cache.rb in activesupport-5.0.0.beta1

- old
+ new

@@ -6,11 +6,11 @@
 require 'active_support/core_ext/module/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'
-require 'active_support/deprecation'
+require 'active_support/core_ext/string/strip'
 
 module ActiveSupport
   # See ActiveSupport::Cache::Store for documentation.
   module Cache
     autoload :FileStore,     'active_support/cache/file_store'
@@ -177,22 +177,10 @@
         yield
       ensure
         @silence = previous_silence
       end
 
-      # :deprecated:
-      def self.instrument=(boolean)
-        ActiveSupport::Deprecation.warn "ActiveSupport::Cache.instrument= is deprecated and will be removed in Rails 5. Instrumentation is now always on so you can safely stop using it."
-        true
-      end
-
-      # :deprecated:
-      def self.instrument
-        ActiveSupport::Deprecation.warn "ActiveSupport::Cache.instrument is deprecated and will be removed in Rails 5. Instrumentation is now always on so you can safely stop using it."
-        true
-      end
-
       # Fetches data from the cache, using the given key. If there is data in
       # the cache with the given key, then that data is returned.
       #
       # If there is no such data in the cache (a cache miss), then +nil+ will be
       # returned. However, if a block has been passed, that block will be passed
@@ -286,19 +274,24 @@
       #   end
       #   cache.fetch('foo') # => "bar"
       def fetch(name, options = nil)
         if block_given?
           options = merged_options(options)
-          key = namespaced_key(name, options)
+          key = normalize_key(name, options)
 
-          cached_entry = find_cached_entry(key, name, options) unless options[:force]
-          entry = handle_expired_entry(cached_entry, key, options)
+          instrument(:read, name, options) do |payload|
+            cached_entry = read_entry(key, options) unless options[:force]
+            payload[:super_operation] = :fetch if payload
+            entry = handle_expired_entry(cached_entry, key, options)
 
-          if entry
-            get_entry_value(entry, name, options)
-          else
-            save_block_result_to_cache(name, options) { |_name| yield _name }
+            if entry
+              payload[:hit] = true if payload
+              get_entry_value(entry, name, options)
+            else
+              payload[:hit] = false if payload
+              save_block_result_to_cache(name, options) { |_name| yield _name }
+            end
           end
         else
           read(name, options)
         end
       end
@@ -308,11 +301,11 @@
       # +nil+ is returned.
       #
       # Options are passed to the underlying cache implementation.
       def read(name, options = nil)
         options = merged_options(options)
-        key = namespaced_key(name, options)
+        key = normalize_key(name, options)
         instrument(:read, name, options) do |payload|
           entry = read_entry(key, options)
           if entry
             if entry.expired?
               delete_entry(key, options)
@@ -336,23 +329,26 @@
       #
       # 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, options)
-            else
-              results[name] = entry.value
+
+        instrument_multi(:read, names, options) do |payload|
+          results = {}
+          names.each do |name|
+            key = normalize_key(name, options)
+            entry = read_entry(key, options)
+            if entry
+              if entry.expired?
+                delete_entry(key, options)
+              else
+                results[name] = entry.value
+              end
             end
           end
+          results
         end
-        results
       end
 
       # Fetches data from the cache, using the given keys. If there is data in
       # the cache with the given keys, then that data is returned. Otherwise,
       # the supplied block is called for each key for which there was no data,
@@ -361,12 +357,15 @@
       # Options are passed to the underlying cache implementation.
       #
       # Returns a hash with the data for each of the names. For example:
       #
       #   cache.write("bim", "bam")
-      #   cache.fetch_multi("bim", "boom") { |key| key * 2 }
-      #   # => { "bam" => "bam", "boom" => "boomboom" }
+      #   cache.fetch_multi("bim", "unknown_key") do |key|
+      #     "Fallback value for key: #{key}"
+      #   end
+      #   # => { "bim" => "bam",
+      #   #      "unknown_key" => "Fallback value for key: unknown_key" }
       #
       def fetch_multi(*names)
         options = names.extract_options!
         options = merged_options(options)
         results = read_multi(*names, options)
@@ -386,33 +385,33 @@
       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)
+          write_entry(normalize_key(name, options), entry, options)
         end
       end
 
       # Deletes an entry in the cache. Returns +true+ if an entry is deleted.
       #
       # 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)
+          delete_entry(normalize_key(name, options), options)
         end
       end
 
       # Returns +true+ if the cache contains an entry for the given key.
       #
       # 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)
+          entry = read_entry(normalize_key(name, options), options)
           (entry && !entry.expired?) || false
         end
       end
 
