discourse/lib/stylesheet/manager.rb
Alan Guo Xiang Tan 8cfe203383 PERF: Defer setting of distributed cache in performance critical paths.
Setting a key/value pair in DistributedCache involves waiting on the
write to Redis to finish. In most cases, we don't need to wait on the
setting of the cache to finish. We just need to take our return value
and move on.
2021-06-03 09:30:52 +08:00

467 lines
14 KiB
Ruby

# frozen_string_literal: true
require_dependency 'distributed_cache'
require_dependency 'stylesheet/compiler'
module Stylesheet; end
class Stylesheet::Manager
CACHE_PATH ||= 'tmp/stylesheet-cache'
MANIFEST_DIR ||= "#{Rails.root}/tmp/cache/assets/#{Rails.env}"
MANIFEST_FULL_PATH ||= "#{MANIFEST_DIR}/stylesheet-manifest"
THEME_REGEX ||= /_theme$/
COLOR_SCHEME_STYLESHEET ||= "color_definitions"
@lock = Mutex.new
def self.cache
@cache ||= DistributedCache.new("discourse_stylesheet")
end
def self.clear_theme_cache!
cache.hash.keys.select { |k| k =~ /theme/ }.each { |k| cache.delete(k) }
end
def self.clear_color_scheme_cache!
cache.hash.keys.select { |k| k =~ /color_definitions/ }.each { |k| cache.delete(k) }
end
def self.clear_core_cache!(targets)
cache.hash.keys.select { |k| k =~ /#{targets.join('|')}/ }.each { |k| cache.delete(k) }
end
def self.clear_plugin_cache!(plugin)
cache.hash.keys.select { |k| k =~ /#{plugin}/ }.each { |k| cache.delete(k) }
end
def self.stylesheet_data(target = :desktop, theme_ids = :missing)
stylesheet_details(target, "all", theme_ids)
end
def self.stylesheet_link_tag(target = :desktop, media = 'all', theme_ids = :missing)
stylesheets = stylesheet_details(target, media, theme_ids)
stylesheets.map do |stylesheet|
href = stylesheet[:new_href]
theme_id = stylesheet[:theme_id]
data_theme_id = theme_id ? "data-theme-id=\"#{theme_id}\"" : ""
%[<link href="#{href}" media="#{media}" rel="stylesheet" data-target="#{target}" #{data_theme_id}/>]
end.join("\n").html_safe
end
def self.stylesheet_details(target = :desktop, media = 'all', theme_ids = :missing)
if theme_ids == :missing
theme_ids = [SiteSetting.default_theme_id]
end
target = target.to_sym
theme_ids = [theme_ids] unless Array === theme_ids
theme_ids = [theme_ids.first] unless target =~ THEME_REGEX
include_components = !!(target =~ THEME_REGEX)
theme_ids = Theme.transform_ids(theme_ids, extend: include_components)
current_hostname = Discourse.current_hostname
array_cache_key = "array_themes_#{theme_ids.join(",")}_#{target}_#{current_hostname}"
stylesheets = cache[array_cache_key]
return stylesheets if stylesheets.present?
@lock.synchronize do
stylesheets = []
theme_ids.each do |theme_id|
data = { target: target }
cache_key = "path_#{target}_#{theme_id}_#{current_hostname}"
href = cache[cache_key]
unless href
builder = self.new(target, theme_id)
is_theme = builder.is_theme?
has_theme = builder.theme.present?
if is_theme && !has_theme
next
else
next if builder.theme&.component && !builder.theme&.has_scss(target)
data[:theme_id] = builder.theme.id if has_theme && is_theme
builder.compile unless File.exists?(builder.stylesheet_fullpath)
href = builder.stylesheet_path(current_hostname)
end
cache.defer_set(cache_key, href)
end
data[:theme_id] = theme_id if theme_id.present? && data[:theme_id].blank?
