Class: LetterAvatar

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

Defined Under Namespace

Classes: Identity

Constant Summary collapse

VERSION =

BUMP UP if avatar algorithm changes

5
FULLSIZE =

CHANGE these values to support more pixel ratios

120 * 3
POINTSIZE = 
280
COLORS =

palette of optimally distinct colors cf. tools.medialab.sciences-po.fr/iwanthue/index.php parameters used:

- H: 0 - 360
- C: 0 - 2
- L: 0.75 - 1.5

[
  [198, 125, 40],
  [61, 155, 243],
  [74, 243, 75],
  [238, 89, 166],
  [52, 240, 224],
  [177, 156, 155],
  [240, 120, 145],
  [111, 154, 78],
  [237, 179, 245],
  [237, 101, 95],
  [89, 239, 155],
  [43, 254, 70],
  [163, 212, 245],
  [65, 152, 142],
  [165, 135, 246],
  [181, 166, 38],
  [187, 229, 206],
  [77, 164, 25],
  [179, 246, 101],
  [234, 93, 37],
  [225, 155, 115],
  [142, 140, 188],
  [223, 120, 140],
  [249, 174, 27],
  [244, 117, 225],
  [137, 141, 102],
  [75, 191, 146],
  [188, 239, 142],
  [164, 199, 145],
  [173, 120, 149],
  [59, 195, 89],
  [222, 198, 220],
  [68, 145, 187],
  [236, 204, 179],
  [159, 195, 72],
  [188, 121, 189],
  [166, 160, 85],
  [181, 233, 37],
  [236, 177, 85],
  [121, 147, 160],
  [234, 218, 110],
  [241, 157, 191],
  [62, 200, 234],
  [133, 243, 34],
  [88, 149, 110],
  [59, 228, 248],
  [183, 119, 118],
  [251, 195, 45],
  [113, 196, 122],
  [197, 115, 70],
  [80, 175, 187],
  [103, 231, 238],
  [240, 72, 133],
  [228, 149, 241],
  [180, 188, 159],
  [172, 132, 85],
  [180, 135, 251],
  [236, 194, 58],
  [217, 176, 109],
  [88, 244, 199],
  [186, 157, 239],
  [113, 230, 96],
  [206, 115, 165],
  [244, 178, 163],
  [230, 139, 26],
  [241, 125, 89],
  [83, 160, 66],
  [107, 190, 166],
  [197, 161, 210],
  [198, 203, 245],
  [238, 117, 19],
  [228, 119, 116],
  [131, 156, 41],
  [145, 178, 168],
  [139, 170, 220],
  [233, 95, 125],
  [87, 178, 230],
  [157, 200, 119],
  [237, 140, 76],
  [229, 185, 186],
  [144, 206, 212],
  [236, 209, 158],
  [185, 189, 79],
  [34, 208, 66],
  [84, 238, 129],
  [133, 140, 134],
  [67, 157, 94],
  [168, 179, 25],
  [140, 145, 240],
  [151, 241, 125],
  [67, 162, 107],
  [200, 156, 21],
  [169, 173, 189],
  [226, 116, 189],
  [133, 231, 191],
  [194, 161, 63],
  [241, 77, 99],
  [241, 217, 53],
  [123, 204, 105],
  [210, 201, 119],
  [229, 108, 155],
  [240, 91, 72],
  [187, 115, 210],
  [240, 163, 100],
  [178, 217, 57],
  [179, 135, 116],
  [204, 211, 24],
  [186, 135, 57],
  [223, 176, 135],
  [204, 148, 151],
  [116, 223, 50],
  [95, 195, 46],
  [123, 160, 236],
  [181, 172, 131],
  [142, 220, 202],
  [240, 140, 112],
  [172, 145, 164],
  [228, 124, 45],
  [135, 151, 243],
  [42, 205, 125],
  [192, 233, 116],
  [119, 170, 114],
  [158, 138, 26],
  [73, 190, 183],
  [185, 229, 243],
  [227, 107, 55],
  [196, 205, 202],
  [132, 143, 60],
  [233, 192, 237],
  [62, 150, 220],
  [205, 201, 141],
  [106, 140, 190],
  [161, 131, 205],
  [135, 134, 158],
  [198, 139, 81],
  [115, 171, 32],
  [101, 181, 67],
  [149, 137, 119],
  [37, 142, 183],
  [183, 130, 175],
  [168, 125, 133],
  [124, 142, 87],
  [236, 156, 171],
  [232, 194, 91],
  [219, 200, 69],
  [144, 219, 34],
  [219, 95, 187],
  [145, 154, 217],
  [165, 185, 100],
  [127, 238, 163],
  [224, 178, 198],
  [119, 153, 120],
  [124, 212, 92],
  [172, 161, 105],
  [231, 155, 135],
  [157, 132, 101],
  [122, 185, 146],
  [53, 166, 51],
  [70, 163, 90],
  [150, 190, 213],
  [210, 107, 60],
  [166, 152, 185],
  [159, 194, 159],
  [39, 141, 222],
  [202, 176, 161],
  [95, 140, 229],
  [168, 142, 87],
  [93, 170, 203],
  [159, 142, 54],
  [14, 168, 39],
  [94, 150, 149],
  [187, 206, 136],
  [157, 224, 166],
  [235, 158, 208],
  [109, 232, 216],
  [141, 201, 87],
  [208, 124, 118],
  [142, 125, 214],
  [19, 237, 174],
  [72, 219, 41],
  [234, 102, 111],
  [168, 142, 79],
  [188, 135, 35],
  [95, 155, 143],
  [148, 173, 116],
  [223, 112, 95],
  [228, 128, 236],
  [206, 114, 54],
  [195, 119, 88],
  [235, 140, 94],
  [235, 202, 125],
  [233, 155, 153],
  [214, 214, 238],
  [246, 200, 35],
  [151, 125, 171],
  [132, 145, 172],
  [131, 142, 118],
  [199, 126, 150],
  [61, 162, 123],
  [58, 176, 151],
  [215, 141, 69],
  [225, 154, 220],
  [220, 77, 167],
  [233, 161, 64],
  [130, 221, 137],
  [81, 191, 129],
  [169, 162, 140],
  [174, 177, 222],
  [236, 174, 47],
  [233, 188, 180],
  [69, 222, 172],
  [71, 232, 93],
  [118, 211, 238],
  [157, 224, 83],
  [218, 105, 73],
  [126, 169, 36],
]