       # Delete all entries with keys matching the pattern.
@@ -529,44 +528,56 @@
           key.to_param
         end
 
         # Prefix a key with the namespace. Namespace and key will be delimited
         # with a colon.
-        def namespaced_key(key, options)
+        def normalize_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 namespaced_key(*args)
+          ActiveSupport::Deprecation.warn(<<-MESSAGE.strip_heredoc)
+            `namespaced_key` is deprecated and will be removed from Rails 5.1.
+            Please use `normalize_key` which will return a fully resolved key.
+          MESSAGE
+          normalize_key(*args)
+        end
+
         def instrument(operation, key, options = nil)
-          log(operation, key, options)
+          log { "Cache #{operation}: #{normalize_key(key, options)}#{options.blank? ? "" : " (#{options.inspect})"}" }
 
           payload = { :key => key }
           payload.merge!(options) if options.is_a?(Hash)
           ActiveSupport::Notifications.instrument("cache_#{operation}.active_support", payload){ yield(payload) }
         end
 
-        def log(operation, key, options = nil)
-          return unless logger && logger.debug? && !silence?
-          logger.debug("Cache #{operation}: #{key}#{options.blank? ? "" : " (#{options.inspect})"}")
+        def instrument_multi(operation, keys, options = nil)
+          log do
+            formatted_keys = keys.map { |k| "- #{k}" }.join("\n")
+            "Caches multi #{operation}:\n#{formatted_keys}#{options.blank? ? "" : " (#{options.inspect})"}"
+          end
+
+          payload = { key: keys }
+          payload.merge!(options) if options.is_a?(Hash)
+          ActiveSupport::Notifications.instrument("cache_#{operation}_multi.active_support", payload) { yield(payload) }
         end
 
-        def find_cached_entry(key, name, options)
-          instrument(:read, name, options) do |payload|
-            payload[:super_operation] = :fetch if payload
-            read_entry(key, options)
-          end
+        def log
+          return unless logger && logger.debug? && !silence?
+          logger.debug(yield)
         end
 
         def handle_expired_entry(entry, key, options)
           if entry && entry.expired?
             race_ttl = options[:race_condition_ttl].to_i
             if (race_ttl > 0) && (Time.now.to_f - entry.expires_at <= race_ttl)
-              # When an entry has :race_condition_ttl defined, put the stale entry back into the cache
-              # for a brief period while the entry is begin recalculated.
+              # When an entry has a positive :race_condition_ttl defined, put the stale entry back into the cache
+              # for a brief period while the entry is being recalculated.
               entry.expires_at = Time.now + race_ttl
               write_entry(key, entry, :expires_in => race_ttl * 2)
             else
               delete_entry(key, options)
             end
@@ -613,18 +624,16 @@
         @expires_in = options[:expires_in]
         @expires_in = @expires_in.to_f if @expires_in
       end
 
       def value
-        convert_version_4beta1_entry! if defined?(@v)
         compressed? ? uncompress(@value) : @value
       end
 
       # Check if the entry is expired. The +expires_in+ parameter can override
       # the value set when the entry was created.
       def expired?
-        convert_version_4beta1_entry! if defined?(@v)
         @expires_in && @created_at + @expires_in <= Time.now.to_f
       end
 
       def expires_at
         @expires_in ? @created_at + @expires_in : nil
@@ -656,12 +665,10 @@
       end
 
       # Duplicate the value in a class. This is used by cache implementations that don't natively
       # serialize entries to protect against accidental cache modifications.
       def dup_value!
-        convert_version_4beta1_entry! if defined?(@v)
-
         if @value && !compressed? && !(@value.is_a?(Numeric) || @value == true || @value == false)
           if @value.is_a?(String)
             @value = @value.dup
           else
             @value = Marshal.load(Marshal.dump(@value))
@@ -689,29 +696,9 @@
           Zlib::Deflate.deflate(Marshal.dump(value))
         end
 
         def uncompress(value)
           Marshal.load(Zlib::Inflate.inflate(value))
-        end
-
-        # The internals of this method changed between Rails 3.x and 4.0. This method provides the glue
-        # to ensure that cache entries created under the old version still work with the new class definition.
-        def convert_version_4beta1_entry!
-          if defined?(@v)
-            @value = @v
-            remove_instance_variable(:@v)
-          end
-
-          if defined?(@c)
-            @compressed = @c
-            remove_instance_variable(:@c)
-          end
-
-          if defined?(@x) && @x
-            @created_at ||= Time.now.to_f
-            @expires_in = @x - @created_at
-            remove_instance_variable(:@x)
-          end
         end
     end
   end
 end