data[:new_href] = href
stylesheets << data
end
cache.defer_set(array_cache_key, stylesheets.freeze)
stylesheets
end
end
def self.color_scheme_stylesheet_details(color_scheme_id = nil, media, theme_id)
theme_id = theme_id || SiteSetting.default_theme_id
color_scheme = begin
ColorScheme.find(color_scheme_id)
rescue
# don't load fallback when requesting dark color scheme
return false if media != "all"
Theme.find_by_id(theme_id)&.color_scheme || ColorScheme.base
end
return false if !color_scheme
target = COLOR_SCHEME_STYLESHEET.to_sym
current_hostname = Discourse.current_hostname
cache_key = color_scheme_cache_key(color_scheme, theme_id)
stylesheets = cache[cache_key]
return stylesheets if stylesheets.present?
stylesheet = { color_scheme_id: color_scheme&.id }
builder = self.new(target, theme_id, color_scheme)
builder.compile unless File.exists?(builder.stylesheet_fullpath)
href = builder.stylesheet_path(current_hostname)
stylesheet[:new_href] = href
cache.defer_set(cache_key, stylesheet.freeze)
stylesheet
end
def self.color_scheme_stylesheet_link_tag(color_scheme_id = nil, media = 'all', theme_ids = nil)
theme_id = theme_ids&.first
stylesheet = color_scheme_stylesheet_details(color_scheme_id, media, theme_id)
return '' if !stylesheet
href = stylesheet[:new_href]
css_class = media == 'all' ? "light-scheme" : "dark-scheme"
%[<link href="#{href}" media="#{media}" rel="stylesheet" class="#{css_class}"/>].html_safe
end
def self.color_scheme_cache_key(color_scheme, theme_id = nil)
color_scheme_name = Slug.for(color_scheme.name) + color_scheme&.id.to_s
theme_string = theme_id ? "_theme#{theme_id}" : ""
"#{COLOR_SCHEME_STYLESHEET}_#{color_scheme_name}#{theme_string}_#{Discourse.current_hostname}"
end
def self.precompile_css
themes = Theme.where('user_selectable OR id = ?', SiteSetting.default_theme_id).pluck(:id, :name, :color_scheme_id)
themes << nil
color_schemes = ColorScheme.where(user_selectable: true).to_a
color_schemes << ColorScheme.find_by(id: SiteSetting.default_dark_mode_color_scheme_id)
color_schemes = color_schemes.compact.uniq
targets = [:desktop, :mobile, :desktop_rtl, :mobile_rtl, :desktop_theme, :mobile_theme, :admin, :wizard]
targets += Discourse.find_plugin_css_assets(include_disabled: true, mobile_view: true, desktop_view: true)
themes.each do |id, name, color_scheme_id|
targets.each do |target|
theme_id = id || SiteSetting.default_theme_id
if target =~ THEME_REGEX
next if theme_id == -1
theme_ids = Theme.transform_ids([theme_id], extend: true)
theme_ids.each do |t_id|
builder = self.new(target, t_id)
STDERR.puts "precompile target: #{target} #{builder.theme.name}"
next if builder.theme.component && !builder.theme.has_scss(target)
builder.compile(force: true)
end
else
STDERR.puts "precompile target: #{target} #{name}"
builder = self.new(target, theme_id)
builder.compile(force: true)
end
end
theme_color_scheme = ColorScheme.find_by_id(color_scheme_id) || ColorScheme.base
[theme_color_scheme, *color_schemes].uniq.each do |scheme|
STDERR.puts "precompile target: #{COLOR_SCHEME_STYLESHEET} #{name} (#{scheme.name})"
builder = self.new(COLOR_SCHEME_STYLESHEET, id, scheme)
builder.compile(force: true)
end
clear_color_scheme_cache!
end
nil
end
def self.last_file_updated
if Rails.env.production?
