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-rw-r--r--activesupport/lib/active_support/cache.rb143
1 files changed, 71 insertions, 72 deletions
diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index 610105f41c..ad02546755 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -1,29 +1,27 @@
-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/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/core_ext/string/strip'
+require "zlib"
+require "active_support/core_ext/array/extract_options"
+require "active_support/core_ext/array/wrap"
+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/core_ext/string/strip"
module ActiveSupport
# See ActiveSupport::Cache::Store for documentation.
module Cache
- autoload :FileStore, 'active_support/cache/file_store'
- autoload :MemoryStore, 'active_support/cache/memory_store'
- autoload :MemCacheStore, 'active_support/cache/mem_cache_store'
- autoload :NullStore, 'active_support/cache/null_store'
+ autoload :FileStore, "active_support/cache/file_store"
+ autoload :MemoryStore, "active_support/cache/memory_store"
+ autoload :MemCacheStore, "active_support/cache/mem_cache_store"
+ autoload :NullStore, "active_support/cache/null_store"
# These options mean something to all cache implementations. Individual cache
# implementations may support additional options.
UNIVERSAL_OPTIONS = [:namespace, :compress, :compress_threshold, :expires_in, :race_condition_ttl]
module Strategy
- autoload :LocalCache, 'active_support/cache/strategy/local_cache'
+ autoload :LocalCache, "active_support/cache/strategy/local_cache"
end
class << self
@@ -153,25 +151,25 @@ module ActiveSupport
# or +write+. To specify the threshold at which to compress values, set the
# <tt>:compress_threshold</tt> option. The default threshold is 16K.
class Store
- cattr_accessor :logger, :instance_writer => true
+ cattr_accessor :logger, instance_writer: true
attr_reader :silence, :options
alias :silence? :silence
- # Create a new cache. The options will be passed to any write method calls
+ # Creates a new cache. The options will be passed to any write method calls
# except for <tt>:namespace</tt> which can be used to set the global
# namespace for the cache.
def initialize(options = nil)
@options = options ? options.dup : {}
end
- # Silence the logger.
+ # Silences the logger.
def silence!
@silence = true
self
end
- # Silence the logger within a block.
+ # Silences the logger within a block.
def mute
previous_silence, @silence = defined?(@silence) && @silence, true
yield
@@ -198,10 +196,17 @@ module ActiveSupport
# cache.fetch('city') # => "Duckburgh"
#
# You may also specify additional options via the +options+ argument.
- # Setting <tt>force: true</tt> will force a cache miss:
+ # Setting <tt>force: true</tt> forces a cache "miss," meaning we treat
+ # the cache value as missing even if it's present. Passing a block is
+ # required when +force+ is true so this always results in a cache write.
#
# cache.write('today', 'Monday')
- # cache.fetch('today', force: true) # => nil
+ # cache.fetch('today', force: true) { 'Tuesday' } # => 'Tuesday'
+ # cache.fetch('today', force: true) # => ArgumentError
+ #
+ # The +:force+ option is useful when you're calling some other method to
+ # ask whether you should force a cache write. Otherwise, it's clearer to
+ # just call <tt>Cache#write</tt>.
#
# Setting <tt>:compress</tt> will store a large cache entry set by the call
# in a compressed format.
@@ -243,14 +248,14 @@ module ActiveSupport
# sleep 60
#
# Thread.new do
- # val_1 = cache.fetch('foo', race_condition_ttl: 10) do
+ # val_1 = cache.fetch('foo', race_condition_ttl: 10.seconds) do
# sleep 1
# 'new value 1'
# end
# end
#
# Thread.new do
- # val_2 = cache.fetch('foo', race_condition_ttl: 10) do
+ # val_2 = cache.fetch('foo', race_condition_ttl: 10.seconds) do
# 'new value 2'
# end
# end
@@ -292,6 +297,8 @@ module ActiveSupport
else
save_block_result_to_cache(name, options) { |_name| yield _name }
end
+ elsif options && options[:force]
+ raise ArgumentError, "Missing block: Calling `Cache#fetch` with `force: true` requires a block."
else
read(name, options)
end
@@ -323,7 +330,7 @@ module ActiveSupport
end
end
- # Read multiple values at once from the cache. Options can be passed
+ # Reads multiple values at once from the cache. Options can be passed
# in the last argument.
#
# Some cache implementation may optimize this method.
@@ -333,27 +340,28 @@ module ActiveSupport
options = names.extract_options!
options = merged_options(options)
- 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
+ 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
- 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,
# and the result will be written to the cache and returned.
+ # Therefore, you need to pass a block that returns the data to be written
+ # to the cache. If you do not want to write the cache when the cache is
+ # not found, use #read_multi.
#
# Options are passed to the underlying cache implementation.
#
@@ -367,6 +375,8 @@ module ActiveSupport
# # "unknown_key" => "Fallback value for key: unknown_key" }
#
def fetch_multi(*names)
+ raise ArgumentError, "Missing block: `Cache#fetch_multi` requires a block." unless block_given?
+
options = names.extract_options!
options = merged_options(options)
results = read_multi(*names, options)
@@ -415,7 +425,7 @@ module ActiveSupport
end
end
- # Delete all entries with keys matching the pattern.
+ # Deletes all entries with keys matching the pattern.
