ActiveSupport::Cache refactoring

All Caches

* Add default options to initializer that will be sent to all read, write, fetch, exist?, increment, and decrement
* Add support for the :expires_in option to fetch and write for all caches. Cache entries are stored with the create timestamp and a ttl so that expiration can be handled independently of the implementation.
* Add support for a :namespace option. This can be used to set a global prefix for cache entries.
* Deprecate expand_cache_key on ActiveSupport::Cache and move it to ActionController::Caching and ActionDispatch::Http::Cache since the logic in the method used some Rails specific environment variables and was only used by ActionPack classes. Not very DRY but there didn't seem to be a good shared spot and ActiveSupport really shouldn't be Rails specific.
* Add support for :race_condition_ttl to fetch. This setting can prevent race conditions on fetch calls where several processes try to regenerate a recently expired entry at once.
* Add support for :compress option to fetch and write which will compress any data over a configurable threshold.
* Nil values can now be stored in the cache and are distinct from cache misses for fetch.
* Easier API to create new implementations. Just need to implement the methods read_entry, write_entry, and delete_entry instead of overwriting existing methods.
* Since all cache implementations support storing objects, update the docs to state that ActiveCache::Cache::Store implementations should store objects. Keys, however, must be strings since some implementations require that.
* Increase test coverage.
* Document methods which are provided as convenience but which may not be universally available.

MemoryStore

* MemoryStore can now safely be used as the cache for single server sites.
* Make thread safe so that the default cache implementation used by Rails is thread safe. The overhead is minimal and it is still the fastest store available.
* Provide :size initialization option indicating the maximum size of the cache in memory (defaults to 32Mb).
* Add prune logic that removes the least recently used cache entries to keep the cache size from exceeding the max.
* Deprecated SynchronizedMemoryStore since it isn't needed anymore.

FileStore

* Escape key values so they will work as file names on all file systems, be consistent, and case sensitive
* Use a hash algorithm to segment the cache into sub directories so that a large cache doesn't exceed file system limits.
* FileStore can be slow so implement the LocalCache strategy to cache reads for the duration of a request.
* Add cleanup method to keep the disk from filling up with expired entries.
* Fix increment and decrement to use file system locks so they are consistent between processes.

MemCacheStore

* Support all keys. Previously keys with spaces in them would fail
* Deprecate CompressedMemCacheStore since it isn't needed anymore (use :compress => true)

[#4452 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

9 files changed, 1403 insertions, 509 deletions

diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index c47839b001..7bfc377ff1 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,37 @@
 *Rails 3.0.0 [beta 4/release candidate] (unreleased)*
 
+* Harmonize the caching API and refactor the backends.  #4452 [Brian Durand]
+  All caches:
+  * Add default options to initializer that will be sent to all read, write, fetch, exist?, increment, and decrement
+  * Add support for the :expires_in option to fetch and write for all caches. Cache entries are stored with the create timestamp and a ttl so that expiration can be handled independently of the implementation.
+  * Add support for a :namespace option. This can be used to set a global prefix for cache entries.
+  * Deprecate expand_cache_key on ActiveSupport::Cache and move it to ActionController::Caching and ActionDispatch::Http::Cache since the logic in the method used some Rails specific environment variables and was only used by ActionPack classes. Not very DRY but there didn't seem to be a good shared spot and ActiveSupport really shouldn't be Rails specific.
+  * Add support for :race_condition_ttl to fetch. This setting can prevent race conditions on fetch calls where several processes try to regenerate a recently expired entry at once.
+  * Add support for :compress option to fetch and write which will compress any data over a configurable threshold.
+  * Nil values can now be stored in the cache and are distinct from cache misses for fetch.
+  * Easier API to create new implementations. Just need to implement the methods read_entry, write_entry, and delete_entry instead of overwriting existing methods.
+  * Since all cache implementations support storing objects, update the docs to state that ActiveCache::Cache::Store implementations should store objects. Keys, however, must be strings since some implementations require that.
+  * Increase test coverage.
+  * Document methods which are provided as convenience but which may not be universally available.
+
+  MemoryStore:
+  * MemoryStore can now safely be used as the cache for single server sites.
+  * Make thread safe so that the default cache implementation used by Rails is thread safe. The overhead is minimal and it is still the fastest store available.
+  * Provide :size initialization option indicating the maximum size of the cache in memory (defaults to 32Mb).
+  * Add prune logic that removes the least recently used cache entries to keep the cache size from exceeding the max.
+  * Deprecated SynchronizedMemoryStore since it isn't needed anymore.
+
+  FileStore:
+  * Escape key values so they will work as file names on all file systems, be consistent, and case sensitive
+  * Use a hash algorithm to segment the cache into sub directories so that a large cache doesn't exceed file system limits.
+  * FileStore can be slow so implement the LocalCache strategy to cache reads for the duration of a request.
+  * Add cleanup method to keep the disk from filling up with expired entries.
+  * Fix increment and decrement to use file system locks so they are consistent between processes.
+
+  MemCacheStore:
+  * Support all keys. Previously keys with spaces in them would fail
+  * Deprecate CompressedMemCacheStore since it isn't needed anymore (use :compress => true)
+
 * JSON: encode objects that don't have a native JSON representation using to_hash, if available, instead of instance_values (the old fallback) or to_s (other encoders' default). Encode BigDecimal and Regexp encode as strings to conform with other encoders. Try to transcode non-UTF-8 strings.  [Jeremy Kemper]
 
 
diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index 7213b24f2d..ec5007c284 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -1,8 +1,12 @@
 require 'benchmark'
+require 'zlib'
+require 'active_support/core_ext/array/extract_options'
 require 'active_support/core_ext/array/wrap'
 require 'active_support/core_ext/benchmark'
 require 'active_support/core_ext/exception'
 require 'active_support/core_ext/class/attribute_accessors'
+require 'active_support/core_ext/numeric/bytes'
+require 'active_support/core_ext/numeric/time'
 require 'active_support/core_ext/object/to_param'
 require 'active_support/core_ext/string/inflections'
 
@@ -11,10 +15,16 @@ module ActiveSupport
   module Cache
     autoload :FileStore, 'active_support/cache/file_store'
     autoload :MemoryStore, 'active_support/cache/memory_store'
-    autoload :SynchronizedMemoryStore, 'active_support/cache/synchronized_memory_store'
     autoload :MemCacheStore, 'active_support/cache/mem_cache_store'
+    autoload :SynchronizedMemoryStore, 'active_support/cache/synchronized_memory_store'
     autoload :CompressedMemCacheStore, 'active_support/cache/compressed_mem_cache_store'
 
+    EMPTY_OPTIONS = {}.freeze
+
+    # These options mean something to all cache implementations. Individual cache
+    # implementations may support additional optons.
+    UNIVERSAL_OPTIONS = [:namespace, :compress, :compress_threshold, :expires_in, :race_condition_ttl]
+
     module Strategy
       autoload :LocalCache, 'active_support/cache/strategy/local_cache'
     end
@@ -59,15 +69,12 @@ module ActiveSupport
       end
     end
 
-    RAILS_CACHE_ID   = ENV["RAILS_CACHE_ID"]
-    RAILS_APP_VERION = ENV["RAILS_APP_VERION"]
-    EXPANDED_CACHE   = RAILS_CACHE_ID || RAILS_APP_VERION
-
     def self.expand_cache_key(key, namespace = nil)
       expanded_cache_key = namespace ? "#{namespace}/" : ""
 
-      if EXPANDED_CACHE
-        expanded_cache_key << "#{RAILS_CACHE_ID || RAILS_APP_VERION}/"
+      prefix = ENV["RAILS_CACHE_ID"] || ENV["RAILS_APP_VERSION"]
+      if prefix
+        expanded_cache_key << "#{prefix}/"
       end
 
       expanded_cache_key <<
@@ -92,26 +99,75 @@ module ActiveSupport
     # ActiveSupport::Cache::MemCacheStore. MemCacheStore is currently the most
     # popular cache store for large production websites.
     #
-    # ActiveSupport::Cache::Store is meant for caching strings. Some cache
-    # store implementations, like MemoryStore, are able to cache arbitrary
-    # Ruby objects, but don't count on every cache store to be able to do that.
+    # Some implementations may not support all methods beyond the basic cache
+    # methods of +fetch+, +write+, +read+, +exist?+, and +delete+.
+    #
+    # ActiveSupport::Cache::Store can store any serializable Ruby object.
     #
     #   cache = ActiveSupport::Cache::MemoryStore.new
     #
     #   cache.read("city")   # => nil
     #   cache.write("city", "Duckburgh")
     #   cache.read("city")   # => "Duckburgh"
+    #
+    # Keys are always translated into Strings and are case sensitive. When an
+    # object is specified as a key, its +cache_key+ method will be called if it
+    # is defined. Otherwise, the +to_param+ method will be called. Hashes and
+    # Arrays can be used as keys. The elements will be delimited by slashes
+    # and Hashes elements will be sorted by key so they are consistent.
+    #
+    #   cache.read("city") == cache.read(:city)   # => true
+    #
+    # Nil values can be cached.
+    #
+    # If your cache is on a shared infrastructure, you can define a namespace for
+    # your cache entries. If a namespace is defined, it will be prefixed on to every
+    # key. The namespace can be either a static value or a Proc. If it is a Proc, it
+    # will be invoked when each key is evaluated so that you can use application logic
+    # to invalidate keys.
+    #
+    #   cache.namespace = lambda { @last_mod_time }  # Set the namespace to a variable
+    #   @last_mod_time = Time.now  # Invalidate the entire cache by changing namespace
+    #
+    # All caches support auto expiring content after a specified number of seconds.
+    # To set the cache entry time to live, you can either specify +:expires_in+ as
+    # an option to the constructor to have it affect all entries or to the +fetch+
+    # or +write+ methods for just one entry.
+    #
+    #   cache = ActiveSupport::Cache::MemoryStore.new(:expire_in => 5.minutes)
+    #   cache.write(key, value, :expire_in => 1.minute)  # Set a lower value for one entry
+    #
+    # Caches can also store values in a compressed format to save space and reduce
+    # time spent sending data. Since there is some overhead, values must be large
+    # enough to warrant compression. To turn on compression either pass
+    # <tt>:compress => true</tt> in the initializer or to +fetch+ or +write+.
+    # To specify the threshold at which to compress values, set
+    # <tt>:compress_threshold</tt>. The default threshold is 32K.
     class Store
-      cattr_accessor :logger, :instance_writter => false
+
+      cattr_accessor :logger, :instance_writer => true
 
       attr_reader :silence
       alias :silence? :silence
 
+      # Create a new cache. The options will be passed to any write method calls except
+      # for :namespace which can be used to set the global namespace for the cache.
+      def initialize (options = nil)
+        @options = options ? options.dup : {}
+      end
+
+      # Get the default options set when the cache was created.
+      def options
+        @options ||= {}
+      end
+
+      # Silence the logger.
       def silence!
         @silence = true
         self
       end
 
