class ActiveSupport::Cache::Store

Active Support Cache Store

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. ActiveSupport::Cache::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.

ActiveSupport::Cache::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")
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

Constants

DEFAULT_POOL_OPTIONS

Attributes

options[R]
silence[R]
silence?[R]

Public Class Methods

new(options = nil) click to toggle source

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 mutally 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.

# File lib/active_support/cache.rb, line 319
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

Private Class Methods

retrieve_pool_options(options) click to toggle source
# File lib/active_support/cache.rb, line 206
          def retrieve_pool_options(options)
            if options.key?(:pool)
              pool_options = options.delete(:pool)
            elsif options.key?(:pool_size) || options.key?(:pool_timeout)
              pool_options = {}

              if options.key?(:pool_size)
                ActiveSupport.deprecator.warn(<<~MSG)
                  Using :pool_size is deprecated and will be removed in Rails 7.2.
                  Use `pool: { size: #{options[:pool_size].inspect} }` instead.
                MSG
                pool_options[:size] = options.delete(:pool_size)
              end

              if options.key?(:pool_timeout)
                ActiveSupport.deprecator.warn(<<~MSG)
                  Using :pool_timeout is deprecated and will be removed in Rails 7.2.
                  Use `pool: { timeout: #{options[:pool_timeout].inspect} }` instead.
                MSG
                pool_options[:timeout] = options.delete(:pool_timeout)
              end
            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

Public Instance Methods

cleanup(options = nil) click to toggle source

Cleans up the cache by removing expired entries.

Options are passed to the underlying cache implementation.

Some implementations may not support this method.

# File lib/active_support/cache.rb, line 738
def cleanup(options = nil)
  raise NotImplementedError.new("#{self.class.name} does not support cleanup")
end
clear(options = nil) click to toggle source

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.

# File lib/active_support/cache.rb, line 748
def clear(options = nil)
  raise NotImplementedError.new("#{self.class.name} does not support clear")
end
decrement(name, amount = 1, options = nil) click to toggle source

Decrements an integer value in the cache.

Options are passed to the underlying cache implementation.

Some implementations may not support this method.

# File lib/active_support/cache.rb, line 729
def decrement(name, amount = 1, options = nil)
  raise NotImplementedError.new("#{self.class.name} does not support decrement")
end
delete(name, options = nil) click to toggle source

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

Options are passed to the underlying cache implementation.

# File lib/active_support/cache.rb, line 667
def delete(name, options = nil)
  options = merged_options(options)

  instrument(:delete, name) do
    delete_entry(normalize_key(name, options), **options)
  end
end
delete_matched(matcher, options = nil) click to toggle source

Deletes all entries with keys matching the pattern.

Options are passed to the underlying cache implementation.

Some implementations may not support this method.

# File lib/active_support/cache.rb, line 711
def delete_matched(matcher, options = nil)
  raise NotImplementedError.new("#{self.class.name} does not support delete_matched")
end
delete_multi(names, options = nil) click to toggle source

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

Options are passed to the underlying cache implementation.

# File lib/active_support/cache.rb, line 679
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 do
    delete_multi_entries(names, **options)
  end
end
exist?(name, options = nil) click to toggle source

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

Options are passed to the underlying cache implementation.

# File lib/active_support/cache.rb, line 693
def exist?(name, options = nil)
  options = merged_options(options)

  instrument(:exist?, name) do |payload|
    entry = read_entry(normalize_key(name, options), **options, event: payload)
    (entry && !entry.expired? && !entry.mismatched?(normalize_version(name, options))) || false
  end
end
fetch(name, options = nil, &block) click to toggle source

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.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.seconds) do
        sleep 1
        'new value 1'
      end
    end
    
    Thread.new do
      val_2 = cache.fetch('foo', race_condition_ttl: 10.seconds) do
        'new value 2'
      end
    end
    
    cache.fetch('foo') # => "original value"
    sleep 10 # First thread extended the life of cache by another 10 seconds
    cache.fetch('foo') # => "new value 1"
    val_1 # => "new value 1"
    val_2 # => "original value"
    

