discourse/app/models/optimized_image.rb

107 lines
3.0 KiB
Ruby

require "digest/sha1"
class OptimizedImage < ActiveRecord::Base
belongs_to :upload
def self.create_for(upload, width, height, opts={})
return unless width > 0 && height > 0
# do we already have that thumbnail?
thumbnail = find_by(upload_id: upload.id, width: width, height: height)
# make sure the previous thumbnail has not failed
if thumbnail && thumbnail.url.blank?
thumbnail.destroy
thumbnail = nil
end
# create the thumbnail otherwise
unless thumbnail
external_copy = Discourse.store.download(upload) if Discourse.store.external?
original_path = if Discourse.store.external?
external_copy.path
else
Discourse.store.path_for(upload)
end
# create a temp file with the same extension as the original
extension = File.extname(original_path)
temp_file = Tempfile.new(["discourse-thumbnail", extension])
temp_path = temp_file.path
original_path += "[0]" unless opts[:allow_animation]
if resize(original_path, temp_path, width, height)
thumbnail = OptimizedImage.create!(
upload_id: upload.id,
sha1: Digest::SHA1.file(temp_path).hexdigest,
extension: File.extname(temp_path),
width: width,
height: height,
url: "",
)
# store the optimized image and update its url
url = Discourse.store.store_optimized_image(temp_file, thumbnail)
if url.present?
thumbnail.url = url
thumbnail.save
else
Rails.logger.error("Failed to store avatar #{size} for #{upload.url} from #{source}")
end
else
Rails.logger.error("Failed to create optimized image #{width}x#{height} for #{upload.url}")
end
# close && remove temp file
temp_file.close!
# make sure we remove the cached copy from external stores
external_copy.close! if Discourse.store.external?
end
thumbnail
end
def destroy
OptimizedImage.transaction do
Discourse.store.remove_optimized_image(self)
super
end
end
def self.resize(from, to, width, height)
# NOTE: ORDER is important!
instructions = %W{
#{from}
-background transparent
-gravity center
-thumbnail #{width}x#{height}^
-extent #{width}x#{height}
-interpolate bicubic
-unsharp 2x0.5+0.7+0
-quality 98
#{to}
}.join(" ")
`convert #{instructions}`
$?.exitstatus == 0
end
end
# == Schema Information
#
# Table name: optimized_images
#
# id :integer not null, primary key
# sha1 :string(40) not null
# extension :string(10) not null
# width :integer not null
# height :integer not null
# upload_id :integer not null
# url :string(255) not null
#
# Indexes
#
# index_optimized_images_on_upload_id (upload_id)
# index_optimized_images_on_upload_id_and_width_and_height (upload_id,width,height) UNIQUE
#