Class: Audioscrobbler::SubmissionQueue

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

Overview

A synchronized, backed-up-to-disk queue holding tracks for submission. The synchronization is only sufficient for a single reader and writer.

Defined Under Namespace

Classes: PlayedTrack

Instance Method Summary collapse

Constructor Details

#initialize(filename = nil) ⇒ SubmissionQueue

constructor If a filename is supplied, it will be used to: a) load tracks that were previously played but not submitted b) save the state of the queue for later use in a)

Parameters:

  • filename (defaults to: nil) —

    queue filename (optional)



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# File 'lib/audioscrobbler.rb', line 479

def initialize(filename=nil)
  @filename = filename
  @queue = Array.new
  @mutex = Mutex.new
  @condvar = ConditionVariable.new
  if @filename and File.exist?(@filename)
    File.open(@filename, "r").each do |line|
      @queue.push(PlayedTrack.deserialize(line.chomp))
    end
  end
end

Instance Method Details

#append(artist, title, length, start_time, album = "", mbid = "", track_num = nil) ⇒ Object

Append a played track to the submission queue.

Parameters:

  • artist —

    artist name

  • title —

    track name

  • length —

    track length

  • start_time —

    track start time, as UTC unix time

  • album (defaults to: "") —

    album name

  • mbid (defaults to: "") —

    MusicBrainz ID

  • track_num (defaults to: nil) —

    track number on album



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# File 'lib/audioscrobbler.rb', line 502

def append(artist, title, length, start_time, album="", mbid="",
           track_num=nil)
  @mutex.synchronize do
    track = PlayedTrack.new(artist, title, length, start_time, album, mbid,
                            track_num)
    File.open(@filename, "a") {|f| f.puts(track.serialize) } if @filename
    @queue.push(track)
    @condvar.signal
  end
  self
end

#delete(num_tracks) ⇒ Object

Delete tracks from the beginning of the queue. If more tracks are requested than are in the queue, the queue is cleared.

Parameters:

  • num_tracks —

    number of tracks to delete



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# File 'lib/audioscrobbler.rb', line 536

def delete(num_tracks)
  if not @queue.empty?
    @mutex.synchronize do
      @queue = @queue[num_tracks..@queue.length-1]
      if @filename
        file = File.open(@filename, "w")
        @queue.each {|track| file.puts(track.serialize) }
        file.close
      end
    end
  end
  self
end

#peek(max_tracks = 1) ⇒ Object

Get tracks from the beginning of the queue. An array of PlayedTrack objects is returned. The tracks are not removed from the queue. If the queue is empty, the method blocks until a track is placed on the queue.

Parameters:

  • max_tracks (defaults to: 1) —

    maximum number of tracks to return



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# File 'lib/audioscrobbler.rb', line 522

def peek(max_tracks=1)
  @mutex.synchronize do
    @condvar.wait(@mutex) if @queue.empty?
    @queue[0, max_tracks]
  end
end