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class ActiveSupport::Cache::MemoryStore

Parent:: ActiveSupport::Cache::Store

A cache store implementation which stores everything into memory in the same process. If you're running multiple Ruby on Rails server processes (which is the case if you're using Phusion Passenger or puma clustered mode), then this means that Rails server process instances won't be able to share cache data with each other and this may not be the most appropriate cache in that scenario.

This cache has a bounded size specified by the :size options to the initializer (default is 32Mb). When the cache exceeds the allotted size, a cleanup will occur which tries to prune the cache down to three quarters of the maximum size by removing the least recently used entries.

MemoryStore is thread-safe.

Constants

PER_ENTRY_OVERHEAD

Public Class Methods

new(options = nil) Show source

# File activesupport/lib/active_support/cache/memory_store.rb, line 21
def initialize(options = nil)
  options ||= {}
  super(options)
  @data = {}
  @key_access = {}
  @max_size = options[:size] || 32.megabytes
  @max_prune_time = options[:max_prune_time] || 2
  @cache_size = 0
  @monitor = Monitor.new
  @pruning = false
end

Calls superclass method ActiveSupport::Cache::Store.new

supports_cache_versioning?() Show source

# File activesupport/lib/active_support/cache/memory_store.rb, line 34
def self.supports_cache_versioning?
  true
end

Advertise cache versioning support.

Public Instance Methods

cleanup(options = nil) Show source

# File activesupport/lib/active_support/cache/memory_store.rb, line 48
def cleanup(options = nil)
  options = merged_options(options)
  instrument(:cleanup, size: @data.size) do
    keys = synchronize { @data.keys }
    keys.each do |key|
      entry = @data[key]
      delete_entry(key, options) if entry && entry.expired?
    end
  end
end

Preemptively iterates through all stored keys and removes the ones which have expired.

clear(options = nil) Show source

# File activesupport/lib/active_support/cache/memory_store.rb, line 39
def clear(options = nil)
  synchronize do
    @data.clear
    @key_access.clear
    @cache_size = 0
  end
end

Delete all data stored in a given cache store.

decrement(name, amount = 1, options = nil) Show source

# File activesupport/lib/active_support/cache/memory_store.rb, line 90
def decrement(name, amount = 1, options = nil)
  modify_value(name, -amount, options)
end

Decrement an integer value in the cache.

delete_matched(matcher, options = nil) Show source

# File activesupport/lib/active_support/cache/memory_store.rb, line 95
def delete_matched(matcher, options = nil)
  options = merged_options(options)
  instrument(:delete_matched, matcher.inspect) do
    matcher = key_matcher(matcher, options)
    keys = synchronize { @data.keys }
    keys.each do |key|
      delete_entry(key, options) if key.match(matcher)
    end
  end
end

Deletes cache entries if the cache key matches a given pattern.

increment(name, amount = 1, options = nil) Show source

# File activesupport/lib/active_support/cache/memory_store.rb, line 85
def increment(name, amount = 1, options = nil)
  modify_value(name, amount, options)
end

Increment an integer value in the cache.

prune(target_size, max_time = nil) Show source

# File activesupport/lib/active_support/cache/memory_store.rb, line 61
def prune(target_size, max_time = nil)
  return if pruning?
  @pruning = true
  begin
    start_time = Concurrent.monotonic_time
    cleanup
    instrument(:prune, target_size, from: @cache_size) do
      keys = synchronize { @key_access.keys.sort { |a, b| @key_access[a].to_f <=> @key_access[b].to_f } }
      keys.each do |key|
        delete_entry(key, options)
        return if @cache_size <= target_size || (max_time && Concurrent.monotonic_time - start_time > max_time)
      end
    end
  ensure
    @pruning = false
  end
end

To ensure entries fit within the specified memory prune the cache by removing the least recently accessed entries.

pruning?() Show source

# File activesupport/lib/active_support/cache/memory_store.rb, line 80
def pruning?
  @pruning
end

Returns true if the cache is currently being pruned.