Class: Picombo::Cache

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

Overview

Cache Class

The cache class allows you to serialize ruby objects, store them in a backend system, and retreive them later.

Caching can be useful for methods that take a long time to run, or complex database queries that cannot be made quicker.

Usage

To set a cache item, use the set method: Picombo::Cache.new.set(:test, ‘<h1>It Works!</h1><p>This is a test.</p>’) You can also pass a hash into the first parameter to set multiple items

To retreive a cache item, use the get method: html = Picombo::Cache.new.get(:test) # html will contain ‘<h1>It Works!</h1><p>This is a test.</p>’

To delete an existing cache item, use the delete method Picombo::Cache.new.delete(:test)

Drivers

The cache class supports drivers, which will allow you to use different backend systems to store your cache items. Right now only a file driver is available. You can write your own cache drivers to behave how you want as well.

By default the cache driver will use the “default” group in your config file: cache.yaml You can specify multiple groups as well.

Usage

To call the cache driver with an alternate group, just pass that group name into the new method Picombo::Cache.new(‘my_other_group’)

To do this, you need to define the ‘my_other_group’ in your config file

Lifetimes

The cache class supports lifetimes, which will automatically expire cache items after the specified time period. These are specifies in seconds from the current time. When you use the set method, you can set a specific lifetime with the third parameter. The default is located in the config file group

Constant Summary collapse

@@driver = 
nil
@@config = 
nil
@@group = 
nil

Instance Method Summary collapse

Constructor Details

#initialize(group = nil) ⇒ Cache

Set up the driver



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# File 'lib/classes/cache.rb', line 52

def initialize(group = nil)
	group = 'default' if group == nil
	@@group = group
	@@config = Picombo::Config.get('cache.'+group)
	driver_name = 'Cache_'+@@config['driver'].capitalize!
	@@driver = Picombo::const_get(driver_name).new(@@config)
end

Instance Method Details

#delete(keys) ⇒ Object

Deletes a cache item



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# File 'lib/classes/cache.rb', line 76

def delete(keys)
	unless key.is_a? Array
		key = [key]
	end

	@@driver.delete(keys)
end

#delete_all ⇒ Object

Deletes all the cache items



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# File 'lib/classes/cache.rb', line 85

def delete_all
	@@driver.delete_all
end

#get(key) ⇒ Object

Retreives a cache item



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# File 'lib/classes/cache.rb', line 71

def get(key)
	@@driver.get(key.to_s, (key.is_a? Array) ? true : false)
end

#set(key, value = nil, lifetime = nil) ⇒ Object

Sets a cache item



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# File 'lib/classes/cache.rb', line 61

def set(key, value = nil, lifetime = nil)
	lifetime = Picombo::Config.get('cache.'+@@group+'.lifetime').to_i if lifetime == nil
	unless key.is_a? Hash
		key = {key => value}
	end

	@@driver.set(key, lifetime)
end