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|
class Chef
class Node
class AttributeTrait
module Decorator
attr_accessor :wrapped_object
#
# Delegate methods common to Array and Hash
# - this is done for speed over method_missing
# - some of these methods are overridden later with different semantics
#
methods = ( Array.instance_methods & Hash.instance_methods ) - Object.instance_methods +
[ :!, :!=, :<=>, :==, :===, :eql?, :to_s, :hash ]
methods.each do |method|
define_method method do |*args, &block|
wrapped_object.public_send(method, *args, &block)
end
end
def self.included(base)
base.extend(ClassMethods)
end
module ClassMethods
def [](*args)
new(wrapped_object: Hash[ *args ])
end
end
def initialize(wrapped_object: nil, **args)
@wrapped_object = wrapped_object
end
def ffi_yajl(*opts)
for_json.ffi_yajl(*opts)
end
def to_json(*opts)
Chef::JSONCompat.to_json(for_json, *opts)
end
def for_json
if is_a?(Hash)
to_hash
elsif is_a?(Array)
to_ary
else
wrapped_object
end
end
def is_a?(klass)
wrapped_object.is_a?(klass) || super
end
def kind_of?(klass)
wrapped_object.kind_of?(klass) || super
end
def regular_writer(*path, value)
last_key = path.pop
obj = path.inject(wrapped_object) { |memo, key| memo[key] }
obj[last_key] = value
end
def regular_reader(*path)
ret = maybe_decorated_value(
path.inject(wrapped_object) { |memo, key| memo[key] }
)
end
def safe_reader(*path)
begin
regular_reader(*path)
rescue NoMethodError
nil
end
end
def safe_delete(*path)
last = path.pop
hash = safe_reader(*path)
return nil unless hash.is_a?(Hash)
hash.delete(last)
end
def [](key)
maybe_decorated_value(wrapped_object[key])
end
def maybe_decorated_value(val)
if val.is_a?(Hash) || val.is_a?(Array)
new_decorator(wrapped_object: val)
else
val
end
end
def new_decorator(**args)
self.class.new(**args)
end
def method_missing(method, *args, &block)
if wrapped_object.respond_to?(method, false)
# cannot define_method here
wrapped_object.public_send(method, *args, &block)
else
super
end
end
def respond_to?(method, include_private = false)
# since we define these methods, :respond_to_missing? doesn't work.
return false if is_a?(Array) && method == :each_pair
return false if is_a?(Array) && method == :key?
return false if is_a?(Array) && method == :has_key?
wrapped_object.respond_to?(method, false) || super
end
def respond_to_missing?(method, include_private = false)
wrapped_object.respond_to?(method, false) || super
end
def initialize_copy(source)
super
@wrapped_object = safe_dup(source.wrapped_object)
end
def include?(key)
wrapped_object.include?(key)
end
# performance
def key?(key)
wrapped_object.key?(key)
end
# performance
def has_key?(key)
wrapped_object.has_key?(key)
end
# we need to be careful to return decorated values when appropriate
def each(&block)
return enum_for(:each) unless block_given?
if wrapped_object.is_a?(Array)
wrapped_object.each_with_index do |value, i|
yield self[i]
end
elsif wrapped_object.is_a?(Hash)
if block.arity > 1
wrapped_object.each do |key, value|
yield key, self[key]
end
else
wrapped_object.each do |key, value|
yield [ key, self[key] ]
end
end
else
# dunno...
wrapped_object.each(&block)
end
end
# return decorated values when appropriate
alias_method :each_pair, :each
# nil, true, false and Fixnums are not dup'able
def safe_dup(e)
e.dup
rescue TypeError
e
end
def dup
if is_a?(Array)
map(&method(:safe_dup))
elsif is_a?(Hash)
h = {}
each { |k, v| h[safe_dup(k)] = safe_dup(v) }
h
else
safe_dup(wrapped_object)
end
end
end
end
end
end
#
# Ruby is arguably buggy here. The Module.=== operator does not call
# kind_of? or is_a? but only looks up the ancestor heirarchy, so only
# things that directly inherit from Array or Hash can be matched in a
# case statement. TODO: supply a patch to ruby to fix its behavior.
#
# Please see the implementation of Module.=== in the ruby source code
#
class Hash
def self.===(other)
other.kind_of?(Chef::Node::AttributeTrait::Decorator) || super
end
end
class Array
def self.===(other)
other.kind_of?(Chef::Node::AttributeTrait::Decorator) || super
end
end
|