Dynamic Options

In some cases it may be necessary to to dynamically compute options based on the cached value. For this purpose, a ActiveSupport::Cache::WriteOptions instance is passed as a second argument to the block

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

Only some options can be set dynamically:

- +:expires_in+
- +:expires_at+
- +:version+
# File lib/active_support/cache.rb, line 458
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, name, options) do |payload|
        cached_entry = read_entry(key, **options, event: payload)
        entry = handle_expired_entry(cached_entry, key, options)
        entry = nil if entry && entry.mismatched?(normalize_version(name, options))
        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, 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) { |name| ... } click to toggle source

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
# File lib/active_support/cache.rb, line 592
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)

  instrument_multi :read_multi, names, options do |payload|
    if options[:force]
      reads = {}
    else
      reads = read_multi_entries(names, **options)
    end

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

    payload[:hits] = reads.keys
    payload[:super_operation] = :fetch_multi

    write_multi(writes, options)

    ordered
  end
end
increment(name, amount = 1, options = nil) click to toggle source

Increments an integer value in the cache.

Options are passed to the underlying cache implementation.

Some implementations may not support this method.

# File lib/active_support/cache.rb, line 720
def increment(name, amount = 1, options = nil)
  raise NotImplementedError.new("#{self.class.name} does not support increment")
end
mute() { || ... } click to toggle source

Silences the logger within a block.

# File lib/active_support/cache.rb, line 346
def mute
  previous_silence, @silence = defined?(@silence) && @silence, true
  yield
ensure
  @silence = previous_silence
end
read(name, options = nil) click to toggle source

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.

# File lib/active_support/cache.rb, line 502
def read(name, options = nil)
  options = merged_options(options)
  key     = normalize_key(name, options)
  version = normalize_version(name, options)

  instrument(:read, name, 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
        entry.value
      end
    else
      payload[:hit] = false if payload
      nil
    end
  end
end
read_multi(*names) click to toggle source

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.

# File lib/active_support/cache.rb, line 535
def read_multi(*names)
  return {} if names.empty?

  options = names.extract_options!
  options = merged_options(options)

  instrument_multi :read_multi, names, options do |payload|
    read_multi_entries(names, **options, event: payload).tap do |results|
      payload[:hits] = results.keys
    end
  end
end
silence!() click to toggle source

Silences the logger.

# File lib/active_support/cache.rb, line 340
def silence!
  @silence = true
  self
end
write(name, value, options = nil) click to toggle source

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

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.

# File lib/active_support/cache.rb, line 654
def write(name, value, options = nil)
  options = merged_options(options)

  instrument(:write, name, options) do
    entry = Entry.new(value, **options.merge(version: normalize_version(name, options)))
    write_entry(normalize_key(name, options), entry, **options)
  end
end
write_multi(hash, options = nil) click to toggle source

Cache Storage API to write multiple values at once.

# File lib/active_support/cache.rb, line 549
def write_multi(hash, options = nil)
  return hash if hash.empty?

  options = merged_options(options)

  instrument_multi :write_multi, 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

Private Instance Methods

_instrument(operation, multi: false, options: nil, **payload, &block) click to toggle source
# File lib/active_support/cache.rb, line 1004
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]
        ": #{normalize_key(payload[:key], options)}"
      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
default_serializer() click to toggle source
# File lib/active_support/cache.rb, line 753
        def default_serializer
          case Cache.format_version
          when 6.1
            ActiveSupport.deprecator.warn <<~EOM
              Support for `config.active_support.cache_format_version = 6.1` has been deprecated and will be removed in Rails 7.2.

