discourse/app/models/optimized_image.rb
Sam Saffron 30990006a9 DEV: enable frozen string literal on all files
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.

Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
2019-05-13 09:31:32 +08:00

382 lines
10 KiB
Ruby

# frozen_string_literal: true
require_dependency "file_helper"
require_dependency "url_helper"
require_dependency "db_helper"
require_dependency "file_store/local_store"
class OptimizedImage < ActiveRecord::Base
include HasUrl
belongs_to :upload
# BUMP UP if optimized image algorithm changes
VERSION = 2
URL_REGEX ||= /(\/optimized\/\dX[\/\.\w]*\/([a-zA-Z0-9]+)[\.\w]*)/
def self.lock(upload_id, width, height)
@hostname ||= `hostname`.strip rescue "unknown"
# note, the extra lock here ensures we only optimize one image per machine on webs
# this can very easily lead to runaway CPU so slowing it down is beneficial and it is hijacked
#
# we can not afford this blocking in Sidekiq cause it can lead to starvation
if Sidekiq.server?
DistributedMutex.synchronize("optimized_image_#{upload_id}_#{width}_#{height}") do
yield
end
else
DistributedMutex.synchronize("optimized_image_host_#{@hostname}") do
DistributedMutex.synchronize("optimized_image_#{upload_id}_#{width}_#{height}") do
yield
end
end
end
end
def self.create_for(upload, width, height, opts = {})
return unless width > 0 && height > 0
return if upload.try(:sha1).blank?
# no extension so try to guess it
if (!upload.extension)
upload.fix_image_extension
end
if !upload.extension.match?(IM_DECODERS) && upload.extension != "svg"
if !opts[:raise_on_error]
# nothing to do ... bad extension, not an image
return
else
raise InvalidAccess
end
end
# prefer to look up the thumbnail without grabbing any locks
thumbnail = find_by(upload_id: upload.id, width: width, height: height)
# correct bad thumbnail if needed
if thumbnail && (thumbnail.url.blank? || thumbnail.version != VERSION)
thumbnail.destroy!
thumbnail = nil
end
return thumbnail if thumbnail
lock(upload.id, width, height) do
# may have been generated since we got the lock
thumbnail = find_by(upload_id: upload.id, width: width, height: height)
# return the previous thumbnail if any
return thumbnail if thumbnail
# create the thumbnail otherwise
original_path = Discourse.store.path_for(upload)
if original_path.blank?
external_copy = Discourse.store.download(upload) rescue nil
original_path = external_copy.try(:path)
end
if original_path.blank?
Rails.logger.error("Could not find file in the store located at url: #{upload.url}")
else
# create a temp file with the same extension as the original
extension = ".#{opts[:format] || upload.extension}"
if extension.length == 1
return nil
end
temp_file = Tempfile.new(["discourse-thumbnail", extension])
temp_path = temp_file.path
if upload.extension == "svg"
FileUtils.cp(original_path, temp_path)
resized = true
elsif opts[:crop]
resized = crop(original_path, temp_path, width, height, opts)
else
resized = resize(original_path, temp_path, width, height, opts)
end
if resized
thumbnail = OptimizedImage.create!(
upload_id: upload.id,
sha1: Upload.generate_digest(temp_path),
extension: extension,
width: width,
height: height,
url: "",
filesize: File.size(temp_path),
version: VERSION
)
# store the optimized image and update its url
File.open(temp_path) do |file|
url = Discourse.store.store_optimized_image(file, thumbnail)
if url.present?
thumbnail.url = url
thumbnail.save
end
end
end
# close && remove temp file
temp_file.close!
end
# make sure we remove the cached copy from external stores
if Discourse.store.external?
external_copy&.close
end
thumbnail
end
end
def destroy
OptimizedImage.transaction do
Discourse.store.remove_optimized_image(self) if self.upload
super
end
end
def local?
!(url =~ /^(https?:)?\/\//)
end
def calculate_filesize
path =
if local?
Discourse.store.path_for(self)
else
Discourse.store.download(self).path
end
File.size(path)
end
def filesize
if size = read_attribute(:filesize)
size
else
# we may have a bad optimized image so just skip for now
# and do not break here
size = calculate_filesize rescue nil
write_attribute(:filesize, size)
if !new_record?
update_columns(filesize: size)
end
size
end
end
def self.safe_path?(path)
# this matches instructions which call #to_s
path = path.to_s
return false if path != File.expand_path(path)
return false if path !~ /\A[\w\-\.\/]+\z/m
true
end
def self.ensure_safe_paths!(*paths)
