Class: ActiveSupport::Cache::Store

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Subclasses: FileStore, MemCacheStore, MemoryStore, NullStore, RedisCacheStore
Inherits:	Object
Defined in:	activesupport/lib/active_support/cache.rb

Overview

An abstract cache store class. There are multiple cache store implementations, each having its own additional features. See the classes under the ::ActiveSupport::Cache module, e.g. MemCacheStore. MemCacheStore is currently the most popular cache store for large production websites.

Some implementations may not support all methods beyond the basic cache methods of #fetch, #write, #read, #exist?, and #delete.

Store can store any Ruby object that is supported by its coder‘s dump and load methods.

cache = ActiveSupport::Cache::MemoryStore.new

cache.read('city')   # => nil
cache.write('city', "Duckburgh") # => true
cache.read('city')   # => "Duckburgh"

cache.write('not serializable', Proc.new {}) # => TypeError

Keys are always translated into Strings and are case sensitive. When an object is specified as a key and has a cache_key method defined, this method will be called to define the key. Otherwise, the to_param method will be called. Hashes and Arrays can also be used as keys. The elements will be delimited by slashes, and the elements within a ::Hash 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 = -> { @last_mod_time }  # Set the namespace to a variable
@last_mod_time = Time.now  # Invalidate the entire cache by changing namespace

Constant Summary

DEFAULT_POOL_OPTIONS = private
# File 'activesupport/lib/active_support/cache.rb', line 197
```
{ size: 5, timeout: 5 }.freeze
```

Class Attribute Summary

.logger (also: #logger) rw
.raise_on_invalid_cache_expiration_time (also: #raise_on_invalid_cache_expiration_time) rw

Class Method Summary

.new(options = nil) ⇒ Store constructor

Creates a new cache.
.retrieve_pool_options(options) private

Instance Attribute Summary

#logger rw
#options readonly
#raise_on_invalid_cache_expiration_time rw
#silence? readonly

Alias for #silence.

Instance Method Summary

#cleanup(options = nil)

Cleans up the cache by removing expired entries.
#clear(options = nil)

Clears the entire cache.
#decrement(name, amount = 1, options = nil)

Decrements an integer value in the cache.
#delete(name, options = nil)

Deletes an entry in the cache.
#delete_matched(matcher, options = nil)

Deletes all entries with keys matching the pattern.
#delete_multi(names, options = nil)

Deletes multiple entries in the cache.
#exist?(name, options = nil) ⇒ Boolean

Returns true if the cache contains an entry for the given key.
#fetch(name, options = nil, &block)

Fetches data from the cache, using the given key.
#fetch_multi(*names)

Fetches data from the cache, using the given keys.
#increment(name, amount = 1, options = nil)

Increments an integer value in the cache.
#mute

Silences the logger within a block.
#read(name, options = nil)

Reads data from the cache, using the given key.
#read_multi(*names)

Reads multiple values at once from the cache.
#silence (also: #silence?) readonly
#silence!

Silences the logger.
#write(name, value, options = nil)

Writes the value to the cache with the key.
#write_multi(hash, options = nil)

::ActiveSupport::Cache Storage API to write multiple values at once.
#_instrument(operation, multi: false, options: nil, **payload, &block) private
#default_serializer private
#delete_entry(key, **options) private

Deletes an entry from the cache implementation.
#delete_multi_entries(entries, **options) private

Deletes multiples entries in the cache implementation.
#deserialize_entry(payload) private
#expanded_key(key) private

Expands key to be a consistent string value.
#expanded_version(key) private
#get_entry_value(entry, name, options) private
#handle_expired_entry(entry, key, options) private
#handle_invalid_expires_in(message) private
#instrument(operation, key, options = nil, &block) private
#instrument_multi(operation, keys, options = nil, &block) private
#key_matcher(pattern, options) private

Adds the namespace defined in the options to a pattern designed to match keys.
#merged_options(call_options) private

Merges the default options with ones specific to a method call.
#namespace_key(key, call_options = nil) private

Prefix the key with a namespace string:
#normalize_key(key, options = nil) private

