Class: Petra::Components::ProxyCache

Inherits:
Object
  • Object
show all
Defined in:
lib/petra/components/proxy_cache.rb

Overview

This class encapsulates the methods a transaction may use to gather information about the objects which were used during its execution.

It also functions as an object cache, mapping proxy keys to (temporary) object proxies

Instance Method Summary collapse

Constructor Details

#initialize(transaction) ⇒ ProxyCache

Returns a new instance of ProxyCache.



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# File 'lib/petra/components/proxy_cache.rb', line 12

def initialize(transaction)
  @transaction = transaction
end

Instance Method Details

#created(klass = nil) ⇒ Array<Petra::Proxies::ObjectProxy>

Objects that were initialized and persisted during the transaction

Parameters:

  • klass (Class) (defaults to: nil)

Returns:



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# File 'lib/petra/components/proxy_cache.rb', line 77

def created(klass = nil)
  filtered_objects(:created_objects, klass)
end

#created?(proxy) ⇒ Boolean

Returns true if the given object (proxy) was initialized AND persisted during the transaction.

Parameters:

Returns:

  • (Boolean) —

    true if the given object (proxy) was initialized AND persisted during the transaction.



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# File 'lib/petra/components/proxy_cache.rb', line 121

def created?(proxy)
  created.include?(proxy)
end

#current_numerical_id ⇒ Object 

Helpers



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# File 'lib/petra/components/proxy_cache.rb', line 168

def current_numerical_id
  # FIXME: The string comparison will not work for numbers > 10! It has to be replaced with a numeric comparison!
  # FIXME: This also causes problems when the last new element is deleted and a new one created
  @current_numerical_id ||= (initialized_or_created.max_by(&:__object_id)&.__object_id || 'new_0')
                            .match(/new_(\d+)/)[1].to_i
end

#destroyed(klass = nil) ⇒ Array<Petra::Proxies::ObjectProxy>

Returns objects which were destroyed within the transaction.

Parameters:

  • klass (Class) (defaults to: nil)

Returns:

See Also:

  • #filtered_objects


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# File 'lib/petra/components/proxy_cache.rb', line 112

def destroyed(klass = nil)
  filtered_objects(:destroyed_objects, klass)
end

#destroyed?(proxy) ⇒ Boolean

Returns true if the given object was destroyed during this transaction.

Parameters:

Returns:

  • (Boolean) —

    true if the given object was destroyed during this transaction



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# File 'lib/petra/components/proxy_cache.rb', line 160

def destroyed?(proxy)
  destroyed.include?(proxy)
end

#existing?(proxy) ⇒ Boolean

Returns true if the given object existed before the transaction started.

Parameters:

Returns:

  • (Boolean) —

    true if the given object existed before the transaction started



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# File 'lib/petra/components/proxy_cache.rb', line 151

def existing?(proxy)
  !new?(proxy)
end

#fateful(klass = nil) ⇒ Object

Objects that will have impact during the commit phase in order of their appearance during the transaction’s execution.



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# File 'lib/petra/components/proxy_cache.rb', line 55

def fateful(klass = nil)
  filtered_objects(:objects, klass)
end

#fetch(key) ⇒ Petra::Proxies::ObjectProxy Also known as: []

Returns the proxy for the given object key from cache. If there is no valid object cached yet, the given block is executed and its result saved under the given key.

Returns:



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# File 'lib/petra/components/proxy_cache.rb', line 23

def fetch(key)
  @cache ||= {}
  return @cache[key.to_s] if @cache.key?(key.to_s)
  fail ArgumentError, "Object `#{key}` is not cached and no block was given." unless block_given?
  @cache[key.to_s] = yield
end

#inc_current_numerical_id ⇒ Object 



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# File 'lib/petra/components/proxy_cache.rb', line 175

def inc_current_numerical_id
  @current_numerical_id = current_numerical_id + 1
end

#initialized(klass = nil) ⇒ Array<Petra::Proxies::ObjectProxy>

Returns objects which were initialized within the transaction, but not yet object persisted.

Parameters:

  • klass (Class) (defaults to: nil)

Returns:

See Also:

  • #filtered_objects


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# File 'lib/petra/components/proxy_cache.rb', line 101

def initialized(klass = nil)
  filtered_objects(:initialized_objects, klass)
end

#initialized?(proxy) ⇒ Boolean

Returns true if the given object (proxy) was initialized, but not yet persisted during this transaction. This means in particular that the object did not exist before the transaction started.

Parameters:

Returns:

  • (Boolean) —

    true if the given object (proxy) was initialized, but not yet persisted during this transaction. This means in particular that the object did not exist before the transaction started.



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# File 'lib/petra/components/proxy_cache.rb', line 132

def initialized?(proxy)
  initialized.include?(proxy)
end

#initialized_or_created(klass = nil) ⇒ Array<Petra::Proxies::ObjectProxy>

Like #created, but it will also include not-yet persisted objects of non-persisted sections

Parameters:

  • klass (Class) (defaults to: nil)

Returns:



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# File 'lib/petra/components/proxy_cache.rb', line 89

def initialized_or_created(klass = nil)
  filtered_objects(:initialized_or_created_objects, klass)
end

#new?(proxy) ⇒ Boolean

Returns true if the given object did not exist outside of the transaction, meaning that it was initialized and optionally persisted during its execution.

Parameters:

Returns:

  • (Boolean) —

    true if the given object did not exist outside of the transaction, meaning that it was initialized and optionally persisted during its execution



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# File 'lib/petra/components/proxy_cache.rb', line 142

def new?(proxy)
  current_section.recently_initialized_object?(proxy) || initialized_or_created.include?(proxy)
end

#next_id ⇒ Object 



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# File 'lib/petra/components/proxy_cache.rb', line 179

def next_id
  format('new_%05d', inc_current_numerical_id)
end

#read(klass = nil) ⇒ Array<Petra::Proxies::ObjectProxy>

Objects that were read during the transaction

Parameters:

  • klass (Class) (defaults to: nil)

Returns:



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# File 'lib/petra/components/proxy_cache.rb', line 66

def read(klass = nil)
  filtered_objects(:read_objects, klass)
end

#read_attributes ⇒ Hash<Petra::Proxies::ObjectProxy, Array<String,Symbol>>

Returns All attributes which were read during this transaction grouped by the objects (proxies) they belong to.

Returns:

  • (Hash<Petra::Proxies::ObjectProxy, Array<String,Symbol>>) —

    All attributes which were read during this transaction grouped by the objects (proxies) they belong to.



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# File 'lib/petra/components/proxy_cache.rb', line 42

def read_attributes
  sections.each_with_object({}) do |section, h|
    section.read_attributes.each do |proxy, attributes|
      h[proxy] ||= []
      h[proxy] = (h[proxy] + attributes).uniq
    end
  end
end

#verify_read_attributes!(force: false) ⇒ Object

Performs an integrity check on all attributes which were read in this transaction

Raises:



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# File 'lib/petra/components/proxy_cache.rb', line 188

def verify_read_attributes!(force: false)
  read_attributes.each do |proxy, attributes|
    attributes.each { |a| verify_attribute_integrity!(proxy, attribute: a, force: force) }
  end
end