Class: Moneta::Adapters::LRUHash

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

Overview

LRUHash backend

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

Defined Under Namespace

Classes: Entry

Instance Method Summary collapse

Methods included from IncrementSupport

#increment

Methods included from Defaults

#[], #[]=, #close, #decrement, #fetch, #increment

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 total byte size of hash values


14
15
16
17
# File 'lib/moneta/adapters/lruhash.rb', line 14

def initialize(options = {})
  @max_size = options[:max_size] || 1024000
  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: {})

57
58
59
60
61
62
# File 'lib/moneta/adapters/lruhash.rb', line 57

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 `Moneta::Transformer`)

  • :prefix (String)

    Prefix key (See `Moneta::Transformer`)

  • Other (Object)

    options as defined by the adapters or middleware

Returns:

  • (Object)

    current value


48
49
50
51
52
53
54
# File 'lib/moneta/adapters/lruhash.rb', line 48

def delete(key, options = {})
  if entry = @entry.delete(key)
    @size -= entry.value.bytesize
    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 `Moneta::Expires`)

  • :prefix (String)

    Prefix key (See `Moneta::Transformer`)

  • Other (Object)

    options as defined by the adapters or middleware

Returns:

  • (Boolean)

20
21
22
# File 'lib/moneta/adapters/lruhash.rb', line 20

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 `Moneta::Expires`)

  • :raw (Boolean)

    Raw access without value transformation (See `Moneta::Transformer`)

  • :prefix (String)

    Prefix key (See `Moneta::Transformer`)

  • Other (Object)

    options as defined by the adapters or middleware

Returns:

  • (Object)

    value


25
26
27
28
29
30
# File 'lib/moneta/adapters/lruhash.rb', line 25

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 `Moneta::Expires`)

  • :raw (Boolean)

    Raw access without value transformation (See `Moneta::Transformer`)

  • :prefix (String)

    Prefix key (See `Moneta::Transformer`)

  • Other (Object)

    options as defined by the adapters or middleware

Returns:

  • value


33
34
35
36
37
38
39
40
41
42
43
44
45
# File 'lib/moneta/adapters/lruhash.rb', line 33

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