Class: DTAS::Sink

Inherits:
Object
  • Object
show all
Includes:
Command, Process, Serialize, WritableIter
Defined in:
lib/dtas/sink.rb

Overview

this is a sink (endpoint, audio enters but never leaves)

Constant Summary collapse

SINK_DEFAULTS = 
COMMAND_DEFAULTS.merge({
  "name" => nil, # order matters, this is first
  "command" => "exec play -q $SOXFMT -",
  "prio" => 0,
  "nonblock" => false,
  "pipe_size" => nil,
  "active" => false,
  "respawn" => false,
})
DEVFD_RE = 
%r{/dev/fd/([a-zA-Z]\w*)\b}
SIVS =

order matters for Ruby 1.9+, this defines to_hsh serialization so we can make the state file human-friendly

%w(name env command prio nonblock pipe_size active)

Constants included from Process

Process::PIDS

Constants included from Command

Command::COMMAND_DEFAULTS

Instance Attribute Summary collapse

Attributes included from WritableIter

#on_writable

Attributes included from Command

#command, #env, #pid, #spawn_at, #to_io

Class Method Summary collapse

Instance Method Summary collapse

Methods included from WritableIter

#writable_iter, #writable_iter_init

Methods included from Serialize

#ivars_to_hash

Methods included from Process

#dtas_spawn, #qx, reaper, #xs

Methods included from Command

#command_init, #command_string, #kill

Constructor Details

#initialize ⇒ Sink

Returns a new instance of Sink.



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# File 'lib/dtas/sink.rb', line 42

def initialize
  command_init(SINK_DEFAULTS)
  writable_iter_init
  @sink = self
end

Instance Attribute Details

#active ⇒ Object

boolean



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# File 'lib/dtas/sink.rb', line 16

def active
  @active
end

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/dtas/sink.rb', line 17

def name
  @name
end

#nonblock ⇒ Object

Returns the value of attribute nonblock.



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# File 'lib/dtas/sink.rb', line 18

def nonblock
  @nonblock
end

#prio ⇒ Object

:nodoc:



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# File 'lib/dtas/sink.rb', line 15

def prio
  @prio
end

#respawn ⇒ Object

Returns the value of attribute respawn.



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# File 'lib/dtas/sink.rb', line 19

def respawn
  @respawn
end

Class Method Details

.load(hash) ⇒ Object 



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# File 'lib/dtas/sink.rb', line 54

def self.load(hash)
  sink = new
  return sink unless hash
  (SIVS & hash.keys).each do |k|
    sink.instance_variable_set("@#{k}", hash[k])
  end
  sink.valid_name?(sink.name) or raise ArgumentError, "invalid sink name"
  sink
end

Instance Method Details

#on_death(status) ⇒ Object 



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# File 'lib/dtas/sink.rb', line 70

def on_death(status)
  super
end

#parse(str) ⇒ Object 



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# File 'lib/dtas/sink.rb', line 64

def parse(str)
  inputs = {}
  str.scan(DEVFD_RE) { |w| inputs[w[0]] = nil }
  inputs
end

#spawn(format, opts = {}) ⇒ Object 



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# File 'lib/dtas/sink.rb', line 74

def spawn(format, opts = {})
  raise "BUG: #{self.inspect}#spawn called twice" if @pid
  rv = []

  pclass = @nonblock ? DTAS::PipeNB : DTAS::Pipe

  cmd = command_string
  inputs = parse(cmd)

  if inputs.empty?
    # /dev/fd/* not specified in the command, assume one input for stdin
    r, w = pclass.new
    w.pipe_size = @pipe_size if @pipe_size
    inputs[:in] = opts[:in] = r
    w.sink = self
    rv << w
  else
    # multiple inputs, fun!, we'll tee to them
    inputs.each_key do |name|
      r, w = pclass.new
      w.pipe_size = @pipe_size if @pipe_size
      inputs[name] = r
      w.sink = self
      rv << w
    end
    opts[:in] = "/dev/null"

    # map to real /dev/fd/* values and setup proper redirects
    cmd = cmd.gsub(DEVFD_RE) do
      read_fd = inputs[$1].fileno
      opts[read_fd] = read_fd # do not close-on-exec
      "/dev/fd/#{read_fd}"
    end
  end

  @pid = dtas_spawn(format.to_env.merge!(@env), cmd, opts)
  inputs.each_value { |rpipe| rpipe.close }
  rv
end

#to_hash ⇒ Object 



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# File 'lib/dtas/sink.rb', line 114

def to_hash
  ivars_to_hash(SIVS)
end

#to_hsh ⇒ Object 



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# File 'lib/dtas/sink.rb', line 118

def to_hsh
  to_hash.delete_if { |k,v| v == SINK_DEFAULTS[k] }
end

#valid_name?(s) ⇒ Boolean

allow things that look like audio device names (“hw:1,0” , “/dev/dsp”) or variable names.

Returns:

  • (Boolean) 


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# File 'lib/dtas/sink.rb', line 50

def valid_name?(s)
  !!(s =~ %r{\A[\w:,/-]+\z})
end