+      # Silence the logger within a block.
       def mute
         previous_silence, @silence = defined?(@silence) && @silence, true
         yield
@@ -152,28 +208,85 @@ module ActiveSupport
       #   cache.write("today", "Monday")
       #   cache.fetch("today", :force => true)  # => nil
       #
+      # Setting <tt>:compress</tt> will store a large cache entry set by the call
+      # in a compressed format.
+      #
+      # Setting <tt>:expires_in</tt> will set an expiration time on the cache
+      # entry if it is set by call.
+      #
+      # Setting <tt>:race_condition_ttl</tt> will invoke logic on entries set with
+      # an <tt>:expires_in</tt> option. If an entry is found in the cache that is
+      # expired and it has been expired for less than the number of seconds specified
+      # by this option and a block was passed to the method call, then the expiration
+      # future time of the entry in the cache will be updated to that many seconds
+      # in the and the block will be evaluated and written to the cache.
+      #
+      # This is very useful in situations where a cache entry is used very frequently
+      # under heavy load. The first process to find an expired cache entry will then
+      # become responsible for regenerating that entry while other processes continue
+      # to use the slightly out of date entry. This can prevent race conditions where
+      # too many processes are trying to regenerate the entry all at once. If the
+      # process regenerating the entry errors out, the entry will be regenerated
+      # after the specified number of seconds.
+      #
+      #   # Set all values to expire after one minute.
+      #   cache = ActiveSupport::Cache::MemoryCache.new(:expires_in => 1.minute)
+      #
+      #   cache.write("foo", "original value")
+      #   val_1 = nil
+      #   val_2 = nil
+      #   sleep 60
+      #
+      #   Thread.new do
+      #     val_1 = cache.fetch("foo", :race_condition_ttl => 10) do
+      #       sleep 1
+      #       "new value 1"
+      #     end
+      #   end
+      #
+      #   Thread.new do
+      #     val_2 = cache.fetch("foo", :race_condition_ttl => 10) do
+      #       "new value 2"
+      #     end
+      #   end
+      #
+      #   # val_1 => "new value 1"
+      #   # val_2 => "original value"
+      #   # cache.fetch("foo") => "new value 1"
+      #
       # Other options will be handled by the specific cache store implementation.
-      # Internally, #fetch calls #read, and calls #write on a cache miss.
+      # Internally, #fetch calls #read_entry, and calls #write_entry on a cache miss.
       # +options+ will be passed to the #read and #write calls.
       #
-      # For example, MemCacheStore's #write method supports the +:expires_in+
-      # option, which tells the memcached server to automatically expire the
-      # cache item after a certain period. This options is also supported by
-      # FileStore's #read method. We can use this option with #fetch too:
+      # For example, MemCacheStore's #write method supports the +:raw+
+      # option, which tells the memcached server to store all values as strings.
+      # We can use this option with #fetch too:
       #
       #   cache = ActiveSupport::Cache::MemCacheStore.new
-      #   cache.fetch("foo", :force => true, :expires_in => 5.seconds) do
-      #     "bar"
+      #   cache.fetch("foo", :force => true, :raw => true) do
+      #     :bar
       #   end
       #   cache.fetch("foo")  # => "bar"
-      #   sleep(6)
-      #   cache.fetch("foo")  # => nil
-      def fetch(key, options = {}, &block)
-        if !options[:force] && value = read(key, options)
-          value
+      def fetch(name, options = nil, &block)
+        options = merged_options(options)
+        key = namespaced_key(name, options)
+        entry = instrument(:read, name, options) { read_entry(key, options) } unless options[:force]
+        if entry && entry.expired?
+          race_ttl = options[:race_condition_ttl].to_f
+          if race_ttl and Time.now.to_f - entry.expires_at <= race_ttl
+            entry.expires_at = Time.now + race_ttl
+            write_entry(key, entry, :expires_in => race_ttl * 2)
+          else
+            delete_entry(key, options)
+          end
+          entry = nil
+        end
+
+        if entry
+          entry.value
         elsif block_given?
-          result = instrument(:generate, key, options, &block)
-          write(key, result, options)
+          result = instrument(:generate, name, options, &block)
+          write(name, result, options)
           result
         end
       end
@@ -182,15 +295,47 @@ module ActiveSupport
       # the cache with the given key, then that data is returned. Otherwise,
       # nil is returned.
       #
-      # You may also specify additional options via the +options+ argument.
-      # The specific cache store implementation will decide what to do with
-      # +options+.
+      # Options are passed to the underlying cache implementation.
+      def read(name, options = nil)
+        options = merged_options(options)
+        key = namespaced_key(name, options)
+        instrument(:read, name, options) do
+          entry = read_entry(key, options)
+          if entry
+            if entry.expired?
+              delete_entry(key, options)
+              nil
+            else
+              entry.value
+            end
+          else
+            nil
+          end
+        end
+      end
+
+      # Read multiple values at once from the cache. Options can be passed
+      # in the last argument.
       #
-      # For example, FileStore supports the +:expires_in+ option, which
-      # makes the method return nil for cache items older than the specified
-      # period.
-      def read(key, options = nil, &block)
-        instrument(:read, key, options, &block)
+      # Some cache implementation may optimize this method.
+      #
+      # Returns a hash mapping the names provided to the values found.
+      def read_multi(*names)
+        options = names.extract_options!
+        options = merged_options(options)
+        results = {}
+        names.each do |name|
+          key = namespaced_key(name, options)
+          entry = read_entry(key, options)
+          if entry
+            if entry.expired?
+              delete_entry(key)
+            else
+              results[name] = entry.value
+            end
+          end
+        end
+        results
       end
 
       # Writes the given value to the cache, with the given key.
@@ -198,56 +343,160 @@ module ActiveSupport
       # You may also specify additional options via the +options+ argument.
       # The specific cache store implementation will decide what to do with
       # +options+.
+      def write(name, value, options = nil)
+        options = merged_options(options)
+        instrument(:write, name, options) do
+          entry = Entry.new(value, options)
+          write_entry(namespaced_key(name, options), entry, options)
+        end
+      end
+
+      # Delete an entry in the cache. Returns +true+ if there was an entry to delete.
       #
-      # For example, MemCacheStore supports the +:expires_in+ option, which
-      # tells the memcached server to automatically expire the cache item after
-      # a certain period:
+      # Options are passed to the underlying cache implementation.
+      def delete(name, options = nil)
+        options = merged_options(options)
+        instrument(:delete, name) do
+          delete_entry(namespaced_key(name, options), options)
+        end
+      end
+
+      # Return true if the cache contains an entry with this name.
       #
-      #   cache = ActiveSupport::Cache::MemCacheStore.new
-      #   cache.write("foo", "bar", :expires_in => 5.seconds)
-      #   cache.read("foo")  # => "bar"
-      #   sleep(6)
-      #   cache.read("foo")  # => nil
-      def write(key, value, options = nil, &block)
-        instrument(:write, key, options, &block)
+      # Options are passed to the underlying cache implementation.
+      def exist?(name, options = nil)
+        options = merged_options(options)
+        instrument(:exist?, name) do
+          entry = read_entry(namespaced_key(name, options), options)
+          if entry && !entry.expired?
+            true
+          else
+            false
+          end
+        end
       end
 
-      def delete(key, options = nil, &block)
-        instrument(:delete, key, options, &block)
+      # Delete all entries whose keys match a pattern.
+      #
+      # Options are passed to the underlying cache implementation.
+      #
+      # Not all implementations may support +delete_matched+.
+      def delete_matched(matcher, options = nil)
+        raise NotImplementedError.new("#{self.class.name} does not support delete_matched")
       end
 
-      def delete_matched(matcher, options = nil, &block)
-        instrument(:delete_matched, matcher.inspect, options, &block)
+      # Increment an integer value in the cache.
+      #
+      # Options are passed to the underlying cache implementation.
+      #
+      # Not all implementations may support +delete_matched+.
+      def increment(name, amount = 1, options = nil)
+        raise NotImplementedError.new("#{self.class.name} does not support increment")
       end
 
-      def exist?(key, options = nil, &block)
-        instrument(:exist?, key, options, &block)
+      # Increment an integer value in the cache.
+      #
+      # Options are passed to the underlying cache implementation.
+      #
+      # Not all implementations may support +delete_matched+.
+      def decrement(name, amount = 1, options = nil)
+        raise NotImplementedError.new("#{self.class.name} does not support decrement")
       end
 
-      def increment(key, amount = 1)
-        if num = read(key)
-          write(key, num + amount)
-        else
-          nil
-        end
+      # Cleanup the cache by removing expired entries. Not all cache implementations may
+      # support this method.
+      #
+      # Options are passed to the underlying cache implementation.
+      #
+      # Not all implementations may support +delete_matched+.
+      def cleanup(options = nil)
+        raise NotImplementedError.new("#{self.class.name} does not support cleanup")
       end
 
-      def decrement(key, amount = 1)
-        if num = read(key)
-          write(key, num - amount)
-        else
-          nil
-        end
+      # Clear the entire cache. Not all cache implementations may support this method.
+      # You should be careful with this method since it could affect other processes
+      # if you are using a shared cache.
+      #
+      # Options are passed to the underlying cache implementation.
+      #
+      # Not all implementations may support +delete_matched+.
+      def clear(options = nil)
+        raise NotImplementedError.new("#{self.class.name} does not support clear")
       end
 
+      protected
+        # Add the namespace defined in the options to a pattern designed to match keys.
+        # Implementations that support delete_matched should call this method to translate
+        # a pattern that matches names into one that matches namespaced keys.
+        def key_matcher(pattern, options)
+          prefix = options[:namespace].is_a?(Proc) ? options[:namespace].call : options[:namespace]
+          if prefix
+            source = pattern.source
+            if source.start_with?('^')
+              source = source[1, source.length]
+            else
+              source = ".*#{source[0, source.length]}"
+            end
+            Regexp.new("^#{Regexp.escape(prefix)}:#{source}", pattern.options)
+          else
+            pattern
+          end
+        end
+
+        # Read an entry from the cache implementation. Subclasses must implement this method.
+        def read_entry(key, options) # :nodoc:
+          raise NotImplementedError.new
+        end
+
+        # Write an entry to the cache implementation. Subclasses must implement this method.
+        def write_entry(key, entry, options) # :nodoc:
+          raise NotImplementedError.new
+        end
+
+        # Delete an entry from the cache implementation. Subclasses must implement this method.
+        def delete_entry(key, options) # :nodoc:
+          raise NotImplementedError.new
+        end
+
       private
-        def expires_in(options)
-          expires_in = options && options[:expires_in]
-          raise ":expires_in must be a number" if expires_in && !expires_in.is_a?(Numeric)
-          expires_in || 0
+        # Merge the default options with ones specific to a method call.
+        def merged_options(call_options) # :nodoc:
+          if call_options
+            options.merge(call_options)
+          else
+            options.dup
+          end
+        end
+
+        # Expand a key to be a consistent string value. If the object responds to +cache_key+,
+        # it will be called. Otherwise, the to_param method will be called. If the key is a
+        # Hash, the keys will be sorted alphabetically.
+        def expanded_key(key) # :nodoc:
+          if key.respond_to?(:cache_key)
+            key = key.cache_key.to_s
+          elsif key.is_a?(Array)
+            if key.size > 1
+              key.collect{|element| expanded_key(element)}.to_param
+            else
+              key.first.to_param
+            end
+          elsif key.is_a?(Hash)
+            key = key.to_a.sort{|a,b| a.first.to_s <=> b.first.to_s}.collect{|k,v| "#{k}=#{v}"}.to_param
+          else
+            key = key.to_param
+          end
+        end
+
+        # Prefix a key with the namespace. The two values will be delimited with a colon.
+        def namespaced_key(key, options)
+          key = expanded_key(key)
+          namespace = options[:namespace] if options
+          prefix = namespace.is_a?(Proc) ? namespace.call : namespace
+          key = "#{prefix}:#{key}" if prefix
+          key
         end
 
