Class: Btape::Settings

Inherits:
Object
  • Object
show all
Defined in:
lib/btape/settings.rb

Overview

The knobs a script turns with Set NAME VALUE, along with their defaults, their coercions, and the validation the parser calls while reading a tape.

Values arrive from three places, in increasing order of precedence: the defaults here, the Set lines in the tape, and whatever the caller passes to Runner#run or the CLI passes from its flags.

Constant Summary collapse

CAPTURE_MODES = 
%w[interval manual].freeze
QUANTIZERS = 
%w[adaptive rgb332].freeze
URL_SCHEMES = 
%w[ws:// wss:// http:// https://].freeze
DEFINITIONS =

Script name => [attribute, coercion, default]. Defaults are already coerced, so durations are seconds and not "100ms".

{
  'WsUrl' => [:ws_url, :url, nil],
  'CaptureMode' => [:capture_mode, CAPTURE_MODES, 'interval'],
  'Framerate' => [:framerate, :positive_float, 10.0],
  'FrameDelay' => [:frame_delay, :duration, 0.1],
  'Loop' => [:loop_count, :count, 0],
  'Scale' => [:scale, :positive_float, 1.0],
  'OutputWidth' => [:output_width, :positive_integer, nil],
  'Quantizer' => [:quantizer, QUANTIZERS, 'adaptive'],
  'Timeout' => [:timeout, :duration, 120.0],
  'WaitTimeout' => [:wait_timeout, :duration, 10.0],
  'WaitInterval' => [:wait_interval, :duration, 0.1],
  'WaitStable' => [:wait_stable, :positive_integer, 1],
  'MaxFrames' => [:max_frames, :positive_integer, 600]
}.freeze
ATTRIBUTES = 
DEFINITIONS.each_value.map(&:first).freeze

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(values = {}) ⇒ Settings

Returns a new instance of Settings.



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# File 'lib/btape/settings.rb', line 115

def initialize(values = {})
  @values = defaults_merged_with(values).freeze
  freeze
end

Class Method Details

.defaults ⇒ Object 



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# File 'lib/btape/settings.rb', line 40

def defaults
  DEFINITIONS.each_value.to_h { |attribute, _coercion, default| [attribute, default] }
end

.from_commands(commands) ⇒ Object 



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# File 'lib/btape/settings.rb', line 51

def from_commands(commands)
  values = commands.select { |command| command.name == 'Set' }.to_h do |command|
    validate!(*command.arguments)
  rescue ArgumentError => e
    raise ScriptError.new(command.line_number, e.message)
  end
  new(values)
end

.validate!(name, value) ⇒ Object

Validates one Set line and returns the coerced value. Raises ArgumentError, which Parser turns into a ScriptError carrying the line.



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# File 'lib/btape/settings.rb', line 46

def validate!(name, value)
  attribute, coercion, = DEFINITIONS.fetch(name) { raise ArgumentError, "unknown setting #{name.inspect}" }
  [attribute, coerce(coercion, value, name)]
end

Instance Method Details

#merge(overrides) ⇒ Object 



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# File 'lib/btape/settings.rb', line 120

def merge(overrides)
  return self if overrides.nil? || (overrides.respond_to?(:empty?) && overrides.empty?)

  self.class.new(@values.merge(normalize(overrides)))
end

#to_h ⇒ Object 



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# File 'lib/btape/settings.rb', line 126

def to_h
  @values.dup
end