test of itunes xml parse

xml-parser.rb

require 'rexml/parsers/sax2parser'
require 'rexml/sax2listener'

# define types

module Modes
  Unknown = 'Unknown' # unknown key name, ignore parse
  TrackID = 'Track ID'
  Name = 'Name'
end

class Music
  attr :id, :name
  def initialize(id)
    @id = id
  end
end

class Playlist
  attr :name, :musics
  def initialize(name)
    @name = name
    @musics = []
  end
end

# state control variables

$is_musics = true # a music mode(true) or a playlist mode(false)
$mode =  Modes::Unknown
$current_music = nil # instance of current parcing Music
$current_playlist = nil # instance of current parcing Playlist

# code

parser = REXML::Parsers::SAX2Parser.new(ARGF.read)

musics = {} # Hashtable of track_id:Music
playlists = {} # Hashtable of playlist_name:[Playlist]

parser.listen(:characters, ["key"]) do |c|
  case c
  when Modes::TrackID, Modes::Name
    $mode = c
  else
    $mode = Modes::Unknown
  end

  $is_music = false if c == 'Playlists'
end

parser.listen(:characters, ["string"]) do |c|
  case
  when $is_musics && $mode == Modes::Name
    # assing music title
    $current_music.name = c
  when !$is_musics && $mode == Modes::Name
    # initialize Playlist
    pl = Playlists.new(c)
    $current_playlist = pl
    playlists[c] = pl
  end
end

parser.listen(:characters, ["integer"]) do |c|
  case
  when $is_musics && $mode == Modes::TrackID
    # initialize Music
    m = Music.new(c)
    $current_music = m
    musics[c] = m
  when !$is_musics && $mode == Modes::TrackID
    # get music and assing to current playlist
    m = music[c]
    $current_playlist.musics << m
  end
end

# mode change to a playlist
parser.listen(:characters, ["key"]){|c| $mode = c == 'Playlists' }

parser.parse

バカ遅いのでXMLパーサつかうのやめた。爆速。

# define types

class Music
  attr_accessor :id, :name
  def initialize(id)
    @id = id
    @name = nil
  end
end

class Playlist
  attr_accessor :name, :musics
  def initialize(name)
    @name = name
    @musics = []
  end
end

# state control variables

is_musics = true # a music mode(true) or a playlist mode(false)
current_music = nil # instance of current parcing Music
current_playlist = nil # instance of current parcing Playlist

musics = {} # Hashtable of track_id:Music
playlists = {} # Hashtable of playlist_name:[Playlist]

while line = ARGF.gets
  # do something
  case
  when is_musics && line =~ %r|<key>Track ID</key><integer>(\d+)|
    id = Regexp.last_match[1]
    m = Music.new(id)
    current_music = m
    musics[id] = m
  when !is_musics && line =~ %r|<key>Track ID</key><integer>(\d+)|
    id = Regexp.last_match[1]
    current_playlist.musics << musics[id]
  when is_musics && line =~ %r|<key>Name</key><string>(.+?)<|
    name = Regexp.last_match[1]
    current_music.name = name
  when !is_musics && line =~ %r|<key>Name</key><string>(.+)<|
    name = Regexp.last_match[1]
    p = Playlist.new(name)
    current_playlist = p
    playlists[name] = p
  when is_musics && line =~ %r|<key>Playlists</key>|
    is_musics = false
  end

end

p playlists['ライブラリ']