-        def instrument(operation, key, options)
+        def instrument(operation, key, options = nil)
           log(operation, key, options)
 
           if self.class.instrument
@@ -259,9 +508,118 @@ module ActiveSupport
           end
         end
 
-        def log(operation, key, options)
-          return unless logger && !silence?
-          logger.debug("Cache #{operation}: #{key}#{options ? " (#{options.inspect})" : ""}")
+        def log(operation, key, options = nil)
+          return unless logger && logger.debug? && !silence?
+          logger.debug("Cache #{operation}: #{key}#{options.blank? ? "" : " (#{options.inspect})"}")
+        end
+    end
+
+    # Entry that is put into caches. It supports expiration time on entries and can compress values
+    # to save space in the cache.
+    class Entry
+      attr_reader :created_at, :expires_in
+
+      DEFAULT_COMPRESS_LIMIT = 16.kilobytes
+
+      class << self
+        # Create an entry with internal attributes set. This method is intended to be
+        # used by implementations that store cache entries in a native format instead
+        # of as serialized Ruby objects.
+        def create (raw_value, created_at, options = {})
+          entry = new(nil)
+          entry.instance_variable_set(:@value, raw_value)
+          entry.instance_variable_set(:@created_at, created_at.to_f)
+          entry.instance_variable_set(:@compressed, !!options[:compressed])
+          entry.instance_variable_set(:@expires_in, options[:expires_in])
+          entry
+        end
+      end
+
+      # Create a new cache entry for the specified value. Options supported are
+      # +:compress+, +:compress_threshold+, and +:expires_in+.
+      def initialize(value, options = {})
+        @compressed = false
+        @expires_in = options[:expires_in]
+        @expires_in = @expires_in.to_f if @expires_in
+        @created_at = Time.now.to_f
+        if value
+          if should_compress?(value, options)
+            @value = Zlib::Deflate.deflate(Marshal.dump(value))
+            @compressed = true
+          else
+            @value = value
+          end
+        else
+          @value = nil
+        end
+      end
+
+      # Get the raw value. This value may be serialized and compressed.
+      def raw_value
+        @value
+      end
+
+      # Get the value stored in the cache.
+      def value
+        if @value
+          val = compressed? ? Marshal.load(Zlib::Inflate.inflate(@value)) : @value
+          unless val.frozen?
+            val.freeze rescue nil
+          end
+          val
+        end
+      end
+
+      def compressed?
+        @compressed
+      end
+
+      # Check if the entry is expired. The +expires_in+ parameter can override the
+      # value set when the entry was created.
+      def expired?
+        if @expires_in && @created_at + @expires_in <= Time.now.to_f
+          true
+        else
+          false
+        end
+      end
+
+      # Set a new time to live on the entry so it expires at the given time.
+      def expires_at=(time)
+        if time
+          @expires_in = time.to_f - @created_at
+        else
+          @expires_in = nil
+        end
+      end
+
+      # Seconds since the epoch when the cache entry will expire.
+      def expires_at
+        @expires_in ? @created_at + @expires_in : nil
+      end
+
+      # Get the size of the cached value. This could be less than value.size
+      # if the data is compressed.
+      def size
+        if @value.nil?
+          0
+        elsif @value.respond_to?(:bytesize)
+          @value.bytesize
+        else
+          Marshal.dump(@value).bytesize
+        end
+      end
+
+      private
+        def should_compress?(value, options)
+          if options[:compress] && value
+            unless value.is_a?(Numeric)
+              compress_threshold = options[:compress_threshold] || DEFAULT_COMPRESS_LIMIT
+              serialized_value = value.is_a?(String) ? value : Marshal.dump(value)
+              return true if serialized_value.size >= compress_threshold
+            end
+          end
+          false
         end
     end
   end
diff --git a/activesupport/lib/active_support/cache/compressed_mem_cache_store.rb b/activesupport/lib/active_support/cache/compressed_mem_cache_store.rb
index d2370d78c5..7c7d1c4b00 100644
--- a/activesupport/lib/active_support/cache/compressed_mem_cache_store.rb
+++ b/activesupport/lib/active_support/cache/compressed_mem_cache_store.rb
@@ -1,21 +1,12 @@
-require 'active_support/gzip'
-
 module ActiveSupport
   module Cache
     class CompressedMemCacheStore < MemCacheStore
-      def read(name, options = nil)
-        if value = super(name, (options || {}).merge(:raw => true))
-          if raw?(options)
-            value
-          else
-            Marshal.load(ActiveSupport::Gzip.decompress(value))
-          end
-        end
-      end
-
-      def write(name, value, options = nil)
-        value = ActiveSupport::Gzip.compress(Marshal.dump(value)) unless raw?(options)
-        super(name, value, (options || {}).merge(:raw => true))
+      def initialize(*args)
+        ActiveSupport::Deprecation.warn('ActiveSupport::Cache::CompressedMemCacheStore has been deprecated in favor of ActiveSupport::Cache::MemCacheStore(:compress => true).', caller)
+        addresses = args.dup
+        options = addresses.extract_options!
+        args = addresses + [options.merge(:compress => true)]
+        super(*args)
       end
     end
   end
diff --git a/activesupport/lib/active_support/cache/file_store.rb b/activesupport/lib/active_support/cache/file_store.rb
index 7521efe7c5..fc225e77a2 100644
--- a/activesupport/lib/active_support/cache/file_store.rb
+++ b/activesupport/lib/active_support/cache/file_store.rb
@@ -3,73 +3,171 @@ require 'active_support/core_ext/file/atomic'
 module ActiveSupport
   module Cache
     # A cache store implementation which stores everything on the filesystem.
+    #
+    # FileStore implements the Strategy::LocalCache strategy which implements
+    # an in memory cache inside of a block.
     class FileStore < Store
       attr_reader :cache_path
 
-      def initialize(cache_path)
+      DIR_FORMATTER = "%03X"
+      ESCAPE_FILENAME_CHARS = /[^a-z0-9_.-]/i
+      UNESCAPE_FILENAME_CHARS = /%[0-9A-F]{2}/
+
+      def initialize(cache_path, options = nil)
+        super(options)
         @cache_path = cache_path
+        extend Strategy::LocalCache
       end
 
-      # Reads a value from the cache.
-      #
-      # Possible options:
-      # - +:expires_in+ - the number of seconds that this value may stay in
-      #   the cache.
-      def read(name, options = nil)
-        super do
-          file_name = real_file_path(name)
-          expires = expires_in(options)
-
-          if File.exist?(file_name) && (expires <= 0 || Time.now - File.mtime(file_name) < expires)
-            File.open(file_name, 'rb') { |f| Marshal.load(f) }
-          end
+      def clear(options = nil)
+        root_dirs = Dir.entries(cache_path).reject{|f| ['.', '..'].include?(f)}
+        FileUtils.rm_r(root_dirs.collect{|f| File.join(cache_path, f)})
+      end
+
+      def cleanup(options = nil)
+        options = merged_options(options)
+        each_key(options) do |key|
+          entry = read_entry(key, options)
+          delete_entry(key, options) if entry && entry.expired?
         end
       end
 
-      # Writes a value to the cache.
-      def write(name, value, options = nil)
-        super do
-          ensure_cache_path(File.dirname(real_file_path(name)))
-          File.atomic_write(real_file_path(name), cache_path) { |f| Marshal.dump(value, f) }
-          value
+      def increment(name, amount = 1, options = nil)
+        file_name = key_file_path(namespaced_key(name, options))
+        lock_file(file_name) do
+          options = merged_options(options)
+          if num = read(name, options)
+            num = num.to_i + amount
+            write(name, num, options)
+            num
+          else
+            nil
+          end
         end
-      rescue => e
-        logger.error "Couldn't create cache directory: #{name} (#{e.message})" if logger
       end
 
-      def delete(name, options = nil)
-        super do
-          File.delete(real_file_path(name))
+      def decrement(name, amount = 1, options = nil)
+        file_name = key_file_path(namespaced_key(name, options))
+        lock_file(file_name) do
+          options = merged_options(options)
+          if num = read(name, options)
+            num = num.to_i - amount
+            write(name, num, options)
+            num
+          else
+            nil
+          end
         end
-      rescue SystemCallError => e
-        # If there's no cache, then there's nothing to complain about
       end
 
       def delete_matched(matcher, options = nil)
-        super do
-          search_dir(@cache_path) do |f|
-            if f =~ matcher
-              begin
-                File.delete(f)
-              rescue SystemCallError => e
-                # If there's no cache, then there's nothing to complain about
+        options = merged_options(options)
+        instrument(:delete_matched, matcher.inspect) do
+          matcher = key_matcher(matcher, options)
+          search_dir(cache_path) do |path|
+            key = file_path_key(path)
+            delete_entry(key, options) if key.match(matcher)
+          end
+        end
+      end
+
+      protected
+
+        def read_entry(key, options)
+          file_name = key_file_path(key)
+          if File.exist?(file_name)
+            entry = File.open(file_name) { |f| Marshal.load(f) }
+            if entry && !entry.expired? && !entry.expires_in && !self.options[:expires_in]
+              # Check for deprecated use of +:expires_in+ option from versions < 3.0
+              deprecated_expires_in = options[:expires_in]
+              if deprecated_expires_in
+                ActiveSupport::Deprecation.warn('Setting :expires_in on read has been deprecated in favor of setting it on write.', caller)
+                if entry.created_at + deprecated_expires_in.to_f <= Time.now.to_f
+                  delete_entry(key, options)
+                  entry = nil
+                end
               end
             end
+            entry
           end
+        rescue
+          nil
         end
-      end
 