Expands and namespaces the cache key.
#normalize_options(options) private

Normalize aliased options to their canonical form.
#normalize_version(key, options = nil) private
#read_entry(key, **options) private

Reads an entry from the cache implementation.
#read_multi_entries(names, **options) private

Reads multiple entries from the cache implementation.
#save_block_result_to_cache(name, key, options) private
#serialize_entry(entry, **options) private
#validate_options(options) private
#write_entry(key, entry, **options) private

Writes an entry to the cache implementation.
#write_multi_entries(hash, **options) private

Writes multiple entries to the cache implementation.
#new_entry(value, options = nil) Internal use only

Constructor Details

.new(options = nil) ⇒ `Store`

Creates a new cache.

Options

:namespace

Sets the namespace for the cache. This option is especially useful if your application shares a cache with other applications.

:serializer

The serializer for cached values. Must respond to dump and load.

The default serializer depends on the cache format version (set via config.active_support.cache_format_version when using Rails). The default serializer for each format version includes a fallback mechanism to deserialize values from any format version. This behavior makes it easy to migrate between format versions without invalidating the entire cache.

You can also specify serializer: :message_pack to use a preconfigured serializer based on ActiveSupport::MessagePack. The :message_pack serializer includes the same deserialization fallback mechanism, allowing easy migration from (or to) the default serializer. The :message_pack serializer may improve performance, but it requires the msgpack gem.

:compressor

The compressor for serialized cache values. Must respond to deflate and inflate.

The default compressor is Zlib. To define a new custom compressor that also decompresses old cache entries, you can check compressed values for Zlib’s "\x78" signature:

module MyCompressor
  def self.deflate(dumped)
    # compression logic... (make sure result does not start with "\x78"!)
  end

  def self.inflate(compressed)
    if compressed.start_with?("\x78")
      Zlib.inflate(compressed)
    else
      # decompression logic...
    end
  end
end

ActiveSupport::Cache.lookup_store(:redis_cache_store, compressor: MyCompressor)

:coder

The coder for serializing and (optionally) compressing cache entries. Must respond to dump and load.

The default coder composes the serializer and compressor, and includes some performance optimizations. If you only need to override the serializer or compressor, you should specify the :serializer or :compressor options instead.

If the store can handle cache entries directly, you may also specify coder: nil to omit the serializer, compressor, and coder. For example, if you are using ActiveSupport::Cache::MemoryStore and can guarantee that cache values will not be mutated, you can specify coder: nil to avoid the overhead of safeguarding against mutation.

The :coder option is mutually exclusive with the :serializer and :compressor options. Specifying them together will raise an ArgumentError.

Any other specified options are treated as default options for the relevant cache operations, such as #read, #write, and #fetch.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 295


def initialize(options = nil)
  @options = options ? validate_options(normalize_options(options)) : {}

  @options[:compress] = true unless @options.key?(:compress)
  @options[:compress_threshold] ||= DEFAULT_COMPRESS_LIMIT

  @coder = @options.delete(:coder) do
    legacy_serializer = Cache.format_version < 7.1 && !@options[:serializer]
    serializer = @options.delete(:serializer) || default_serializer
    serializer = Cache::SerializerWithFallback[serializer] if serializer.is_a?(Symbol)
    compressor = @options.delete(:compressor) { Zlib }

    Cache::Coder.new(serializer, compressor, legacy_serializer: legacy_serializer)
  end

  @coder ||= Cache::SerializerWithFallback[:passthrough]

  @coder_supports_compression = @coder.respond_to?(:dump_compressed)
end

Class Attribute Details

.logger (rw) Also known as: #logger

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 189


cattr_accessor :logger, instance_writer: true

.raise_on_invalid_cache_expiration_time (rw) Also known as: #raise_on_invalid_cache_expiration_time