@last_file_updated ||= if File.exists?(MANIFEST_FULL_PATH)
File.readlines(MANIFEST_FULL_PATH, 'r')[0]
else
mtime = max_file_mtime
FileUtils.mkdir_p(MANIFEST_DIR)
File.open(MANIFEST_FULL_PATH, "w") { |f| f.print(mtime) }
mtime
end
else
max_file_mtime
end
end
def self.max_file_mtime
globs = ["#{Rails.root}/app/assets/stylesheets/**/*.*css",
"#{Rails.root}/app/assets/images/**/*.*"]
Discourse.plugins.map { |plugin| File.dirname(plugin.path) }.each do |path|
globs << "#{path}/plugin.rb"
globs << "#{path}/assets/stylesheets/**/*.*css"
end
globs.map do |pattern|
Dir.glob(pattern).map { |x| File.mtime(x) }.max
end.compact.max.to_i
end
def self.cache_fullpath
"#{Rails.root}/#{CACHE_PATH}"
end
def initialize(target = :desktop, theme_id = nil, color_scheme = nil)
@target = target
@theme_id = theme_id
@color_scheme = color_scheme
end
def compile(opts = {})
unless opts[:force]
if File.exists?(stylesheet_fullpath)
unless StylesheetCache.where(target: qualified_target, digest: digest).exists?
begin
source_map = begin
File.read(source_map_fullpath)
rescue Errno::ENOENT
end
StylesheetCache.add(qualified_target, digest, File.read(stylesheet_fullpath), source_map)
rescue => e
Rails.logger.warn "Completely unexpected error adding contents of '#{stylesheet_fullpath}' to cache #{e}"
end
end
return true
end
end
rtl = @target.to_s =~ /_rtl$/
css, source_map = with_load_paths do |load_paths|
Stylesheet::Compiler.compile_asset(
@target,
rtl: rtl,
theme_id: theme&.id,
theme_variables: theme&.scss_variables.to_s,
source_map_file: source_map_filename,
color_scheme_id: @color_scheme&.id,
load_paths: load_paths
)
rescue SassC::SyntaxError => e
if Stylesheet::Importer::THEME_TARGETS.include?(@target.to_s)
# no special errors for theme, handled in theme editor
["", nil]
elsif @target.to_s == COLOR_SCHEME_STYLESHEET
# log error but do not crash for errors in color definitions SCSS
Rails.logger.error "SCSS compilation error: #{e.message}"
["", nil]
else
raise Discourse::ScssError, e.message
end
end
FileUtils.mkdir_p(cache_fullpath)
File.open(stylesheet_fullpath, "w") do |f|
f.puts css
end
if source_map.present?
File.open(source_map_fullpath, "w") do |f|
f.puts source_map
end
end
begin
StylesheetCache.add(qualified_target, digest, css, source_map)
rescue => e
Rails.logger.warn "Completely unexpected error adding item to cache #{e}"
end
css
end
def cache_fullpath
self.class.cache_fullpath
end
def stylesheet_fullpath
"#{cache_fullpath}/#{stylesheet_filename}"
end
def source_map_fullpath
"#{cache_fullpath}/#{source_map_filename}"
end
def source_map_filename
"#{stylesheet_filename}.map"
end
def stylesheet_fullpath_no_digest
"#{cache_fullpath}/#{stylesheet_filename_no_digest}"
end
def stylesheet_cdnpath(hostname)
"#{GlobalSetting.cdn_url}#{stylesheet_relpath}?__ws=#{hostname}"
end
def stylesheet_path(hostname)
stylesheet_cdnpath(hostname)
end
def root_path
"#{GlobalSetting.relative_url_root}/"
end
def stylesheet_relpath
"#{root_path}stylesheets/#{stylesheet_filename}"
end
def stylesheet_relpath_no_digest
"#{root_path}stylesheets/#{stylesheet_filename_no_digest}"
end
def qualified_target
if is_theme?
