Class: ActiveSupport::Cache::MemoryStore
- Defined in:
- lib/active_support/cache/memory_store.rb
Overview
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.
Defined Under Namespace
Modules: DupCoder
Instance Attribute Summary
Attributes inherited from Store
Class Method Summary collapse
-
.supports_cache_versioning? ⇒ Boolean
Advertise cache versioning support.
Instance Method Summary collapse
-
#cleanup(options = nil) ⇒ Object
Preemptively iterates through all stored keys and removes the ones which have expired.
-
#clear(options = nil) ⇒ Object
Delete all data stored in a given cache store.
-
#decrement(name, amount = 1, options = nil) ⇒ Object
Decrement a cached integer value.
-
#delete_matched(matcher, options = nil) ⇒ Object
Deletes cache entries if the cache key matches a given pattern.
-
#increment(name, amount = 1, options = nil) ⇒ Object
Increment a cached integer value.
-
#initialize(options = nil) ⇒ MemoryStore
constructor
A new instance of MemoryStore.
-
#inspect ⇒ Object
:nodoc:.
-
#prune(target_size, max_time = nil) ⇒ Object
To ensure entries fit within the specified memory prune the cache by removing the least recently accessed entries.
-
#pruning? ⇒ Boolean
Returns true if the cache is currently being pruned.
-
#synchronize(&block) ⇒ Object
Synchronize calls to the cache.
Methods inherited from Store
#delete, #delete_multi, #exist?, #fetch, #fetch_multi, #mute, #new_entry, #read, #read_multi, #silence!, #write, #write_multi
Constructor Details
#initialize(options = nil) ⇒ MemoryStore
Returns a new instance of MemoryStore.
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# File 'lib/active_support/cache/memory_store.rb', line 73 def initialize( = nil) ||= {} [:coder] = DupCoder unless .key?(:coder) || .key?(:serializer) # Disable compression by default. [:compress] ||= false super() @data = {} @max_size = [:size] || 32.megabytes @max_prune_time = [:max_prune_time] || 2 @cache_size = 0 @monitor = Monitor.new @pruning = false end |
Class Method Details
.supports_cache_versioning? ⇒ Boolean
Advertise cache versioning support.
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# File 'lib/active_support/cache/memory_store.rb', line 88 def self.supports_cache_versioning? true end |
Instance Method Details
#cleanup(options = nil) ⇒ Object
Preemptively iterates through all stored keys and removes the ones which have expired.
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# File 'lib/active_support/cache/memory_store.rb', line 101 def cleanup( = nil) = () _instrument(:cleanup, size: @data.size) do keys = synchronize { @data.keys } keys.each do |key| entry = @data[key] delete_entry(key, **) if entry && entry.expired? end end end |
#clear(options = nil) ⇒ Object
Delete all data stored in a given cache store.
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# File 'lib/active_support/cache/memory_store.rb', line 93 def clear( = nil) synchronize do @data.clear @cache_size = 0 end end |
#decrement(name, amount = 1, options = nil) ⇒ Object
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
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# File 'lib/active_support/cache/memory_store.rb', line 164 def decrement(name, amount = 1, = nil) modify_value(name, -amount, ) end |
#delete_matched(matcher, options = nil) ⇒ Object
Deletes cache entries if the cache key matches a given pattern.
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# File 'lib/active_support/cache/memory_store.rb', line 169 def delete_matched(matcher, = nil) = () instrument(:delete_matched, matcher.inspect) do matcher = key_matcher(matcher, ) keys = synchronize { @data.keys } keys.each do |key| delete_entry(key, **) if key.match(matcher) end end end |
#increment(name, amount = 1, options = nil) ⇒ Object
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
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# File 'lib/active_support/cache/memory_store.rb', line 149 def increment(name, amount = 1, = nil) modify_value(name, amount, ) end |
#inspect ⇒ Object
:nodoc:
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# File 'lib/active_support/cache/memory_store.rb', line 180 def inspect # :nodoc: "#<#{self.class.name} entries=#{@data.size}, size=#{@cache_size}, options=#{@options.inspect}>" end |
#prune(target_size, max_time = nil) ⇒ Object
To ensure entries fit within the specified memory prune the cache by removing the least recently accessed entries.
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# File 'lib/active_support/cache/memory_store.rb', line 114 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, **) 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? ⇒ Boolean
Returns true if the cache is currently being pruned.
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# File 'lib/active_support/cache/memory_store.rb', line 133 def pruning? @pruning end |
#synchronize(&block) ⇒ Object
Synchronize calls to the cache. This should be called wherever the underlying cache implementation is not thread safe.
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# File 'lib/active_support/cache/memory_store.rb', line 186 def synchronize(&block) # :nodoc: @monitor.synchronize(&block) end |