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 190


cattr_accessor :raise_on_invalid_cache_expiration_time, default: false

Class Method Details

.retrieve_pool_options(options) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 200


def retrieve_pool_options(options)
  if options.key?(:pool)
    pool_options = options.delete(:pool)
  else
    pool_options = true
  end

  case pool_options
  when false, nil
    return false
  when true
    pool_options = DEFAULT_POOL_OPTIONS
  when Hash
    pool_options[:size] = Integer(pool_options[:size]) if pool_options.key?(:size)
    pool_options[:timeout] = Float(pool_options[:timeout]) if pool_options.key?(:timeout)
    pool_options = DEFAULT_POOL_OPTIONS.merge(pool_options)
  else
    raise TypeError, "Invalid :pool argument, expected Hash, got: #{pool_options.inspect}"
  end

  pool_options unless pool_options.empty?
end

Instance Attribute Details

#logger (rw)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 189


cattr_accessor :logger, instance_writer: true

#options (readonly)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 192


attr_reader :silence, :options

#raise_on_invalid_cache_expiration_time (rw)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 190


cattr_accessor :raise_on_invalid_cache_expiration_time, default: false

#silence? (readonly)

Alias for #silence.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 193


alias :silence? :silence

Instance Method Details

#_instrument(operation, multi: false, options: nil, **payload, &block) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 1010


def _instrument(operation, multi: false, options: nil, **payload, &block)
  if logger && logger.debug? && !silence?
    debug_key =
      if multi
        ": #{payload[:key].size} key(s) specified"
      elsif payload[:key]
        ": #{payload[:key]}"
      end

    debug_options = " (#{options.inspect})" unless options.blank?

    logger.debug "Cache #{operation}#{debug_key}#{debug_options}"
  end

  payload[:store] = self.class.name
  payload.merge!(options) if options.is_a?(Hash)
  ActiveSupport::Notifications.instrument("cache_#{operation}.active_support", payload) do
    block&.call(payload)
  end
end

#cleanup(options = nil)

Cleans up the cache by removing expired entries.

Options are passed to the underlying cache implementation.

Some implementations may not support this method.

Raises:

(NotImplementedError)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 749


def cleanup(options = nil)
  raise NotImplementedError.new("#{self.class.name} does not support cleanup")
end

#clear(options = nil)

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.

Some implementations may not support this method.

Raises:

(NotImplementedError)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 759


def clear(options = nil)
  raise NotImplementedError.new("#{self.class.name} does not support clear")
end

#decrement(name, amount = 1, options = nil)

Decrements an integer value in the cache.

Options are passed to the underlying cache implementation.

Some implementations may not support this method.

Raises:

(NotImplementedError)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 740


def decrement(name, amount = 1, options = nil)
  raise NotImplementedError.new("#{self.class.name} does not support decrement")
end

#default_serializer (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 764


def default_serializer
  case Cache.format_version
  when 7.0
    Cache::SerializerWithFallback[:marshal_7_0]
  when 7.1
    Cache::SerializerWithFallback[:marshal_7_1]
  else
    raise ArgumentError, "Unrecognized ActiveSupport::Cache.format_version: #{Cache.format_version.inspect}"
  end
end

#delete(name, options = nil)

Deletes an entry in the cache. Returns true if an entry is deleted and false otherwise.

Options are passed to the underlying cache implementation.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 676


def delete(name, options = nil)
  options = merged_options(options)
  key = normalize_key(name, options)

  instrument(:delete, key, options) do
    delete_entry(key, **options)
  end
end

#delete_entry(key, **options) (private)

Deletes an entry from the cache implementation. Subclasses must implement this method.

Raises:

(NotImplementedError)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 850


def delete_entry(key, **options)
  raise NotImplementedError.new
end

#delete_matched(matcher, options = nil)

Deletes all entries with keys matching the pattern.

Options are passed to the underlying cache implementation.

Some implementations may not support this method.

Raises:

(NotImplementedError)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 722


def delete_matched(matcher, options = nil)
  raise NotImplementedError.new("#{self.class.name} does not support delete_matched")
end

#delete_multi(names, options = nil)

Deletes multiple entries in the cache. Returns the number of deleted entries.