#
# Options are passed to the underlying cache implementation.
#
@@ -424,7 +434,7 @@ module ActiveSupport
raise NotImplementedError.new("#{self.class.name} does not support delete_matched")
end
- # Increment an integer value in the cache.
+ # Increments an integer value in the cache.
#
# Options are passed to the underlying cache implementation.
#
@@ -433,7 +443,7 @@ module ActiveSupport
raise NotImplementedError.new("#{self.class.name} does not support increment")
end
- # Decrement an integer value in the cache.
+ # Decrements an integer value in the cache.
#
# Options are passed to the underlying cache implementation.
#
@@ -442,7 +452,7 @@ module ActiveSupport
raise NotImplementedError.new("#{self.class.name} does not support decrement")
end
- # Cleanup the cache by removing expired entries.
+ # Cleanups the cache by removing expired entries.
#
# Options are passed to the underlying cache implementation.
#
@@ -451,18 +461,18 @@ module ActiveSupport
raise NotImplementedError.new("#{self.class.name} does not support cleanup")
end
- # Clear the entire cache. Be careful with this method since it could
+ # Clears the entire cache. Be careful with this method since it could
# affect other processes if shared cache is being used.
#
# The options hash is passed to the underlying cache implementation.
#
# All implementations may not support this method.
- def clear(options = nil)
+ def clear
raise NotImplementedError.new("#{self.class.name} does not support clear")
end
protected
- # Add the namespace defined in the options to a pattern designed to
+ # Adds 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.
@@ -470,7 +480,7 @@ module ActiveSupport
prefix = options[:namespace].is_a?(Proc) ? options[:namespace].call : options[:namespace]
if prefix
source = pattern.source
- if source.start_with?('^')
+ if source.start_with?("^")
source = source[1, source.length]
else
source = ".*#{source[0, source.length]}"
@@ -481,26 +491,26 @@ module ActiveSupport
end
end
- # Read an entry from the cache implementation. Subclasses must implement
+ # Reads 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
+ # Writes 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
+ # Deletes an entry from the cache implementation. Subclasses must
# implement this method.
def delete_entry(key, options) # :nodoc:
raise NotImplementedError.new
end
private
- # Merge the default options with ones specific to a method call.
+ # Merges the default options with ones specific to a method call.
def merged_options(call_options) # :nodoc:
if call_options
options.merge(call_options)
@@ -509,7 +519,7 @@ module ActiveSupport
end
end
- # Expand key to be a consistent string value. Invoke +cache_key+ if
+ # Expands key to be a consistent string value. Invokes +cache_key+ if
# object responds to +cache_key+. Otherwise, +to_param+ method will be
# called. If the key is a Hash, then keys will be sorted alphabetically.
def expanded_key(key) # :nodoc:
@@ -518,18 +528,18 @@ module ActiveSupport
case key
when Array
if key.size > 1
- key = key.collect{|element| expanded_key(element)}
+ key = key.collect { |element| expanded_key(element) }
else
key = key.first
end
when Hash
- key = key.sort_by { |k,_| k.to_s }.collect{|k,v| "#{k}=#{v}"}
+ key = key.sort_by { |k,_| k.to_s }.collect { |k,v| "#{k}=#{v}" }
end
key.to_param
end
- # Prefix a key with the namespace. Namespace and key will be delimited
+ # Prefixes a key with the namespace. Namespace and key will be delimited
# with a colon.
def normalize_key(key, options)
key = expanded_key(key)
@@ -550,20 +560,9 @@ module ActiveSupport
def instrument(operation, key, options = nil)
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 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 = { key: key }
payload.merge!(options) if options.is_a?(Hash)
- ActiveSupport::Notifications.instrument("cache_#{operation}_multi.active_support", payload) { yield(payload) }
+ ActiveSupport::Notifications.instrument("cache_#{operation}.active_support", payload) { yield(payload) }
end
def log
@@ -578,7 +577,7 @@ module ActiveSupport
# 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)
+ write_entry(key, entry, expires_in: race_ttl * 2)
else
delete_entry(key, options)
end
@@ -588,12 +587,12 @@ module ActiveSupport
end
def get_entry_value(entry, name, options)
- instrument(:fetch_hit, name, options) { |payload| }
+ instrument(:fetch_hit, name, options) {}
entry.value
end
def save_block_result_to_cache(name, options)
- result = instrument(:generate, name, options) do |payload|
+ result = instrument(:generate, name, options) do
yield(name)
end
@@ -611,7 +610,7 @@ module ActiveSupport
class Entry # :nodoc:
DEFAULT_COMPRESS_LIMIT = 16.kilobytes
- # Create a new cache entry for the specified value. Options supported are
+ # Creates a new cache entry for the specified value. Options supported are
# +:compress+, +:compress_threshold+, and +:expires_in+.
def initialize(value, options = {})
if should_compress?(value, options)
@@ -630,7 +629,7 @@ module ActiveSupport
compressed? ? uncompress(@value) : @value
end
- # Check if the entry is expired. The +expires_in+ parameter can override
+ # Checks 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
@@ -665,7 +664,7 @@ module ActiveSupport
end
end
- # Duplicate the value in a class. This is used by cache implementations that don't natively
+ # Duplicates 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!
if @value && !compressed? && !(@value.is_a?(Numeric) || @value == true || @value == false)