-      def exist?(name, options = nil)
-        super do
-          File.exist?(real_file_path(name))
+        def write_entry(key, entry, options)
+          file_name = key_file_path(key)
+          ensure_cache_path(File.dirname(file_name))
+          File.atomic_write(file_name, cache_path) {|f| Marshal.dump(entry, f)}
+          true
+        end
+
+        def delete_entry(key, options)
+          file_name = key_file_path(key)
+          if File.exist?(file_name)
+            begin
+              File.delete(file_name)
+              delete_empty_directories(File.dirname(file_name))
+              true
+            rescue => e
+              # Just in case the error was caused by another process deleting the file first.
+              raise e if File.exist?(file_name)
+              false
+            end
+          end
         end
-      end
 
       private
-        def real_file_path(name)
-          '%s/%s.cache' % [@cache_path, name.gsub('?', '.').gsub(':', '.')]
+        # Lock a file for a block so only one process can modify it at a time.
+        def lock_file(file_name, &block) # :nodoc:
+          if File.exist?(file_name)
+            File.open(file_name, 'r') do |f|
+              begin
+                f.flock File::LOCK_EX
+                yield
+              ensure
+                f.flock File::LOCK_UN
+              end
+            end
+          else
+            yield
+          end
+        end
+
+        # Translate a key into a file path.
+        def key_file_path(key)
+          fname = key.to_s.gsub(ESCAPE_FILENAME_CHARS){|match| "%#{match.ord.to_s(16).upcase}"}
+          hash = Zlib.adler32(fname)
+          hash, dir_1 = hash.divmod(0x1000)
+          dir_2 = hash.modulo(0x1000)
+          fname_paths = []
+          # Make sure file name is < 255 characters so it doesn't exceed file system limits.
+          if fname.size <= 255
+            fname_paths << fname
+          else
+            while fname.size <= 255
+              fname_path << fname[0, 255]
+              fname = fname[255, -1]
+            end
+          end
+          File.join(cache_path, DIR_FORMATTER % dir_1, DIR_FORMATTER % dir_2, *fname_paths)
+        end
+
+        # Translate a file path into a key.
+        def file_path_key(path)
+          fname = path[cache_path.size, path.size].split(File::SEPARATOR, 4).last
+          fname.gsub(UNESCAPE_FILENAME_CHARS){|match| $1.ord.to_s(16)}
+        end
+
+        # Delete empty directories in the cache.
+        def delete_empty_directories(dir)
+          return if dir == cache_path
+          if Dir.entries(dir).reject{|f| ['.', '..'].include?(f)}.empty?
+            File.delete(dir) rescue nil
+            delete_empty_directories(File.dirname(dir))
+          end
         end
 
+        # Make sure a file path's directories exist.
         def ensure_cache_path(path)
           FileUtils.makedirs(path) unless File.exist?(path)
         end
diff --git a/activesupport/lib/active_support/cache/mem_cache_store.rb b/activesupport/lib/active_support/cache/mem_cache_store.rb
index c56fedc12e..d8377a208f 100644
--- a/activesupport/lib/active_support/cache/mem_cache_store.rb
+++ b/activesupport/lib/active_support/cache/mem_cache_store.rb
@@ -1,5 +1,5 @@
 require 'memcache'
-require 'active_support/core_ext/array/extract_options'
+require 'digest/md5'
 
 module ActiveSupport
   module Cache
@@ -13,8 +13,9 @@ module ActiveSupport
     #   and MemCacheStore will load balance between all available servers. If a
     #   server goes down, then MemCacheStore will ignore it until it goes back
     #   online.
-    # - Time-based expiry support. See #write and the <tt>:expires_in</tt> option.
-    # - Per-request in memory cache for all communication with the MemCache server(s).
+    #
+    # MemCacheStore implements the Strategy::LocalCache strategy which implements
+    # an in memory cache inside of a block.
     class MemCacheStore < Store
       module Response # :nodoc:
         STORED      = "STORED\r\n"
@@ -24,6 +25,8 @@ module ActiveSupport
         DELETED     = "DELETED\r\n"
       end
 
+      ESCAPE_KEY_CHARS = /[\x00-\x20%\x7F-\xFF]/
+
       def self.build_mem_cache(*addresses)
         addresses = addresses.flatten
         options = addresses.extract_options!
@@ -45,108 +48,139 @@ module ActiveSupport
       #   require 'memcached' # gem install memcached; uses C bindings to libmemcached
       #   ActiveSupport::Cache::MemCacheStore.new(Memcached::Rails.new("localhost:11211"))
       def initialize(*addresses)
+        addresses = addresses.flatten
+        options = addresses.extract_options!
+        super(options)
+
         if addresses.first.respond_to?(:get)
           @data = addresses.first
         else
-          @data = self.class.build_mem_cache(*addresses)
+          mem_cache_options = options.dup
+          UNIVERSAL_OPTIONS.each{|name| mem_cache_options.delete(name)}
+          @data = self.class.build_mem_cache(*(addresses + [mem_cache_options]))
         end
 
         extend Strategy::LocalCache
+        extend LocalCacheWithRaw
       end
 
-      # Reads multiple keys from the cache.
-      def read_multi(*keys)
-        @data.get_multi keys
-      end
-
-      def read(key, options = nil) # :nodoc:
-        super do
-          @data.get(key, raw?(options))
-        end
-      rescue MemCache::MemCacheError => e
-        logger.error("MemCacheError (#{e}): #{e.message}") if logger
-        nil
-      end
-
-      # Writes a value to the cache.
-      #
-      # Possible options:
-      # - <tt>:unless_exist</tt> - set to true if you don't want to update the cache
-      #   if the key is already set.
-      # - <tt>:expires_in</tt> - the number of seconds that this value may stay in
-      #   the cache. See ActiveSupport::Cache::Store#write for an example.
-      def write(key, value, options = nil)
-        super do
-          method = options && options[:unless_exist] ? :add : :set
-          # memcache-client will break the connection if you send it an integer
-          # in raw mode, so we convert it to a string to be sure it continues working.
-          value = value.to_s if raw?(options)
-          response = @data.send(method, key, value, expires_in(options), raw?(options))
-          response == Response::STORED
-        end
-      rescue MemCache::MemCacheError => e
-        logger.error("MemCacheError (#{e}): #{e.message}") if logger
-        false
-      end
-
-      def delete(key, options = nil) # :nodoc:
-        super do
-          response = @data.delete(key)
-          response == Response::DELETED
-        end
-      rescue MemCache::MemCacheError => e
-        logger.error("MemCacheError (#{e}): #{e.message}") if logger
-        false
-      end
-
-      def exist?(key, options = nil) # :nodoc:
-        # Doesn't call super, cause exist? in memcache is in fact a read
-        # But who cares? Reading is very fast anyway
-        # Local cache is checked first, if it doesn't know then memcache itself is read from
-        super do
-          !read(key, options).nil?
+      # Reads multiple keys from the cache using a single call to the
+      # servers for all keys. Options can be passed in the last argument.
+      def read_multi(*names)
+        options = names.extract_options!
+        options = merged_options(options)
+        keys_to_names = names.inject({}){|map, name| map[escape_key(namespaced_key(name, options))] = name; map}
+        raw_values = @data.get_multi(keys_to_names.keys, :raw => true)
+        values = {}
+        raw_values.each do |key, value|
+          entry = deserialize_entry(value)
+          values[keys_to_names[key]] = entry.value unless entry.expired?
         end
+        values
       end
 
-      def increment(key, amount = 1) # :nodoc:
-        response = instrument(:increment, key, :amount => amount) do
-          @data.incr(key, amount)
+      # Increment a cached value. This method uses the memcached incr atomic
+      # operator and can only be used on values written with the :raw option.
+      # Calling it on a value not stored with :raw will initialize that value
+      # to zero.
+      def increment(name, amount = 1, options = nil) # :nodoc:
+        options = merged_options(options)
+        response = instrument(:increment, name, :amount => amount) do
+          @data.incr(escape_key(namespaced_key(name, options)), amount)
         end
-
-        response == Response::NOT_FOUND ? nil : response
+        response == Response::NOT_FOUND ? nil : response.to_i
       rescue MemCache::MemCacheError
         nil
       end
 
-      def decrement(key, amount = 1) # :nodoc:
-        response = instrument(:decrement, key, :amount => amount) do
-          @data.decr(key, amount)
+      # Decrement a cached value. This method uses the memcached decr atomic
+      # operator and can only be used on values written with the :raw option.
+      # Calling it on a value not stored with :raw will initialize that value
+      # to zero.
+      def decrement(name, amount = 1, options = nil) # :nodoc:
+        options = merged_options(options)
+        response = instrument(:decrement, name, :amount => amount) do
+          @data.decr(escape_key(namespaced_key(name, options)), amount)
         end
-
-        response == Response::NOT_FOUND ? nil : response
+        response == Response::NOT_FOUND ? nil : response.to_i
       rescue MemCache::MemCacheError
         nil
       end
 
-      def delete_matched(matcher, options = nil) # :nodoc:
-        # don't do any local caching at present, just pass
-        # through and let the error happen
-        super
-        raise "Not supported by Memcache"
-      end
-
-      def clear
+      # Clear the entire cache on all memcached servers. This method should
+      # be used with care when using a shared cache.
+      def clear(options = nil)
         @data.flush_all
       end
 
+      # Get the statistics from the memcached servers.
       def stats
         @data.stats
       end
 