Options are passed to the underlying cache implementation.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 689


def delete_multi(names, options = nil)
  return 0 if names.empty?

  options = merged_options(options)
  names.map! { |key| normalize_key(key, options) }

  instrument_multi(:delete_multi, names, options) do
    delete_multi_entries(names, **options)
  end
end

#delete_multi_entries(entries, **options) (private)

Deletes multiples entries in the cache implementation. Subclasses MAY implement this method.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 856


def delete_multi_entries(entries, **options)
  entries.count { |key| delete_entry(key, **options) }
end

#deserialize_entry(payload) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 815


def deserialize_entry(payload, **)
  payload.nil? ? nil : @coder.load(payload)
rescue DeserializationError
  nil
end

#exist?(name, options = nil) ⇒ `Boolean`

Returns true if the cache contains an entry for the given key.

Options are passed to the underlying cache implementation.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 703


def exist?(name, options = nil)
  options = merged_options(options)
  key = normalize_key(name, options)

  instrument(:exist?, key) do |payload|
    entry = read_entry(key, **options, event: payload)
    (entry && !entry.expired? && !entry.mismatched?(normalize_version(name, options))) || false
  end
end

#expanded_key(key) (private)

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.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 973


def expanded_key(key)
  return key.cache_key.to_s if key.respond_to?(:cache_key)

  case key
  when Array
    if key.size > 1
      key.collect { |element| expanded_key(element) }
    else
      expanded_key(key.first)
    end
  when Hash
    key.collect { |k, v| "#{k}=#{v}" }.sort!
  else
    key
  end.to_param
end

#expanded_version(key) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 994


def expanded_version(key)
  case
  when key.respond_to?(:cache_version) then key.cache_version.to_param
  when key.is_a?(Array)                then key.map { |element| expanded_version(element) }.tap(&:compact!).to_param
  when key.respond_to?(:to_a)          then expanded_version(key.to_a)
  end
end

#fetch(name, options = nil, &block)

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 the key and executed in the event of a cache miss. The return value of the block will be written to the cache under the given cache key, and that return value will be returned.

cache.write('today', 'Monday')
cache.fetch('today')  # => "Monday"

cache.fetch('city')   # => nil
cache.fetch('city') do
  'Duckburgh'
end
cache.fetch('city')   # => "Duckburgh"

Options

Internally, fetch calls #read_entry, and calls #write_entry on a cache miss. Thus, fetch supports the same options as #read and #write. Additionally, fetch supports the following options:

force: true - 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) { '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 #write.

skip_nil: true - Prevents caching a nil result:

cache.fetch('foo') { nil }
cache.fetch('bar', skip_nil: true) { nil }
cache.exist?('foo') # => true
cache.exist?('bar') # => false

:race_condition_ttl - Specifies the number of seconds during which an expired value can be reused while a new value is being generated. This can be used to prevent race conditions when cache entries expire, by preventing multiple processes from simultaneously regenerating the same entry (also known as the dog pile effect).

When a process encounters a cache entry that has expired less than :race_condition_ttl seconds ago, it will bump the expiration time by :race_condition_ttl seconds before generating a new value. During this extended time window, while the process generates a new value, other processes will continue to use the old value. After the first process writes the new value, other processes will then use it.

If the first process errors out while generating a new value, another process can try to generate a new value after the extended time window has elapsed.

# Set all values to expire after one minute.
cache = ActiveSupport::Cache::MemoryStore.new(expires_in: 1)

cache.write("foo", "original value")
val_1 = nil
val_2 = nil
p cache.read("foo") # => "original value"

sleep 1 # wait until the cache expires

t1 = Thread.new do
  # fetch does the following:
  # 1. gets an recent expired entry
  # 2. extends the expiry by 2 seconds (race_condition_ttl)
  # 3. regenerates the new value
  val_1 = cache.fetch("foo", race_condition_ttl: 2) do
    sleep 1
    "new value 1"
  end
end

# Wait until t1 extends the expiry of the entry
# but before generating the new value
sleep 0.1

val_2 = cache.fetch("foo", race_condition_ttl: 2) do
  # This block won't be executed because t1 extended the expiry
  "new value 2"
end

t1.join

p val_1 # => "new value 1"
p val_2 # => "original value"
p cache.fetch("foo") # => "new value 1"