Class Method Summary collapse

Class Method Details

.cache_path ⇒ Object 



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# File 'lib/letter_avatar.rb', line 30

def cache_path
  "tmp/letter_avatars/#{version}"
end

.cached_path(identity, size) ⇒ Object 



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# File 'lib/letter_avatar.rb', line 58

def cached_path(identity, size)
  dir = "#{cache_path}/#{identity.letter}/#{identity.color.join("_")}"
  FileUtils.mkdir_p(dir)
  File.expand_path "#{dir}/#{size}.png"
end

.cleanup_old ⇒ Object 



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# File 'lib/letter_avatar.rb', line 116

def cleanup_old
  begin
    skip = File.basename(cache_path)
    parent_path = File.dirname(cache_path)
    Dir
      .entries(parent_path)
      .each do |path|
        FileUtils.rm_rf(parent_path + "/" + path) unless %w[. ..].include?(path) || path == skip
      end
  rescue Errno::ENOENT
    # no worries, folder doesn't exists
  end
end

.fullsize_path(identity) ⇒ Object 



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# File 'lib/letter_avatar.rb', line 64

def fullsize_path(identity)
  File.expand_path cached_path(identity, FULLSIZE)
end

.generate(username, size, opts = nil) ⇒ Object 



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# File 'lib/letter_avatar.rb', line 34

def generate(username, size, opts = nil)
  DistributedMutex.synchronize("letter_avatar_#{version}_#{username}") do
    identity = (opts && opts[:identity]) || LetterAvatar::Identity.from_username(username)

    cache = true
    cache = false if opts && opts[:cache] == false

    size = FULLSIZE if size > FULLSIZE
    filename = cached_path(identity, size)

    return filename if cache && File.exist?(filename)

    fullsize = fullsize_path(identity)
    generate_fullsize(identity) if !cache || !File.exist?(fullsize)

    # Optimizing here is dubious, it can save up to 2x for large images (eg 359px)
    # BUT... we are talking 2400 bytes down to 1200 bytes, both fit in one packet
    # The cost of this is huge, its a 40% perf hit
    OptimizedImage.resize(fullsize, filename, size, size)

    filename
  end
end

.generate_fullsize(identity) ⇒ Object 



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# File 'lib/letter_avatar.rb', line 68

def generate_fullsize(identity)
  color = identity.color
  letter = identity.letter

  filename = fullsize_path(identity)

  instructions = %W[
    -size
    #{FULLSIZE}x#{FULLSIZE}
    xc:#{to_rgb(color)}
    -pointsize
    #{POINTSIZE}
    -fill
    #FFFFFFCC
    -font
    Helvetica
    -gravity
    Center
    -annotate
    -0+26
    #{letter}
    -depth
    8
    #{filename}
  ]

  Discourse::Utils.execute_command("convert", *instructions)

  ## do not optimize image, it will end up larger than original
  filename
end

.image_magick_version ⇒ Object 



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# File 'lib/letter_avatar.rb', line 105

def image_magick_version
  @image_magick_version ||=
    begin
      Thread.new do
        sleep 2
        cleanup_old
      end
      Digest::MD5.hexdigest(`convert --version` << `convert -list font`)
    end
end

.to_rgb(color) ⇒ Object 



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# File 'lib/letter_avatar.rb', line 100

def to_rgb(color)
  r, g, b = color
  "rgb(#{r},#{g},#{b})"
end

.version ⇒ Object 



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# File 'lib/letter_avatar.rb', line 26

def version
  "#{VERSION}_#{image_magick_version}"
end