Class: Faulty::Cache::Default

Inherits:

Object

• Object
• Faulty::Cache::Default

Extended by:

Forwardable

Defined in:

lib/faulty/cache/default.rb

Overview

The default cache implementation

It tries to make a logical decision of what cache implementation to use based on the current environment.

• If Rails is loaded, it will use Rails.cache
• If ActiveSupport is available, it will use an ActiveSupport::Cache::MemoryStore
• Otherwise it will use a Null

Instance Method Summary

• #fault_tolerant ⇒ Boolean

  Can this cache backend raise an error?.

• #initialize ⇒ Default constructor

  A new instance of Default.

• #read(key) ⇒ Object^?

  Retrieve a value from the cache if available.

• #write(key, value, expires_in: expires_in) ⇒ void

  Write a value to the cache.

Constructor Details

#initialize ⇒ Default

Returns a new instance of Default.

# File 'lib/faulty/cache/default.rb', line 16

def initialize
  @cache = if defined?(::Rails)
    Cache::Rails.new(::Rails.cache)
  elsif defined?(::ActiveSupport::Cache::MemoryStore)
    Cache::Rails.new(ActiveSupport::Cache::MemoryStore.new, fault_tolerant: true)
  else
    Cache::Null.new
  end
end

Instance Method Details

#fault_tolerant ⇒ Boolean

Can this cache backend raise an error?

If the cache backend returns false from this method, it will be wrapped in a FaultTolerantProxy, otherwise it will be used as-is.

Returns:

• (Boolean) —

  True if this cache backend is fault tolerant

# File 'lib/faulty/cache/default.rb', line 34

def_delegators :@cache, :read, :write, :fault_tolerant?

#read(key) ⇒ Object^?

Retrieve a value from the cache if available

Parameters:

• key (String) —

  The cache key

Returns:

• (Object, nil) —

  The object if present, otherwise nil

Raises:

• If the cache backend encounters a failure

# File 'lib/faulty/cache/default.rb', line 34

def_delegators :@cache, :read, :write, :fault_tolerant?

#write(key, value, expires_in: expires_in) ⇒ void

This method returns an undefined value.

Write a value to the cache

This may be any object. It's up to the cache implementation to serialize if necessary or raise an error if unsupported.

Parameters:

• key (String) —

  The cache key

• expires_in (Integer, nil) (defaults to: expires_in) —

  The number of seconds until this cache entry expires. If nil, no expiration is set.

• value (Object) —

  The value to write to the cache

Raises:

• If the cache backend encounters a failure

# File 'lib/faulty/cache/default.rb', line 34

def_delegators :@cache, :read, :write, :fault_tolerant?