# The entry requires 3 seconds to expire (expires_in + race_condition_ttl)
# We have waited 2 seconds already (sleep(1) + t1.join) thus we need to wait 1
# more second to see the entry expire.
sleep 1

p cache.fetch("foo") # => nil

Dynamic Options

In some cases it may be necessary to dynamically compute options based on the cached value. To support this, an WriteOptions instance is passed as the second argument to the block. For example:

cache.fetch("authentication-token:#{user.id}") do |key, options|
  token = authenticate_to_service
  options.expires_at = token.expires_at
  token
end

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 444


def fetch(name, options = nil, &block)
  if block_given?
    options = merged_options(options)
    key = normalize_key(name, options)

    entry = nil
    unless options[:force]
      instrument(:read, key, options) do |payload|
        cached_entry = read_entry(key, **options, event: payload)
        entry = handle_expired_entry(cached_entry, key, options)
        if entry
          if entry.mismatched?(normalize_version(name, options))
            entry = nil
          else
            begin
              entry.value
            rescue DeserializationError
              entry = nil
            end
          end
        end
        payload[:super_operation] = :fetch if payload
        payload[:hit] = !!entry if payload
      end
    end

    if entry
      get_entry_value(entry, name, options)
    else
      save_block_result_to_cache(name, key, options, &block)
    end
  elsif options && options[:force]
    raise ArgumentError, "Missing block: Calling `Cache#fetch` with `force: true` requires a block."
  else
    read(name, options)
  end
end

#fetch_multi(*names)

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.

Returns a hash with the data for each of the names. For example:

cache.write("bim", "bam")
cache.fetch_multi("bim", "unknown_key") do |key|
  "Fallback value for key: #{key}"
end
# => { "bim" => "bam",
#      "unknown_key" => "Fallback value for key: unknown_key" }

You may also specify additional options via the #options argument. See #fetch for details. Other options are passed to the underlying cache implementation. For example:

cache.fetch_multi("fizz", expires_in: 5.seconds) do |key|
  "buzz"
end
# => {"fizz"=>"buzz"}
cache.read("fizz")
# => "buzz"
sleep(6)
cache.read("fizz")
# => nil

Raises:

(ArgumentError)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 595


def fetch_multi(*names)
  raise ArgumentError, "Missing block: `Cache#fetch_multi` requires a block." unless block_given?
  return {} if names.empty?

  options = names.extract_options!
  options = merged_options(options)
  keys    = names.map { |name| normalize_key(name, options) }
  writes  = {}
  ordered = instrument_multi :read_multi, keys, options do |payload|
    if options[:force]
      reads = {}
    else
      reads = read_multi_entries(names, **options)
    end

    ordered = names.index_with do |name|
      reads.fetch(name) { writes[name] = yield(name) }
    end
    writes.compact! if options[:skip_nil]

    payload[:hits] = reads.keys.map { |name| normalize_key(name, options) }
    payload[:super_operation] = :fetch_multi

    ordered
  end

  write_multi(writes, options)

  ordered
end

#get_entry_value(entry, name, options) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 1048


def get_entry_value(entry, name, options)
  instrument(:fetch_hit, name, options)
  entry.value
end

#handle_expired_entry(entry, key, options) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 1031


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 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.to_f + race_ttl
      options[:expires_in] = race_ttl * 2
      write_entry(key, entry, **options)
    else
      delete_entry(key, **options)
    end
    entry = nil
  end
  entry
end

#handle_invalid_expires_in(message) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 890


def handle_invalid_expires_in(message)
  error = ArgumentError.new(message)
  if ActiveSupport::Cache::Store.raise_on_invalid_cache_expiration_time
    raise error
  else
    ActiveSupport.error_reporter&.report(error, handled: true, severity: :warning)
    logger.error("#{error.class}: #{error.message}") if logger
  end
end

#increment(name, amount = 1, options = nil)

Increments an integer value in the cache.

Options are passed to the underlying cache implementation.

Some implementations may not support this method.