+      protected
+        # Read an entry from the cache.
+        def read_entry(key, options) # :nodoc:
+          deserialize_entry(@data.get(escape_key(key), true))
+        rescue MemCache::MemCacheError => e
+          logger.error("MemCacheError (#{e}): #{e.message}") if logger
+          nil
+        end
+
+        # Write an entry to the cache.
+        def write_entry(key, entry, options) # :nodoc:
+          method = options && options[:unless_exist] ? :add : :set
+          value = options[:raw] ? entry.value.to_s : entry
+          expires_in = options[:expires_in].to_i
+          if expires_in > 0 && !options[:raw]
+            # Set the memcache expire a few minutes in the future to support race condition ttls on read
+            expires_in += 5.minutes
+          end
+          response = @data.send(method, escape_key(key), value, expires_in, options[:raw])
+          response == Response::STORED
+        rescue MemCache::MemCacheError => e
+          logger.error("MemCacheError (#{e}): #{e.message}") if logger
+          false
+        end
+
+        # Delete an entry from the cache.
+        def delete_entry(key, options) # :nodoc:
+          response = @data.delete(escape_key(key))
+          response == Response::DELETED
+        rescue MemCache::MemCacheError => e
+          logger.error("MemCacheError (#{e}): #{e.message}") if logger
+          false
+        end
+
       private
-        def raw?(options)
-          options && options[:raw]
+        def escape_key(key)
+          key = key.to_s.gsub(ESCAPE_KEY_CHARS){|match| "%#{match[0].to_s(16).upcase}"}
+          key = "#{key[0, 213]}:md5:#{Digest::MD5.hexdigest(key)}" if key.size > 250
+          key
         end
+
+        def deserialize_entry(raw_value)
+          if raw_value
+            entry = Marshal.load(raw_value) rescue raw_value
+            entry.is_a?(Entry) ? entry : Entry.new(entry)
+          else
+            nil
+          end
+        end
+
+      # Provide support for raw values in the local cache strategy.
+      module LocalCacheWithRaw # :nodoc:
+        protected
+          def write_entry(key, entry, options) # :nodoc:
+            retval = super
+            if options[:raw] && local_cache && retval
+              raw_entry = Entry.new(entry.value.to_s)
+              raw_entry.expires_at = entry.expires_at
+              local_cache.write_entry(key, raw_entry, options)
+            end
+            retval
+          end
+      end
     end
   end
 end
diff --git a/activesupport/lib/active_support/cache/memory_store.rb b/activesupport/lib/active_support/cache/memory_store.rb
index 379922f986..b1d14a0d8f 100644
--- a/activesupport/lib/active_support/cache/memory_store.rb
+++ b/activesupport/lib/active_support/cache/memory_store.rb
@@ -1,4 +1,4 @@
-require 'active_support/core_ext/object/duplicable'
+require 'monitor'
 
 module ActiveSupport
   module Cache
@@ -6,60 +6,154 @@ module ActiveSupport
     # same process. If you're running multiple Ruby on Rails server processes
     # (which is the case if you're using mongrel_cluster or Phusion Passenger),
     # then this means that your Rails server process instances won't be able
-    # to share cache data with each other. If your application never performs
-    # manual cache item expiry (e.g. when you're using generational cache keys),
-    # then using MemoryStore is ok. Otherwise, consider carefully whether you
-    # should be using this cache store.
+    # to share cache data with each other and this may not be the most
+    # appropriate cache for you.
     #
-    # MemoryStore is not only able to store strings, but also arbitrary Ruby
-    # objects.
+    # This cache has a bounded size specified by the :size options to the
+    # initializer (default is 32Mb). When the cache exceeds the alotted size,
+    # a cleanup will occur which tries to prune the cache down to three quarters
+    # of the maximum size by removing the least recently used entries.
     #
-    # MemoryStore is not thread-safe. Use SynchronizedMemoryStore instead
-    # if you need thread-safety.
+    # MemoryStore is thread-safe.
     class MemoryStore < Store
-      def initialize
+      def initialize(options = nil)
+        options ||= {}
+        super(options)
         @data = {}
+        @key_access = {}
+        @max_size = options[:size] || 32.megabytes
+        @max_prune_time = options[:max_prune_time] || 2
+        @cache_size = 0
+        @monitor = Monitor.new
+        @pruning = false
       end
 
-      def read_multi(*names)
-        results = {}
-        names.each { |n| results[n] = read(n) }
-        results
+      def clear(options = nil)
+        synchronize do
+          @data.clear
+          @key_access.clear
+          @cache_size = 0
+        end
       end
 
-      def read(name, options = nil)
-        super do
-          @data[name]
+      def cleanup(options = nil)
+        options = merged_options(options)
+        instrument(:cleanup, :size => @data.size) do
+          keys = synchronize{ @data.keys }
+          keys.each do |key|
+            entry = @data[key]
+            delete_entry(key, options) if entry && entry.expired?
+          end
         end
       end
 
-      def write(name, value, options = nil)
-        super do
-          @data[name] = (value.duplicable? ? value.dup : value).freeze
+      # Prune the cache down so the entries fit within the specified memory size by removing
+      # the least recently accessed entries.
+      def prune(target_size, max_time = nil)
+        return if pruning?
+        @pruning = true
+        begin
+          start_time = Time.now
+          cleanup
+          instrument(:prune, target_size, :from => @cache_size) do
+            keys = synchronize{ @key_access.keys.sort{|a,b| @key_access[a].to_f <=> @key_access[b].to_f} }
+            keys.each do |key|
+              delete_entry(key, options)
+              return if @cache_size <= target_size || (max_time && Time.now - start_time > max_time)
+            end
+          end
+        ensure
+          @pruning = false
         end
       end
 
-      def delete(name, options = nil)
-        super do
-          @data.delete(name)
+      # Return true if the cache is currently be pruned to remove older entries.
+      def pruning?
+        @pruning
+      end
+
+      # Increment an integer value in the cache.
+      def increment(name, amount = 1, options = nil)
+        synchronize do
+          options = merged_options(options)
+          if num = read(name, options)
+            num = num.to_i + amount
+            write(name, num, options)
+            num
+          else
+            nil
+          end
         end
       end
 
-      def delete_matched(matcher, options = nil)
-        super do
-          @data.delete_if { |k,v| k =~ matcher }
+      # Decrement an integer value in the cache.
+      def decrement(name, amount = 1, options = nil)
+        synchronize do
+          options = merged_options(options)
+          if num = read(name, options)
+            num = num.to_i - amount
+            write(name, num, options)
+            num
+          else
+            nil
+          end
         end
       end
 
-      def exist?(name, options = nil)
-        super do
-          @data.has_key?(name)
+      def delete_matched(matcher, options = nil)
+        options = merged_options(options)
+        instrument(:delete_matched, matcher.inspect) do
+          matcher = key_matcher(matcher, options)
+          keys = synchronize { @data.keys }
+          keys.each do |key|
+            delete_entry(key, options) if key.match(matcher)
+          end
         end
       end
 
-      def clear
-        @data.clear
+      def inspect # :nodoc:
+        "<##{self.class.name} entries=#{@data.size}, size=#{@cache_size}, options=#{@options.inspect}>"
+      end
+
+      # Synchronize calls to the cache. This should be called wherever the underlying cache implementation
+      # is not thread safe.
+      def synchronize(&block) # :nodoc:
+        @monitor.synchronize(&block)
       end
+
+      protected
+        def read_entry(key, options) # :nodoc:
+          entry = @data[key]
+          synchronize do
+            if entry
+              @key_access[key] = Time.now.to_f
+            else
+              @key_access.delete(key)
+            end
+          end
+          entry
+        end
+
+        def write_entry(key, entry, options) # :nodoc:
+          synchronize do
+            old_entry = @data[key]
+            @cache_size -= old_entry.size if old_entry
+            @cache_size += entry.size
+            @key_access[key] = Time.now.to_f
+            @data[key] = entry
+            prune(@max_size * 0.75, @max_prune_time) if @cache_size > @max_size
+            true
+          end
+        end
+
+        def delete_entry(key, options) # :nodoc:
+          synchronize do
+            @key_access.delete(key)
+            entry = @data.delete(key)
+            @cache_size -= entry.size if entry
+            !!entry
+          end
+        end
     end
   end
 end
diff --git a/activesupport/lib/active_support/cache/strategy/local_cache.rb b/activesupport/lib/active_support/cache/strategy/local_cache.rb
index bbbd643736..8942587ac8 100644
--- a/activesupport/lib/active_support/cache/strategy/local_cache.rb
+++ b/activesupport/lib/active_support/cache/strategy/local_cache.rb
@@ -4,17 +4,54 @@ require 'active_support/core_ext/string/inflections'
 module ActiveSupport
   module Cache
     module Strategy
+      # Caches that implement LocalCache will be backed by an in memory cache for the
+      # duration of a block. Repeated calls to the cache for the same key will hit the
+      # in memory cache for faster access.
       module LocalCache
-        # this allows caching of the fact that there is nothing in the remote cache
-        NULL = 'remote_cache_store:null'
+        # Simple memory backed cache. This cache is not thread safe but is intended only
+        # for serving as a temporary memory cache for a single thread.
+        class LocalStore < Store
+          def initialize
+            super
+            @data = {}
+          end
+
+          # Since it isn't thread safe, don't allow synchronizing.
+          def synchronize # :nodoc:
+            yield
+          end
+
+          def clear(options = nil)
+            @data.clear
+          end
+
+          def read_entry(key, options)
+            @data[key]
+          end
 
+          def write_entry(key, value, options)
+            @data[key] = value
+            true
+          end
+
+          def delete_entry(key, options)
+            !!@data.delete(key)
+          end
+        end
+
+        # Use a local cache to front for the cache for the duration of a block.
         def with_local_cache
-          Thread.current[thread_local_key] = MemoryStore.new
-          yield
-        ensure
-          Thread.current[thread_local_key] = nil
+          save_val = Thread.current[thread_local_key]
+          begin
+            Thread.current[thread_local_key] = LocalStore.new
+            yield
+          ensure
+            Thread.current[thread_local_key] = save_val
+          end
         end
 
+        # Middleware class can be inserted as a Rack handler to use a local cache for the
+        # duration of a request.
         def middleware
           @middleware ||= begin
             klass = Class.new
@@ -24,7 +61,7 @@ module ActiveSupport
               end
 
               def call(env)
-                Thread.current[:#{thread_local_key}] = MemoryStore.new
+                Thread.current[:#{thread_local_key}] = LocalStore.new
                 @app.call(env)
               ensure
                 Thread.current[:#{thread_local_key}] = nil
@@ -39,73 +76,86 @@ module ActiveSupport
           end
         end
 
-        def read(key, options = nil)
-          value = local_cache && local_cache.read(key)
-          if value == NULL
-            nil
-          elsif value.nil?
-            value = super
-            local_cache.mute { local_cache.write(key, value || NULL) } if local_cache
-            value.duplicable? ? value.dup : value
-          else
-            # forcing the value to be immutable
-            value.duplicable? ? value.dup : value
-          end
-        end
-
-        def write(key, value, options = nil)
-          value = value.to_s if respond_to?(:raw?) && raw?(options)
-          local_cache.mute { local_cache.write(key, value || NULL) } if local_cache
+        def clear(options = nil) # :nodoc:
+          local_cache.clear(options) if local_cache
           super
         end
 
-        def delete(key, options = nil)
-          local_cache.mute { local_cache.write(key, NULL) } if local_cache
+        def cleanup(options = nil) # :nodoc:
+          local_cache.clear(options) if local_cache
           super
         end
 
-        def exist(key, options = nil)
-          value = local_cache.read(key) if local_cache
-          if value == NULL
-            false
-          elsif value
-            true
-          else
-            super
+        def increment(name, amount = 1, options = nil) # :nodoc:
+          value = bypass_local_cache{super}
+          if local_cache
+            local_cache.mute do
+              if value
+                local_cache.write(name, value, options)
+              else
+                local_cache.delete(name, options)
+              end
+            end
           end
+          value
         end
 
