Class: Moneta::Adapters::LRUHash

Inherits:
Object
  • Object
show all
Includes:
CreateSupport, Defaults, IncrementSupport
Defined in:
lib/moneta/adapters/lruhash.rb

Overview

LRUHash backend

Based on Hashery::LRUHash but simpler and measures both memory usage and hash size.

Defined Under Namespace

Classes: Entry

Constant Summary collapse

DEFAULT_MAX_SIZE = 
1024000
DEFAULT_MAX_COUNT = 
10240

Instance Method Summary collapse

Methods included from CreateSupport

#create, included

Methods included from IncrementSupport

included, #increment

Methods included from Defaults

#[], #[]=, #close, #create, #decrement, #features, #fetch, included, #increment, #supports?

Methods included from OptionSupport

#expires, #prefix, #raw, #with

Constructor Details

#initialize(options = {}) ⇒ LRUHash

Returns a new instance of LRUHash.

Parameters:

  • options (Hash) (defaults to: {})

Options Hash (options):

  • :max_size (Integer) — default: 1024000 —

    Maximum byte size of all values, nil disables the limit

  • :max_value (Integer) — default: options[:max_size] —

    Maximum byte size of one value, nil disables the limit

  • :max_count (Integer) — default: 10240 —

    Maximum number of values, nil disables the limit



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# File 'lib/moneta/adapters/lruhash.rb', line 20

def initialize(options = {})
  @max_size = options.fetch(:max_size) { DEFAULT_MAX_SIZE }
  @max_count = options.fetch(:max_count) { DEFAULT_MAX_COUNT }
  @max_value = [options[:max_value], @max_size].compact.min
  clear
end

Instance Method Details

#clear(options = {}) ⇒ void

This method returns an undefined value.

Clear all keys in this store

Parameters:

  • options (Hash) (defaults to: {}) 


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# File 'lib/moneta/adapters/lruhash.rb', line 69

def clear(options = {})
  @entry, @size = {}, 0
  @list = Entry.new
  @list.prev = @list.next = @list
  self
end

#delete(key, options = {}) ⇒ Object

Delete the key from the store and return the current value

Parameters:

  • key (Object)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :raw (Boolean) —

    Raw access without value transformation (See Transformer)

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware

Returns:

  • (Object) —

    current value



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# File 'lib/moneta/adapters/lruhash.rb', line 60

def delete(key, options = {})
  if entry = @entry.delete(key)
    @size -= entry.value.bytesize if @max_size
    entry.unlink
    entry.value
  end
end

#key?(key, options = {}) ⇒ Boolean

Exists the value with key

Parameters:

  • key (Object)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :expires (Integer) —

    Update expiration time (See Expires)

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware

Returns:

  • (Boolean) 


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# File 'lib/moneta/adapters/lruhash.rb', line 28

def key?(key, options = {})
  @entry.key?(key)
end

#load(key, options = {}) ⇒ Object

Fetch value with key. Return nil if the key doesn’t exist

Parameters:

  • key (Object)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :expires (Integer) —

    Update expiration time (See Expires)

  • :raw (Boolean) —

    Raw access without value transformation (See Transformer)

  • :prefix (String) —

    Prefix key (See Transformer)

  • :sync (Boolean) —

    Synchronized load (Cache reloads from adapter, Daybreak syncs with file)

  • Other (Object) —

    options as defined by the adapters or middleware

Returns:

  • (Object) —

    value



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# File 'lib/moneta/adapters/lruhash.rb', line 33

def load(key, options = {})
  if entry = @entry[key]
    entry.insert_after(@list)
    entry.value
  end
end

#store(key, value, options = {}) ⇒ Object

Store value with key

Parameters:

  • key (Object)
  • value (Object)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :expires (Integer) —

    Set expiration time (See Expires)

  • :raw (Boolean) —

    Raw access without value transformation (See Transformer)

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware

Returns:

  • value



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# File 'lib/moneta/adapters/lruhash.rb', line 41

def store(key, value, options = {})
  if @max_value && value.bytesize > @max_value
    delete(key)
  else
    if entry = @entry[key]
      @size -= entry.value.bytesize if @max_size
    else
      @entry[key] = entry = Entry.new
      entry.key = key
    end
    entry.value = value
    @size += entry.value.bytesize if @max_size
    entry.insert_after(@list)
    delete(@list.prev.key) while @list.next != @list.prev && (@max_size && @size > @max_size || @max_count && @entry.size > @max_count)
  end
  value
end