Raises:

(NotImplementedError)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 731


def increment(name, amount = 1, options = nil)
  raise NotImplementedError.new("#{self.class.name} does not support increment")
end

#instrument(operation, key, options = nil, &block) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 1002


def instrument(operation, key, options = nil, &block)
  _instrument(operation, key: key, options: options, &block)
end

#instrument_multi(operation, keys, options = nil, &block) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 1006


def instrument_multi(operation, keys, options = nil, &block)
  _instrument(operation, multi: true, key: keys, options: options, &block)
end

#key_matcher(pattern, options) (private)

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.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 779


def key_matcher(pattern, options) # :doc:
  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

#merged_options(call_options) (private)

Merges the default options with ones specific to a method call.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 861


def merged_options(call_options)
  if call_options
    call_options = normalize_options(call_options)
    if call_options.key?(:expires_in) && call_options.key?(:expires_at)
      raise ArgumentError, "Either :expires_in or :expires_at can be supplied, but not both"
    end

    expires_at = call_options.delete(:expires_at)
    call_options[:expires_in] = (expires_at - Time.now) if expires_at

    if call_options[:expires_in].is_a?(Time)
      expires_in = call_options[:expires_in]
      raise ArgumentError.new("expires_in parameter should not be a Time. Did you mean to use expires_at? Got: #{expires_in}")
    end
    if call_options[:expires_in]&.negative?
      expires_in = call_options.delete(:expires_in)
      handle_invalid_expires_in("Cache expiration time is invalid, cannot be negative: #{expires_in}")
    end

    if options.empty?
      call_options
    else
      options.merge(call_options)
    end
  else
    options
  end
end

#mute

Silences the logger within a block.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 322


def mute
  previous_silence, @silence = @silence, true
  yield
ensure
  @silence = previous_silence
end

#namespace_key(key, call_options = nil) (private)

Prefix the key with a namespace string:

namespace_key 'foo', namespace: 'cache'
# => 'cache:foo'

With a namespace block:

namespace_key 'foo', namespace: -> { 'cache' }
# => 'cache:foo'

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 948


def namespace_key(key, call_options = nil)
  namespace = if call_options&.key?(:namespace)
    call_options[:namespace]
  else
    options[:namespace]
  end

  if namespace.respond_to?(:call)
    namespace = namespace.call
  end

  if key && key.encoding != Encoding::UTF_8
    key = key.dup.force_encoding(Encoding::UTF_8)
  end

  if namespace
    "#{namespace}:#{key}"
  else
    key
  end
end

#new_entry(value, options = nil)

This method is for internal use only.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 713


def new_entry(value, options = nil) # :nodoc:
  Entry.new(value, **merged_options(options))
end

#normalize_key(key, options = nil) (private)

Expands and namespaces the cache key. Raises an exception when the key is nil or an empty string. May be overridden by cache stores to do additional normalization.

Raises:

(ArgumentError)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 932


def normalize_key(key, options = nil)
  str_key = expanded_key(key)
  raise(ArgumentError, "key cannot be blank") if !str_key || str_key.empty?

  namespace_key str_key, options
end

#normalize_options(options) (private)

Normalize aliased options to their canonical form

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 901


def normalize_options(options)
  options = options.dup
  OPTION_ALIASES.each do |canonical_name, aliases|
    alias_key = aliases.detect { |key| options.key?(key) }
    options[canonical_name] ||= options[alias_key] if alias_key
    options.except!(*aliases)
  end

  options
end

#normalize_version(key, options = nil) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 990


def normalize_version(key, options = nil)
  (options && options[:version].try(:to_param)) || expanded_version(key)
end

#read(name, options = nil)

Reads data from the cache, using the given key. If there is data in the cache with the given key, then that data is returned. Otherwise, nil is returned.

Note, if data was written with the :expires_in or :version options, both of these conditions are applied before the data is returned.

Options

:namespace - Replace the store namespace for this call.
:version - Specifies a version for the cache entry. If the cached version does not match the requested version, the read will be treated as a cache miss. This feature is used to support recyclable cache keys.

