Module: Concurrent::SettableStruct

Defined in:
lib/concurrent-ruby/concurrent/settable_struct.rb

Overview

An thread-safe, write-once variation of Ruby's standard Struct. Each member can have its value set at most once, either at construction or any time thereafter. Attempting to assign a value to a member that has already been set will result in a Concurrent::ImmutabilityError.

See Also:

Instance Method Summary collapse

Instance Method Details

#==(other) ⇒ Boolean

Equality

Returns:

  • (Boolean) —

    true if other has the same struct subclass and has equal member values (according to Object#==)



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 50

def ==(other)
  synchronize { ns_equality(other) }
end

#[](member) ⇒ Object

Attribute Reference

Parameters:

  • member (Symbol, String, Integer) —

    the string or symbol name of the member for which to obtain the value or the member's index

Returns:

  • (Object) —

    the value of the given struct member or the member at the given index.

Raises:

  • (NameError) —

    if the member does not exist

  • (IndexError) —

    if the index is out of range.



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 45

def [](member)
  synchronize { ns_get(member) }
end

#[]=(member, value) ⇒ Object

Attribute Assignment

Sets the value of the given struct member or the member at the given index.

Parameters:

  • member (Symbol, String, Integer) —

    the string or symbol name of the member for which to obtain the value or the member's index

Returns:

  • (Object) —

    the value of the given struct member or the member at the given index.

Raises:

  • (NameError) —

    if the name does not exist

  • (IndexError) —

    if the index is out of range.

  • (Concurrent::ImmutabilityError) —

    if the given member has already been set



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 75

def []=(member, value)
  if member.is_a? Integer
    length = synchronize { @values.length }
    if member >= length
      raise IndexError.new("offset #{member} too large for struct(size:#{length})")
    end
    synchronize do
      unless @values[member].nil?
        raise Concurrent::ImmutabilityError.new('struct member has already been set')
      end
      @values[member] = value
    end
  else
    send("#{member}=", value)
  end
rescue NoMethodError
  raise NameError.new("no member '#{member}' in struct")
end

#each {|value| ... } ⇒ undocumented

Yields the value of each struct member in order. If no block is given an enumerator is returned.

Yields:

  • the operation to be performed on each struct member

Yield Parameters:

  • value (Object) —

    each struct value (in order)



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 55

def each(&block)
  return enum_for(:each) unless block_given?
  synchronize { ns_each(&block) }
end

#each_pair {|member, value| ... } ⇒ undocumented

Yields the name and value of each struct member in order. If no block is given an enumerator is returned.

Yields:

  • the operation to be performed on each struct member/value pair

Yield Parameters:

  • member (Object) —

    each struct member (in order)

  • value (Object) —

    each struct value (in order)



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 61

def each_pair(&block)
  return enum_for(:each_pair) unless block_given?
  synchronize { ns_each_pair(&block) }
end

#inspect ⇒ String Also known as: to_s

Describe the contents of this struct in a string.

Returns:

  • (String) —

    the contents of this struct in a string



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 29

def inspect
  synchronize { ns_inspect }
end

#merge(other) {|member, selfvalue, othervalue| ... } ⇒ Synchronization::AbstractStruct

Returns a new struct containing the contents of other and the contents of self. If no block is specified, the value for entries with duplicate keys will be that of other. Otherwise the value for each duplicate key is determined by calling the block with the key, its value in self and its value in other.

Parameters:

  • other (Hash) —

    the hash from which to set the new values

Yields:

  • an options block for resolving duplicate keys

Yield Parameters:

  • member (String, Symbol) —

    the name of the member which is duplicated

  • selfvalue (Object) —

    the value of the member in self

  • othervalue (Object) —

    the value of the member in other

Returns:

  • (Synchronization::AbstractStruct) —

    a new struct with the new values

Raises:

  • (ArgumentError) —

    of given a member that is not defined in the struct



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 35

def merge(other, &block)
  synchronize { ns_merge(other, &block) }
end

#select {|value| ... } ⇒ Array

Yields each member value from the struct to the block and returns an Array containing the member values from the struct for which the given block returns a true value (equivalent to Enumerable#select).

Yields:

  • the operation to be performed on each struct member

Yield Parameters:

  • value (Object) —

    each struct value (in order)

Returns:

  • (Array) —

    an array containing each value for which the block returns true



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 67

def select(&block)
  return enum_for(:select) unless block_given?
  synchronize { ns_select(&block) }
end

#to_h ⇒ Hash

Returns a hash containing the names and values for the struct’s members.

Returns:

  • (Hash) —

    the names and values for the struct’s members



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 40

def to_h
  synchronize { ns_to_h }
end

#values ⇒ Array Also known as: to_a

Returns the values for this struct as an Array.

Returns:

  • (Array) —

    the values for this struct



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 18

def values
  synchronize { ns_values }
end

#values_at(*indexes) ⇒ undocumented

Returns the struct member values for each selector as an Array.

A selector may be either an Integer offset or a Range of offsets (as in Array#values_at).

Parameters:

  • indexes (Fixnum, Range) —

    the index(es) from which to obatin the values (in order)



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# File 'lib/concurrent-ruby/concurrent/settable_struct.rb', line 24

def values_at(*indexes)
  synchronize { ns_values_at(indexes) }
end