-        def increment(key, amount = 1)
-          if value = super
-            local_cache.mute { local_cache.write(key, value.to_s) } if local_cache
-            value
-          else
-            nil
+        def decrement(name, amount = 1, options = nil) # :nodoc:
+          value = bypass_local_cache{super}
+          if local_cache
+            local_cache.mute do
+              if value
+                local_cache.write(name, value, options)
+              else
+                local_cache.delete(name, options)
+              end
+            end
           end
+          value
         end
 
-        def decrement(key, amount = 1)
-          if value = super
-            local_cache.mute { local_cache.write(key, value.to_s) } if local_cache
-            value
-          else
-            nil
+        protected
+          def read_entry(key, options) # :nodoc:
+            if local_cache
+              entry = local_cache.read_entry(key, options)
+              unless entry
+                entry = super
+                local_cache.write_entry(key, entry, options)
+              end
+              entry
+            else
+              super
+            end
           end
-        end
 
-        def clear
-          local_cache.clear if local_cache
-          super
-        end
+          def write_entry(key, entry, options) # :nodoc:
+            local_cache.write_entry(key, entry, options) if local_cache
+            super
+          end
+
+          def delete_entry(key, options) # :nodoc:
+            local_cache.delete_entry(key, options) if local_cache
+            super
+          end
 
         private
           def thread_local_key
-            @thread_local_key ||= "#{self.class.name.underscore}_local_cache".gsub("/", "_").to_sym
+            @thread_local_key ||= "#{self.class.name.underscore}_local_cache_#{self.object_id}".gsub("/", "_").to_sym
           end
 
           def local_cache
             Thread.current[thread_local_key]
           end
+
+          def bypass_local_cache
+            save_cache = Thread.current[thread_local_key]
+            begin
+              Thread.current[thread_local_key] = nil
+              yield
+            ensure
+              Thread.current[thread_local_key] = save_cache
+            end
+          end
       end
     end
   end
diff --git a/activesupport/lib/active_support/cache/synchronized_memory_store.rb b/activesupport/lib/active_support/cache/synchronized_memory_store.rb
index ea03a119c6..37caa6b6f1 100644
--- a/activesupport/lib/active_support/cache/synchronized_memory_store.rb
+++ b/activesupport/lib/active_support/cache/synchronized_memory_store.rb
@@ -2,45 +2,9 @@ module ActiveSupport
   module Cache
     # Like MemoryStore, but thread-safe.
     class SynchronizedMemoryStore < MemoryStore
-      def initialize
+      def initialize(*args)
+        ActiveSupport::Deprecation.warn('ActiveSupport::Cache::SynchronizedMemoryStore has been deprecated in favor of ActiveSupport::Cache::MemoryStore.', caller)
         super
-        @guard = Monitor.new
-      end
-
-      def fetch(key, options = {})
-        @guard.synchronize { super }
-      end
-
-      def read(name, options = nil)
-        @guard.synchronize { super }
-      end
-
-      def write(name, value, options = nil)
-        @guard.synchronize { super }
-      end
-
-      def delete(name, options = nil)
-        @guard.synchronize { super }
-      end
-
-      def delete_matched(matcher, options = nil)
-        @guard.synchronize { super }
-      end
-
-      def exist?(name,options = nil)
-        @guard.synchronize { super }
-      end
-
-      def increment(key, amount = 1)
-        @guard.synchronize { super }
-      end
-
-      def decrement(key, amount = 1)
-        @guard.synchronize { super }
-      end
-
-      def clear
-        @guard.synchronize { super }
       end
     end
   end
diff --git a/activesupport/test/caching_test.rb b/activesupport/test/caching_test.rb
index e62e7ef9aa..d9ff1207e7 100644
--- a/activesupport/test/caching_test.rb
+++ b/activesupport/test/caching_test.rb
@@ -4,6 +4,7 @@ require 'active_support/cache'
 
 class CacheKeyTest < ActiveSupport::TestCase
   def test_expand_cache_key
+    assert_equal '1/2/true', ActiveSupport::Cache.expand_cache_key([1, '2', true])
     assert_equal 'name/1/2/true', ActiveSupport::Cache.expand_cache_key([1, '2', true], :name)
   end
 end
@@ -43,9 +44,10 @@ class CacheStoreSettingTest < ActiveSupport::TestCase
   end
 
   def test_mem_cache_fragment_cache_store_with_options
-    MemCache.expects(:new).with(%w[localhost 192.168.1.1], { :namespace => "foo" })
-    store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost", '192.168.1.1', :namespace => 'foo'
+    MemCache.expects(:new).with(%w[localhost 192.168.1.1], { :timeout => 10 })
+    store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost", '192.168.1.1', :namespace => 'foo', :timeout => 10
     assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
+    assert_equal 'foo', store.options[:namespace]
   end
 
   def test_object_assigned_fragment_cache_store
@@ -55,124 +57,170 @@ class CacheStoreSettingTest < ActiveSupport::TestCase
   end
 end
 
-class CacheStoreTest < ActiveSupport::TestCase
-  def setup
-    @cache = ActiveSupport::Cache.lookup_store(:memory_store)
+class CacheStoreNamespaceTest < ActiveSupport::TestCase
+  def test_static_namespace
+    cache = ActiveSupport::Cache.lookup_store(:memory_store, :namespace => "tester")
+    cache.write("foo", "bar")
+    assert_equal "bar", cache.read("foo")
+    assert_equal "bar", cache.instance_variable_get(:@data)["tester:foo"].value
+  end
+
+  def test_proc_namespace
+    test_val = "tester"
+    proc = lambda{test_val}
+    cache = ActiveSupport::Cache.lookup_store(:memory_store, :namespace => proc)
+    cache.write("foo", "bar")
+    assert_equal "bar", cache.read("foo")
+    assert_equal "bar", cache.instance_variable_get(:@data)["tester:foo"].value
+  end
+
+  def test_delete_matched_key_start
+    cache = ActiveSupport::Cache.lookup_store(:memory_store, :namespace => "tester")
+    cache.write("foo", "bar")
+    cache.write("fu", "baz")
+    cache.delete_matched(/^fo/)
+    assert_equal false, cache.exist?("foo")
+    assert_equal true, cache.exist?("fu")
+  end
+
+  def test_delete_matched_key
+    cache = ActiveSupport::Cache.lookup_store(:memory_store, :namespace => "foo")
+    cache.write("foo", "bar")
+    cache.write("fu", "baz")
+    cache.delete_matched(/OO/i)
+    assert_equal false, cache.exist?("foo")
+    assert_equal true, cache.exist?("fu")
+  end
+end
+
+# Tests the base functionality that should be identical across all cache stores.
+module CacheStoreBehavior
+  def test_should_read_and_write_strings
+    assert_equal true, @cache.write('foo', 'bar')
+    assert_equal 'bar', @cache.read('foo')
+  end
+
+  def test_should_overwrite
+    @cache.write('foo', 'bar')
+    @cache.write('foo', 'baz')
+    assert_equal 'baz', @cache.read('foo')
   end
 
   def test_fetch_without_cache_miss
-    @cache.stubs(:read).with('foo', {}).returns('bar')
+    @cache.write('foo', 'bar')
     @cache.expects(:write).never
     assert_equal 'bar', @cache.fetch('foo') { 'baz' }
   end
 
   def test_fetch_with_cache_miss
-    @cache.stubs(:read).with('foo', {}).returns(nil)
-    @cache.expects(:write).with('foo', 'baz', {})
+    @cache.expects(:write).with('foo', 'baz', @cache.options)
     assert_equal 'baz', @cache.fetch('foo') { 'baz' }
   end
 
   def test_fetch_with_forced_cache_miss
+    @cache.write('foo', 'bar')
     @cache.expects(:read).never
-    @cache.expects(:write).with('foo', 'bar', :force => true)
+    @cache.expects(:write).with('foo', 'bar', @cache.options.merge(:force => true))
     @cache.fetch('foo', :force => true) { 'bar' }
   end
-end
 
-# Tests the base functionality that should be identical across all cache stores.
-module CacheStoreBehavior
-  def test_should_read_and_write_strings
-    @cache.write('foo', 'bar')
-    assert_equal 'bar', @cache.read('foo')
+  def test_fetch_with_cached_nil
+    @cache.write('foo', nil)
+    @cache.expects(:write).never
+    assert_nil @cache.fetch('foo') { 'baz' }
   end
 
   def test_should_read_and_write_hash
-    @cache.write('foo', {:a => "b"})
+    assert_equal true, @cache.write('foo', {:a => "b"})
     assert_equal({:a => "b"}, @cache.read('foo'))
   end
 
   def test_should_read_and_write_integer
-    @cache.write('foo', 1)
+    assert_equal true, @cache.write('foo', 1)
     assert_equal 1, @cache.read('foo')
   end
 
   def test_should_read_and_write_nil
-    @cache.write('foo', nil)
+    assert_equal true, @cache.write('foo', nil)
     assert_equal nil, @cache.read('foo')
   end
 
-  def test_fetch_without_cache_miss
+  def test_read_multi
     @cache.write('foo', 'bar')
-    assert_equal 'bar', @cache.fetch('foo') { 'baz' }
+    @cache.write('fu', 'baz')
+    @cache.write('fud', 'biz')
+    assert_equal({"foo" => "bar", "fu" => "baz"}, @cache.read_multi('foo', 'fu'))
   end
 
-  def test_fetch_with_cache_miss
-    assert_equal 'baz', @cache.fetch('foo') { 'baz' }
+  def test_read_and_write_compressed_small_data
+    @cache.write('foo', 'bar', :compress => true)
+    raw_value = @cache.send(:read_entry, 'foo', {}).raw_value
+    assert_equal 'bar', @cache.read('foo')
+    assert_equal 'bar', raw_value
   end
 
-  def test_fetch_with_forced_cache_miss
-    @cache.fetch('foo', :force => true) { 'bar' }
+  def test_read_and_write_compressed_large_data
+    @cache.write('foo', 'bar', :compress => true, :compress_threshold => 2)
+    raw_value = @cache.send(:read_entry, 'foo', {}).raw_value
+    assert_equal 'bar', @cache.read('foo')
+    assert_equal 'bar', Marshal.load(Zlib::Inflate.inflate(raw_value))
   end
 
-  def test_increment
-    @cache.write('foo', 1, :raw => true)
-    assert_equal 1, @cache.read('foo', :raw => true).to_i
-    assert_equal 2, @cache.increment('foo')
-    assert_equal 2, @cache.read('foo', :raw => true).to_i
-    assert_equal 3, @cache.increment('foo')
-    assert_equal 3, @cache.read('foo', :raw => true).to_i
+  def test_read_and_write_compressed_nil
+    @cache.write('foo', nil, :compress => true)
+    assert_nil @cache.read('foo')
   end
 
