Node.jsでInkscapeを子プロセスとして動かしてSVGをPNGに変換する（svg2pngとの速度比較も）

fs = require "pn/fs"
svg2png = require "svg2png"
debug = require("debug")("svgtest")
Q = require "q"
 
filename = process.argv[2]
cycle = process.argv[3]
tasks = [1..cycle]
        
# pvg2pngを使って変換するファンクション
convert = (index) ->
  debug "start to convert", index
  fs.readFile filename
  .then svg2png
  .then (buffer) ->
    fs.writeFile "#{filename.replace(/\..+$/, '')}.png", buffer
  .then ->
    debug "convert finished", index

# cycleの数だけ順次繰り返す
tasks.reduce (prev, cur, index) ->
  prev.then ->
    Q.fcall convert, index
, Q()
.catch (e) ->
  console.error e
.done ->
  console.log "finish"

$ npm install svg2png
$ npm install pn
$ npm install q
$ DEBUG=svgtest coffee svg2png_convert.coffee color_circles.svg 1
  svgtest start to convert +0ms 0
  svgtest convert finished +1s 0
finish

inkscapeHelper = require "./inkscape_helper"
debug = require("debug")("svgtest")
Q = require "q"

filename = process.argv[2]
cycle = process.argv[3]
tasks = [1..cycle]

# Inkscapeを使って変換するファンクション
convert = (index) ->
  debug "start to convert", index
  Q.nfcall inkscapeHelper.convert,
    filename, "#{filename.replace(/\..+$/, '')}.png"
  .then ->
    debug "convert finished", index

# cycleの数だけ順次繰り返す
Q.nfcall inkscapeHelper.open
.then ->
  debug "opened"
  tasks.reduce (prev, cur, index) ->
    prev.then ->
      Q.fcall convert, index
  , Q()
.then ->
  inkscapeHelper.close()
.catch (e) ->
  console.error e
.done ->
  console.log "finish"

spawn = require("child_process").spawn
Q = require "q"

 # Inkscape実行ファイルへのパスは環境によって読み替えてください
INKSCAPE_PATH = "/Applications/Inkscape.app/Contents/Resources/bin/inkscape"
inkscape = null
completion = null

# 子プロセスの起動
exports.open = (cb) ->
  inkscape = spawn INKSCAPE_PATH, ["--shell"]
  completion = cb

  inkscape.stdout.on "data", (data) ->
    # console.log data.toString('utf-8')
    if (data.toString().search /(\r\n?)?>$/) isnt -1
      # Inkscapeのshellモードで入力プロンプトが表示された
      if completion?
        completion()
        completion = null

  inkscape.stderr.on "data", (data) ->
    console.error "INKSCAPE ERROR", data.toString('utf-8')

  inkscape.on "close", (code) ->
    console.log "INKSCAPE EXITED", code

# 変換処理
exports.convert = (svgPath, pngPath, cb) ->
  completion = cb
  inkscape.stdin.write "#{svgPath} \
    --export-png=#{pngPath} --export-background-opacity=0 \r\n"

# 子プロセスの終了
exports.close = ->
  inkscape.stdin.write "quit\r\n"

$ npm install q
$ DEBUG=svgtest coffee inkscape_convert.coffee color_circles.svg 1
INKSCAPE ERROR W: AppleCollationOrder setting not found, using AppleLocale.

INKSCAPE ERROR Setting LANGSTR from AppleLocale: en

INKSCAPE ERROR Overriding empty LANG from /usr/share/locale/locale.alias

INKSCAPE ERROR Setting Language: en_US.UTF-8

INKSCAPE ERROR 
(process:54607): Gtk-WARNING **: Locale not supported by C library.
	Using the fallback 'C' locale.

  svgtest opened +0ms
  svgtest start to convert +3ms 0
  svgtest convert finished +155ms 0
finish
INKSCAPE EXITED 0

$ time DEBUG=svgtest coffee svg2png_convert.coffee color_circles.svg 50
$ time DEBUG=svgtest coffee svg2png_convert.coffee cat.svg 50
$ time DEBUG=svgtest coffee inkscape_convert.coffee color_circles.svg 50
$ time DEBUG=svgtest coffee inkscape_convert.coffee cat.svg 50