Class: Audioscrobbler

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

Overview

Audioscrobbler

Description

Queue music tracks as they are played and submit the track information to Last.fm (www.last.fm) using the Audioscrobbler plugin protocol (www.audioscrobbler.net/).

Version 1.2 of the plugin protocol (www.audioscrobbler.net/development/protocol/) is currently used.

Usage

require "audioscrobbler"
scrob = Audioscrobbler.new("user",       # Audioscrobbler username
                           "pass",       # Audioscrobbler password
                           "queue.txt",  # file for storing queue
                          )

# Replace these with the client ID that's been assigned to your
# plugin by the Audioscrobbler folks and your plugin's version number.
scrob.client = "tst"
scrob.version = "1.0"

# If you don't start the submitter, tracks will just pile up in the
# submission queue.
scrob.start_submitter_thread

# Report the currently-playing song:
scrob.report_now_playing("Beach Boys",      # artist
                         "God Only Knows",  # title
                         175,               # track length, in seconds
                         "Pet Sounds",      # album (optional)
                         "",                # MusicBrainzID (optional)
                         "8",               # track number (optional)
                        )

# Now wait until the Audioscrobbler submission criteria has been met and
# the track has finished playing.

# And then queue the track for submission:
scrob.enqueue("Beach Boys",      # artist
              "God Only Knows",  # title
              175,               # track length, in seconds
              1125378558,        # track start time
              "Pet Sounds",      # album (optional)
              "",                # MusicBrainzID (optional)
              "8",               # track number (optional)
             )

Defined Under Namespace

Classes: SubmissionQueue

Constant Summary collapse

DEFAULT_HANDSHAKE_URL =

Default URL to connect to for the handshake.

"http://post.audioscrobbler.com/"
DEFAULT_SUBMIT_INTERVAL_SEC =

Default minimum interval to wait between successful submissions.

5
DEFAULT_CLIENT =

Default plugin name and version to report to the server. You MUST set these to the values that you’ve registered before you can distribute your plugin to anyone (including beta testers).

"tst"
DEFAULT_VERSION = 
"1.0"
MAX_TRACKS_IN_SUBMISSION =

Maximum number of tracks that will be accepted in a single submission. This is a server-imposed limit.

10

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(username, password, filename = nil, proxy = nil) ⇒ Audioscrobbler

Create a new Audioscrobbler object.

Parameters:

  • username —

    Audioscrobbler account username

  • password —

    Audioscrobbler account password

  • filename (defaults to: nil) —

    file used for on-disk storage of not-yet-submitted tracks

  • proxy (defaults to: nil) —

    optional HTTP proxy to use for outgoing connections



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# File 'lib/audioscrobbler.rb', line 124

def initialize(username, password, filename=nil, proxy=nil)
  @username = username
  @password = password
  @queue = SubmissionQueue.new(filename)
  @logger = Logger.new($stdout)
  @client = DEFAULT_CLIENT
  @version = DEFAULT_VERSION

  @handshake_url = DEFAULT_HANDSHAKE_URL
  @last_handshake_time = nil
  @handshake_backoff_sec = 0
  @hard_failures = 0

  @session_id = nil
  @submit_url = nil
  @now_playing_url = nil
  @submit_interval_sec = DEFAULT_SUBMIT_INTERVAL_SEC

  @proxy = {}
  if proxy
    uri = URI.parse(proxy)
    @proxy[:host], @proxy[:port] = uri.host, uri.port
    if uri.userinfo
      @proxy[:username], @proxy[:password] = uri.userinfo.split(':', 1)
    end
  end
end

Instance Attribute Details

#client ⇒ Object

Returns the value of attribute client.



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# File 'lib/audioscrobbler.rb', line 152

def client
  @client
end

#handshake_url ⇒ Object

Returns the value of attribute handshake_url.



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# File 'lib/audioscrobbler.rb', line 152

def handshake_url
  @handshake_url
end

#logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/audioscrobbler.rb', line 151

def logger
  @logger
end

#password ⇒ Object

Returns the value of attribute password.



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# File 'lib/audioscrobbler.rb', line 151

def password
  @password
end

#username ⇒ Object

Returns the value of attribute username.



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# File 'lib/audioscrobbler.rb', line 151

def username
  @username
end

#version ⇒ Object

Returns the value of attribute version.



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# File 'lib/audioscrobbler.rb', line 152

def version
  @version
end

Instance Method Details

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

Enqueue a track for submission. Returns true if track was successfully queued and false otherwise (currently, it only fails if the track’s metadata didn’t meet the Audioscrobbler submission rules).

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 456

def enqueue(artist, title, length, start_time, album="", mbid="",
            track_num=nil)
  if not valid_metadata?(artist, title, length, start_time)
    @logger.warn("Ignoring track with invalid metadata for submission")
    return false
  end
  @queue.append(artist, title, length, start_time, album, mbid, track_num)
  true
end

#report_now_playing(artist, title, length, album = "", mbid = "", track_num = '') ⇒ Object

Report the track that is currently playing. Returns true if the report was successful and false otherwise.