-  def test_decrement
-    @cache.write('foo', 3, :raw => true)
-    assert_equal 3, @cache.read('foo', :raw => true).to_i
-    assert_equal 2, @cache.decrement('foo')
-    assert_equal 2, @cache.read('foo', :raw => true).to_i
-    assert_equal 1, @cache.decrement('foo')
-    assert_equal 1, @cache.read('foo', :raw => true).to_i
+  def test_cache_key
+    obj = Object.new
+    def obj.cache_key
+      :foo
+    end
+    @cache.write(obj, "bar")
+    assert_equal "bar", @cache.read("foo")
   end
 
-  def test_exist
-    @cache.write('foo', 'bar')
-    assert @cache.exist?('foo')
-    assert !@cache.exist?('bar')
+  def test_param_as_cache_key
+    obj = Object.new
+    def obj.to_param
+      "foo"
+    end
+    @cache.write(obj, "bar")
+    assert_equal "bar", @cache.read("foo")
   end
-end
 
-class FileStoreTest < ActiveSupport::TestCase
-  def setup
-    @cache = ActiveSupport::Cache.lookup_store(:file_store, Dir.pwd)
+  def test_array_as_cache_key
+    @cache.write([:fu, "foo"], "bar")
+    assert_equal "bar", @cache.read("fu/foo")
   end
 
-  def teardown
-    File.delete("foo.cache")
+  def test_hash_as_cache_key
+    @cache.write({:foo => 1, :fu => 2}, "bar")
+    assert_equal "bar", @cache.read("foo=1/fu=2")
   end
 
-  include CacheStoreBehavior
-
-  def test_expires_in
-    time = Time.local(2008, 4, 24)
-    Time.stubs(:now).returns(time)
-    File.stubs(:mtime).returns(time)
+  def test_keys_are_case_sensitive
+    @cache.write("foo", "bar")
+    assert_nil @cache.read("FOO")
+  end
 
+  def test_exist
     @cache.write('foo', 'bar')
-    cache_read = lambda { @cache.read('foo', :expires_in => 60) }
-    assert_equal 'bar', cache_read.call
-
-    Time.stubs(:now).returns(time + 30)
-    assert_equal 'bar', cache_read.call
-
-    Time.stubs(:now).returns(time + 120)
-    assert_nil cache_read.call
+    assert_equal true, @cache.exist?('foo')
+    assert_equal false, @cache.exist?('bar')
   end
-end
 
-class MemoryStoreTest < ActiveSupport::TestCase
-  def setup
-    @cache = ActiveSupport::Cache.lookup_store(:memory_store)
+  def test_nil_exist
+    @cache.write('foo', nil)
+    assert_equal true, @cache.exist?('foo')
   end
 
-  include CacheStoreBehavior
+  def test_delete
+    @cache.write('foo', 'bar')
+    assert @cache.exist?('foo')
+    assert_equal true, @cache.delete('foo')
+    assert !@cache.exist?('foo')
+  end
 
   def test_store_objects_should_be_immutable
     @cache.write('foo', 'bar')
@@ -186,175 +234,365 @@ class MemoryStoreTest < ActiveSupport::TestCase
     assert_nothing_raised { bar.gsub!(/.*/, 'baz') }
   end
 
-  def test_multi_get
-    @cache.write('foo', 1)
-    @cache.write('goo', 2)
-    result = @cache.read_multi('foo', 'goo')
-    assert_equal({'foo' => 1, 'goo' => 2}, result)
+  def test_expires_in
+    time = Time.local(2008, 4, 24)
+    Time.stubs(:now).returns(time)
+
+    @cache.write('foo', 'bar')
+    assert_equal 'bar', @cache.read('foo')
+
+    Time.stubs(:now).returns(time + 30)
+    assert_equal 'bar', @cache.read('foo')
+
+    Time.stubs(:now).returns(time + 61)
+    assert_nil @cache.read('foo')
   end
-end
 
-uses_memcached 'memcached backed store' do
-  class MemCacheStoreTest < ActiveSupport::TestCase
-    def setup
-      @cache = ActiveSupport::Cache.lookup_store(:mem_cache_store)
-      @data = @cache.instance_variable_get(:@data)
-      @cache.clear
-      @cache.silence!
-      @cache.logger = Logger.new("/dev/null")
+  def test_race_condition_protection
+    time = Time.now
+    @cache.write('foo', 'bar', :expires_in => 60)
+    Time.stubs(:now).returns(time + 61)
+    result = @cache.fetch('foo', :race_condition_ttl => 10) do
+      assert_equal 'bar', @cache.read('foo')
+      "baz"
     end
+    assert_equal "baz", result
+  end
 
-    include CacheStoreBehavior
+  def test_race_condition_protection_is_limited
+    time = Time.now
+    @cache.write('foo', 'bar', :expires_in => 60)
+    Time.stubs(:now).returns(time + 71)
+    result = @cache.fetch('foo', :race_condition_ttl => 10) do
+      assert_equal nil, @cache.read('foo')
+      "baz"
+    end
+    assert_equal "baz", result
+  end
 
-    def test_store_objects_should_be_immutable
-      @cache.with_local_cache do
-        @cache.write('foo', 'bar')
-        @cache.read('foo').gsub!(/.*/, 'baz')
+  def test_race_condition_protection_is_safe
+    time = Time.now
+    @cache.write('foo', 'bar', :expires_in => 60)
+    Time.stubs(:now).returns(time + 61)
+    begin
+      @cache.fetch('foo', :race_condition_ttl => 10) do
         assert_equal 'bar', @cache.read('foo')
+        raise ArgumentError.new
       end
+    rescue ArgumentError => e
     end
+    assert_equal "bar", @cache.read('foo')
+    Time.stubs(:now).returns(time + 71)
+    assert_nil @cache.read('foo')
+  end
+
+  def test_crazy_key_characters
+    crazy_key = "#/:*(<+=> )&$%@?;'\"\'`~-"
+    assert_equal true, @cache.write(crazy_key, "1", :raw => true)
+    assert_equal "1", @cache.read(crazy_key)
+    assert_equal "1", @cache.fetch(crazy_key)
+    assert_equal true, @cache.delete(crazy_key)
+    assert_equal "2", @cache.fetch(crazy_key, :raw => true) { "2" }
+    assert_equal 3, @cache.increment(crazy_key)
+    assert_equal 2, @cache.decrement(crazy_key)
+  end
+
+  def test_really_long_keys
+    key = ""
+    1000.times{key << "x"}
+    assert_equal true, @cache.write(key, "bar")
+    assert_equal "bar", @cache.read(key)
+    assert_equal "bar", @cache.fetch(key)
+    assert_nil @cache.read("#{key}x")
+    assert_equal({key => "bar"}, @cache.read_multi(key))
+    assert_equal true, @cache.delete(key)
+  end
+end
 
-    def test_stored_objects_should_not_be_frozen
-      @cache.with_local_cache do
-        @cache.write('foo', 'bar')
-      end
-      @cache.with_local_cache do
-        assert !@cache.read('foo').frozen?
-      end
+module CacheDeleteMatchedBehavior
+  def test_delete_matched
+    @cache.write("foo", "bar")
+    @cache.write("fu", "baz")
+    @cache.delete_matched(/oo/)
+    assert_equal false, @cache.exist?("foo")
+    assert_equal true, @cache.exist?("fu")
+  end
+end
+
+module CacheIncrementDecrementBehavior
+  def test_increment
+    @cache.write('foo', 1, :raw => true)
+    assert_equal 1, @cache.read('foo').to_i
+    assert_equal 2, @cache.increment('foo')
+    assert_equal 2, @cache.read('foo').to_i
+    assert_equal 3, @cache.increment('foo')
+    assert_equal 3, @cache.read('foo').to_i
+  end
+
+  def test_decrement
+    @cache.write('foo', 3, :raw => true)
+    assert_equal 3, @cache.read('foo').to_i
+    assert_equal 2, @cache.decrement('foo')
+    assert_equal 2, @cache.read('foo').to_i
+    assert_equal 1, @cache.decrement('foo')
+    assert_equal 1, @cache.read('foo').to_i
+  end
+end
+
+module LocalCacheBehavior
+  def test_local_writes_are_persistent_on_the_remote_cache
+    retval = @cache.with_local_cache do
+      @cache.write('foo', 'bar')
     end
+    assert_equal true, retval
+    assert_equal 'bar', @cache.read('foo')
+  end
 
-    def test_write_should_return_true_on_success
-      @cache.with_local_cache do
-        result = @cache.write('foo', 'bar')
-        assert_equal 'bar', @cache.read('foo') # make sure 'foo' was written
-        assert result
-      end
+  def test_clear_also_clears_local_cache
+    @cache.with_local_cache do
+      @cache.write('foo', 'bar')
+      @cache.clear
+      assert_nil @cache.read('foo')
     end
 
-    def test_local_writes_are_persistent_on_the_remote_cache
-      @cache.with_local_cache do
-        @cache.write('foo', 'bar')
-      end
+    assert_nil @cache.read('foo')
+  end
 
+  def test_local_cache_of_write
+    @cache.with_local_cache do
+      @cache.write('foo', 'bar')
+      @peek.delete('foo')
       assert_equal 'bar', @cache.read('foo')
     end
+  end
 
-    def test_clear_also_clears_local_cache
-      @cache.with_local_cache do
-        @cache.write('foo', 'bar')
-        @cache.clear
-        assert_nil @cache.read('foo')
-      end
+  def test_local_cache_of_read
+    @cache.write('foo', 'bar')
+    @cache.with_local_cache do
+      assert_equal 'bar', @cache.read('foo')
     end
+  end
 
-    def test_local_cache_of_read_and_write
-      @cache.with_local_cache do
-        @cache.write('foo', 'bar')
-        @data.flush_all # Clear remote cache
-        assert_equal 'bar', @cache.read('foo')
-      end
+  def test_local_cache_of_write_nil
+    @cache.with_local_cache do
+      assert true, @cache.write('foo', nil)
+      assert_nil @cache.read('foo')
+      @peek.write('foo', 'bar')
+      assert_nil @cache.read('foo')
     end
+  end
 
-    def test_local_cache_should_read_and_write_integer
-      @cache.with_local_cache do
-        @cache.write('foo', 1)
-        assert_equal 1, @cache.read('foo')
-      end
+  def test_local_cache_of_delete
+    @cache.with_local_cache do
+      @cache.write('foo', 'bar')
+      @cache.delete('foo')
+      assert_nil @cache.read('foo')
     end
+  end
 
-    def test_local_cache_of_delete
-      @cache.with_local_cache do
-        @cache.write('foo', 'bar')
-        @cache.delete('foo')
-        @data.flush_all # Clear remote cache
-        assert_nil @cache.read('foo')
-      end
+  def test_local_cache_of_exist
+    @cache.with_local_cache do
+      @cache.write('foo', 'bar')
+      @peek.delete('foo')
+      assert true, @cache.exist?('foo')
     end
+  end
 
