aboutsummaryrefslogtreecommitdiffstats
path: root/activesupport/lib/active_support
diff options
context:
space:
mode:
Diffstat (limited to 'activesupport/lib/active_support')
-rw-r--r--activesupport/lib/active_support/cache.rb148
-rw-r--r--activesupport/lib/active_support/cache/memory_store.rb1
2 files changed, 86 insertions, 63 deletions
diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index f98ba16cdd..a681a8d6a9 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -284,7 +284,9 @@ module ActiveSupport
end
if entry && entry.expired?
race_ttl = options[:race_condition_ttl].to_i
- if race_ttl and Time.now.to_f - entry.expires_at <= race_ttl
+ if race_ttl && (Time.now - 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.
entry.expires_at = Time.now + race_ttl
write_entry(key, entry, :expires_in => race_ttl * 2)
else
@@ -532,102 +534,122 @@ module ActiveSupport
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
-
+ # This class is used to represent cache entries. Cache entries have a value and an optional
+ # expiration time. The expiration time is used to support the :race_condition_ttl option
+ # on the cache.
+ #
+ # Since cache entries in most instances will be serialized, the internals of this class are highly optimized
+ # using short instance variable names that are lazily defined.
+ class Entry # :nodoc:
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.nil?
- @value = nil
+ if should_compress?(value, options)
+ @v = compress(value)
+ @c = true
else
- @value = Marshal.dump(value)
- if should_compress?(@value, options)
- @value = Zlib::Deflate.deflate(@value)
- @compressed = true
- end
+ @v = value
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 the original value was exactly false @value is still true because
- # it is marshalled and eventually compressed. Both operations yield
- # strings.
- if @value
- Marshal.load(compressed? ? Zlib::Inflate.inflate(@value) : @value)
+ if expires_in = options[:expires_in]
+ @x = (Time.now + expires_in).to_i
end
end
- def compressed?
- @compressed
+ def value
+ convert_version_3_entry! if defined?(@value)
+ compressed? ? uncompress(@v) : @v
end
# Check if the entry is expired. The +expires_in+ parameter can override
# the value set when the entry was created.
def expired?
- @expires_in && @created_at + @expires_in <= Time.now.to_f
- end
-
- # Set a new time when the entry will expire.
- def expires_at=(time)
- if time
- @expires_in = time.to_f - @created_at
+ convert_version_3_entry! if defined?(@value)
+ if defined?(@x)
+ @x && @x < Time.now.to_i
else
- @expires_in = nil
+ false
end
end
- # Seconds since the epoch when the entry will expire.
def expires_at
- @expires_in ? @created_at + @expires_in : nil
+ Time.at(@x) if defined?(@x)
+ end
+
+ def expires_at=(value)
+ @x = value.to_i
end
# Returns the size of the cached value. This could be less than
# <tt>value.size</tt> if the data is compressed.
def size
- if @value.nil?
- 0
+ if defined?(@s)
+ @s
else
- @value.bytesize
+ case value
+ when NilClass
+ 0
+ when String
+ value.bytesize
+ else
+ @s = Marshal.dump(value).bytesize
+ end
+ end
+ 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_3_entry! if defined?(@value)
+ if @v && !compressed? && !(@v.is_a?(Numeric) || @v == true || @v == false)
+ if @v.is_a?(String)
+ @v = @v.dup
+ else
+ @v = Marshal.load(Marshal.dump(@v))
+ end
end
end
private
- def should_compress?(serialized_value, options)
- if options[:compress]
+ def should_compress?(value, options)
+ if value && options[:compress]
compress_threshold = options[:compress_threshold] || DEFAULT_COMPRESS_LIMIT
- return true if serialized_value.size >= compress_threshold
+ serialized_value_size = (value.is_a?(String) ? value : Marshal.dump(value)).bytesize
+ return true if serialized_value_size >= compress_threshold
end
false
end
+
+ def compressed?
+ defined?(@c) ? @c : false
+ end
+
+ def compress(value)
+ 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_3_entry!
+ if defined?(@value)
+ @v = @value
+ remove_instance_variable(:@value)
+ end
+ if defined?(@compressed)
+ @c = @compressed
+ remove_instance_variable(:@compressed)
+ end
+ if defined?(@expires_in) && defined?(@created_at)
+ @x = (@created_at + @expires_in).to_i
+ remove_instance_variable(:@created_at)
+ remove_instance_variable(:@expires_in)
+ 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 7fd5e3b53d..4d26fb7e42 100644
--- a/activesupport/lib/active_support/cache/memory_store.rb
+++ b/activesupport/lib/active_support/cache/memory_store.rb
@@ -135,6 +135,7 @@ module ActiveSupport
end
def write_entry(key, entry, options) # :nodoc:
+ entry.dup_value!
synchronize do
old_entry = @data[key]
return false if @data.key?(key) && options[:unless_exist]