Other options will be handled by the specific cache store implementation.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 498


def read(name, options = nil)
  options = merged_options(options)
  key     = normalize_key(name, options)
  version = normalize_version(name, options)

  instrument(:read, key, options) do |payload|
    entry = read_entry(key, **options, event: payload)

    if entry
      if entry.expired?
        delete_entry(key, **options)
        payload[:hit] = false if payload
        nil
      elsif entry.mismatched?(version)
        payload[:hit] = false if payload
        nil
      else
        payload[:hit] = true if payload
        begin
          entry.value
        rescue DeserializationError
          payload[:hit] = false
          nil
        end
      end
    else
      payload[:hit] = false if payload
      nil
    end
  end
end

#read_entry(key, **options) (private)

Reads an entry from the cache implementation. Subclasses must implement this method.

Raises:

(NotImplementedError)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 796


def read_entry(key, **options)
  raise NotImplementedError.new
end

#read_multi(*names)

Reads multiple values at once from the cache. Options can be passed in the last argument.

Some cache implementation may optimize this method.

Returns a hash mapping the names provided to the values found.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 536


def read_multi(*names)
  return {} if names.empty?

  options = names.extract_options!
  options = merged_options(options)
  keys    = names.map { |name| normalize_key(name, options) }

  instrument_multi :read_multi, keys, options do |payload|
    read_multi_entries(names, **options, event: payload).tap do |results|
      payload[:hits] = results.keys.map { |name| normalize_key(name, options) }
    end
  end
end

#read_multi_entries(names, **options) (private)

Reads multiple entries from the cache implementation. Subclasses MAY implement this method.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 823


def read_multi_entries(names, **options)
  names.each_with_object({}) do |name, results|
    key   = normalize_key(name, options)
    entry = read_entry(key, **options)

    next unless entry

    version = normalize_version(name, options)

    if entry.expired?
      delete_entry(key, **options)
    elsif !entry.mismatched?(version)
      results[name] = entry.value
    end
  end
end

#save_block_result_to_cache(name, key, options) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 1053


def save_block_result_to_cache(name, key, options)
  options = options.dup

  result = instrument(:generate, key, options) do
    yield(name, WriteOptions.new(options))
  end

  write(name, result, options) unless result.nil? && options[:skip_nil]
  result
end

#serialize_entry(entry, **options) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 806


def serialize_entry(entry, **options)
  options = merged_options(options)
  if @coder_supports_compression && options[:compress]
    @coder.dump_compressed(entry, options[:compress_threshold])
  else
    @coder.dump(entry)
  end
end

#silence (readonly) Also known as: #silence?

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 192


attr_reader :silence, :options

#silence!

Silences the logger.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 316


def silence!
  @silence = true
  self
end

#validate_options(options) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 912


def validate_options(options)
  if options.key?(:coder) && options[:serializer]
    raise ArgumentError, "Cannot specify :serializer and :coder options together"
  end

  if options.key?(:coder) && options[:compressor]
    raise ArgumentError, "Cannot specify :compressor and :coder options together"
  end

  if Cache.format_version < 7.1 && !options[:serializer] && options[:compressor]
    raise ArgumentError, "Cannot specify :compressor option when using" \
      " default serializer and cache format version is < 7.1"
  end

  options
end

#write(name, value, options = nil)

Writes the value to the cache with the key. The value must be supported by the coder‘s dump and load methods.

Returns true if the write succeeded, nil if there was an error talking to the cache backend, or false if the write failed for another reason.

By default, cache entries larger than 1kB are compressed. Compression allows more data to be stored in the same memory footprint, leading to fewer cache evictions and higher hit rates.

Options

compress: false - Disables compression of the cache entry.
:compress_threshold - The compression threshold, specified in bytes. Cache entries larger than this threshold will be compressed. Defaults to 1.kilobyte.

:expires_in - Sets a relative expiration time for the cache entry, specified in seconds. :expire_in and :expired_in are aliases for :expires_in.

cache = ActiveSupport::Cache::MemoryStore.new(expires_in: 5.minutes)
cache.write(key, value, expires_in: 1.minute) # Set a lower value for one entry

:expires_at - Sets an absolute expiration time for the cache entry.

cache = ActiveSupport::Cache::MemoryStore.new
cache.write(key, value, expires_at: Time.now.at_end_of_hour)

:version - Specifies a version for the cache entry. When reading from the cache, if the cached version does not match the requested version, the read will be treated as a cache miss. This feature is used to support recyclable cache keys.