Parameters:

  • artist —

    artist name

  • title —

    track name

  • length —

    track length

  • album (defaults to: "") —

    album name

  • mbid (defaults to: "") —

    MusicBrainz ID

  • track_num (defaults to: '') —

    track number on album



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# File 'lib/audioscrobbler.rb', line 384

def report_now_playing(artist, title, length, album="", mbid="",
                       track_num='')
  @logger.debug("Reporting \"#{artist} - #{title}\" as now-playing")

  if not valid_metadata?(artist, title, length, Time.now.to_i)
    @logger.warn("Ignoring track with invalid metadata for now-playing")
    return false
  end

  # FIXME(derat): Huge race condition here between us and the submission
  # thread, but I am to lazy to fix it right now.
  if not @session_id
    do_handshake(false)
  end

  # Construct our argument list.
  args = {
    's' => @session_id,
    'a' => artist,
    't' => title,
    'b' => album,
    'l' => length.to_i,
    'n' => track_num,
    'm' => mbid,
  }
  # Convert it into a single escaped string for the body.
  body = args.collect {|k, v| "#{k}=" + CGI.escape(v.to_s) }.join('&')

  success = false
  begin
    url = URI.parse(@now_playing_url)
  rescue Exception
    @logger.warn("Submission failed -- couldn't parse now-playing " +
                 "URL \"#@now_playing_url\"")
  else
    headers = { 'Content-Type' => 'application/x-www-form-urlencoded' }
    begin
      data = Net::HTTP.start(url.host, url.port,
                             @proxy[:host], @proxy[:port],
                             @proxy[:username], @proxy[:password]) do |http|
        http.post(url.path, body, headers).body
      end
    rescue Exception
      @logger.warn("Submission failed -- couldn't read " \
                   "#@now_playing_url: #{$!}")
    else
      data.chomp!
      if data == "OK"
        @logger.debug("Now-playing report was successful")
        success = true
      else
        @logger.warn("Now-playing report failed -- got \"#{data}\"")
      end
    end
  end
  success
end

#start_submitter_thread ⇒ Object

Start the submitter thread and return.



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# File 'lib/audioscrobbler.rb', line 299

def start_submitter_thread
  @submit_thread = Thread.new do
    while true
      # Wait until there are some tracks in the queue.
      tracks = @queue.peek(MAX_TRACKS_IN_SUBMISSION)

      # Keep trying to handshake until we're successful.
      do_handshake while not @session_id

      # Might as well re-check in case more tracks have shown up
      # during the handshake.
      tracks = @queue.peek(MAX_TRACKS_IN_SUBMISSION)
      @logger.debug("Submitting #{tracks.length} track(s)")

      # Construct our argument list.
      args = { "s" => @session_id }
      for i in 0..tracks.length-1
        args.update({
          "a[#{i}]" => tracks[i].artist,
          "t[#{i}]" => tracks[i].title,
          "i[#{i}]" => Time.at(tracks[i].start_time).to_i,
          "o[#{i}]" => 'P',
          "r[#{i}]" => '',
          "l[#{i}]" => tracks[i].length.to_s,
          "b[#{i}]" => tracks[i].album,
          "n[#{i}]" => tracks[i].track_num,
          "m[#{i}]" => tracks[i].mbid,
        })
      end
      # Convert it into a single escaped string for the body.
      body = args.collect {|k, v| "#{k}=" + CGI.escape(v.to_s) }.join('&')

      begin
        url = URI.parse(@submit_url)
        headers = { 'Content-Type' => 'application/x-www-form-urlencoded' }
        data = Net::HTTP.start(url.host, url.port,
                               @proxy[:host], @proxy[:port],
                               @proxy[:username], @proxy[:password]) do |http|
          http.post(url.path, body, headers).body
        end
      rescue Exception
        @logger.warn("Submission failed -- couldn't read " \
                     "#@submit_url: #{$!}")
      else
        # Check whether the submission was successful.
        lines = data.split("\n")
        if not lines[0]
          @logger.warn("Submission failed -- got empty response")
        elsif lines[0] == "OK"
          @logger.debug("Submission was successful")
          @queue.delete(tracks.length)
        elsif lines[0] == "BADSESSION"
          @logger.warn("Submission failed -- session is invalid")
          # Unset the session ID so we'll re-handshake.
          @session_id = nil
        else
          @logger.warn("Submission failed -- got unknown response " \
                       "\"#{lines[0]}\"")
          @hard_failures += 1
        end
      end

      if @hard_failures >= 3
        @logger.warn("Got #@hard_failures failures; re-handshaking")
        @session_id = nil
      end

      @logger.debug("Sleeping #@submit_interval_sec sec before checking " \
                    "for more tracks")
      sleep(@submit_interval_sec)
    end
  end
end

#verbose ⇒ Object 



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# File 'lib/audioscrobbler.rb', line 159

def verbose
  @logger.sev_threshold == Logger::DEBUG
end

#verbose=(v) ⇒ Object

Backwards-compatability methods to control the logging level.



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# File 'lib/audioscrobbler.rb', line 156

def verbose=(v)
  @logger.sev_threshold = v ? Logger::DEBUG : Logger::WARN
end