-    def test_local_cache_of_exist
-      @cache.with_local_cache do
-        @cache.write('foo', 'bar')
-        @cache.instance_variable_set(:@data, nil)
-        @data.flush_all # Clear remote cache
-        assert @cache.exist?('foo')
-      end
+  def test_local_cache_of_increment
+    @cache.with_local_cache do
+      @cache.write('foo', 1, :raw => true)
+      @peek.write('foo', 2, :raw => true)
+      @cache.increment('foo')
+      assert_equal 3, @cache.read('foo')
     end
+  end
 
-    def test_local_cache_of_increment
-      @cache.with_local_cache do
-        @cache.write('foo', 1, :raw => true)
-        @cache.increment('foo')
-        @data.flush_all # Clear remote cache
-        assert_equal 2, @cache.read('foo', :raw => true).to_i
-      end
+  def test_local_cache_of_decrement
+    @cache.with_local_cache do
+      @cache.write('foo', 1, :raw => true)
+      @peek.write('foo', 3, :raw => true)
+      @cache.decrement('foo')
+      assert_equal 2, @cache.read('foo')
     end
+  end
 
-    def test_local_cache_of_decrement
-      @cache.with_local_cache do
-        @cache.write('foo', 1, :raw => true)
-        @cache.decrement('foo')
-        @data.flush_all # Clear remote cache
-        assert_equal 0, @cache.read('foo', :raw => true).to_i
-      end
-    end
+  def test_middleware
+    app = lambda { |env|
+      result = @cache.write('foo', 'bar')
+      assert_equal 'bar', @cache.read('foo') # make sure 'foo' was written
+      assert result
+    }
+    app = @cache.middleware.new(app)
+    app.call({})
+  end
+end
 
-    def test_exist_with_nulls_cached_locally
-      @cache.with_local_cache do
-        @cache.write('foo', 'bar')
-        @cache.delete('foo')
-        assert !@cache.exist?('foo')
-      end
+class FileStoreTest < ActiveSupport::TestCase
+  def setup
+    Dir.mkdir(cache_dir) unless File.exist?(cache_dir)
+    @cache = ActiveSupport::Cache.lookup_store(:file_store, cache_dir, :expires_in => 60)
+    @peek = ActiveSupport::Cache.lookup_store(:file_store, cache_dir, :expires_in => 60)
+  end
+
+  def teardown
+    FileUtils.rm_r(cache_dir)
+  end
+
+  def cache_dir
+    File.join(Dir.pwd, 'tmp_cache')
+  end
+
+  include CacheStoreBehavior
+  include LocalCacheBehavior
+  include CacheDeleteMatchedBehavior
+  include CacheIncrementDecrementBehavior
+
+  def test_deprecated_expires_in_on_read
+    ActiveSupport::Deprecation.silence do
+      old_cache = ActiveSupport::Cache.lookup_store(:file_store, cache_dir)
+
+      time = Time.local(2008, 4, 24)
+      Time.stubs(:now).returns(time)
+
+      old_cache.write("foo", "bar")
+      assert_equal 'bar', old_cache.read('foo', :expires_in => 60)
+
+      Time.stubs(:now).returns(time + 30)
+      assert_equal 'bar', old_cache.read('foo', :expires_in => 60)
+
+      Time.stubs(:now).returns(time + 61)
+      assert_equal 'bar', old_cache.read('foo')
+      assert_nil old_cache.read('foo', :expires_in => 60)
+      assert_nil old_cache.read('foo')
     end
+  end
+end
 
-    def test_multi_get
-      @cache.with_local_cache do
-        @cache.write('foo', 1)
-        @cache.write('goo', 2)
-        result = @cache.read_multi('foo', 'goo')
-        assert_equal({'foo' => 1, 'goo' => 2}, result)
-      end
+class MemoryStoreTest < ActiveSupport::TestCase
+  def setup
+    @cache = ActiveSupport::Cache.lookup_store(:memory_store, :expires_in => 60, :size => 100)
+  end
+
+  include CacheStoreBehavior
+  include CacheDeleteMatchedBehavior
+  include CacheIncrementDecrementBehavior
+
+  def test_prune_size
+    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
+    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
+    @cache.write(3, "cccccccccc") && sleep(0.001)
+    @cache.write(4, "dddddddddd") && sleep(0.001)
+    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
+    @cache.read(2) && sleep(0.001)
+    @cache.read(4)
+    @cache.prune(30)
+    assert_equal true, @cache.exist?(5)
+    assert_equal true, @cache.exist?(4)
+    assert_equal false, @cache.exist?(3)
+    assert_equal true, @cache.exist?(2)
+    assert_equal false, @cache.exist?(1)
+  end
+
+  def test_prune_size_on_write
+    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
+    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
+    @cache.write(3, "cccccccccc") && sleep(0.001)
+    @cache.write(4, "dddddddddd") && sleep(0.001)
+    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
+    @cache.write(6, "ffffffffff") && sleep(0.001)
+    @cache.write(7, "gggggggggg") && sleep(0.001)
+    @cache.write(8, "hhhhhhhhhh") && sleep(0.001)
+    @cache.write(9, "iiiiiiiiii") && sleep(0.001)
+    @cache.write(10, "kkkkkkkkkk") && sleep(0.001)
+    @cache.read(2) && sleep(0.001)
+    @cache.read(4) && sleep(0.001)
+    @cache.write(11, "llllllllll")
+    assert_equal true, @cache.exist?(11)
+    assert_equal true, @cache.exist?(10)
+    assert_equal true, @cache.exist?(9)
+    assert_equal true, @cache.exist?(8)
+    assert_equal true, @cache.exist?(7)
+    assert_equal false, @cache.exist?(6)
+    assert_equal false, @cache.exist?(5)
+    assert_equal true, @cache.exist?(4)
+    assert_equal false, @cache.exist?(3)
+    assert_equal true, @cache.exist?(2)
+    assert_equal false, @cache.exist?(1)
+  end
+
+  def test_pruning_is_capped_at_a_max_time
+    def @cache.delete_entry (*args)
+      sleep(0.01)
+      super
     end
+    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
+    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
+    @cache.write(3, "cccccccccc") && sleep(0.001)
+    @cache.write(4, "dddddddddd") && sleep(0.001)
+    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
+    @cache.prune(30, 0.001)
+    assert_equal true, @cache.exist?(5)
+    assert_equal true, @cache.exist?(4)
+    assert_equal true, @cache.exist?(3)
+    assert_equal true, @cache.exist?(2)
+    assert_equal false, @cache.exist?(1)
+  end
+end
 
-    def test_middleware
-      app = lambda { |env|
-        result = @cache.write('foo', 'bar')
-        assert_equal 'bar', @cache.read('foo') # make sure 'foo' was written
-        assert result
-      }
-      app = @cache.middleware.new(app)
-      app.call({})
+class SynchronizedStoreTest < ActiveSupport::TestCase
+  def setup
+    ActiveSupport::Deprecation.silence do
+      @cache = ActiveSupport::Cache.lookup_store(:memory_store, :expires_in => 60)
     end
+  end
 
-    def test_expires_in
-      result = @cache.write('foo', 'bar', :expires_in => 1)
-      assert_equal 'bar', @cache.read('foo')
-      sleep 2
-      assert_equal nil, @cache.read('foo')
+  include CacheStoreBehavior
+  include CacheDeleteMatchedBehavior
+  include CacheIncrementDecrementBehavior
+end
+
+uses_memcached 'memcached backed store' do
+  class MemCacheStoreTest < ActiveSupport::TestCase
+    def setup
+      @cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, :expires_in => 60)
+      @peek = ActiveSupport::Cache.lookup_store(:mem_cache_store)
+      @data = @cache.instance_variable_get(:@data)
+      @cache.clear
+      @cache.silence!
+      @cache.logger = Logger.new("/dev/null")
     end
 
-    def test_expires_in_with_invalid_value
-      @cache.write('baz', 'bat')
-      assert_raise(RuntimeError) do
-        @cache.write('foo', 'bar', :expires_in => 'Mon Jun 29 13:10:40 -0700 2150')
-      end
-      assert_equal 'bat', @cache.read('baz')
-      assert_equal nil, @cache.read('foo')
+    include CacheStoreBehavior
+    include LocalCacheBehavior
+    include CacheIncrementDecrementBehavior
+
+    def test_raw_values
+      cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, :raw => true)
+      cache.clear
+      cache.write("foo", 2)
+      assert_equal "2", cache.read("foo")
     end
 
-    def test_delete_should_only_pass_key_to_data
-      key = 'foo'
-      @data.expects(:delete).with(key)
-      @cache.delete(key)
+    def test_local_cache_raw_values
+      cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, :raw => true)
+      cache.clear
+      cache.with_local_cache do
+        cache.write("foo", 2)
+        assert_equal "2", cache.read("foo")
+      end
     end
   end
 
   class CompressedMemCacheStore < ActiveSupport::TestCase
     def setup
-      @cache = ActiveSupport::Cache.lookup_store(:compressed_mem_cache_store)
-      @cache.clear
+      ActiveSupport::Deprecation.silence do
+        @cache = ActiveSupport::Cache.lookup_store(:compressed_mem_cache_store, :expires_in => 60)
+        @cache.clear
+      end
     end
 
     include CacheStoreBehavior
+    include CacheIncrementDecrementBehavior
   end
 end
 
@@ -376,3 +614,38 @@ class CacheStoreLoggerTest < ActiveSupport::TestCase
     assert @buffer.string.blank?
   end
 end
+
+class CacheEntryTest < ActiveSupport::TestCase
+  def test_create_raw_entry
+    time = Time.now
+    entry = ActiveSupport::Cache::Entry.create("raw", time, :compress => false, :expires_in => 300)
+    assert_equal "raw", entry.raw_value
+    assert_equal time.to_f, entry.created_at
+    assert_equal false, entry.compressed?
+    assert_equal 300, entry.expires_in
+  end
+
+  def test_expired
+    entry = ActiveSupport::Cache::Entry.new("value")
+    assert_equal false, entry.expired?
+    entry = ActiveSupport::Cache::Entry.new("value", :expires_in => 60)
+    assert_equal false, entry.expired?
+    time = Time.now + 61
+    Time.stubs(:now).returns(time)
+    assert_equal true, entry.expired?
+  end
+
+  def test_compress_values
+    entry = ActiveSupport::Cache::Entry.new("value", :compress => true, :compress_threshold => 1)
+    assert_equal "value", entry.value
+    assert_equal true, entry.compressed?
+    assert_equal "value", Marshal.load(Zlib::Inflate.inflate(entry.raw_value))
+  end
+
+  def test_non_compress_values
+    entry = ActiveSupport::Cache::Entry.new("value")
+    assert_equal "value", entry.value
+    assert_equal "value", entry.raw_value
+    assert_equal false, entry.compressed?
+  end
+end