"#{@target}_#{theme.id}"
elsif @color_scheme
"#{@target}_#{scheme_slug}_#{@color_scheme&.id.to_s}"
else
scheme_string = theme && theme.color_scheme ? "_#{theme.color_scheme.id}" : ""
"#{@target}#{scheme_string}"
end
end
def stylesheet_filename(with_digest = true)
digest_string = "_#{self.digest}" if with_digest
"#{qualified_target}#{digest_string}.css"
end
def stylesheet_filename_no_digest
stylesheet_filename(_with_digest = false)
end
def is_theme?
!!(@target.to_s =~ THEME_REGEX)
end
def scheme_slug
Slug.for(ActiveSupport::Inflector.transliterate(@color_scheme.name), 'scheme')
end
# digest encodes the things that trigger a recompile
def digest
@digest ||= begin
if is_theme?
theme_digest
else
color_scheme_digest
end
end
end
def theme
@theme ||= Theme.find_by(id: @theme_id) || :nil
@theme == :nil ? nil : @theme
end
def with_load_paths
if theme
theme.with_scss_load_paths { |p| yield p }
else
yield nil
end
end
def theme_digest
if [:mobile_theme, :desktop_theme].include?(@target)
scss_digest = theme.resolve_baked_field(:common, :scss)
scss_digest += theme.resolve_baked_field(@target.to_s.sub("_theme", ""), :scss)
elsif @target == :embedded_theme
scss_digest = theme.resolve_baked_field(:common, :embedded_scss)
else
raise "attempting to look up theme digest for invalid field"
end
Digest::SHA1.hexdigest(scss_digest.to_s + color_scheme_digest.to_s + settings_digest + plugins_digest + uploads_digest)
end
# this protects us from situations where new versions of a plugin removed a file
# old instances may still be serving CSS and not aware of the change
# so we could end up poisoning the cache with a bad file that can not be removed
def plugins_digest
assets = []
DiscoursePluginRegistry.stylesheets.each { |_, paths| assets += paths.to_a }
DiscoursePluginRegistry.mobile_stylesheets.each { |_, paths| assets += paths.to_a }
DiscoursePluginRegistry.desktop_stylesheets.each { |_, paths| assets += paths.to_a }
Digest::SHA1.hexdigest(assets.sort.join)
end
def settings_digest
theme_ids = Theme.components_for(@theme_id).dup
theme_ids << @theme_id
fields = ThemeField.where(
name: "yaml",
type_id: ThemeField.types[:yaml],
theme_id: theme_ids
).pluck(:updated_at)
settings = ThemeSetting.where(theme_id: theme_ids).pluck(:updated_at)
timestamps = fields.concat(settings).map!(&:to_f).sort!.join(",")
Digest::SHA1.hexdigest(timestamps)
end
def uploads_digest
Digest::SHA1.hexdigest(ThemeField.joins(:upload).where(id: theme&.all_theme_variables).pluck(:sha1).join(","))
end
def color_scheme_digest
cs = @color_scheme || theme&.color_scheme
categories_updated = self.class.cache["categories_updated"] ||= begin
Category
.where("uploaded_background_id IS NOT NULL")
.pluck(:updated_at)
.map(&:to_i)
.sum
end
fonts = "#{SiteSetting.base_font}-#{SiteSetting.heading_font}"
if cs || categories_updated > 0
theme_color_defs = theme&.resolve_baked_field(:common, :color_definitions)
Digest::SHA1.hexdigest "#{RailsMultisite::ConnectionManagement.current_db}-#{cs&.id}-#{cs&.version}-#{theme_color_defs}-#{Stylesheet::Manager.last_file_updated}-#{categories_updated}-#{fonts}"
else
digest_string = "defaults-#{Stylesheet::Manager.last_file_updated}-#{fonts}"
if cdn_url = GlobalSetting.cdn_url
digest_string = "#{digest_string}-#{cdn_url}"
end
Digest::SHA1.hexdigest digest_string
end
end
end