              Check the Rails upgrade guide at https://guides.rubyonrails.org/upgrading_ruby_on_rails.html#new-activesupport-cache-serialization-format
              for more information on how to upgrade.
            EOM
            Cache::SerializerWithFallback[:marshal_6_1]
          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_entry(key, **options) click to toggle source

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

# File lib/active_support/cache.rb, line 847
def delete_entry(key, **options)
  raise NotImplementedError.new
end
delete_multi_entries(entries, **options) click to toggle source

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

# File lib/active_support/cache.rb, line 853
def delete_multi_entries(entries, **options)
  entries.count { |key| delete_entry(key, **options) }
end
deserialize_entry(payload) click to toggle source
# File lib/active_support/cache.rb, line 812
def deserialize_entry(payload)
  payload.nil? ? nil : @coder.load(payload)
rescue DeserializationError
  nil
end
expanded_key(key) click to toggle source

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.

# File lib/active_support/cache.rb, line 967
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) click to toggle source
# File lib/active_support/cache.rb, line 988
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
get_entry_value(entry, name, options) click to toggle source
# File lib/active_support/cache.rb, line 1041
def get_entry_value(entry, name, options)
  instrument(:fetch_hit, name, options)
  entry.value
end
handle_expired_entry(entry, key, options) click to toggle source
# File lib/active_support/cache.rb, line 1025
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
      write_entry(key, entry, expires_in: race_ttl * 2)
    else
      delete_entry(key, **options)
    end
    entry = nil
  end
  entry
end
handle_invalid_expires_in(message) click to toggle source
# File lib/active_support/cache.rb, line 887
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
instrument(operation, key, options = nil, &block) click to toggle source
# File lib/active_support/cache.rb, line 996
def instrument(operation, key, options = nil, &block)
  _instrument(operation, key: key, options: options, &block)
end
instrument_multi(operation, keys, options = nil, &block) click to toggle source
# File lib/active_support/cache.rb, line 1000
def instrument_multi(operation, keys, options = nil, &block)
  _instrument(operation, multi: true, key: keys, options: options, &block)
end
key_matcher(pattern, options) click to toggle source

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.

# File lib/active_support/cache.rb, line 776
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) click to toggle source

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

# File lib/active_support/cache.rb, line 858
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
namespace_key(key, options = nil) click to toggle source

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'
# File lib/active_support/cache.rb, line 945
def namespace_key(key, options = nil)
  options = merged_options(options)
  namespace = options[:namespace]

  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
normalize_key(key, options = nil) click to toggle source

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.

# File lib/active_support/cache.rb, line 929
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) click to toggle source

Normalize aliased options to their canonical form

# File lib/active_support/cache.rb, line 898
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) click to toggle source
# File lib/active_support/cache.rb, line 984
def normalize_version(key, options = nil)
  (options && options[:version].try(:to_param)) || expanded_version(key)
end
read_entry(key, **options) click to toggle source

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

# File lib/active_support/cache.rb, line 793
def read_entry(key, **options)
  raise NotImplementedError.new
end
read_multi_entries(names, **options) click to toggle source

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

# File lib/active_support/cache.rb, line 820
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, options) { |name, write_options| ... } click to toggle source
# File lib/active_support/cache.rb, line 1046
def save_block_result_to_cache(name, options)
  result = instrument(:generate, name, options) do
    yield(name, WriteOptions.new(options))
  end

  write(name, result, options) unless result.nil? && options[:skip_nil]
  result
end
serialize_entry(entry, **options) click to toggle source
# File lib/active_support/cache.rb, line 803
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
validate_options(options) click to toggle source
# File lib/active_support/cache.rb, line 909
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_entry(key, entry, **options) click to toggle source

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

# File lib/active_support/cache.rb, line 799
def write_entry(key, entry, **options)
  raise NotImplementedError.new
end
write_multi_entries(hash, **options) click to toggle source

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

# File lib/active_support/cache.rb, line 839
def write_multi_entries(hash, **options)
  hash.each do |key, entry|
    write_entry key, entry, **options
  end
end