Class: CMDx::Retriers

Inherits:
Object
  • Object
show all
Defined in:
lib/cmdx/retriers.rb,
lib/cmdx/retriers/linear.rb,
lib/cmdx/retriers/fibonacci.rb,
lib/cmdx/retriers/exponential.rb,
lib/cmdx/retriers/full_random.rb,
lib/cmdx/retriers/half_random.rb,
lib/cmdx/retriers/bounded_random.rb,
lib/cmdx/retriers/decorrelated_jitter.rb

Overview

Registry of named retry/jitter strategies used by ‘Retry` to compute the sleep duration between attempts. Ships with built-ins for `:exponential`, `:half_random`, `:full_random`, `:bounded_random`, `:linear`, `:fibonacci`, and `:decorrelated_jitter`. A retrier is any callable accepting `call(attempt, delay, prev_delay)` that returns the next delay in seconds.

Defined Under Namespace

Modules: BoundedRandom, DecorrelatedJitter, Exponential, Fibonacci, FullRandom, HalfRandom, Linear

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Retriers

Returns a new instance of Retriers.



13
14
15
16
17
18
19
20
21
22
23
 
# File 'lib/cmdx/retriers.rb', line 13

def initialize
  @registry = {
    exponential: Retriers::Exponential,
    half_random: Retriers::HalfRandom,
    full_random: Retriers::FullRandom,
    bounded_random: Retriers::BoundedRandom,
    linear: Retriers::Linear,
    fibonacci: Retriers::Fibonacci,
    decorrelated_jitter: Retriers::DecorrelatedJitter
  }
end

Instance Attribute Details

#registry ⇒ Object (readonly)

Returns the value of attribute registry.



11
12
13
 
# File 'lib/cmdx/retriers.rb', line 11

def registry
  @registry
end

Instance Method Details

#deregister(name) ⇒ Retriers

Returns self for chaining.

Parameters:

  • name (Symbol)

Returns:



58
59
60
61
 
# File 'lib/cmdx/retriers.rb', line 58

def deregister(name)
  registry.delete(name)
  self
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


105
106
107
 
# File 'lib/cmdx/retriers.rb', line 105

def empty?
  registry.empty?
end

#initialize_copy(source) ⇒ void

This method returns an undefined value.

Parameters:

  • source (Retriers) —

    registry to duplicate



27
28
29
 
# File 'lib/cmdx/retriers.rb', line 27

def initialize_copy(source)
  @registry = source.registry.dup
end

#key?(name) ⇒ Boolean

Returns whether a retrier is registered under ‘name`.

Parameters:

  • name (Symbol)

Returns:

  • (Boolean) —

    whether a retrier is registered under ‘name`



65
66
67
 
# File 'lib/cmdx/retriers.rb', line 65

def key?(name)
  registry.key?(name)
end

#lookup(name) ⇒ #call

Returns the registered retrier.

Parameters:

  • name (Symbol)

Returns:

  • (#call) —

    the registered retrier

Raises:



72
73
74
75
76
77
78
79
 
# File 'lib/cmdx/retriers.rb', line 72

def lookup(name)
  registry[name] || begin
    raise UnknownEntryError, <<~MSG.chomp
      unknown retrier #{name.inspect}; registered: #{registry.keys.inspect}.
      See https://drexed.github.io/cmdx/retries/#built-in-strategies
    MSG
  end
end

#register(name, callable = nil, &block) { ... } ⇒ Retriers

Registers a named retrier, overwriting any existing entry.

Parameters:

  • name (Symbol)
  • callable (#call, nil) (defaults to: nil) —

    pass either this or a block

  • block (#call, nil) —

    retrier callable when ‘callable` is omitted

Yields:

  • retrier body — ‘call(attempt, delay, prev_delay)`

Returns:

Raises:

  • (ArgumentError) —

    when both ‘callable` and a block are given, or when the resolved retrier isn’t callable



40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
 
# File 'lib/cmdx/retriers.rb', line 40

def register(name, callable = nil, &block)
  retrier = callable || block

  if callable && block
    raise ArgumentError, "retrier: provide either a callable or a block, not both"
  elsif !retrier.respond_to?(:call)
    raise ArgumentError, <<~MSG.chomp
      retrier must respond to #call (got #{retrier.class}).
      See https://drexed.github.io/cmdx/retries/#custom-strategies-via-the-retriers-registry
    MSG
  end

  registry[name.to_sym] = retrier
  self
end

#resolve(spec) ⇒ #call?

Resolves a ‘:jitter` spec to a concrete callable. Accepts a Symbol (registry lookup) or any object responding to `#call`. `nil` resolves to `nil` so callers can fall back to the unjittered base delay.

Parameters:

  • spec (Symbol, #call, nil)

Returns:

  • (#call, nil)

Raises:



88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
 
# File 'lib/cmdx/retriers.rb', line 88

def resolve(spec)
  case spec
  when NilClass
    nil
  when Symbol
    lookup(spec)
  else
    return spec if spec.respond_to?(:call)

    raise UnknownEntryError, <<~MSG.chomp
      unknown retrier #{spec.inspect}; expected a Symbol from #{registry.keys.inspect} or a callable.
      See https://drexed.github.io/cmdx/retries/#built-in-strategies
    MSG
  end
end

#size ⇒ Integer

Returns:

  • (Integer) 


110
111
112
 
# File 'lib/cmdx/retriers.rb', line 110

def size
  registry.size
end