Class: Merb::Cache::DatabaseStore

Inherits:
Object
  • Object
show all
Includes:
ActiveRecord, DataMapper, Sequel
Defined in:
lib/merb-cache/cache-store/database.rb

Defined Under Namespace

Classes: OrmNotFound

Instance Method Summary collapse

Constructor Details

#initialize ⇒ DatabaseStore

Provides the database cache store for merb-cache



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# File 'lib/merb-cache/cache-store/database.rb', line 4

def initialize
  @config = Merb::Controller._cache.config
  prepare
end

Instance Method Details

#cache(_controller, key, from_now = nil, &block) ⇒ Object

Capture or restore the data in cache. If the cache entry expired or does not exist, the data are taken from the execution of the block, marshalled and stored in cache. Otherwise, the data are loaded from the cache and returned unmarshalled

Parameters

_controller<Merb::Controller>

The instance of the current controller

key<String>

The key identifying the cache entry

from_now<~minutes>

The number of minutes (from now) the cache should persist

&block

The template to be used or not

Additional information

When fetching data (the cache entry exists and has not expired) The data are loaded from the cache and returned unmarshalled. Otherwise: The controller is used to capture the rendered template (from the block). It uses the capture_#engine and concat_#engine methods to do so. The captured data are then marshalled and stored.



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# File 'lib/merb-cache/cache-store/database.rb', line 68

def cache(_controller, key, from_now = nil, &block)
  _data = CacheModel.cache_get(key)
  if _data.nil?
    _expire = from_now ? from_now.minutes.from_now : nil
    _data = _controller.send(:capture, &block)
    CacheModel.cache_set(key, Marshal.dump(_data), _expire, false)
  else
    _data = Marshal.load(_data)
  end
  _controller.send(:concat, _data, block.binding)
  true
end

#cache_get(key) ⇒ Object

Fetch data from the database using the specified key The entry is deleted if it has expired

Parameter

key<Sting>

The key identifying the cache entry

Returns

data<String, NilClass>

nil is returned whether the entry expired or was not found



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# File 'lib/merb-cache/cache-store/database.rb', line 104

def cache_get(key)
  data = CacheModel.cache_get(key)
  Merb.logger.info("cache: #{data.nil? ? "miss" : "hit"} (#{key})")
  data.nil? ? nil : Marshal.load(data)
end

#cache_set(key, data, from_now = nil) ⇒ Object

Store data to the database using the specified key

Parameters

key<Sting>

The key identifying the cache entry

data<String>

The data to be put in cache

from_now<~minutes>

The number of minutes (from now) the cache should persist



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# File 'lib/merb-cache/cache-store/database.rb', line 88

def cache_set(key, data, from_now = nil)
  _expire = from_now ? from_now.minutes.from_now : nil
  CacheModel.cache_set(key, Marshal.dump(data), _expire)
  Merb.logger.info("cache: set (#{key})")
  true
end

#cache_store_type ⇒ Object

Gives info on the current cache store

Returns

The type of the current cache store



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# File 'lib/merb-cache/cache-store/database.rb', line 141

def cache_store_type
  "database"
end

#cached?(key) ⇒ Boolean

Checks whether a cache entry exists

Parameter

key<String>

The key identifying the cache entry

Returns

true if the cache entry exists, false otherwise

Returns:

  • (Boolean) 


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# File 'lib/merb-cache/cache-store/database.rb', line 45

def cached?(key)
  not CacheModel.cache_get(key).nil?
end

#expire(key) ⇒ Object

Expire the cache entry identified by the given key

Parameter

key<Sting>

The key identifying the cache entry



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# File 'lib/merb-cache/cache-store/database.rb', line 114

def expire(key)
  CacheModel.expire(key)
  Merb.logger.info("cache: expired (#{key})")
  true
end

#expire_all ⇒ Object

Expire all the cache entries



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# File 'lib/merb-cache/cache-store/database.rb', line 131

def expire_all
  CacheModel.expire_all
  Merb.logger.info("cache: expired all")
  true
end

#expire_match(key) ⇒ Object

Expire the cache entries matching the given key

Parameter

key<Sting>

The key matching the cache entries



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# File 'lib/merb-cache/cache-store/database.rb', line 124

def expire_match(key)
  CacheModel.expire_match(key)
  Merb.logger.info("cache: expired matching (#{key})")
  true
end

#prepare ⇒ Object

This method is there to ensure minimal requirements are met (file permissions, table exists, connected to server, …)



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# File 'lib/merb-cache/cache-store/database.rb', line 33

def prepare
  CacheModel.check_table
  true
end