Other options will be handled by the specific cache store implementation.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 662


def write(name, value, options = nil)
  options = merged_options(options)
  key = normalize_key(name, options)

  instrument(:write, key, options) do
    entry = Entry.new(value, **options.merge(version: normalize_version(name, options)))
    write_entry(key, entry, **options)
  end
end

#write_entry(key, entry, **options) (private)

Writes an entry to the cache implementation. Subclasses must implement this method.

Raises:

(NotImplementedError)

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 802


def write_entry(key, entry, **options)
  raise NotImplementedError.new
end

#write_multi(hash, options = nil)

::ActiveSupport::Cache Storage API to write multiple values at once.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 551


def write_multi(hash, options = nil)
  return hash if hash.empty?

  options = merged_options(options)
  normalized_hash = hash.transform_keys { |key| normalize_key(key, options) }

  instrument_multi :write_multi, normalized_hash, options do |payload|
    entries = hash.each_with_object({}) do |(name, value), memo|
      memo[normalize_key(name, options)] = Entry.new(value, **options.merge(version: normalize_version(name, options)))
    end

    write_multi_entries entries, **options
  end
end

#write_multi_entries(hash, **options) (private)

Writes multiple entries to the cache implementation. Subclasses MAY implement this method.

[ GitHub ]

# File 'activesupport/lib/active_support/cache.rb', line 842


def write_multi_entries(hash, **options)
  hash.each do |key, entry|
    write_entry key, entry, **options
  end
end

Class: ActiveSupport::Cache::Store

Overview

Constant Summary

Class Attribute Summary

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new(options = nil) ⇒ Store

Options

Class Attribute Details

.logger (rw) Also known as: #logger

.raise_on_invalid_cache_expiration_time (rw) Also known as: #raise_on_invalid_cache_expiration_time

Class Method Details

.retrieve_pool_options(options) (private)

Instance Attribute Details

#logger (rw)

#options (readonly)

#raise_on_invalid_cache_expiration_time (rw)

#silence? (readonly)

Instance Method Details

#_instrument(operation, multi: false, options: nil, **payload, &block) (private)

#cleanup(options = nil)

#clear(options = nil)

#decrement(name, amount = 1, options = nil)

#default_serializer (private)

#delete(name, options = nil)

#delete_entry(key, **options) (private)

#delete_matched(matcher, options = nil)

#delete_multi(names, options = nil)

#delete_multi_entries(entries, **options) (private)

#deserialize_entry(payload) (private)

#exist?(name, options = nil) ⇒ Boolean

#expanded_key(key) (private)

#expanded_version(key) (private)

#fetch(name, options = nil, &block)

Options

Dynamic Options

#fetch_multi(*names)

#get_entry_value(entry, name, options) (private)

#handle_expired_entry(entry, key, options) (private)

#handle_invalid_expires_in(message) (private)

#increment(name, amount = 1, options = nil)

#instrument(operation, key, options = nil, &block) (private)

#instrument_multi(operation, keys, options = nil, &block) (private)

#key_matcher(pattern, options) (private)

#merged_options(call_options) (private)

#mute

#namespace_key(key, call_options = nil) (private)

#new_entry(value, options = nil)

#normalize_key(key, options = nil) (private)

#normalize_options(options) (private)

#normalize_version(key, options = nil) (private)

#read(name, options = nil)

Options

#read_entry(key, **options) (private)

#read_multi(*names)

#read_multi_entries(names, **options) (private)

#save_block_result_to_cache(name, key, options) (private)

#serialize_entry(entry, **options) (private)

#silence (readonly) Also known as: #silence?

#silence!

#validate_options(options) (private)

#write(name, value, options = nil)

Options

#write_entry(key, entry, **options) (private)

#write_multi(hash, options = nil)

#write_multi_entries(hash, **options) (private)

.new(options = nil) ⇒ `Store`

#exist?(name, options = nil) ⇒ `Boolean`