Class: TinyMemcache

Inherits:
Object
  • Object
show all
Defined in:
lib/tiny_memcache.rb

Overview

a small in-memory cache, barely more than a Hash.

it supports the following commands from the memcache protocol:

* get <key>
* set <key> <value>
* del <key>

the key and value lengths are configurable, but default to 1k and 64k respectively.

example:

cache = TinyMemcache.new
cache.set("foo", "bar")
cache.get("foo") #=> "bar"
cache.del("foo")
cache.get("foo") #=> nil

Defined Under Namespace

Classes: KeyTooLongError, ValueTooLongError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(max_key_size: 1_024, max_value_size: 65_536) ⇒ TinyMemcache

initializes a new tiny_memcache object.

options:

:max_key_length   - the maximum length of a key in bytes (default: 1024)
:max_value_length - the maximum length of a value in bytes (default: 65536)



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# File 'lib/tiny_memcache.rb', line 33

def initialize(max_key_size: 1_024, max_value_size: 65_536)
  @data = {}

  @total_keys = 0
  @total_key_size = 0
  @total_value_size = 0

  @max_key_length = max_key_size
  @max_value_length = max_value_size
end

Instance Attribute Details

#total_key_size ⇒ Object (readonly)

Returns the value of attribute total_key_size.



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# File 'lib/tiny_memcache.rb', line 22

def total_key_size
  @total_key_size
end

#total_keys ⇒ Object (readonly)

Returns the value of attribute total_keys.



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# File 'lib/tiny_memcache.rb', line 22

def total_keys
  @total_keys
end

#total_value_size ⇒ Object (readonly)

Returns the value of attribute total_value_size.



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# File 'lib/tiny_memcache.rb', line 22

def total_value_size
  @total_value_size
end

Instance Method Details

#del(key) ⇒ Object 



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# File 'lib/tiny_memcache.rb', line 58

def del(key)
  @total_keys -= 1
  @total_key_size -= ObjectSpace.memsize_of(key)
  @total_value_size -= ObjectSpace.memsize_of(get(key))

  @data.delete(key)
end

#get(key) ⇒ Object 



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# File 'lib/tiny_memcache.rb', line 44

def get(key)
  @data[key]
end

#set(key, value) ⇒ Object

Raises:



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# File 'lib/tiny_memcache.rb', line 48

def set(key, value)
  raise KeyTooLongError if ObjectSpace.memsize_of(key) > @max_key_length
  raise ValueTooLongError if ObjectSpace.memsize_of(value) > @max_value_length

  @total_keys += 1
  @total_key_size += ObjectSpace.memsize_of(key)
  @total_value_size += ObjectSpace.memsize_of(value)
  @data[key] = value
end