
-      Zlib.crc32 "#{self.class.name}#{base_url}#{options}"
+      Zlib.crc32 cache_key
+    end
+
+    # Returns a cache key for use with caching methods that required a string
+    # for a key. Will get used by ActiveSupport::Cache stores automatically.
+    #
+    # @return [ String ] The cache key.
+    def cache_key
+      "#{self.class.name}#{base_url}#{hashable_string_for(options)}"
     end
 
     # Mimics libcurls POST body generation. This is not accurate, but good
@@ -187,6 +195,17 @@ def fuzzy_hash_eql?(left, right)
       end
     end
 
+    def hashable_string_for(obj)
+      case obj
+      when Hash
+        hashable_string_for(obj.sort_by {|sub_obj| sub_obj.first.to_s})
+      when Array
+        obj.map {|sub_obj| hashable_string_for(sub_obj)}.to_s
+      else
+        obj.to_s
+      end
+    end
+
     # Sets default header and verbose when turned on.
     def set_defaults
       if @options[:headers]

diff --git a/spec/typhoeus/request_spec.rb b/spec/typhoeus/request_spec.rb
@@ -143,15 +143,37 @@
 
   describe "#hash" do
     context "when request.eql?(other)" do
-      let(:other) { Typhoeus::Request.new(base_url, options) }
+      context "when different order" do
+        let(:other_options) {
+          {:headers => { 'User-Agent' => "Fubar" }, :verbose => true }
+        }
+        let(:other) { Typhoeus::Request.new(base_url, other_options)}
+
+        it "has same hashes" do
+          expect(request.hash).to eq(other.hash)
+        end
+      end
 
-      it "has same hashes" do
-        expect(request.hash).to eq(other.hash)
+      context "when same order" do
+        let(:other) { Typhoeus::Request.new(base_url, options) }
+
+        it "has same hashes" do
+          expect(request.hash).to eq(other.hash)
+        end
+      end
+
+      context "when hashes with different orders are contained in arrays" do
+        let(:request) { Typhoeus::Request.new(base_url, :params => [{:b => 2, :a => 1}]) }
+        let(:other) { Typhoeus::Request.new(base_url, :params => [{:a => 1, :b => 2}]) }
+        it "has different hashes" do
+          expect(request.hash).to eq(other.hash)
+        end
       end
     end
 
     context "when not request.eql?(other)" do
-      let(:other) { Typhoeus::Request.new("base_url", {}) }
+      let(:request) { Typhoeus::Request.new(base_url, :params => {:foo => 'bar'}) }
+      let(:other) { Typhoeus::Request.new(base_url, :params => {:foo => 'baz'}) }
 
       it "has different hashes" do
         expect(request.hash).to_not eq(other.hash)