1 files changed, 122 insertions, 0 deletions
diff --git a/lib/dtas/sink.rb b/lib/dtas/sink.rb
new file mode 100644
index 0000000..7931694
--- /dev/null
+++ b/lib/dtas/sink.rb
@@ -0,0 +1,122 @@
+# -*- encoding: binary -*-
+# :stopdoc:
+# Copyright (C) 2013, Eric Wong <normalperson@yhbt.net>
+# License: GPLv3 or later (https://www.gnu.org/licenses/gpl-3.0.txt)
+require 'yaml'
+require_relative '../dtas'
+require_relative 'pipe'
+require_relative 'process'
+require_relative 'command'
+require_relative 'format'
+require_relative 'serialize'
+require_relative 'writable_iter'
+
+# this is a sink (endpoint, audio enters but never leaves)
+class DTAS::Sink
+  attr_accessor :prio    # any Integer
+  attr_accessor :active  # boolean
+  attr_accessor :name
+  attr_accessor :nonblock
+  attr_accessor :respawn
+
+  include DTAS::Command
+  include DTAS::Process
+  include DTAS::Serialize
+  include DTAS::WritableIter
+
+  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}
+
+  # order matters for Ruby 1.9+, this defines to_hsh serialization so we
+  # can make the state file human-friendly
+  SIVS = %w(name env command prio nonblock pipe_size active)
+
+  def initialize
+    command_init(SINK_DEFAULTS)
+    writable_iter_init
+    @sink = self
+  end
+
+  # allow things that look like audio device names ("hw:1,0" , "/dev/dsp")
+  # or variable names.
+  def valid_name?(s)
+    !!(s =~ %r{\A[\w:,/-]+\z})
+  end
+
+  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
+
+  def parse(str)
+    inputs = {}
+    str.scan(DEVFD_RE) { |w| inputs[w[0]] = nil }
+    inputs
+  end
+
+  def on_death(status)
+    super
+  end
+
+  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
+
+  def to_hash
+    ivars_to_hash(SIVS)
+  end
+
+  def to_hsh
+    to_hash.delete_if { |k,v| v == SINK_DEFAULTS[k] }
+  end
+end