paths.each do |path|
raise Discourse::InvalidAccess unless safe_path?(path)
end
end
IM_DECODERS ||= /\A(jpe?g|png|ico|gif)\z/i
def self.prepend_decoder!(path, ext_path = nil, opts = nil)
opts ||= {}
# This logic is a little messy but the result of using mocks for most
# of the image tests. The idea here is you shouldn't trust the "original"
# path of a file to figure out its extension. However, in certain cases
# such as generating the loading upload thumbnail, we force the format,
# and this allows us to use the forced format in that case.
extension = nil
if (opts[:format] && path != ext_path)
extension = File.extname(path)[1..-1]
else
extension = File.extname(opts[:filename] || ext_path || path)[1..-1]
end
raise Discourse::InvalidAccess if !extension || !extension.match?(IM_DECODERS)
"#{extension}:#{path}"
end
def self.thumbnail_or_resize
SiteSetting.strip_image_metadata ? "thumbnail" : "resize"
end
def self.resize_instructions(from, to, dimensions, opts = {})
ensure_safe_paths!(from, to)
# note FROM my not be named correctly
from = prepend_decoder!(from, to, opts)
to = prepend_decoder!(to, to, opts)
instructions = ['convert', "#{from}[0]"]
if opts[:colors]
instructions << "-colors" << opts[:colors].to_s
end
# NOTE: ORDER is important!
instructions.concat(%W{
-auto-orient
-gravity center
-background transparent
-#{thumbnail_or_resize} #{dimensions}^
-extent #{dimensions}
-interpolate catrom
-unsharp 2x0.5+0.7+0
-interlace none
-quality 98
-profile #{File.join(Rails.root, 'vendor', 'data', 'RT_sRGB.icm')}
#{to}
})
end
def self.resize_instructions_animated(from, to, dimensions, opts = {})
ensure_safe_paths!(from, to)
%W{
gifsicle
--colors=#{opts[:colors] || 256}
--resize-fit #{dimensions}
--optimize=3
--output #{to}
#{from}
}
end
def self.crop_instructions(from, to, dimensions, opts = {})
ensure_safe_paths!(from, to)
from = prepend_decoder!(from, to, opts)
to = prepend_decoder!(to, to, opts)
%W{
convert
#{from}[0]
-auto-orient
-gravity north
-background transparent
-#{thumbnail_or_resize} #{opts[:width]}
-crop #{dimensions}+0+0
-unsharp 2x0.5+0.7+0
-interlace none
-quality 98
-profile #{File.join(Rails.root, 'vendor', 'data', 'RT_sRGB.icm')}
#{to}
}
end
def self.crop_instructions_animated(from, to, dimensions, opts = {})
ensure_safe_paths!(from, to)
%W{
gifsicle
--crop 0,0+#{dimensions}
--colors=#{opts[:colors] || 256}
--optimize=3
--output #{to}
#{from}
}
end
def self.downsize_instructions(from, to, dimensions, opts = {})
ensure_safe_paths!(from, to)
from = prepend_decoder!(from, to, opts)
to = prepend_decoder!(to, to, opts)
%W{
convert
#{from}[0]
-auto-orient
-gravity center
-background transparent
-interlace none
-resize #{dimensions}
-profile #{File.join(Rails.root, 'vendor', 'data', 'RT_sRGB.icm')}
#{to}
}
end
def self.downsize_instructions_animated(from, to, dimensions, opts = {})
resize_instructions_animated(from, to, dimensions, opts)
end
def self.resize(from, to, width, height, opts = {})
optimize("resize", from, to, "#{width}x#{height}", opts)
end
def self.crop(from, to, width, height, opts = {})
opts[:width] = width
optimize("crop", from, to, "#{width}x#{height}", opts)
end
def self.downsize(from, to, dimensions, opts = {})
optimize("downsize", from, to, dimensions, opts)
end
def self.optimize(operation, from, to, dimensions, opts = {})
method_name = "#{operation}_instructions"
if !!opts[:allow_animation] && (from =~ /\.GIF$/i)
method_name += "_animated"
end
instructions = self.public_send(method_name.to_sym, from, to, dimensions, opts)
convert_with(instructions, to, opts)
end
MAX_PNGQUANT_SIZE = 500_000
def self.convert_with(instructions, to, opts = {})
Discourse::Utils.execute_command("nice", "-n", "10", *instructions)
allow_pngquant = to.downcase.ends_with?(".png") && File.size(to) < MAX_PNGQUANT_SIZE
FileHelper.optimize_image!(to, allow_pngquant: allow_pngquant)
true
rescue => e
if opts[:raise_on_error]
raise e
else
error = +"Failed to optimize image:"
if e.message =~ /^convert:([^`]+)/
error << $1
else
error << " unknown reason"
end
Discourse.warn(error, location: to, error_message: e.message)
false
end
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 not null
# filesize :integer
# etag :string
# version :integer
#
# Indexes
#
# index_optimized_images_on_etag (etag)
# index_optimized_images_on_upload_id (upload_id)
# index_optimized_images_on_upload_id_and_width_and_height (upload_id,width,height) UNIQUE
#