ActiveSupport::Cache::MemoryStore (original) (raw)
Memory 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.
Unlike other Cache store implementations, MemoryStore does not compress values by default. MemoryStore does not benefit from compression as much as other Store implementations, as it does not send data over a network. However, when compression is enabled, it still pays the full cost of compression in terms of cpu use.
MemoryStore is thread-safe.
Methods
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Class Public methods
new(options = nil)Link
def initialize(options = nil) options ||= {} options[:coder] = DupCoder unless options.key?(:coder) || options.key?(:serializer)
options[:compress] ||= false super(options) @data = {} @max_size = options[:size] || 32.megabytes @max_prune_time = options[:max_prune_time] || 2 @cache_size = 0 @monitor = Monitor.new @pruning = false end
supports_cache_versioning?()Link
Advertise cache versioning support.
def self.supports_cache_versioning? true end
Instance Public methods
cleanup(options = nil)Link
Preemptively iterates through all stored keys and removes the ones which have expired.
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
clear(options = nil)Link
Delete all data stored in a given cache store.
def clear(options = nil) synchronize do @data.clear @cache_size = 0 end end
decrement(name, amount = 1, **options)Link
Decrement a cached integer value. Returns the updated value.
If the key is unset or has expired, it will be set to -amount.
cache.decrement("foo") # => -1
To set a specific value, call write:
cache.write("baz", 5)
cache.decrement("baz") # => 4
def decrement(name, amount = 1, **options) instrument(:decrement, name, amount: amount) do modify_value(name, -amount, **options) end end
delete_matched(matcher, options = nil)Link
Deletes cache entries if the cache key matches a given pattern.
def delete_matched(matcher, options = nil) options = merged_options(options) matcher = key_matcher(matcher, options)
instrument(:delete_matched, matcher.inspect) do keys = synchronize { @data.keys } keys.each do |key| delete_entry(key, **options) if key.match(matcher) end end end
increment(name, amount = 1, **options)Link
Increment a cached integer value. Returns the updated value.
If the key is unset, it will be set to amount:
cache.increment("foo") # => 1
cache.increment("bar", 100) # => 100
To set a specific value, call write:
cache.write("baz", 5)
cache.increment("baz") # => 6
def increment(name, amount = 1, **options) instrument(:increment, name, amount: amount) do modify_value(name, amount, **options) end end
prune(target_size, max_time = nil)Link
To ensure entries fit within the specified memory prune the cache by removing the least recently accessed entries.
def prune(target_size, max_time = nil) return if pruning? @pruning = true begin start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC) cleanup instrument(:prune, target_size, from: @cache_size) do keys = synchronize { @data.keys } keys.each do |key| delete_entry(key, **options) return if @cache_size <= target_size || (max_time && Process.clock_gettime(Process::CLOCK_MONOTONIC) - start_time > max_time) end end ensure @pruning = false end end
pruning?()Link
Returns true if the cache is currently being pruned.