Module: Wash

Defined in:
lib/wash.rb,
lib/wash/entry.rb,
lib/wash/method.rb,
lib/wash/streamer.rb

Defined Under Namespace

Modules: Method Classes: Entry, Streamer

Class Method Summary collapse

Class Method Details

.enable_entry_schemas ⇒ Object

enable_entry_schemas enables Entry schema support. See Entry‘s documentation for more details on the available Entry schema helpers.



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# File 'lib/wash.rb', line 15

def self.enable_entry_schemas
  @entry_schemas_enabled = true
end

.on_sigterm(&block) ⇒ Object

on_sigterm will execute the provided block when the plugin script receives a SIGTERM/SIGINT signal. It is useful for handling plugin-specific cleanup like dangling processes, files, etc.

Examples:

class Foo
  # ...
  def stream
    # ...
    Wash.on_sigterm do
      # Kill any orphaned processes/files
    end
    # ...
  end
end


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# File 'lib/wash.rb', line 42

def self.on_sigterm(&block)
  sigterm_handlers << block
end

.prefetch_entry_schemas ⇒ Object

prefetch_entry_schemas enables schema-prefetching. This option should be enabled once external plugin development’s finished. If the external plugin is not using Entry schemas, then this option can be ignored.



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# File 'lib/wash.rb', line 23

def self.prefetch_entry_schemas
  @prefetch_entry_schemas = true
end

.pretty_print ⇒ Object

pretty_print enables pretty printing of methods that produce JSON output. It is a useful debugging tool.



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# File 'lib/wash.rb', line 8

def self.pretty_print
  @pretty_print = true
end

.run(root_klass, argv) ⇒ Object

run is the plugin script’s run function. All plugin scripts using this gem should invoke this function once they’ve specified the desired configuration options (e.g. like pretty_print).

Parameters:

  • root_klass (Wash::Entry) —

    The plugin root’s class object

  • argv (Array<String>) —

    The plugin script’s arguments (usually ARGV).



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# File 'lib/wash.rb', line 53

def self.run(root_klass, argv)
  Signal.trap('INT') do
    handle_sigterm
    exit 130
  end
  Signal.trap('TERM') do
    handle_sigterm
    exit 143
  end

  method, argv = next_arg(argv)

  if method == "init"
    config, argv = next_arg(argv)
    root = root_klass.new
    unless root.respond_to?(:init)
      raise "Plugin root #{root.type_id} does not implement init."
    end
    config = parse_json(config)
    root.init(config)
    if @prefetch_entry_schemas
      root.prefetch :schema
    end
    print_json(root)
    return
  end

  _, argv = next_arg(argv)

  state, argv = next_arg(argv)
  state = parse_json(state)
  klass = const_get(state.delete(:klass))
  # Use klass#allocate instead of klass#new to give plugin authors
  # more freedom in how they decide to setup their constructors
  entry = klass.allocate
  entry.send(:restore_state, state)

  Method.send(:invoke, method, entry, *argv)
end